linux/drivers/pci/msi.c

823 lines
21 KiB
C
Raw Normal View History

/*
* File: msi.c
* Purpose: PCI Message Signaled Interrupt (MSI)
*
* Copyright (C) 2003-2004 Intel
* Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
*/
#include <linux/err.h>
#include <linux/mm.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/msi.h>
#include <linux/smp.h>
#include <asm/errno.h>
#include <asm/io.h>
#include "pci.h"
#include "msi.h"
static int pci_msi_enable = 1;
/* Arch hooks */
#ifndef arch_msi_check_device
int arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
{
return 0;
}
#endif
#ifndef arch_setup_msi_irqs
int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
struct msi_desc *entry;
int ret;
/*
* If an architecture wants to support multiple MSI, it needs to
* override arch_setup_msi_irqs()
*/
if (type == PCI_CAP_ID_MSI && nvec > 1)
return 1;
list_for_each_entry(entry, &dev->msi_list, list) {
ret = arch_setup_msi_irq(dev, entry);
if (ret < 0)
return ret;
if (ret > 0)
return -ENOSPC;
}
return 0;
}
#endif
#ifndef arch_teardown_msi_irqs
void arch_teardown_msi_irqs(struct pci_dev *dev)
{
struct msi_desc *entry;
list_for_each_entry(entry, &dev->msi_list, list) {
int i, nvec;
if (entry->irq == 0)
continue;
nvec = 1 << entry->msi_attrib.multiple;
for (i = 0; i < nvec; i++)
arch_teardown_msi_irq(entry->irq + i);
}
}
#endif
static void msi_set_enable(struct pci_dev *dev, int pos, int enable)
{
u16 control;
BUG_ON(!pos);
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
control &= ~PCI_MSI_FLAGS_ENABLE;
if (enable)
control |= PCI_MSI_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
}
static void msix_set_enable(struct pci_dev *dev, int enable)
{
int pos;
u16 control;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos) {
pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
control &= ~PCI_MSIX_FLAGS_ENABLE;
if (enable)
control |= PCI_MSIX_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
}
}
static inline __attribute_const__ u32 msi_mask(unsigned x)
{
/* Don't shift by >= width of type */
if (x >= 5)
return 0xffffffff;
return (1 << (1 << x)) - 1;
}
static inline __attribute_const__ u32 msi_capable_mask(u16 control)
{
return msi_mask((control >> 1) & 7);
}
static inline __attribute_const__ u32 msi_enabled_mask(u16 control)
{
return msi_mask((control >> 4) & 7);
}
/*
* PCI 2.3 does not specify mask bits for each MSI interrupt. Attempting to
* mask all MSI interrupts by clearing the MSI enable bit does not work
* reliably as devices without an INTx disable bit will then generate a
* level IRQ which will never be cleared.
*/
PCI MSI: Fix restoration of MSI/MSI-X mask states in suspend/resume There are 2 problems on mask states in suspend/resume. [1]: It is better to restore the mask states of MSI/MSI-X to initial states (MSI is unmasked, MSI-X is masked) when we release the device. The pci_msi_shutdown() does the restoration of mask states for MSI, while the msi_free_irqs() does it for MSI-X. In other words, in the "disable" path both of MSI and MSI-X are handled, but in the "shutdown" path only MSI is handled. MSI: pci_disable_msi() => pci_msi_shutdown() [ mask states for MSI restored ] => msi_set_enable(dev, pos, 0); => msi_free_irqs() MSI-X: pci_disable_msix() => pci_msix_shutdown() => msix_set_enable(dev, 0); => msix_free_all_irqs => msi_free_irqs() [ mask states for MSI-X restored ] This patch moves the masking for MSI-X from msi_free_irqs() to pci_msix_shutdown(). This change has some positive side effects: - It prevents OS from touching mask states before reading preserved bits in the register, which can be happen if msi_free_irqs() is called from error path in msix_capability_init(). - It also prevents touching the register after turning off MSI-X in "disable" path, which can be a problem on some devices. [2]: We have cache of the mask state in msi_desc, which is automatically updated when msi/msix_mask_irq() is called. This cached states are used for the resume. But since what need to be restored in the resume is the states before the shutdown on the suspend, calling msi/msix_mask_irq() from pci_msi/msix_shutdown() is not appropriate. This patch introduces __msi/msix_mask_irq() that do mask as same as msi/msix_mask_irq() but does not update cached state, for use in pci_msi/msix_shutdown(). [updated: get rid of msi/msix_mask_irq_nocache() (proposed by Matthew Wilcox)] Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-24 03:08:09 +00:00
static u32 __msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
{
u32 mask_bits = desc->masked;
if (!desc->msi_attrib.maskbit)
PCI MSI: Fix restoration of MSI/MSI-X mask states in suspend/resume There are 2 problems on mask states in suspend/resume. [1]: It is better to restore the mask states of MSI/MSI-X to initial states (MSI is unmasked, MSI-X is masked) when we release the device. The pci_msi_shutdown() does the restoration of mask states for MSI, while the msi_free_irqs() does it for MSI-X. In other words, in the "disable" path both of MSI and MSI-X are handled, but in the "shutdown" path only MSI is handled. MSI: pci_disable_msi() => pci_msi_shutdown() [ mask states for MSI restored ] => msi_set_enable(dev, pos, 0); => msi_free_irqs() MSI-X: pci_disable_msix() => pci_msix_shutdown() => msix_set_enable(dev, 0); => msix_free_all_irqs => msi_free_irqs() [ mask states for MSI-X restored ] This patch moves the masking for MSI-X from msi_free_irqs() to pci_msix_shutdown(). This change has some positive side effects: - It prevents OS from touching mask states before reading preserved bits in the register, which can be happen if msi_free_irqs() is called from error path in msix_capability_init(). - It also prevents touching the register after turning off MSI-X in "disable" path, which can be a problem on some devices. [2]: We have cache of the mask state in msi_desc, which is automatically updated when msi/msix_mask_irq() is called. This cached states are used for the resume. But since what need to be restored in the resume is the states before the shutdown on the suspend, calling msi/msix_mask_irq() from pci_msi/msix_shutdown() is not appropriate. This patch introduces __msi/msix_mask_irq() that do mask as same as msi/msix_mask_irq() but does not update cached state, for use in pci_msi/msix_shutdown(). [updated: get rid of msi/msix_mask_irq_nocache() (proposed by Matthew Wilcox)] Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-24 03:08:09 +00:00
return 0;
mask_bits &= ~mask;
mask_bits |= flag;
pci_write_config_dword(desc->dev, desc->mask_pos, mask_bits);
