linux/arch/x86/kernel/hpet.c

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#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/sysdev.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/hpet.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/pm.h>
#include <linux/io.h>
#include <asm/fixmap.h>
#include <asm/i8253.h>
#include <asm/hpet.h>
#define HPET_MASK CLOCKSOURCE_MASK(32)
#define HPET_SHIFT 22
/* FSEC = 10^-15
NSEC = 10^-9 */
#define FSEC_PER_NSEC 1000000L
#define HPET_DEV_USED_BIT 2
#define HPET_DEV_USED (1 << HPET_DEV_USED_BIT)
#define HPET_DEV_VALID 0x8
#define HPET_DEV_FSB_CAP 0x1000
#define HPET_DEV_PERI_CAP 0x2000
#define EVT_TO_HPET_DEV(evt) container_of(evt, struct hpet_dev, evt)
/*
* HPET address is set in acpi/boot.c, when an ACPI entry exists
*/
unsigned long hpet_address;
static unsigned long hpet_num_timers;
static void __iomem *hpet_virt_address;
struct hpet_dev {
struct clock_event_device evt;
unsigned int num;
int cpu;
unsigned int irq;
unsigned int flags;
char name[10];
};
unsigned long hpet_readl(unsigned long a)
{
return readl(hpet_virt_address + a);
}
static inline void hpet_writel(unsigned long d, unsigned long a)
{
writel(d, hpet_virt_address + a);
}
#ifdef CONFIG_X86_64
#include <asm/pgtable.h>
#endif
static inline void hpet_set_mapping(void)
{
hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
#ifdef CONFIG_X86_64
__set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
#endif
}
static inline void hpet_clear_mapping(void)
{
iounmap(hpet_virt_address);
hpet_virt_address = NULL;
}
/*
* HPET command line enable / disable
*/
static int boot_hpet_disable;
int hpet_force_user;
static int __init hpet_setup(char *str)
{
if (str) {
if (!strncmp("disable", str, 7))
boot_hpet_disable = 1;
if (!strncmp("force", str, 5))
hpet_force_user = 1;
}
return 1;
}
__setup("hpet=", hpet_setup);
static int __init disable_hpet(char *str)
{
boot_hpet_disable = 1;
return 1;
}
__setup("nohpet", disable_hpet);
static inline int is_hpet_capable(void)
{
return !boot_hpet_disable && hpet_address;
}
/*
* HPET timer interrupt enable / disable
*/
static int hpet_legacy_int_enabled;
/**
* is_hpet_enabled - check whether the hpet timer interrupt is enabled
*/
int is_hpet_enabled(void)
{
return is_hpet_capable() && hpet_legacy_int_enabled;
}
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
EXPORT_SYMBOL_GPL(is_hpet_enabled);
/*
* When the hpet driver (/dev/hpet) is enabled, we need to reserve
* timer 0 and timer 1 in case of RTC emulation.
*/
#ifdef CONFIG_HPET
x86: using HPET in MSI mode and setting up per CPU HPET timers, fix On Sat, Sep 06, 2008 at 06:03:53AM -0700, Ingo Molnar wrote: > > it crashes two testsystems, the fault on a NULL pointer in hpet init, > with: > > initcall print_all_ICs+0x0/0x520 returned 0 after 26 msecs > calling hpet_late_init+0x0/0x1c0 > BUG: unable to handle kernel NULL pointer dereference at 000000000000008c > IP: [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > PGD 0 > Oops: 0000 [1] SMP > CPU 0 > Modules linked in: > Pid: 1, comm: swapper Not tainted 2.6.27-rc5 #29725 > RIP: 0010:[<ffffffff80d228be>] [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > RSP: 0018:ffff88003fa07dd0 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 > RDX: ffffc20000000160 RSI: 0000000000000000 RDI: 0000000000000003 > RBP: ffff88003fa07e90 R08: 0000000000000000 R09: ffff88003fa07dd0 > R10: 0000000000000001 R11: 0000000000000000 R12: ffff88003fa07dd0 > R13: 0000000000000002 R14: ffffc20000000000 R15: 000000006f57e511 > FS: 0000000000000000(0000) GS:ffffffff80cf6a80(0000) knlGS:0000000000000000 > CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b > CR2: 000000000000008c CR3: 0000000000201000 CR4: 00000000000006e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process swapper (pid: 1, threadinfo ffff88003fa06000, task ffff88003fa08000) > Stack: 00000000fed00000 ffffc20000000000 0000000100000003 0000000800000002 > 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > Call Trace: > [<ffffffff80d227c0>] ? hpet_late_init+0x0/0x1c0 > [<ffffffff80209045>] do_one_initcall+0x45/0x190 > [<ffffffff80296f39>] ? register_irq_proc+0x19/0xe0 > [<ffffffff80d0d140>] ? early_idt_handler+0x0/0x73 > [<ffffffff80d0dabc>] kernel_init+0x14c/0x1b0 > [<ffffffff80942ac1>] ? trace_hardirqs_on_thunk+0x3a/0x3f > [<ffffffff8020dbd9>] child_rip+0xa/0x11 > [<ffffffff8020ceee>] ? restore_args+0x0/0x30 > [<ffffffff80d0d970>] ? kernel_init+0x0/0x1b0 > [<ffffffff8020dbcf>] ? child_rip+0x0/0x11 > Code: 20 48 83 c1 01 48 39 f1 75 e3 44 89 e8 4c 8b 05 29 29 22 00 31 f6 48 8d 78 01 66 66 90 89 f0 48 8d 04 80 48 c1 e0 05 4a 8d 0c 00 <f6> 81 8c 00 00 00 08 74 26 8b 81 80 00 00 00 8b 91 88 00 00 00 > RIP [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > RSP <ffff88003fa07dd0> > CR2: 000000000000008c > Kernel panic - not syncing: Fatal exception There was one code path, with CONFIG_PCI_MSI disabled, where we were accessing hpet_devs without initialization. That resulted in the above crash. The change below adds a check for hpet_devs. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-08 17:18:40 +00:00
static void hpet_reserve_msi_timers(struct hpet_data *hd);
x86: using HPET in MSI mode and setting up per CPU HPET timers, fix On Sat, Sep 06, 2008 at 06:03:53AM -0700, Ingo Molnar wrote: > > it crashes two testsystems, the fault on a NULL pointer in hpet init, > with: > > initcall print_all_ICs+0x0/0x520 returned 0 after 26 msecs > calling hpet_late_init+0x0/0x1c0 > BUG: unable to handle kernel NULL pointer dereference at 000000000000008c > IP: [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > PGD 0 > Oops: 0000 [1] SMP > CPU 0 > Modules linked in: > Pid: 1, comm: swapper Not tainted 2.6.27-rc5 #29725 > RIP: 0010:[<ffffffff80d228be>] [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > RSP: 0018:ffff88003fa07dd0 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 > RDX: ffffc20000000160 RSI: 0000000000000000 RDI: 0000000000000003 > RBP: ffff88003fa07e90 R08: 0000000000000000 R09: ffff88003fa07dd0 > R10: 0000000000000001 R11: 0000000000000000 R12: ffff88003fa07dd0 > R13: 0000000000000002 R14: