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linux/arch/parisc/kernel/cache.c
James Bottomley f311847c2f parisc: flush pages through tmpalias space 
The kernel has an 8M tmpailas space (originally designed for copying
and clearing pages but now only used for clearing).  The idea is
to place zeros into the cache above a physical page rather than into
the physical page and flush the cache, because often the zeros end up
being replaced quickly anyway.

We can also use the tmpalias space for flushing a page.  The difference
here is that we have to do tmpalias processing in the non access data and
instruction traps.  The principle is the same: as long as we know the physical
address and have a virtual address congruent to the real one, the flush will
be effective.

In order to use the tmpalias space, the icache miss path has to be enhanced to
check for the alias region to make the fic instruction effective.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-01-15 08:44:40 -06:00

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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1999-2006 Helge Deller <deller@gmx.de> (07-13-1999)
* Copyright (C) 1999 SuSE GmbH Nuernberg
* Copyright (C) 2000 Philipp Rumpf (prumpf@tux.org)
*
* Cache and TLB management
*
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <asm/pdc.h>
#include <asm/cache.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/sections.h>
#include <asm/shmparam.h>
int split_tlb __read_mostly;
int dcache_stride __read_mostly;
int icache_stride __read_mostly;
EXPORT_SYMBOL(dcache_stride);
void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
EXPORT_SYMBOL(flush_dcache_page_asm);
void flush_icache_page_asm(unsigned long phys_addr, unsigned long vaddr);
/* On some machines (e.g. ones with the Merced bus), there can be
* only a single PxTLB broadcast at a time; this must be guaranteed
* by software. We put a spinlock around all TLB flushes to
* ensure this.
*/
DEFINE_SPINLOCK(pa_tlb_lock);
struct pdc_cache_info cache_info __read_mostly;
#ifndef CONFIG_PA20
static struct pdc_btlb_info btlb_info __read_mostly;
#endif
#ifdef CONFIG_SMP
void
flush_data_cache(void)
{
on_each_cpu(flush_data_cache_local, NULL, 1);
}
void
flush_instruction_cache(void)
{
on_each_cpu(flush_instruction_cache_local, NULL, 1);
}
#endif
void
flush_cache_all_local(void)
{
flush_instruction_cache_local(NULL);
flush_data_cache_local(NULL);
}
EXPORT_SYMBOL(flush_cache_all_local);
void
update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
{
struct page *page = pte_page(*ptep);
if (pfn_valid(page_to_pfn(page)) && page_mapping(page) &&
test_bit(PG_dcache_dirty, &page->flags)) {
flush_kernel_dcache_page(page);
clear_bit(PG_dcache_dirty, &page->flags);
} else if (parisc_requires_coherency())
flush_kernel_dcache_page(page);
}
void
show_cache_info(struct seq_file *m)
{
char buf[32];
seq_printf(m, "I-cache\t\t: %ld KB\n",
cache_info.ic_size/1024 );
if (cache_info.dc_loop != 1)
snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s)\n",
cache_info.dc_size/1024,
(cache_info.dc_conf.cc_wt ? "WT":"WB"),
(cache_info.dc_conf.cc_sh ? ", shared I/D":""),
((cache_info.dc_loop == 1) ? "direct mapped" : buf));
seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
cache_info.it_size,
cache_info.dt_size,
cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
);
#ifndef CONFIG_PA20
/* BTLB - Block TLB */
if (btlb_info.max_size==0) {
seq_printf(m, "BTLB\t\t: not supported\n" );
} else {
seq_printf(m,
"BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
"BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
"BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
btlb_info.max_size, (int)4096,
btlb_info.max_size>>8,
btlb_info.fixed_range_info.num_i,
btlb_info.fixed_range_info.num_d,
btlb_info.fixed_range_info.num_comb,
btlb_info.variable_range_info.num_i,
btlb_info.variable_range_info.num_d,
btlb_info.variable_range_info.num_comb
);
}
#endif
}
void __init
parisc_cache_init(void)
{
if (pdc_cache_info(&cache_info) < 0)
panic("parisc_cache_init: pdc_cache_info failed");
#if 0
printk("ic_size %lx dc_size %lx it_size %lx\n",
cache_info.ic_size,
cache_info.dc_size,
cache_info.it_size);
printk("DC base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
cache_info.dc_base,
cache_info.dc_stride,
cache_info.dc_count,
cache_info.dc_loop);