PCI MSI: Fix restoration of MSI/MSI-X mask states in suspend/resume There are 2 problems on mask states in suspend/resume. [1]: It is better to restore the mask states of MSI/MSI-X to initial states (MSI is unmasked, MSI-X is masked) when we release the device. The pci_msi_shutdown() does the restoration of mask states for MSI, while the msi_free_irqs() does it for MSI-X. In other words, in the "disable" path both of MSI and MSI-X are handled, but in the "shutdown" path only MSI is handled. MSI: pci_disable_msi() => pci_msi_shutdown() [ mask states for MSI restored ] => msi_set_enable(dev, pos, 0); => msi_free_irqs() MSI-X: pci_disable_msix() => pci_msix_shutdown() => msix_set_enable(dev, 0); => msix_free_all_irqs => msi_free_irqs() [ mask states for MSI-X restored ] This patch moves the masking for MSI-X from msi_free_irqs() to pci_msix_shutdown(). This change has some positive side effects: - It prevents OS from touching mask states before reading preserved bits in the register, which can be happen if msi_free_irqs() is called from error path in msix_capability_init(). - It also prevents touching the register after turning off MSI-X in "disable" path, which can be a problem on some devices. [2]: We have cache of the mask state in msi_desc, which is automatically updated when msi/msix_mask_irq() is called. This cached states are used for the resume. But since what need to be restored in the resume is the states before the shutdown on the suspend, calling msi/msix_mask_irq() from pci_msi/msix_shutdown() is not appropriate. This patch introduces __msi/msix_mask_irq() that do mask as same as msi/msix_mask_irq() but does not update cached state, for use in pci_msi/msix_shutdown(). [updated: get rid of msi/msix_mask_irq_nocache() (proposed by Matthew Wilcox)] Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-24 03:08:09 +00:00
return mask_bits;
}
static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
{
desc->masked = __msi_mask_irq(desc, mask, flag);
}
/*
* This internal function does not flush PCI writes to the device.
* All users must ensure that they read from the device before either
* assuming that the device state is up to date, or returning out of this
* file. This saves a few milliseconds when initialising devices with lots
* of MSI-X interrupts.
*/
PCI MSI: Fix restoration of MSI/MSI-X mask states in suspend/resume There are 2 problems on mask states in suspend/resume. [1]: It is better to restore the mask states of MSI/MSI-X to initial states (MSI is unmasked, MSI-X is masked) when we release the device. The pci_msi_shutdown() does the restoration of mask states for MSI, while the msi_free_irqs() does it for MSI-X. In other words, in the "disable" path both of MSI and MSI-X are handled, but in the "shutdown" path only MSI is handled. MSI: pci_disable_msi() => pci_msi_shutdown() [ mask states for MSI restored ] => msi_set_enable(dev, pos, 0); => msi_free_irqs() MSI-X: pci_disable_msix() => pci_msix_shutdown() => msix_set_enable(dev, 0); => msix_free_all_irqs => msi_free_irqs() [ mask states for MSI-X restored ] This patch moves the masking for MSI-X from msi_free_irqs() to pci_msix_shutdown(). This change has some positive side effects: - It prevents OS from touching mask states before reading preserved bits in the register, which can be happen if msi_free_irqs() is called from error path in msix_capability_init(). - It also prevents touching the register after turning off MSI-X in "disable" path, which can be a problem on some devices. [2]: We have cache of the mask state in msi_desc, which is automatically updated when msi/msix_mask_irq() is called. This cached states are used for the resume. But since what need to be restored in the resume is the states before the shutdown on the suspend, calling msi/msix_mask_irq() from pci_msi/msix_shutdown() is not appropriate. This patch introduces __msi/msix_mask_irq() that do mask as same as msi/msix_mask_irq() but does not update cached state, for use in pci_msi/msix_shutdown(). [updated: get rid of msi/msix_mask_irq_nocache() (proposed by Matthew Wilcox)] Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-24 03:08:09 +00:00
static u32 __msix_mask_irq(struct msi_desc *desc, u32 flag)
{
u32 mask_bits = desc->masked;
unsigned offset = desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_VECTOR_CTRL;
mask_bits &= ~1;
mask_bits |= flag;
writel(mask_bits, desc->mask_base + offset);
PCI MSI: Fix restoration of MSI/MSI-X mask states in suspend/resume There are 2 problems on mask states in suspend/resume. [1]: It is better to restore the mask states of MSI/MSI-X to initial states (MSI is unmasked, MSI-X is masked) when we release the device. The pci_msi_shutdown() does the restoration of mask states for MSI, while the msi_free_irqs() does it for MSI-X. In other words, in the "disable" path both of MSI and MSI-X are handled, but in the "shutdown" path only MSI is handled. MSI: pci_disable_msi() => pci_msi_shutdown() [ mask states for MSI restored ] => msi_set_enable(dev, pos, 0); => msi_free_irqs() MSI-X: pci_disable_msix() => pci_msix_shutdown() => msix_set_enable(dev, 0); => msix_free_all_irqs => msi_free_irqs() [ mask states for MSI-X restored ] This patch moves the masking for MSI-X from msi_free_irqs() to pci_msix_shutdown(). This change has some positive side effects: - It prevents OS from touching mask states before reading preserved bits in the register, which can be happen if msi_free_irqs() is called from error path in msix_capability_init(). - It also prevents touching the register after turning off MSI-X in "disable" path, which can be a problem on some devices. [2]: We have cache of the mask state in msi_desc, which is automatically updated when msi/msix_mask_irq() is called. This cached states are used for the resume. But since what need to be restored in the resume is the states before the shutdown on the suspend, calling msi/msix_mask_irq() from pci_msi/msix_shutdown() is not appropriate. This patch introduces __msi/msix_mask_irq() that do mask as same as msi/msix_mask_irq() but does not update cached state, for use in pci_msi/msix_shutdown(). [updated: get rid of msi/msix_mask_irq_nocache() (proposed by Matthew Wilcox)] Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-24 03:08:09 +00:00
return mask_bits;
}
static void msix_mask_irq(struct msi_desc *desc, u32 flag)
{
desc->masked = __msix_mask_irq(desc, flag);
}
static void msi_set_mask_bit(unsigned irq, u32 flag)
{
struct msi_desc *desc = get_irq_msi(irq);
if (desc->msi_attrib.is_msix) {
msix_mask_irq(desc, flag);
readl(desc->mask_base); /* Flush write to device */
} else {
unsigned offset = irq - desc->dev->irq;
msi_mask_irq(desc, 1 << offset, flag << offset);
}
}
void mask_msi_irq(unsigned int irq)
{
msi_set_mask_bit(irq, 1);
}
void unmask_msi_irq(unsigned int irq)
{
msi_set_mask_bit(irq, 0);
}
void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg)
{
struct msi_desc *entry = get_irq_desc_msi(desc);
if (entry->msi_attrib.is_msix) {
void __iomem *base = entry->mask_base +
entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
msg->data = readl(base + PCI_MSIX_ENTRY_DATA);
} else {
struct pci_dev *dev = entry->dev;
int pos = entry->msi_attrib.pos;
u16 data;
pci_read_config_dword(dev, msi_lower_address_reg(pos),
&msg->address_lo);
if (entry->msi_attrib.is_64) {
pci_read_config_dword(dev, msi_upper_address_reg(pos),
&msg->address_hi);
pci_read_config_word(dev, msi_data_reg(pos, 1), &data);
} else {
msg->address_hi = 0;
pci_read_config_word(dev, msi_data_reg(pos, 0), &data);
}
msg->data = data;
}
}
void read_msi_msg(unsigned int irq, struct msi_msg *msg)
{
struct irq_desc *desc = irq_to_desc(irq);
read_msi_msg_desc(desc, msg);
}
void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg)
{
struct msi_desc *entry = get_irq_desc_msi(desc);
if (entry->msi_attrib.is_msix) {
void __iomem *base;
base = entry->mask_base +
entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);
writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);
writel(msg->data, base + PCI_MSIX_ENTRY_DATA);
} else {
struct pci_dev *dev = entry->dev;
int pos = entry->msi_attrib.pos;
u16 msgctl;
pci_read_config_word(dev, msi_control_reg(pos), &msgctl);