ffffc20000000000 R15: 000000006f57e511 > FS: 0000000000000000(0000) GS:ffffffff80cf6a80(0000) knlGS:0000000000000000 > CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b > CR2: 000000000000008c CR3: 0000000000201000 CR4: 00000000000006e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process swapper (pid: 1, threadinfo ffff88003fa06000, task ffff88003fa08000) > Stack: 00000000fed00000 ffffc20000000000 0000000100000003 0000000800000002 > 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > Call Trace: > [<ffffffff80d227c0>] ? hpet_late_init+0x0/0x1c0 > [<ffffffff80209045>] do_one_initcall+0x45/0x190 > [<ffffffff80296f39>] ? register_irq_proc+0x19/0xe0 > [<ffffffff80d0d140>] ? early_idt_handler+0x0/0x73 > [<ffffffff80d0dabc>] kernel_init+0x14c/0x1b0 > [<ffffffff80942ac1>] ? trace_hardirqs_on_thunk+0x3a/0x3f > [<ffffffff8020dbd9>] child_rip+0xa/0x11 > [<ffffffff8020ceee>] ? restore_args+0x0/0x30 > [<ffffffff80d0d970>] ? kernel_init+0x0/0x1b0 > [<ffffffff8020dbcf>] ? child_rip+0x0/0x11 > Code: 20 48 83 c1 01 48 39 f1 75 e3 44 89 e8 4c 8b 05 29 29 22 00 31 f6 48 8d 78 01 66 66 90 89 f0 48 8d 04 80 48 c1 e0 05 4a 8d 0c 00 <f6> 81 8c 00 00 00 08 74 26 8b 81 80 00 00 00 8b 91 88 00 00 00 > RIP [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > RSP <ffff88003fa07dd0> > CR2: 000000000000008c > Kernel panic - not syncing: Fatal exception There was one code path, with CONFIG_PCI_MSI disabled, where we were accessing hpet_devs without initialization. That resulted in the above crash. The change below adds a check for hpet_devs. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-08 17:18:40 +00:00
static void hpet_reserve_platform_timers(unsigned long id)
{
struct hpet __iomem *hpet = hpet_virt_address;
struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
unsigned int nrtimers, i;
struct hpet_data hd;
nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
memset(&hd, 0, sizeof(hd));
hd.hd_phys_address = hpet_address;
hd.hd_address = hpet;
hd.hd_nirqs = nrtimers;
hpet_reserve_timer(&hd, 0);
#ifdef CONFIG_HPET_EMULATE_RTC
hpet_reserve_timer(&hd, 1);
#endif
hpet: /dev/hpet - fixes and cleanup Minor /dev/hpet updates and bugfixes: * Remove dead code, mostly remnants of an incomplete/unusable kernel interface ... noted when addressing "sparse" warnings: + hpet_unregister() and a routine it calls + hpet_task and all references, including hpet_task_lock + hpet_data.hd_flags (and HPET_DATA_PLATFORM) * Correct and improve boot message: + displays *counter* (shared between comparators) bit width, not *timer* bit widths (which are often mixed) + relabel "timers" as "comparators"; this is less confusing, they are not independent like normal timers are (sigh) + display MHz not Hz; it's never less than 10 MHz. * Tighten and correct the userspace interface code + don't accidentally program comparators in 64-bit mode using 32-bit values ... always force comparators into 32-bit mode + provide the correct bit definition flagging comparators with periodic capability ... the ABI is unchanged * Update Documentation/hpet.txt + be more correct and current + expand description a bit + don't mention that now-gone kernel interface Plus, add a FIXME comment for something that could cause big trouble on systems with more capable HPETs than at least Intel seems to ship. It seems that few folk use this userspace interface; it's not very usable given the general lack of HPET IRQ routing. I'm told that the only real point of it any more is to mmap for fast timestamps; IMO that's handled better through the gettimeofday() vsyscall. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-29 19:47:38 +00:00
/*
* NOTE that hd_irq[] reflects IOAPIC input pins (LEGACY_8254
* is wrong for i8259!) not the output IRQ. Many BIOS writers
* don't bother configuring *any* comparator interrupts.
*/
hd.hd_irq[0] = HPET_LEGACY_8254;
hd.hd_irq[1] = HPET_LEGACY_RTC;
for (i = 2; i < nrtimers; timer++, i++) {
hd.hd_irq[i] = (readl(&timer->hpet_config) &
Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
}
x86: using HPET in MSI mode and setting up per CPU HPET timers, fix On Sat, Sep 06, 2008 at 06:03:53AM -0700, Ingo Molnar wrote: > > it crashes two testsystems, the fault on a NULL pointer in hpet init, > with: > > initcall print_all_ICs+0x0/0x520 returned 0 after 26 msecs > calling hpet_late_init+0x0/0x1c0 > BUG: unable to handle kernel NULL pointer dereference at 000000000000008c > IP: [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > PGD 0 > Oops: 0000 [1] SMP > CPU 0 > Modules linked in: > Pid: 1, comm: swapper Not tainted 2.6.27-rc5 #29725 > RIP: 0010:[<ffffffff80d228be>] [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > RSP: 0018:ffff88003fa07dd0 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 > RDX: ffffc20000000160 RSI: 0000000000000000 RDI: 0000000000000003 > RBP: ffff88003fa07e90 R08: 0000000000000000 R09: ffff88003fa07dd0 > R10: 0000000000000001 R11: 0000000000000000 R12: ffff88003fa07dd0 > R13: 0000000000000002 R14: ffffc20000000000 R15: 000000006f57e511 > FS: 0000000000000000(0000) GS:ffffffff80cf6a80(0000) knlGS:0000000000000000 > CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b > CR2: 000000000000008c CR3: 0000000000201000 CR4: 00000000000006e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process swapper (pid: 1, threadinfo ffff88003fa06000, task ffff88003fa08000) > Stack: 00000000fed00000 ffffc20000000000 0000000100000003 0000000800000002 > 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > Call Trace: > [<ffffffff80d227c0>] ? hpet_late_init+0x0/0x1c0 > [<ffffffff80209045>] do_one_initcall+0x45/0x190 > [<ffffffff80296f39>] ? register_irq_proc+0x19/0xe0 > [<ffffffff80d0d140>] ? early_idt_handler+0x0/0x73 > [<ffffffff80d0dabc>] kernel_init+0x14c/0x1b0 > [<ffffffff80942ac1>] ? trace_hardirqs_on_thunk+0x3a/0x3f > [<ffffffff8020dbd9>] child_rip+0xa/0x11 > [<ffffffff8020ceee>] ? restore_args+0x0/0x30 > [<ffffffff80d0d970>] ? kernel_init+0x0/0x1b0 > [<ffffffff8020dbcf>] ? child_rip+0x0/0x11 > Code: 20 48 83 c1 01 48 39 f1 75 e3 44 89 e8 4c 8b 05 29 29 22 00 31 f6 48 8d 78 01 66 66 90 89 f0 48 8d 04 80 48 c1 e0 05 4a 8d 0c 00 <f6> 81 8c 00 00 00 08 74 26 8b 81 80 00 00 00 8b 91 88 00 00 00 > RIP [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > RSP <ffff88003fa07dd0> > CR2: 000000000000008c > Kernel panic - not syncing: Fatal exception There was one code path, with CONFIG_PCI_MSI disabled, where we were accessing hpet_devs without initialization. That resulted in the above crash. The change below adds a check for hpet_devs. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-08 17:18:40 +00:00