printk("dc_conf = 0x%lx alias %d blk %d line %d shift %d\n",
*(unsigned long *) (&cache_info.dc_conf),
cache_info.dc_conf.cc_alias,
cache_info.dc_conf.cc_block,
cache_info.dc_conf.cc_line,
cache_info.dc_conf.cc_shift);
printk(" wt %d sh %d cst %d hv %d\n",
cache_info.dc_conf.cc_wt,
cache_info.dc_conf.cc_sh,
cache_info.dc_conf.cc_cst,
cache_info.dc_conf.cc_hv);
printk("IC base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
cache_info.ic_base,
cache_info.ic_stride,
cache_info.ic_count,
cache_info.ic_loop);
printk("ic_conf = 0x%lx alias %d blk %d line %d shift %d\n",
*(unsigned long *) (&cache_info.ic_conf),
cache_info.ic_conf.cc_alias,
cache_info.ic_conf.cc_block,
cache_info.ic_conf.cc_line,
cache_info.ic_conf.cc_shift);
printk(" wt %d sh %d cst %d hv %d\n",
cache_info.ic_conf.cc_wt,
cache_info.ic_conf.cc_sh,
cache_info.ic_conf.cc_cst,
cache_info.ic_conf.cc_hv);
printk("D-TLB conf: sh %d page %d cst %d aid %d pad1 %d\n",
cache_info.dt_conf.tc_sh,
cache_info.dt_conf.tc_page,
cache_info.dt_conf.tc_cst,
cache_info.dt_conf.tc_aid,
cache_info.dt_conf.tc_pad1);
printk("I-TLB conf: sh %d page %d cst %d aid %d pad1 %d\n",
cache_info.it_conf.tc_sh,
cache_info.it_conf.tc_page,
cache_info.it_conf.tc_cst,
cache_info.it_conf.tc_aid,
cache_info.it_conf.tc_pad1);
#endif
split_tlb = 0;
if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
if (cache_info.dt_conf.tc_sh == 2)
printk(KERN_WARNING "Unexpected TLB configuration. "
"Will flush I/D separately (could be optimized).\n");
split_tlb = 1;
}
/* "New and Improved" version from Jim Hull
* (1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
* The following CAFL_STRIDE is an optimized version, see
* http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
* http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
*/
#define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
icache_stride = CAFL_STRIDE(cache_info.ic_conf);
#undef CAFL_STRIDE
#ifndef CONFIG_PA20
if (pdc_btlb_info(&btlb_info) < 0) {
memset(&btlb_info, 0, sizeof btlb_info);
}
#endif
if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
PDC_MODEL_NVA_UNSUPPORTED) {
printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
#if 0
panic("SMP kernel required to avoid non-equivalent aliasing");
#endif
}
}
void disable_sr_hashing(void)
{
int srhash_type, retval;
unsigned long space_bits;
switch (boot_cpu_data.cpu_type) {
case pcx: /* We shouldn't get this far. setup.c should prevent it. */
BUG();
return;
case pcxs:
case pcxt:
case pcxt_:
srhash_type = SRHASH_PCXST;
break;
case pcxl:
srhash_type = SRHASH_PCXL;
break;
case pcxl2: /* pcxl2 doesn't support space register hashing */
return;
default: /* Currently all PA2.0 machines use the same ins. sequence */
srhash_type = SRHASH_PA20;
break;
}
disable_sr_hashing_asm(srhash_type);
retval = pdc_spaceid_bits(&space_bits);
/* If this procedure isn't implemented, don't panic. */
if (retval < 0 && retval != PDC_BAD_OPTION)
panic("pdc_spaceid_bits call failed.\n");
if (space_bits != 0)
panic("SpaceID hashing is still on!\n");
}
static inline void
__flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
unsigned long physaddr)
{
flush_dcache_page_asm(physaddr, vmaddr);
if (vma->vm_flags & VM_EXEC)
flush_icache_page_asm(physaddr, vmaddr);
}
void flush_dcache_page(struct page *page)
{
struct address_space *mapping = page_mapping(page);
struct vm_area_struct *mpnt;
struct prio_tree_iter iter;
unsigned long offset;
unsigned long addr, old_addr = 0;
pgoff_t pgoff;
if (mapping && !mapping_mapped(mapping)) {
set_bit(PG_dcache_dirty, &page->flags);
return;
}
flush_kernel_dcache_page(page);
if (!mapping)
return;
pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
/* We have carefully arranged in arch_get_unmapped_area() that
* *any* mappings of a file are always congruently mapped (whether
* declared as MAP_PRIVATE or MAP_SHARED), so we only need
* to flush one address here for them all to become coherent */
flush_dcache_mmap_lock(mapping);
vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
addr = mpnt->vm_start + offset;
if (old_addr == 0 || (old_addr & (SHMLBA - 1)) != (addr & (SHMLBA - 1))) {
__flush_cache_page(mpnt, addr, page_to_phys(page));
if (old_addr)
printk(KERN_ERR "INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %s\n", old_addr, addr, mpnt->vm_file ? mpnt->vm_file->f_path.dentry->d_name.name : "(null)");