msgctl &= ~PCI_MSI_FLAGS_QSIZE;
msgctl |= entry->msi_attrib.multiple << 4;
pci_write_config_word(dev, msi_control_reg(pos), msgctl);
pci_write_config_dword(dev, msi_lower_address_reg(pos),
msg->address_lo);
if (entry->msi_attrib.is_64) {
pci_write_config_dword(dev, msi_upper_address_reg(pos),
msg->address_hi);
pci_write_config_word(dev, msi_data_reg(pos, 1),
msg->data);
} else {
pci_write_config_word(dev, msi_data_reg(pos, 0),
msg->data);
}
}
[PATCH] msi: Safer state caching. There are two ways pci_save_state and pci_restore_state are used. As helper functions during suspend/resume, and as helper functions around a hardware reset event. When used as helper functions around a hardware reset event there is no reason to believe the calls will be paired, nor is there a good reason to believe that if we restore the msi state from before the reset that it will match the current msi state. Since arch code may change the msi message without going through the driver, drivers currently do not have enough information to even know when to call pci_save_state to ensure they will have msi state in sync with the other kernel irq reception data structures. It turns out the solution is straight forward, cache the state in the existing msi data structures (not the magic pci saved things) and have the msi code update the cached state each time we write to the hardware. This means we never need to read the hardware to figure out what the hardware state should be. By modifying the caching in this manner we get to remove our save_state routines and only need to provide restore_state routines. The only fields that were at all tricky to regenerate were the msi and msi-x control registers and the way we regenerate them currently is a bit dependent upon assumptions on how we use the allow msi registers to be configured and used making the code a little bit brittle. If we ever change what cases we allow or how we configure the msi bits we can address the fragility then. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Auke Kok <auke-jan.h.kok@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-08 20:04:57 +00:00
entry->msg = *msg;
}
void write_msi_msg(unsigned int irq, struct msi_msg *msg)
{
struct irq_desc *desc = irq_to_desc(irq);
write_msi_msg_desc(desc, msg);
}
static int msi_free_irqs(struct pci_dev* dev);
static struct msi_desc *alloc_msi_entry(struct pci_dev *dev)
{
struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL);
if (!desc)
return NULL;
INIT_LIST_HEAD(&desc->list);
desc->dev = dev;
return desc;
}
static void pci_intx_for_msi(struct pci_dev *dev, int enable)
{
if (!(dev->dev_flags & PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG))
pci_intx(dev, enable);
}
static void __pci_restore_msi_state(struct pci_dev *dev)
{
[PATCH] msi: Safer state caching. There are two ways pci_save_state and pci_restore_state are used. As helper functions during suspend/resume, and as helper functions around a hardware reset event. When used as helper functions around a hardware reset event there is no reason to believe the calls will be paired, nor is there a good reason to believe that if we restore the msi state from before the reset that it will match the current msi state. Since arch code may change the msi message without going through the driver, drivers currently do not have enough information to even know when to call pci_save_state to ensure they will have msi state in sync with the other kernel irq reception data structures. It turns out the solution is straight forward, cache the state in the existing msi data structures (not the magic pci saved things) and have the msi code update the cached state each time we write to the hardware. This means we never need to read the hardware to figure out what the hardware state should be. By modifying the caching in this manner we get to remove our save_state routines and only need to provide restore_state routines. The only fields that were at all tricky to regenerate were the msi and msi-x control registers and the way we regenerate them currently is a bit dependent upon assumptions on how we use the allow msi registers to be configured and used making the code a little bit brittle. If we ever change what cases we allow or how we configure the msi bits we can address the fragility then. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Auke Kok <auke-jan.h.kok@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-08 20:04:57 +00:00
int pos;
u16 control;
[PATCH] msi: Safer state caching. There are two ways pci_save_state and pci_restore_state are used. As helper functions during suspend/resume, and as helper functions around a hardware reset event. When used as helper functions around a hardware reset event there is no reason to believe the calls will be paired, nor is there a good reason to believe that if we restore the msi state from before the reset that it will match the current msi state. Since arch code may change the msi message without going through the driver, drivers currently do not have enough information to even know when to call pci_save_state to ensure they will have msi state in sync with the other kernel irq reception data structures. It turns out the solution is straight forward, cache the state in the existing msi data structures (not the magic pci saved things) and have the msi code update the cached state each time we write to the hardware. This means we never need to read the hardware to figure out what the hardware state should be. By modifying the caching in this manner we get to remove our save_state routines and only need to provide restore_state routines. The only fields that were at all tricky to regenerate were the msi and msi-x control registers and the way we regenerate them currently is a bit dependent upon assumptions on how we use the allow msi registers to be configured and used making the code a little bit brittle. If we ever change what cases we allow or how we configure the msi bits we can address the fragility then. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Auke Kok <auke-jan.h.kok@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-08 20:04:57 +00:00
struct msi_desc *entry;
if (!dev->msi_enabled)
return;
[PATCH] msi: Safer state caching. There are two ways pci_save_state and pci_restore_state are used. As helper functions during suspend/resume, and as helper functions around a hardware reset event. When used as helper functions around a hardware reset event there is no reason to believe the calls will be paired, nor is there a good reason to believe that if we restore the msi state from before the reset that it will match the current msi state. Since arch code may change the msi message without going through the driver, drivers currently do not have enough information to even know when to call pci_save_state to ensure they will have msi state in sync with the other kernel irq reception data structures. It turns out the solution is straight forward, cache the state in the existing msi data structures (not the magic pci saved things) and have the msi code update the cached state each time we write to the hardware. This means we never need to read the hardware to figure out what the hardware state should be. By modifying the caching in this manner we get to remove our save_state routines and only need to provide restore_state routines. The only fields that were at all tricky to regenerate were the msi and msi-x control registers and the way we regenerate them currently is a bit dependent upon assumptions on how we use the allow msi registers to be configured and used making the code a little bit brittle. If we ever change what cases we allow or how we configure the msi bits we can address the fragility then. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Auke Kok <auke-jan.h.kok@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-08 20:04:57 +00:00