hpet_reserve_msi_timers(&hd);
hpet_alloc(&hd);
}
#else
static void hpet_reserve_platform_timers(unsigned long id) { }
#endif
/*
* Common hpet info
*/
static unsigned long hpet_period;
static void hpet_legacy_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt);
static int hpet_legacy_next_event(unsigned long delta,
struct clock_event_device *evt);
/*
* The hpet clock event device
*/
static struct clock_event_device hpet_clockevent = {
.name = "hpet",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = hpet_legacy_set_mode,
.set_next_event = hpet_legacy_next_event,
.shift = 32,
.irq = 0,
.rating = 50,
};
static void hpet_start_counter(void)
{
unsigned long cfg = hpet_readl(HPET_CFG);
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
hpet_writel(0, HPET_COUNTER);
hpet_writel(0, HPET_COUNTER + 4);
cfg |= HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}
static void hpet_resume_device(void)
{
force_hpet_resume();
}
static void hpet_restart_counter(void)
{
hpet_resume_device();
hpet_start_counter();
}
static void hpet_enable_legacy_int(void)
{
unsigned long cfg = hpet_readl(HPET_CFG);
cfg |= HPET_CFG_LEGACY;
hpet_writel(cfg, HPET_CFG);
hpet_legacy_int_enabled = 1;
}
static void hpet_legacy_clockevent_register(void)
{
/* Start HPET legacy interrupts */
hpet_enable_legacy_int();
/*
x86: clean up computation of HPET .mult variables While reading through the HPET code I realized that the computation of .mult variables could be done with less lines of code, resulting in a 1.6% text size saving for hpet.o So I propose the following patch, which applies against today's Linus -git tree. >From 0c6507e400e9ca5f7f14331e18f8c12baf75a9d3 Mon Sep 17 00:00:00 2001 From: Carlos R. Mafra <crmafra@ift.unesp.br> Date: Mon, 5 May 2008 19:38:53 -0300 The computation of clocksource_hpet.mult tmp = (u64)hpet_period << HPET_SHIFT; do_div(tmp, FSEC_PER_NSEC); clocksource_hpet.mult = (u32)tmp; can be streamlined if we note that it is equal to clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT); Furthermore, the computation of hpet_clockevent.mult uint64_t hpet_freq; hpet_freq = 1000000000000000ULL; do_div(hpet_freq, hpet_period); hpet_clockevent.mult = div_sc((unsigned long) hpet_freq, NSEC_PER_SEC, hpet_clockevent.shift); can also be streamlined with the observation that hpet_period and hpet_freq are inverse to each other (in proper units). So instead of computing hpet_freq and using (schematically) div_sc(hpet_freq, 10^9, shift) we use the trick of calling with the arguments in reverse order, div_sc(10^6, hpet_period, shift). The different power of ten is due to frequency being in Hertz (1/sec) and the period being in units of femtosecond. Explicitly, mult = (hpet_freq * 2^shift)/10^9 (before) mult = (10^6 * 2^shift)/hpet_period (after) because hpet_freq = 10^15/hpet_period. The comments in the code are also updated to reflect the changes. As a result, text data bss dec hex filename 2957 425 92 3474 d92 arch/x86/kernel/hpet.o 3006 425 92 3523 dc3 arch/x86/kernel/hpet.o.old a 1.6% reduction in text size. Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-05 23:11:22 +00:00
* The mult factor is defined as (include/linux/clockchips.h)
* mult/2^shift = cyc/ns (in contrast to ns/cyc in clocksource.h)
* hpet_period is in units of femtoseconds (per cycle), so
* mult/2^shift = cyc/ns = 10^6/hpet_period
* mult = (10^6 * 2^shift)/hpet_period
* mult = (FSEC_PER_NSEC << hpet_clockevent.shift)/hpet_period
*/
x86: clean up computation of HPET .mult variables While reading through the HPET code I realized that the computation of .mult variables could be done with less lines of code, resulting in a 1.6% text size saving for hpet.o So I propose the following patch, which applies against today's Linus -git tree. >From 0c6507e400e9ca5f7f14331e18f8c12baf75a9d3 Mon Sep 17 00:00:00 2001 From: Carlos R. Mafra <crmafra@ift.unesp.br> Date: Mon, 5 May 2008 19:38:53 -0300 The computation of clocksource_hpet.mult tmp = (u64)hpet_period << HPET_SHIFT; do_div(tmp, FSEC_PER_NSEC); clocksource_hpet.mult = (u32)tmp; can be streamlined if we note that it is equal to clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT); Furthermore, the computation of hpet_clockevent.mult uint64_t hpet_freq; hpet_freq = 1000000000000000ULL; do_div(hpet_freq, hpet_period); hpet_clockevent.mult = div_sc((unsigned long) hpet_freq, NSEC_PER_SEC, hpet_clockevent.shift); can also be streamlined with the observation that hpet_period and hpet_freq are inverse to each other (in proper units). So instead of computing hpet_freq and using (schematically) div_sc(hpet_freq, 10^9, shift) we use the trick of calling with the arguments in reverse order, div_sc(10^6, hpet_period, shift). The different power of ten is due to frequency being in Hertz (1/sec) and the period being in units of femtosecond. Explicitly, mult = (hpet_freq * 2^shift)/10^9 (before) mult = (10^6 * 2^shift)/hpet_period (after) because hpet_freq = 10^15/hpet_period. The comments in the code are also updated to reflect the changes. As a result, text data bss dec hex filename 2957 425 92 3474 d92 arch/x86/kernel/hpet.o 3006 425 92 3523 dc3 arch/x86/kernel/hpet.o.old a 1.6% reduction in text size. Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-05 23:11:22 +00:00
hpet_clockevent.mult = div_sc((unsigned long) FSEC_PER_NSEC,
hpet_period, hpet_clockevent.shift);
/* Calculate the min / max delta */
hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
&hpet_clockevent);
/* 5 usec minimum reprogramming delta. */
hpet_clockevent.min_delta_ns = 5000;
/*
* Start hpet with the boot cpu mask and make it
* global after the IO_APIC has been initialized.