old_addr = addr;
}
}
flush_dcache_mmap_unlock(mapping);
}
EXPORT_SYMBOL(flush_dcache_page);
/* Defined in arch/parisc/kernel/pacache.S */
EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
EXPORT_SYMBOL(flush_kernel_dcache_page_asm);
EXPORT_SYMBOL(flush_data_cache_local);
EXPORT_SYMBOL(flush_kernel_icache_range_asm);
void clear_user_page_asm(void *page, unsigned long vaddr)
{
unsigned long flags;
/* This function is implemented in assembly in pacache.S */
extern void __clear_user_page_asm(void *page, unsigned long vaddr);
purge_tlb_start(flags);
__clear_user_page_asm(page, vaddr);
purge_tlb_end(flags);
}
#define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
int parisc_cache_flush_threshold __read_mostly = FLUSH_THRESHOLD;
void __init parisc_setup_cache_timing(void)
{
unsigned long rangetime, alltime;
unsigned long size;
alltime = mfctl(16);
flush_data_cache();
alltime = mfctl(16) - alltime;
size = (unsigned long)(_end - _text);
rangetime = mfctl(16);
flush_kernel_dcache_range((unsigned long)_text, size);
rangetime = mfctl(16) - rangetime;
printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
alltime, size, rangetime);
/* Racy, but if we see an intermediate value, it's ok too... */
parisc_cache_flush_threshold = size * alltime / rangetime;
parisc_cache_flush_threshold = (parisc_cache_flush_threshold + L1_CACHE_BYTES - 1) &~ (L1_CACHE_BYTES - 1);
if (!parisc_cache_flush_threshold)
parisc_cache_flush_threshold = FLUSH_THRESHOLD;
if (parisc_cache_flush_threshold > cache_info.dc_size)
parisc_cache_flush_threshold = cache_info.dc_size;
printk(KERN_INFO "Setting cache flush threshold to %x (%d CPUs online)\n", parisc_cache_flush_threshold, num_online_cpus());
}
extern void purge_kernel_dcache_page(unsigned long);
extern void clear_user_page_asm(void *page, unsigned long vaddr);
void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
{
unsigned long flags;
purge_kernel_dcache_page((unsigned long)page);
purge_tlb_start(flags);
pdtlb_kernel(page);
purge_tlb_end(flags);
clear_user_page_asm(page, vaddr);
}
EXPORT_SYMBOL(clear_user_page);
void flush_kernel_dcache_page_addr(void *addr)
{
unsigned long flags;
flush_kernel_dcache_page_asm(addr);
purge_tlb_start(flags);
pdtlb_kernel(addr);
purge_tlb_end(flags);
}
EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
struct page *pg)
{
/* no coherency needed (all in kmap/kunmap) */
copy_user_page_asm(vto, vfrom);
if (!parisc_requires_coherency())
flush_kernel_dcache_page_asm(vto);
}
EXPORT_SYMBOL(copy_user_page);
#ifdef CONFIG_PA8X00
void kunmap_parisc(void *addr)
{
if (parisc_requires_coherency())
flush_kernel_dcache_page_addr(addr);
}
EXPORT_SYMBOL(kunmap_parisc);
#endif
void __flush_tlb_range(unsigned long sid, unsigned long start,
unsigned long end)
{
unsigned long npages;
npages = ((end - (start & PAGE_MASK)) + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (npages >= 512) /* 2MB of space: arbitrary, should be tuned */
flush_tlb_all();
else {
unsigned long flags;
mtsp(sid, 1);
purge_tlb_start(flags);
if (split_tlb) {
while (npages--) {
pdtlb(start);
pitlb(start);
start += PAGE_SIZE;
}
} else {
while (npages--) {
pdtlb(start);
start += PAGE_SIZE;
}
}
purge_tlb_end(flags);
}
}
static void cacheflush_h_tmp_function(void *dummy)
{
flush_cache_all_local();
}
void flush_cache_all(void)
{
on_each_cpu(cacheflush_h_tmp_function, NULL, 1);
}
void flush_cache_mm(struct mm_struct *mm)
{
#ifdef CONFIG_SMP
flush_cache_all();
#else
flush_cache_all_local();
#endif
}
void
flush_user_dcache_range(unsigned long start, unsigned long end)
{
if ((end - start) < parisc_cache_flush_threshold)
flush_user_dcache_range_asm(start,end);
else
flush_data_cache();
}
void
flush_user_icache_range(unsigned long start, unsigned long end)
{
if ((end - start) < parisc_cache_flush_threshold)
flush_user_icache_range_asm(start,end);
else
flush_instruction_cache();
}
void flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
int sr3;
BUG_ON(!vma->vm_mm->context);
sr3 = mfsp(3);
if (vma->vm_mm->context == sr3) {
flush_user_dcache_range(start,end);
flush_user_icache_range(start,end);
} else {
flush_cache_all();
}
}
void
flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
{
BUG_ON(!vma->vm_mm->context);
__flush_cache_page(vma, vmaddr, page_to_phys(pfn_to_page(pfn)));
}
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