entry = get_irq_msi(dev->irq);
pos = entry->msi_attrib.pos;
pci_intx_for_msi(dev, 0);
msi_set_enable(dev, pos, 0);
[PATCH] msi: Safer state caching. There are two ways pci_save_state and pci_restore_state are used. As helper functions during suspend/resume, and as helper functions around a hardware reset event. When used as helper functions around a hardware reset event there is no reason to believe the calls will be paired, nor is there a good reason to believe that if we restore the msi state from before the reset that it will match the current msi state. Since arch code may change the msi message without going through the driver, drivers currently do not have enough information to even know when to call pci_save_state to ensure they will have msi state in sync with the other kernel irq reception data structures. It turns out the solution is straight forward, cache the state in the existing msi data structures (not the magic pci saved things) and have the msi code update the cached state each time we write to the hardware. This means we never need to read the hardware to figure out what the hardware state should be. By modifying the caching in this manner we get to remove our save_state routines and only need to provide restore_state routines. The only fields that were at all tricky to regenerate were the msi and msi-x control registers and the way we regenerate them currently is a bit dependent upon assumptions on how we use the allow msi registers to be configured and used making the code a little bit brittle. If we ever change what cases we allow or how we configure the msi bits we can address the fragility then. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Auke Kok <auke-jan.h.kok@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-08 20:04:57 +00:00
write_msi_msg(dev->irq, &entry->msg);
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
msi_mask_irq(entry, msi_capable_mask(control), entry->masked);
control &= ~PCI_MSI_FLAGS_QSIZE;
control |= (entry->msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
}
static void __pci_restore_msix_state(struct pci_dev *dev)
{
int pos;
struct msi_desc *entry;
[PATCH] msi: Safer state caching. There are two ways pci_save_state and pci_restore_state are used. As helper functions during suspend/resume, and as helper functions around a hardware reset event. When used as helper functions around a hardware reset event there is no reason to believe the calls will be paired, nor is there a good reason to believe that if we restore the msi state from before the reset that it will match the current msi state. Since arch code may change the msi message without going through the driver, drivers currently do not have enough information to even know when to call pci_save_state to ensure they will have msi state in sync with the other kernel irq reception data structures. It turns out the solution is straight forward, cache the state in the existing msi data structures (not the magic pci saved things) and have the msi code update the cached state each time we write to the hardware. This means we never need to read the hardware to figure out what the hardware state should be. By modifying the caching in this manner we get to remove our save_state routines and only need to provide restore_state routines. The only fields that were at all tricky to regenerate were the msi and msi-x control registers and the way we regenerate them currently is a bit dependent upon assumptions on how we use the allow msi registers to be configured and used making the code a little bit brittle. If we ever change what cases we allow or how we configure the msi bits we can address the fragility then. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Auke Kok <auke-jan.h.kok@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-08 20:04:57 +00:00
u16 control;
if (!dev->msix_enabled)
return;
BUG_ON(list_empty(&dev->msi_list));
entry = list_first_entry(&dev->msi_list, struct msi_desc, list);
pos = entry->msi_attrib.pos;
pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
/* route the table */
pci_intx_for_msi(dev, 0);
control |= PCI_MSIX_FLAGS_ENABLE | PCI_MSIX_FLAGS_MASKALL;
pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
list_for_each_entry(entry, &dev->msi_list, list) {
write_msi_msg(entry->irq, &entry->msg);
msix_mask_irq(entry, entry->masked);
}
[PATCH] msi: Safer state caching. There are two ways pci_save_state and pci_restore_state are used. As helper functions during suspend/resume, and as helper functions around a hardware reset event. When used as helper functions around a hardware reset event there is no reason to believe the calls will be paired, nor is there a good reason to believe that if we restore the msi state from before the reset that it will match the current msi state. Since arch code may change the msi message without going through the driver, drivers currently do not have enough information to even know when to call pci_save_state to ensure they will have msi state in sync with the other kernel irq reception data structures. It turns out the solution is straight forward, cache the state in the existing msi data structures (not the magic pci saved things) and have the msi code update the cached state each time we write to the hardware. This means we never need to read the hardware to figure out what the hardware state should be. By modifying the caching in this manner we get to remove our save_state routines and only need to provide restore_state routines. The only fields that were at all tricky to regenerate were the msi and msi-x control registers and the way we regenerate them currently is a bit dependent upon assumptions on how we use the allow msi registers to be configured and used making the code a little bit brittle. If we ever change what cases we allow or how we configure the msi bits we can address the fragility then. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Auke Kok <auke-jan.h.kok@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-08 20:04:57 +00:00
control &= ~PCI_MSIX_FLAGS_MASKALL;
pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
}
void pci_restore_msi_state(struct pci_dev *dev)
{
__pci_restore_msi_state(dev);
__pci_restore_msix_state(dev);
}
EXPORT_SYMBOL_GPL(pci_restore_msi_state);
/**
* msi_capability_init - configure device's MSI capability structure
* @dev: pointer to the pci_dev data structure of MSI device function
* @nvec: number of interrupts to allocate
*
* Setup the MSI capability structure of the device with the requested
* number of interrupts. A return value of zero indicates the successful
* setup of an entry with the new MSI irq. A negative return value indicates
* an error, and a positive return value indicates the number of interrupts
* which could have been allocated.