*/
hpet_clockevent.cpumask = cpumask_of_cpu(smp_processor_id());
clockevents_register_device(&hpet_clockevent);
global_clock_event = &hpet_clockevent;
printk(KERN_DEBUG "hpet clockevent registered\n");
}
static int hpet_setup_msi_irq(unsigned int irq);
static void hpet_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt, int timer)
{
unsigned long cfg, cmp, now;
uint64_t delta;
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * evt->mult;
delta >>= evt->shift;
now = hpet_readl(HPET_COUNTER);
cmp = now + (unsigned long) delta;
cfg = hpet_readl(HPET_Tn_CFG(timer));
cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
HPET_TN_SETVAL | HPET_TN_32BIT;
hpet_writel(cfg, HPET_Tn_CFG(timer));
/*
* The first write after writing TN_SETVAL to the
* config register sets the counter value, the second
* write sets the period.
*/
hpet_writel(cmp, HPET_Tn_CMP(timer));
udelay(1);
hpet_writel((unsigned long) delta, HPET_Tn_CMP(timer));
break;
case CLOCK_EVT_MODE_ONESHOT:
cfg = hpet_readl(HPET_Tn_CFG(timer));
cfg &= ~HPET_TN_PERIODIC;
cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
hpet_writel(cfg, HPET_Tn_CFG(timer));
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
cfg = hpet_readl(HPET_Tn_CFG(timer));
cfg &= ~HPET_TN_ENABLE;
hpet_writel(cfg, HPET_Tn_CFG(timer));
break;
case CLOCK_EVT_MODE_RESUME:
if (timer == 0) {
hpet_enable_legacy_int();
} else {
struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
hpet_setup_msi_irq(hdev->irq);
disable_irq(hdev->irq);
irq_set_affinity(hdev->irq, cpumask_of_cpu(hdev->cpu));
enable_irq(hdev->irq);
}
break;
}
}
static int hpet_next_event(unsigned long delta,
struct clock_event_device *evt, int timer)
{
u32 cnt;
cnt = hpet_readl(HPET_COUNTER);
cnt += (u32) delta;
hpet_writel(cnt, HPET_Tn_CMP(timer));
/*
* We need to read back the CMP register to make sure that
* what we wrote hit the chip before we compare it to the
* counter.
*/
WARN_ON_ONCE((u32)hpet_readl(HPET_Tn_CMP(timer)) != cnt);
return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
}
static void hpet_legacy_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
hpet_set_mode(mode, evt, 0);
}
static int hpet_legacy_next_event(unsigned long delta,
struct clock_event_device *evt)
{
return hpet_next_event(delta, evt, 0);
}
/*
* HPET MSI Support
*/
#ifdef CONFIG_PCI_MSI
static DEFINE_PER_CPU(struct hpet_dev *, cpu_hpet_dev);
static struct hpet_dev *hpet_devs;
void hpet_msi_unmask(unsigned int irq)
{
struct hpet_dev *hdev = get_irq_data(irq);
unsigned long cfg;
/* unmask it */
cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
cfg |= HPET_TN_FSB;
hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
}
void hpet_msi_mask(unsigned int irq)
{
unsigned long cfg;
struct hpet_dev *hdev = get_irq_data(irq);
/* mask it */
cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
cfg &= ~HPET_TN_FSB;
hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
}
void hpet_msi_write(unsigned int irq, struct msi_msg *msg)
{
struct hpet_dev *hdev = get_irq_data(irq);
hpet_writel(msg->data, HPET_Tn_ROUTE(hdev->num));
hpet_writel(msg->address_lo, HPET_Tn_ROUTE(hdev->num) + 4);
}
void hpet_msi_read(unsigned int irq, struct msi_msg *msg)
{
struct hpet_dev *hdev = get_irq_data(irq);
msg->data = hpet_readl(HPET_Tn_ROUTE(hdev->num));
msg->address_lo = hpet_readl(HPET_Tn_ROUTE(hdev->num) + 4);
msg->address_hi = 0;
}
static void hpet_msi_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
hpet_set_mode(mode, evt, hdev->num);
}
static int hpet_msi_next_event(unsigned long delta,
struct clock_event_device *evt)
{
struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
return hpet_next_event(delta, evt, hdev->num);
}
static int hpet_setup_msi_irq(unsigned int irq)
{
if (arch_setup_hpet_msi(irq)) {
destroy_irq(irq);
return -EINVAL;
}
return 0;
}
static int hpet_assign_irq(struct hpet_dev *dev)
{
unsigned int irq;
irq = create_irq();
if (!irq)
return -EINVAL;
set_irq_data(irq, dev);
if (hpet_setup_msi_irq(irq))
return -EINVAL;
dev->irq = irq;
return 0;
}
static irqreturn_t hpet_interrupt_handler(int irq, void *data)
{
struct hpet_dev *dev = (struct hpet_dev *)data;
struct clock_event_device *hevt = &dev->evt;
if (!hevt->event_handler) {
printk(KERN_INFO "Spurious HPET timer interrupt on HPET timer %d\n",
dev->num);
return IRQ_HANDLED;
}
hevt->event_handler(hevt);
return IRQ_HANDLED;
}
static int hpet_setup_irq(struct hpet_dev *dev)
{
if (request_irq(dev->irq, hpet_interrupt_handler,
IRQF_DISABLED|IRQF_NOBALANCING, dev->name, dev))
return -1;
disable_irq(dev->irq);
irq_set_affinity(dev->irq, cpumask_of_cpu(dev->cpu));
enable_irq(dev->irq);
printk(KERN_DEBUG "hpet: %s irq %d for MSI\n",
dev->name, dev->irq);
return 0;
}
/* This should be called in specific @cpu */
static void init_one_hpet_msi_clockevent(struct hpet_dev *hdev, int cpu)
{
struct clock_event_device *evt = &hdev->evt;
uint64_t hpet_freq;
WARN_ON(cpu != smp_processor_id());
if (!(hdev->flags & HPET_DEV_VALID))
return;
if (hpet_setup_msi_irq(hdev->irq))
return;
hdev->cpu = cpu;
per_cpu(cpu_hpet_dev, cpu) = hdev;
evt->name = hdev->name;
hpet_setup_irq(hdev);
evt->irq = hdev->irq;
evt->rating = 110;
evt->features = CLOCK_EVT_FEAT_ONESHOT;
if (hdev->flags & HPET_DEV_PERI_CAP)
evt->features |= CLOCK_EVT_FEAT_PERIODIC;
evt->set_mode = hpet_msi_set_mode;
evt->set_next_event = hpet_msi_next_event;
evt->shift = 32;
/*
* The period is a femto seconds value. We need to calculate the
* scaled math multiplication factor for nanosecond to hpet tick
* conversion.
*/
hpet_freq = 1000000000000000ULL;
do_div(hpet_freq, hpet_period);
evt->mult = div_sc((unsigned long) hpet_freq,
NSEC_PER_SEC, evt->shift);
/* Calculate the max delta */
evt->max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, evt);
/* 5 usec minimum reprogramming delta. */
evt->min_delta_ns = 5000;
evt->cpumask = cpumask_of_cpu(hdev->cpu);
clockevents_register_device(evt);
}
#ifdef CONFIG_HPET
/* Reserve at least one timer for userspace (/dev/hpet) */
#define RESERVE_TIMERS 1
#else
#define RESERVE_TIMERS 0
#endif
static void hpet_msi_capability_lookup(unsigned int start_timer)
{
unsigned int id;
unsigned int num_timers;
unsigned int num_timers_used = 0;
int i;
id = hpet_readl(HPET_ID);
num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
num_timers++; /* Value read out starts from 0 */
hpet_devs = kzalloc(sizeof(struct hpet_dev) * num_timers, GFP_KERNEL);
if (!hpet_devs)
return;
hpet_num_timers = num_timers;
for (i = start_timer; i < num_timers - RESERVE_TIMERS; i++) {
struct hpet_dev *hdev = &hpet_devs[num_timers_used];
unsigned long cfg = hpet_readl(HPET_Tn_CFG(i));
/* Only consider HPET timer with MSI support */
if (!(cfg & HPET_TN_FSB_CAP))
continue;
hdev->flags = 0;
if (cfg & HPET_TN_PERIODIC_CAP)
hdev->flags |= HPET_DEV_PERI_CAP;
hdev->num = i;
sprintf(hdev->name, "hpet%d", i);
if (hpet_assign_irq(hdev))
continue;
hdev->flags |= HPET_DEV_FSB_CAP;
hdev->flags |= HPET_DEV_VALID;
num_timers_used++;
if (num_timers_used == num_possible_cpus())
break;
}
printk(KERN_INFO "HPET: %d timers in total, %d timers will be used for per-cpu timer\n",
num_timers, num_timers_used);
}
#ifdef CONFIG_HPET
static void hpet_reserve_msi_timers(struct hpet_data *hd)
{
int i;
if (!hpet_devs)
return;
for (i = 0; i < hpet_num_timers; i++) {
struct hpet_dev *hdev = &hpet_devs[i];
if (!(hdev->flags & HPET_DEV_VALID))
continue;
hd->hd_irq[hdev->num] = hdev->irq;
hpet_reserve_timer(hd, hdev->num);
}
}
#endif
static struct hpet_dev *hpet_get_unused_timer(void)
{
int i;
if (!hpet_devs)
return NULL;
for (i = 0; i < hpet_num_timers; i++) {
struct hpet_dev *hdev = &hpet_devs[i];
if (!(hdev->flags & HPET_DEV_VALID))
continue;
if (test_and_set_bit(HPET_DEV_USED_BIT,
(unsigned long *)&hdev->flags))
continue;
return hdev;
}
return NULL;
}
struct hpet_work_struct {
struct delayed_work work;
struct completion complete;
};
static void hpet_work(struct work_struct *w)
{
struct hpet_dev *hdev;
int cpu = smp_processor_id();
struct hpet_work_struct *hpet_work;
hpet_work = container_of(w, struct hpet_work_struct, work.work);
hdev = hpet_get_unused_timer();
if (hdev)
init_one_hpet_msi_clockevent(hdev, cpu);
complete(&hpet_work->complete);
}
static int hpet_cpuhp_notify(struct notifier_block *n,
unsigned long action, void *hcpu)
{
unsigned long cpu = (unsigned long)hcpu;
struct hpet_work_struct work;
struct hpet_dev *hdev = per_cpu(cpu_hpet_dev, cpu);
switch (action & 0xf) {
case CPU_ONLINE:
INIT_DELAYED_WORK(&work.work, hpet_work);
init_completion(&work.complete);
/* FIXME: add schedule_work_on() */
schedule_delayed_work_on(cpu, &work.work, 0);
wait_for_completion(&work.complete);
break;
case CPU_DEAD:
if (hdev) {
free_irq(hdev->irq, hdev);
hdev->flags &= ~HPET_DEV_USED;
per_cpu(cpu_hpet_dev, cpu) = NULL;
}
break;
}
return NOTIFY_OK;
}
#else
static int hpet_setup_msi_irq(unsigned int irq)
{
return 0;
}
static void hpet_msi_capability_lookup(unsigned int start_timer)
{
return;
}
#ifdef CONFIG_HPET
static void hpet_reserve_msi_timers(struct hpet_data *hd)
{
return;
}
#endif
static int hpet_cpuhp_notify(struct notifier_block *n,
unsigned long action, void *hcpu)
{
return NOTIFY_OK;
}
#endif
[PATCH] clocksource init adjustments (fix bug #7426) This patch resolves the issue found here: http://bugme.osdl.org/show_bug.cgi?id=7426 The basic summary is: Currently we register most of i386/x86_64 clocksources at module_init time. Then we enable clocksource selection at late_initcall time. This causes some problems for drivers that use gettimeofday for init calibration routines (specifically the es1968 driver in this case), where durring module_init, the only clocksource available is the low-res jiffies clocksource. This may cause slight calibration errors, due to the small sampling time used. It should be noted that drivers that require fine grained time may not function on architectures that do not have better then jiffies resolution timekeeping (there are a few). However, this does not discount the reasonable need for such fine-grained timekeeping at init time. Thus the solution here is to register clocksources earlier (ideally when the hardware is being initialized), and then we enable clocksource selection at fs_initcall (before device_initcall). This patch should probably get some testing time in -mm, since clocksource selection is one of the most important issues for correct timekeeping, and I've only been able to test this on a few of my own boxes. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 08:30:50 +00:00
/*
* Clock source related code
*/
static cycle_t read_hpet(void)
{
return (cycle_t)hpet_readl(HPET_COUNTER);
}
#ifdef CONFIG_X86_64
static cycle_t __vsyscall_fn vread_hpet(void)
{
return readl((const void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
}
#endif
[PATCH] clocksource init adjustments (fix bug #7426) This patch resolves the issue found here: http://bugme.osdl.org/show_bug.cgi?id=7426 The basic summary is: Currently we register most of i386/x86_64 clocksources at module_init time. Then we enable clocksource selection at late_initcall time. This causes some problems for drivers that use gettimeofday for init calibration routines (specifically the es1968 driver in this case), where durring module_init, the only clocksource available is the low-res jiffies clocksource. This may cause slight calibration errors, due to the small sampling time used. It should be noted that drivers that require fine grained time may not function on architectures that do not have better then jiffies resolution timekeeping (there are a few). However, this does not discount the reasonable need for such fine-grained timekeeping at init time. Thus the solution here is to register clocksources earlier (ideally when the hardware is being initialized), and then we enable clocksource selection at fs_initcall (before device_initcall). This patch should probably get some testing time in -mm, since clocksource selection is one of the most important issues for correct timekeeping, and I've only been able to test this on a few of my own boxes. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 08:30:50 +00:00
static struct clocksource clocksource_hpet = {
.name = "hpet",
.rating = 250,
.read = read_hpet,
.mask = HPET_MASK,
.shift = HPET_SHIFT,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.resume = hpet_restart_counter,
#ifdef CONFIG_X86_64
.vread = vread_hpet,
#endif