*/
static int msi_capability_init(struct pci_dev *dev, int nvec)
{
struct msi_desc *entry;
int pos, ret;
u16 control;
unsigned mask;
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
msi_set_enable(dev, pos, 0); /* Disable MSI during set up */
pci_read_config_word(dev, msi_control_reg(pos), &control);
/* MSI Entry Initialization */
entry = alloc_msi_entry(dev);
if (!entry)
return -ENOMEM;
entry->msi_attrib.is_msix = 0;
entry->msi_attrib.is_64 = is_64bit_address(control);
entry->msi_attrib.entry_nr = 0;
entry->msi_attrib.maskbit = is_mask_bit_support(control);
entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */
entry->msi_attrib.pos = pos;
entry->mask_pos = msi_mask_reg(pos, entry->msi_attrib.is_64);
/* All MSIs are unmasked by default, Mask them all */
if (entry->msi_attrib.maskbit)
pci_read_config_dword(dev, entry->mask_pos, &entry->masked);
mask = msi_capable_mask(control);
msi_mask_irq(entry, mask, mask);
list_add_tail(&entry->list, &dev->msi_list);
/* Configure MSI capability structure */
ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
if (ret) {
msi_mask_irq(entry, mask, ~mask);
msi_free_irqs(dev);
return ret;
}
/* Set MSI enabled bits */
pci_intx_for_msi(dev, 0);
msi_set_enable(dev, pos, 1);
dev->msi_enabled = 1;
dev->irq = entry->irq;
return 0;
}
/**
* msix_capability_init - configure device's MSI-X capability
* @dev: pointer to the pci_dev data structure of MSI-X device function
* @entries: pointer to an array of struct msix_entry entries
* @nvec: number of @entries
*
* Setup the MSI-X capability structure of device function with a
* single MSI-X irq. A return of zero indicates the successful setup of
* requested MSI-X entries with allocated irqs or non-zero for otherwise.
**/
static int msix_capability_init(struct pci_dev *dev,
struct msix_entry *entries, int nvec)
{
struct msi_desc *entry;
int pos, i, j, nr_entries, ret;
unsigned long phys_addr;
u32 table_offset;
u16 control;
u8 bir;
void __iomem *base;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
/* Ensure MSI-X is disabled while it is set up */
control &= ~PCI_MSIX_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
/* Request & Map MSI-X table region */
nr_entries = multi_msix_capable(control);
pci_read_config_dword(dev, msix_table_offset_reg(pos), &table_offset);
bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
table_offset &= ~PCI_MSIX_FLAGS_BIRMASK;
phys_addr = pci_resource_start (dev, bir) + table_offset;
base = ioremap_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
if (base == NULL)
return -ENOMEM;
for (i = 0; i < nvec; i++) {
entry = alloc_msi_entry(dev);
if (!entry) {
if (!i)
iounmap(base);
else
msi_free_irqs(dev);
/* No enough memory. Don't try again */
return -ENOMEM;
}
j = entries[i].entry;
entry->msi_attrib.is_msix = 1;
entry->msi_attrib.is_64 = 1;
entry->msi_attrib.entry_nr = j;
entry->msi_attrib.default_irq = dev->irq;
entry->msi_attrib.pos = pos;
entry->mask_base = base;
list_add_tail(&entry->list, &dev->msi_list);
}
ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
if (ret < 0) {
/* If we had some success report the number of irqs
* we succeeded in setting up. */
int avail = 0;
list_for_each_entry(entry, &dev->msi_list, list) {
if (entry->irq != 0) {
avail++;
}
}
if (avail != 0)
ret = avail;
}
if (ret) {
msi_free_irqs(dev);
return ret;
}
/*
* Some devices require MSI-X to be enabled before we can touch the
* MSI-X registers. We need to mask all the vectors to prevent
* interrupts coming in before they're fully set up.
*/
control |= PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
i = 0;
list_for_each_entry(entry, &dev->msi_list, list) {
entries[i].vector = entry->irq;
set_irq_msi(entry->irq, entry);
j = entries[i].entry;
entry->masked = readl(base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_VECTOR_CTRL);
msix_mask_irq(entry, 1);
i++;
}
/* Set MSI-X enabled bits and unmask the function */
pci_intx_for_msi(dev, 0);
dev->msix_enabled = 1;
control &= ~PCI_MSIX_FLAGS_MASKALL;
pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
return 0;
}
/**
* pci_msi_check_device - check whether MSI may be enabled on a device
* @dev: pointer to the pci_dev data structure of MSI device function
* @nvec: how many MSIs have been requested ?