[PATCH] clocksource init adjustments (fix bug #7426) This patch resolves the issue found here: http://bugme.osdl.org/show_bug.cgi?id=7426 The basic summary is: Currently we register most of i386/x86_64 clocksources at module_init time. Then we enable clocksource selection at late_initcall time. This causes some problems for drivers that use gettimeofday for init calibration routines (specifically the es1968 driver in this case), where durring module_init, the only clocksource available is the low-res jiffies clocksource. This may cause slight calibration errors, due to the small sampling time used. It should be noted that drivers that require fine grained time may not function on architectures that do not have better then jiffies resolution timekeeping (there are a few). However, this does not discount the reasonable need for such fine-grained timekeeping at init time. Thus the solution here is to register clocksources earlier (ideally when the hardware is being initialized), and then we enable clocksource selection at fs_initcall (before device_initcall). This patch should probably get some testing time in -mm, since clocksource selection is one of the most important issues for correct timekeeping, and I've only been able to test this on a few of my own boxes. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 08:30:50 +00:00
};
static int hpet_clocksource_register(void)
{
x86: clean up computation of HPET .mult variables While reading through the HPET code I realized that the computation of .mult variables could be done with less lines of code, resulting in a 1.6% text size saving for hpet.o So I propose the following patch, which applies against today's Linus -git tree. >From 0c6507e400e9ca5f7f14331e18f8c12baf75a9d3 Mon Sep 17 00:00:00 2001 From: Carlos R. Mafra <crmafra@ift.unesp.br> Date: Mon, 5 May 2008 19:38:53 -0300 The computation of clocksource_hpet.mult tmp = (u64)hpet_period << HPET_SHIFT; do_div(tmp, FSEC_PER_NSEC); clocksource_hpet.mult = (u32)tmp; can be streamlined if we note that it is equal to clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT); Furthermore, the computation of hpet_clockevent.mult uint64_t hpet_freq; hpet_freq = 1000000000000000ULL; do_div(hpet_freq, hpet_period); hpet_clockevent.mult = div_sc((unsigned long) hpet_freq, NSEC_PER_SEC, hpet_clockevent.shift); can also be streamlined with the observation that hpet_period and hpet_freq are inverse to each other (in proper units). So instead of computing hpet_freq and using (schematically) div_sc(hpet_freq, 10^9, shift) we use the trick of calling with the arguments in reverse order, div_sc(10^6, hpet_period, shift). The different power of ten is due to frequency being in Hertz (1/sec) and the period being in units of femtosecond. Explicitly, mult = (hpet_freq * 2^shift)/10^9 (before) mult = (10^6 * 2^shift)/hpet_period (after) because hpet_freq = 10^15/hpet_period. The comments in the code are also updated to reflect the changes. As a result, text data bss dec hex filename 2957 425 92 3474 d92 arch/x86/kernel/hpet.o 3006 425 92 3523 dc3 arch/x86/kernel/hpet.o.old a 1.6% reduction in text size. Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-05 23:11:22 +00:00
u64 start, now;
cycle_t t1;
/* Start the counter */
hpet_start_counter();
/* Verify whether hpet counter works */
t1 = read_hpet();
rdtscll(start);
/*
* We don't know the TSC frequency yet, but waiting for
* 200000 TSC cycles is safe:
* 4 GHz == 50us
* 1 GHz == 200us
*/
do {
rep_nop();
rdtscll(now);
} while ((now - start) < 200000UL);
if (t1 == read_hpet()) {
printk(KERN_WARNING
"HPET counter not counting. HPET disabled\n");
return -ENODEV;
}
x86: clean up computation of HPET .mult variables While reading through the HPET code I realized that the computation of .mult variables could be done with less lines of code, resulting in a 1.6% text size saving for hpet.o So I propose the following patch, which applies against today's Linus -git tree. >From 0c6507e400e9ca5f7f14331e18f8c12baf75a9d3 Mon Sep 17 00:00:00 2001 From: Carlos R. Mafra <crmafra@ift.unesp.br> Date: Mon, 5 May 2008 19:38:53 -0300 The computation of clocksource_hpet.mult tmp = (u64)hpet_period << HPET_SHIFT; do_div(tmp, FSEC_PER_NSEC); clocksource_hpet.mult = (u32)tmp; can be streamlined if we note that it is equal to clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT); Furthermore, the computation of hpet_clockevent.mult uint64_t hpet_freq; hpet_freq = 1000000000000000ULL; do_div(hpet_freq, hpet_period); hpet_clockevent.mult = div_sc((unsigned long) hpet_freq, NSEC_PER_SEC, hpet_clockevent.shift); can also be streamlined with the observation that hpet_period and hpet_freq are inverse to each other (in proper units). So instead of computing hpet_freq and using (schematically) div_sc(hpet_freq, 10^9, shift) we use the trick of calling with the arguments in reverse order, div_sc(10^6, hpet_period, shift). The different power of ten is due to frequency being in Hertz (1/sec) and the period being in units of femtosecond. Explicitly, mult = (hpet_freq * 2^shift)/10^9 (before) mult = (10^6 * 2^shift)/hpet_period (after) because hpet_freq = 10^15/hpet_period. The comments in the code are also updated to reflect the changes. As a result, text data bss dec hex filename 2957 425 92 3474 d92 arch/x86/kernel/hpet.o 3006 425 92 3523 dc3 arch/x86/kernel/hpet.o.old a 1.6% reduction in text size. Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-05 23:11:22 +00:00
/*
* The definition of mult is (include/linux/clocksource.h)
* mult/2^shift = ns/cyc and hpet_period is in units of fsec/cyc
* so we first need to convert hpet_period to ns/cyc units:
* mult/2^shift = ns/cyc = hpet_period/10^6
* mult = (hpet_period * 2^shift)/10^6
* mult = (hpet_period << shift)/FSEC_PER_NSEC
[PATCH] clocksource init adjustments (fix bug #7426) This patch resolves the issue found here: http://bugme.osdl.org/show_bug.cgi?id=7426 The basic summary is: Currently we register most of i386/x86_64 clocksources at module_init time. Then we enable clocksource selection at late_initcall time. This causes some problems for drivers that use gettimeofday for init calibration routines (specifically the es1968 driver in this case), where durring module_init, the only clocksource available is the low-res jiffies clocksource. This may cause slight calibration errors, due to the small sampling time used. It should be noted that drivers that require fine grained time may not function on architectures that do not have better then jiffies resolution timekeeping (there are a few). However, this does not discount the reasonable need for such fine-grained timekeeping at init time. Thus the solution here is to register clocksources earlier (ideally when the hardware is being initialized), and then we enable clocksource selection at fs_initcall (before device_initcall). This patch should probably get some testing time in -mm, since clocksource selection is one of the most important issues for correct timekeeping, and I've only been able to test this on a few of my own boxes. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 08:30:50 +00:00
*/
x86: clean up computation of HPET .mult variables While reading through the HPET code I realized that the computation of .mult variables could be done with less lines of code, resulting in a 1.6% text size saving for hpet.o So I propose the following patch, which applies against today's Linus -git tree. >From 0c6507e400e9ca5f7f14331e18f8c12baf75a9d3 Mon Sep 17 00:00:00 2001 From: Carlos R. Mafra <crmafra@ift.unesp.br> Date: Mon, 5 May 2008 19:38:53 -0300 The computation of clocksource_hpet.mult tmp = (u64)hpet_period << HPET_SHIFT; do_div(tmp, FSEC_PER_NSEC); clocksource_hpet.mult = (u32)tmp; can be streamlined if we note that it is equal to clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT); Furthermore, the computation of hpet_clockevent.mult uint64_t hpet_freq; hpet_freq = 1000000000000000ULL; do_div(hpet_freq, hpet_period); hpet_clockevent.mult = div_sc((unsigned long) hpet_freq, NSEC_PER_SEC, hpet_clockevent.shift); can also be streamlined with the observation that hpet_period and hpet_freq are inverse to each other (in proper units). So instead of computing hpet_freq and using (schematically) div_sc(hpet_freq, 10^9, shift) we use the trick of calling with the arguments in reverse order, div_sc(10^6, hpet_period, shift). The different power of ten is due to frequency being in Hertz (1/sec) and the period being in units of femtosecond. Explicitly, mult = (hpet_freq * 2^shift)/10^9 (before) mult = (10^6 * 2^shift)/hpet_period (after) because hpet_freq = 10^15/hpet_period. The comments in the code are also updated to reflect the changes. As a result, text data bss dec hex filename 2957 425 92 3474 d92 arch/x86/kernel/hpet.o 3006 425 92 3523 dc3 arch/x86/kernel/hpet.o.old a 1.6% reduction in text size. Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-05 23:11:22 +00:00
clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT);
[PATCH] clocksource init adjustments (fix bug #7426) This patch resolves the issue found here: http://bugme.osdl.org/show_bug.cgi?id=7426 The basic summary is: Currently we register most of i386/x86_64 clocksources at module_init time. Then we enable clocksource selection at late_initcall time. This causes some problems for drivers that use gettimeofday for init calibration routines (specifically the es1968 driver in this case), where durring module_init, the only clocksource available is the low-res jiffies clocksource. This may cause slight calibration errors, due to the small sampling time used. It should be noted that drivers that require fine grained time may not function on architectures that do not have better then jiffies resolution timekeeping (there are a few). However, this does not discount the reasonable need for such fine-grained timekeeping at init time. Thus the solution here is to register clocksources earlier (ideally when the hardware is being initialized), and then we enable clocksource selection at fs_initcall (before device_initcall). This patch should probably get some testing time in -mm, since clocksource selection is one of the most important issues for correct timekeeping, and I've only been able to test this on a few of my own boxes. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 08:30:50 +00:00
clocksource_register(&clocksource_hpet);
return 0;
}
/**
* hpet_enable - Try to setup the HPET timer. Returns 1 on success.
*/
int __init hpet_enable(void)
{
unsigned long id;
int i;
if (!is_hpet_capable())
return 0;
hpet_set_mapping();
/*
* Read the period and check for a sane value:
*/
hpet_period = hpet_readl(HPET_PERIOD);
/*
* AMD SB700 based systems with spread spectrum enabled use a
* SMM based HPET emulation to provide proper frequency
* setting. The SMM code is initialized with the first HPET
* register access and takes some time to complete. During
* this time the config register reads 0xffffffff. We check
* for max. 1000 loops whether the config register reads a non
* 0xffffffff value to make sure that HPET is up and running
* before we go further. A counting loop is safe, as the HPET
* access takes thousands of CPU cycles. On non SB700 based
* machines this check is only done once and has no side
* effects.
*/
for (i = 0; hpet_readl(HPET_CFG) == 0xFFFFFFFF; i++) {
if (i == 1000) {
printk(KERN_WARNING
"HPET config register value = 0xFFFFFFFF. "
"Disabling HPET\n");
goto out_nohpet;
}
}
if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
goto out_nohpet;
/*
* Read the HPET ID register to retrieve the IRQ routing
* information and the number of channels
*/
id = hpet_readl(HPET_ID);
#ifdef CONFIG_HPET_EMULATE_RTC
/*
* The legacy routing mode needs at least two channels, tick timer
* and the rtc emulation channel.
*/
if (!(id & HPET_ID_NUMBER))
goto out_nohpet;
#endif
if (hpet_clocksource_register())
goto out_nohpet;
if (id & HPET_ID_LEGSUP) {
hpet_legacy_clockevent_register();
hpet_msi_capability_lookup(2);
return 1;
}
hpet_msi_capability_lookup(0);
return 0;
out_nohpet:
hpet_clear_mapping();
boot_hpet_disable = 1;
return 0;
}
/*
* Needs to be late, as the reserve_timer code calls kalloc !
*
* Not a problem on i386 as hpet_enable is called from late_time_init,
* but on x86_64 it is necessary !
*/
static __init int hpet_late_init(void)
{
int cpu;
if (boot_hpet_disable)
return -ENODEV;
if (!hpet_address) {
if (!force_hpet_address)
return -ENODEV;
hpet_address = force_hpet_address;
hpet_enable();
if (!hpet_virt_address)
return -ENODEV;
}
hpet_reserve_platform_timers(hpet_readl(HPET_ID));
for_each_online_cpu(cpu) {
hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
}
/* This notifier should be called after workqueue is ready */
hotcpu_notifier(hpet_cpuhp_notify, -20);
return 0;
}
fs_initcall(hpet_late_init);
void hpet_disable(void)
{
if (is_hpet_capable()) {
unsigned long cfg = hpet_readl(HPET_CFG);
if (hpet_legacy_int_enabled) {
cfg &= ~HPET_CFG_LEGACY;
hpet_legacy_int_enabled = 0;
}
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}
}
#ifdef CONFIG_HPET_EMULATE_RTC
/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
* is enabled, we support RTC interrupt functionality in software.
* RTC has 3 kinds of interrupts:
* 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
* is updated
* 2) Alarm Interrupt - generate an interrupt at a specific time of day
* 3) Periodic Interrupt - generate periodic interrupt, with frequencies
* 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
* (1) and (2) above are implemented using polling at a frequency of
* 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
* overhead. (DEFAULT_RTC_INT_FREQ)
* For (3), we use interrupts at 64Hz or user specified periodic
* frequency, whichever is higher.