* @type: are we checking for MSI or MSI-X ?
*
* Look at global flags, the device itself, and its parent busses
* to determine if MSI/-X are supported for the device. If MSI/-X is
* supported return 0, else return an error code.
**/
static int pci_msi_check_device(struct pci_dev* dev, int nvec, int type)
{
struct pci_bus *bus;
int ret;
/* MSI must be globally enabled and supported by the device */
if (!pci_msi_enable || !dev || dev->no_msi)
return -EINVAL;
/*
* You can't ask to have 0 or less MSIs configured.
* a) it's stupid ..
* b) the list manipulation code assumes nvec >= 1.
*/
if (nvec < 1)
return -ERANGE;
/* Any bridge which does NOT route MSI transactions from it's
* secondary bus to it's primary bus must set NO_MSI flag on
* the secondary pci_bus.
* We expect only arch-specific PCI host bus controller driver
* or quirks for specific PCI bridges to be setting NO_MSI.
*/
for (bus = dev->bus; bus; bus = bus->parent)
if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
return -EINVAL;
ret = arch_msi_check_device(dev, nvec, type);
if (ret)
return ret;
if (!pci_find_capability(dev, type))
return -EINVAL;
return 0;
}
/**
* pci_enable_msi_block - configure device's MSI capability structure
* @dev: device to configure
* @nvec: number of interrupts to configure
*
* Allocate IRQs for a device with the MSI capability.
* This function returns a negative errno if an error occurs. If it
* is unable to allocate the number of interrupts requested, it returns
* the number of interrupts it might be able to allocate. If it successfully
* allocates at least the number of interrupts requested, it returns 0 and
* updates the @dev's irq member to the lowest new interrupt number; the
* other interrupt numbers allocated to this device are consecutive.
*/
int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
{
int status, pos, maxvec;
u16 msgctl;
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (!pos)
return -EINVAL;
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
maxvec = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
if (nvec > maxvec)
return maxvec;
status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI);
if (status)
return status;
WARN_ON(!!dev->msi_enabled);
/* Check whether driver already requested MSI-X irqs */
if (dev->msix_enabled) {
dev_info(&dev->dev, "can't enable MSI "
"(MSI-X already enabled)\n");
return -EINVAL;
}
status = msi_capability_init(dev, nvec);
return status;
}
EXPORT_SYMBOL(pci_enable_msi_block);
void pci_msi_shutdown(struct pci_dev *dev)
{
struct msi_desc *desc;
u32 mask;
u16 ctrl;
unsigned pos;
if (!pci_msi_enable || !dev || !dev->msi_enabled)
return;
BUG_ON(list_empty(&dev->msi_list));
desc = list_first_entry(&dev->msi_list, struct msi_desc, list);
pos = desc->msi_attrib.pos;
msi_set_enable(dev, pos, 0);
pci_intx_for_msi(dev, 1);
dev->msi_enabled = 0;
PCI MSI: Fix restoration of MSI/MSI-X mask states in suspend/resume There are 2 problems on mask states in suspend/resume. [1]: It is better to restore the mask states of MSI/MSI-X to initial states (MSI is unmasked, MSI-X is masked) when we release the device. The pci_msi_shutdown() does the restoration of mask states for MSI, while the msi_free_irqs() does it for MSI-X. In other words, in the "disable" path both of MSI and MSI-X are handled, but in the "shutdown" path only MSI is handled. MSI: pci_disable_msi() => pci_msi_shutdown() [ mask states for MSI restored ] => msi_set_enable(dev, pos, 0); => msi_free_irqs() MSI-X: pci_disable_msix() => pci_msix_shutdown() => msix_set_enable(dev, 0); => msix_free_all_irqs => msi_free_irqs() [ mask states for MSI-X restored ] This patch moves the masking for MSI-X from msi_free_irqs() to pci_msix_shutdown(). This change has some positive side effects: - It prevents OS from touching mask states before reading preserved bits in the register, which can be happen if msi_free_irqs() is called from error path in msix_capability_init(). - It also prevents touching the register after turning off MSI-X in "disable" path, which can be a problem on some devices. [2]: We have cache of the mask state in msi_desc, which is automatically updated when msi/msix_mask_irq() is called. This cached states are used for the resume. But since what need to be restored in the resume is the states before the shutdown on the suspend, calling msi/msix_mask_irq() from pci_msi/msix_shutdown() is not appropriate. This patch introduces __msi/msix_mask_irq() that do mask as same as msi/msix_mask_irq() but does not update cached state, for use in pci_msi/msix_shutdown(). [updated: get rid of msi/msix_mask_irq_nocache() (proposed by Matthew Wilcox)] Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-24 03:08:09 +00:00
/* Return the device with MSI unmasked as initial states */
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &ctrl);
mask = msi_capable_mask(ctrl);