*/
#include <linux/mc146818rtc.h>
#include <linux/rtc.h>
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
#include <asm/rtc.h>
#define DEFAULT_RTC_INT_FREQ 64
#define DEFAULT_RTC_SHIFT 6
#define RTC_NUM_INTS 1
static unsigned long hpet_rtc_flags;
static int hpet_prev_update_sec;
static struct rtc_time hpet_alarm_time;
static unsigned long hpet_pie_count;
static unsigned long hpet_t1_cmp;
static unsigned long hpet_default_delta;
static unsigned long hpet_pie_delta;
static unsigned long hpet_pie_limit;
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
static rtc_irq_handler irq_handler;
/*
* Registers a IRQ handler.
*/
int hpet_register_irq_handler(rtc_irq_handler handler)
{
if (!is_hpet_enabled())
return -ENODEV;
if (irq_handler)
return -EBUSY;
irq_handler = handler;
return 0;
}
EXPORT_SYMBOL_GPL(hpet_register_irq_handler);
/*
* Deregisters the IRQ handler registered with hpet_register_irq_handler()
* and does cleanup.
*/
void hpet_unregister_irq_handler(rtc_irq_handler handler)
{
if (!is_hpet_enabled())
return;
irq_handler = NULL;
hpet_rtc_flags = 0;
}
EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler);
/*
* Timer 1 for RTC emulation. We use one shot mode, as periodic mode
* is not supported by all HPET implementations for timer 1.
*
* hpet_rtc_timer_init() is called when the rtc is initialized.
*/
int hpet_rtc_timer_init(void)
{
unsigned long cfg, cnt, delta, flags;
if (!is_hpet_enabled())
return 0;
if (!hpet_default_delta) {
uint64_t clc;
clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
hpet_default_delta = (unsigned long) clc;
}
if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
delta = hpet_default_delta;
else
delta = hpet_pie_delta;
local_irq_save(flags);
cnt = delta + hpet_readl(HPET_COUNTER);
hpet_writel(cnt, HPET_T1_CMP);
hpet_t1_cmp = cnt;
cfg = hpet_readl(HPET_T1_CFG);
cfg &= ~HPET_TN_PERIODIC;
cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
hpet_writel(cfg, HPET_T1_CFG);
local_irq_restore(flags);
return 1;
}
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
EXPORT_SYMBOL_GPL(hpet_rtc_timer_init);
/*
* The functions below are called from rtc driver.
* Return 0 if HPET is not being used.
* Otherwise do the necessary changes and return 1.
*/
int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
{
if (!is_hpet_enabled())
return 0;
hpet_rtc_flags &= ~bit_mask;
return 1;
}
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
EXPORT_SYMBOL_GPL(hpet_mask_rtc_irq_bit);
int hpet_set_rtc_irq_bit(unsigned long bit_mask)
{
unsigned long oldbits = hpet_rtc_flags;
if (!is_hpet_enabled())
return 0;
hpet_rtc_flags |= bit_mask;
if ((bit_mask & RTC_UIE) && !(oldbits & RTC_UIE))
hpet_prev_update_sec = -1;
if (!oldbits)
hpet_rtc_timer_init();
return 1;
}
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit);
int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
unsigned char sec)
{
if (!is_hpet_enabled())
return 0;
hpet_alarm_time.tm_hour = hrs;
hpet_alarm_time.tm_min = min;
hpet_alarm_time.tm_sec = sec;
return 1;
}
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
EXPORT_SYMBOL_GPL(hpet_set_alarm_time);
int hpet_set_periodic_freq(unsigned long freq)
{
uint64_t clc;
if (!is_hpet_enabled())
return 0;
if (freq <= DEFAULT_RTC_INT_FREQ)
hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
else {
clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
do_div(clc, freq);
clc >>= hpet_clockevent.shift;
hpet_pie_delta = (unsigned long) clc;
}
return 1;
}
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
EXPORT_SYMBOL_GPL(hpet_set_periodic_freq);
int hpet_rtc_dropped_irq(void)
{
return is_hpet_enabled();
}
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq);
static void hpet_rtc_timer_reinit(void)
{
unsigned long cfg, delta;
int lost_ints = -1;
if (unlikely(!hpet_rtc_flags)) {
cfg = hpet_readl(HPET_T1_CFG);
cfg &= ~HPET_TN_ENABLE;
hpet_writel(cfg, HPET_T1_CFG);
return;
}
if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
delta = hpet_default_delta;
else
delta = hpet_pie_delta;
/*
* Increment the comparator value until we are ahead of the
* current count.
*/
do {
hpet_t1_cmp += delta;
hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
lost_ints++;
} while ((long)(hpet_readl(HPET_COUNTER) - hpet_t1_cmp) > 0);
if (lost_ints) {
if (hpet_rtc_flags & RTC_PIE)
hpet_pie_count += lost_ints;
if (printk_ratelimit())
printk(KERN_WARNING "hpet1: lost %d rtc interrupts\n",
lost_ints);
}
}
irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
{
struct rtc_time curr_time;
unsigned long rtc_int_flag = 0;
hpet_rtc_timer_reinit();
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
memset(&curr_time, 0, sizeof(struct rtc_time));
if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
get_rtc_time(&curr_time);
if (hpet_rtc_flags & RTC_UIE &&
curr_time.tm_sec != hpet_prev_update_sec) {
if (hpet_prev_update_sec >= 0)
rtc_int_flag = RTC_UF;
hpet_prev_update_sec = curr_time.tm_sec;
}
if (hpet_rtc_flags & RTC_PIE &&
++hpet_pie_count >= hpet_pie_limit) {
rtc_int_flag |= RTC_PF;
hpet_pie_count = 0;
}
if (hpet_rtc_flags & RTC_AIE &&
(curr_time.tm_sec == hpet_alarm_time.tm_sec) &&
(curr_time.tm_min == hpet_alarm_time.tm_min) &&
(curr_time.tm_hour == hpet_alarm_time.tm_hour))
rtc_int_flag |= RTC_AF;
if (rtc_int_flag) {
rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
if (irq_handler)
irq_handler(rtc_int_flag, dev_id);
}
return IRQ_HANDLED;
}
x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules enabled, then interrupts don't work for the rtc-cmos driver which results in RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a polling method is used for unknown reasons.) This patch series now 1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc driver uses to work around that problem, 2. makes it possible to compile the old rtc driver as module, while still having CONFIG_HPET_EMULATE_RTC enabled and 3. makes use of the exported functions in (1) in the new rtc-cmos driver. This patch: This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable for kernel modules. It - exports the functions (EXPORT_SYMBOL_GPL()), - adds an interface to register the interrupt callback function instead of using only a fixed callback function and - replaces the rtc_get_rtc_time() function which depends on CONFIG_RTC with a call to get_rtc_time() which is defined in include/asm-generic/rtc.h. The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is removed by the next patch. After this, there's no (code) dependency of this functions to CONFIG_RTC=y any more. Signed-off-by: Bernhard Walle <bwalle@suse.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:33:28 +00:00
EXPORT_SYMBOL_GPL(hpet_rtc_interrupt);
#endif