PCI MSI: Fix restoration of MSI/MSI-X mask states in suspend/resume There are 2 problems on mask states in suspend/resume. [1]: It is better to restore the mask states of MSI/MSI-X to initial states (MSI is unmasked, MSI-X is masked) when we release the device. The pci_msi_shutdown() does the restoration of mask states for MSI, while the msi_free_irqs() does it for MSI-X. In other words, in the "disable" path both of MSI and MSI-X are handled, but in the "shutdown" path only MSI is handled. MSI: pci_disable_msi() => pci_msi_shutdown() [ mask states for MSI restored ] => msi_set_enable(dev, pos, 0); => msi_free_irqs() MSI-X: pci_disable_msix() => pci_msix_shutdown() => msix_set_enable(dev, 0); => msix_free_all_irqs => msi_free_irqs() [ mask states for MSI-X restored ] This patch moves the masking for MSI-X from msi_free_irqs() to pci_msix_shutdown(). This change has some positive side effects: - It prevents OS from touching mask states before reading preserved bits in the register, which can be happen if msi_free_irqs() is called from error path in msix_capability_init(). - It also prevents touching the register after turning off MSI-X in "disable" path, which can be a problem on some devices. [2]: We have cache of the mask state in msi_desc, which is automatically updated when msi/msix_mask_irq() is called. This cached states are used for the resume. But since what need to be restored in the resume is the states before the shutdown on the suspend, calling msi/msix_mask_irq() from pci_msi/msix_shutdown() is not appropriate. This patch introduces __msi/msix_mask_irq() that do mask as same as msi/msix_mask_irq() but does not update cached state, for use in pci_msi/msix_shutdown(). [updated: get rid of msi/msix_mask_irq_nocache() (proposed by Matthew Wilcox)] Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-24 03:08:09 +00:00
/* Keep cached state to be restored */
__msi_mask_irq(desc, mask, ~mask);
/* Restore dev->irq to its default pin-assertion irq */
dev->irq = desc->msi_attrib.default_irq;
}
void pci_disable_msi(struct pci_dev* dev)
{
if (!pci_msi_enable || !dev || !dev->msi_enabled)
return;
pci_msi_shutdown(dev);
msi_free_irqs(dev);
}
EXPORT_SYMBOL(pci_disable_msi);
static int msi_free_irqs(struct pci_dev* dev)
{
struct msi_desc *entry, *tmp;
list_for_each_entry(entry, &dev->msi_list, list) {
int i, nvec;
if (!entry->irq)
continue;
nvec = 1 << entry->msi_attrib.multiple;
for (i = 0; i < nvec; i++)
BUG_ON(irq_has_action(entry->irq + i));
}
arch_teardown_msi_irqs(dev);
list_for_each_entry_safe(entry, tmp, &dev->msi_list, list) {
if (entry->msi_attrib.is_msix) {
msi: mask the msix vector before we unmap it With these two lines in the reverse order the drives/block/ccis.c was oopsing in msi_free_irqs. Silly us calling writel on an area after we unmap it. BUG: unable to handle kernel paging request at virtual address f8b2200c printing eip: c01e9cc7 *pdpt = 0000000000003001 *pde = 0000000037e48067 *pte = 0000000000000000 Oops: 0002 [#1] SMP Modules linked in: cciss ipv6 parport_pc lp parport autofs4 i2c_dev i2c_core sunrpc loop dm_multipath button battery asus_acpi ac tg3 floppy sg dm_snapshot dm_zero dm_mirror ext3 jbd dm_mod ata_piix libata mptsas scsi_transport_sas mptspi scsi_transport_spi mptscsih mptbase sd_mod scsi_mod CPU: 1 EIP: 0060:[<c01e9cc7>] Not tainted VLI EFLAGS: 00010286 (2.6.22-rc2-gd2579053 #1) EIP is at msi_free_irqs+0x81/0xbe eax: f8b22000 ebx: f71f3180 ecx: f7fff280 edx: c1886eb8 esi: f7c4e800 edi: f7c4ec48 ebp: 00000002 esp: f5a0dec8 ds: 007b es: 007b fs: 00d8 gs: 0033 ss: 0068 Process rmmod (pid: 5286, ti=f5a0d000 task=c47d2550 task.ti=f5a0d000) Stack: 00000002 f8b72294 00000400 f8b69ca7 f8b6bc6c 00000002 00000000 00000000 00000000 00000000 00000000 f5a997f4 f8b69d61 f7c5a4b0 f7c4e848 f7c4e848 f7c4e800 f7c4e800 f8b72294 f7c4e848 f8b72294 c01e3cdf f7c4e848 c024c469 Call Trace: [<f8b69ca7>] cciss_shutdown+0xae/0xc3 [cciss] [<f8b69d61>] cciss_remove_one+0xa5/0x178 [cciss] [<c01e3cdf>] pci_device_remove+0x16/0x35 [<c024c469>] __device_release_driver+0x71/0x8e [<c024c56e>] driver_detach+0xa0/0xde [<c024bc5c>] bus_remove_driver+0x27/0x41 [<c01e3ef3>] pci_unregister_driver+0xb/0x13 [<f8b6a343>] cciss_cleanup+0xf/0x51 [cciss] [<c0139ced>] sys_delete_module+0x110/0x135 [<c0104c7a>] sysenter_past_esp+0x5f/0x85 Here's a patch that just reverses the 2 lines of code as Eric suggests. Please consider this for inclusion. Signed-off-by: Mike Miller <mike.miller@hp.com> Signed-off-by: Chase Maupin <chase.maupin@hp.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andi Kleen <ak@suse.de> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 07:46:33 +00:00
if (list_is_last(&entry->list, &dev->msi_list))
iounmap(entry->mask_base);
}
list_del(&entry->list);
kfree(entry);
}
return 0;
}
/**
* pci_msix_table_size - return the number of device's MSI-X table entries
* @dev: pointer to the pci_dev data structure of MSI-X device function
*/
int pci_msix_table_size(struct pci_dev *dev)
{
int pos;
u16 control;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (!pos)
return 0;
pci_read_config_word(dev, msi_control_reg(pos), &control);
return multi_msix_capable(control);
}
/**
* pci_enable_msix - configure device's MSI-X capability structure
* @dev: pointer to the pci_dev data structure of MSI-X device function
* @entries: pointer to an array of MSI-X entries
* @nvec: number of MSI-X irqs requested for allocation by device driver
*
* Setup the MSI-X capability structure of device function with the number
* of requested irqs upon its software driver call to request for
* MSI-X mode enabled on its hardware device function. A return of zero
* indicates the successful configuration of MSI-X capability structure
* with new allocated MSI-X irqs. A return of < 0 indicates a failure.
* Or a return of > 0 indicates that driver request is exceeding the number
* of irqs or MSI-X vectors available. Driver should use the returned value to
* re-send its request.
**/
int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
{
int status, nr_entries;
int i, j;
if (!entries)
return -EINVAL;
status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
if (status)
return status;
nr_entries = pci_msix_table_size(dev);
if (nvec > nr_entries)
return nr_entries;
/* Check for any invalid entries */
for (i = 0; i < nvec; i++) {
if (entries[i].entry >= nr_entries)
return -EINVAL; /* invalid entry */
for (j = i + 1; j < nvec; j++) {
if (entries[i].entry == entries[j].entry)
return -EINVAL; /* duplicate entry */
}
}
WARN_ON(!!dev->msix_enabled);
/* Check whether driver already requested for MSI irq */
if (dev->msi_enabled) {
dev_info(&dev->dev, "can't enable MSI-X "
"(MSI IRQ already assigned)\n");
return -EINVAL;
}
status = msix_capability_init(dev, entries, nvec);
return status;
}
EXPORT_SYMBOL(pci_enable_msix);
static void msix_free_all_irqs(struct pci_dev *dev)
{
msi_free_irqs(dev);
}
void pci_msix_shutdown(struct pci_dev* dev)
{
PCI MSI: Fix restoration of MSI/MSI-X mask states in suspend/resume There are 2 problems on mask states in suspend/resume. [1]: It is better to restore the mask states of MSI/MSI-X to initial states (MSI is unmasked, MSI-X is masked) when we release the device. The pci_msi_shutdown() does the restoration of mask states for MSI, while the msi_free_irqs() does it for MSI-X. In other words, in the "disable" path both of MSI and MSI-X are handled, but in the "shutdown" path only MSI is handled. MSI: pci_disable_msi() => pci_msi_shutdown() [ mask states for MSI restored ] => msi_set_enable(dev, pos, 0); => msi_free_irqs() MSI-X: pci_disable_msix() => pci_msix_shutdown() => msix_set_enable(dev, 0); => msix_free_all_irqs => msi_free_irqs() [ mask states for MSI-X restored ] This patch moves the masking for MSI-X from msi_free_irqs() to pci_msix_shutdown(). This change has some positive side effects: - It prevents OS from touching mask states before reading preserved bits in the register, which can be happen if msi_free_irqs() is called from error path in msix_capability_init(). - It also prevents touching the register after turning off MSI-X in "disable" path, which can be a problem on some devices. [2]: We have cache of the mask state in msi_desc, which is automatically updated when msi/msix_mask_irq() is called. This cached states are used for the resume. But since what need to be restored in the resume is the states before the shutdown on the suspend, calling msi/msix_mask_irq() from pci_msi/msix_shutdown() is not appropriate. This patch introduces __msi/msix_mask_irq() that do mask as same as msi/msix_mask_irq() but does not update cached state, for use in pci_msi/msix_shutdown(). [updated: get rid of msi/msix_mask_irq_nocache() (proposed by Matthew Wilcox)] Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-24 03:08:09 +00:00
struct msi_desc *entry;
if (!pci_msi_enable || !dev || !dev->msix_enabled)
return;
PCI MSI: Fix restoration of MSI/MSI-X mask states in suspend/resume There are 2 problems on mask states in suspend/resume. [1]: It is better to restore the mask states of MSI/MSI-X to initial states (MSI is unmasked, MSI-X is masked) when we release the device. The pci_msi_shutdown() does the restoration of mask states for MSI, while the msi_free_irqs() does it for MSI-X. In other words, in the "disable" path both of MSI and MSI-X are handled, but in the "shutdown" path only MSI is handled. MSI: pci_disable_msi() => pci_msi_shutdown() [ mask states for MSI restored ] => msi_set_enable(dev, pos, 0); => msi_free_irqs() MSI-X: pci_disable_msix() => pci_msix_shutdown() => msix_set_enable(dev, 0); => msix_free_all_irqs => msi_free_irqs() [ mask states for MSI-X restored ] This patch moves the masking for MSI-X from msi_free_irqs() to pci_msix_shutdown(). This change has some positive side effects: - It prevents OS from touching mask states before reading preserved bits in the register, which can be happen if msi_free_irqs() is called from error path in msix_capability_init(). - It also prevents touching the register after turning off MSI-X in "disable" path, which can be a problem on some devices. [2]: We have cache of the mask state in msi_desc, which is automatically updated when msi/msix_mask_irq() is called. This cached states are used for the resume. But since what need to be restored in the resume is the states before the shutdown on the suspend, calling msi/msix_mask_irq() from pci_msi/msix_shutdown() is not appropriate. This patch introduces __msi/msix_mask_irq() that do mask as same as msi/msix_mask_irq() but does not update cached state, for use in pci_msi/msix_shutdown(). [updated: get rid of msi/msix_mask_irq_nocache() (proposed by Matthew Wilcox)] Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-06-24 03:08:09 +00:00
/* Return the device with MSI-X masked as initial states */
list_for_each_entry(entry, &dev->msi_list, list) {
/* Keep cached states to be restored */
__msix_mask_irq(entry, 1);
}
msix_set_enable(dev, 0);
pci_intx_for_msi(dev, 1);
dev->msix_enabled = 0;
}
void pci_disable_msix(struct pci_dev* dev)
{
if (!pci_msi_enable || !dev || !dev->msix_enabled)
return;
pci_msix_shutdown(dev);
msix_free_all_irqs(dev);
}
EXPORT_SYMBOL(pci_disable_msix);
/**
* msi_remove_pci_irq_vectors - reclaim MSI(X) irqs to unused state
* @dev: pointer to the pci_dev data structure of MSI(X) device function
*
* Being called during hotplug remove, from which the device function
* is hot-removed. All previous assigned MSI/MSI-X irqs, if
* allocated for this device function, are reclaimed to unused state,
* which may be used later on.
**/
void msi_remove_pci_irq_vectors(struct pci_dev* dev)
{
if (!pci_msi_enable || !dev)
return;
if (dev->msi_enabled)
msi_free_irqs(dev);
if (dev->msix_enabled)
msix_free_all_irqs(dev);
}
void pci_no_msi(void)
{
pci_msi_enable = 0;
}
/**
* pci_msi_enabled - is MSI enabled?
*
* Returns true if MSI has not been disabled by the command-line option
* pci=nomsi.
**/
int pci_msi_enabled(void)
{
return pci_msi_enable;
}
EXPORT_SYMBOL(pci_msi_enabled);
void pci_msi_init_pci_dev(struct pci_dev *dev)
{
INIT_LIST_HEAD(&dev->msi_list);
}