[patch 1/4]pageattr: introduce APIs to change pageattr of a pagearray
From: Shaohua Li
Date: Wed Aug 20 2008 - 22:37:17 EST
Add array interface APIs of pageattr. page based cache flush is quite
slow for a lot of pages. If pages are more than 1024 (4M), the patch
will use a wbinvd(). We have a simple test here (run a 3d game - open
arena), nearly all agp memory allocation are small (< 1M), so suppose
this will not impact runtime performance.
Signed-off-by: Dave Airlie <airlied@xxxxxxxxx>
Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
---
arch/x86/mm/pageattr.c | 216 +++++++++++++++++++++++++++++++++----------
include/asm-x86/cacheflush.h | 3
2 files changed, 169 insertions(+), 50 deletions(-)
Index: linux/arch/x86/mm/pageattr.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr.c 2008-08-20 15:34:46.000000000 +0800
+++ linux/arch/x86/mm/pageattr.c 2008-08-21 10:14:47.000000000 +0800
@@ -25,15 +25,19 @@
* The current flushing context - we pass it instead of 5 arguments:
*/
struct cpa_data {
- unsigned long vaddr;
+ unsigned long *vaddr;
pgprot_t mask_set;
pgprot_t mask_clr;
int numpages;
- int flushtlb;
+ int flags;
unsigned long pfn;
unsigned force_split : 1;
+ int curpage;
};
+#define CPA_FLUSHTLB 1
+#define CPA_ARRAY 2
+
#ifdef CONFIG_PROC_FS
static unsigned long direct_pages_count[PG_LEVEL_NUM];
@@ -190,6 +194,41 @@ static void cpa_flush_range(unsigned lon
}
}
+static void cpa_flush_array(unsigned long *start, int numpages, int cache)
+{
+ unsigned int i, level;
+ unsigned long *addr;
+
+ BUG_ON(irqs_disabled());
+
+ on_each_cpu(__cpa_flush_range, NULL, 1);
+
+ if (!cache)
+ return;
+
+ /* 4M threshold */
+ if (numpages >= 1024) {
+ if (boot_cpu_data.x86_model >= 4)
+ wbinvd();
+ return;
+ }
+ /*
+ * We only need to flush on one CPU,
+ * clflush is a MESI-coherent instruction that
+ * will cause all other CPUs to flush the same
+ * cachelines:
+ */
+ for (i = 0, addr = start; i < numpages; i++, addr++) {
+ pte_t *pte = lookup_address(*addr, &level);
+
+ /*
+ * Only flush present addresses:
+ */
+ if (pte && (pte_val(*pte) & _PAGE_PRESENT))
+ clflush_cache_range((void *) *addr, PAGE_SIZE);
+ }
+}
+
/*
* Certain areas of memory on x86 require very specific protection flags,
* for example the BIOS area or kernel text. Callers don't always get this
@@ -398,7 +437,7 @@ try_preserve_large_page(pte_t *kpte, uns
*/
new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot));
__set_pmd_pte(kpte, address, new_pte);
- cpa->flushtlb = 1;
+ cpa->flags |= CPA_FLUSHTLB;
do_split = 0;
}
@@ -584,11 +623,16 @@ out_unlock:
static int __change_page_attr(struct cpa_data *cpa, int primary)
{
- unsigned long address = cpa->vaddr;
+ unsigned long address;
int do_split, err;
unsigned int level;
pte_t *kpte, old_pte;
+ if (cpa->flags & CPA_ARRAY)
+ address = cpa->vaddr[cpa->curpage];
+ else
+ address = *cpa->vaddr;
+
repeat:
kpte = lookup_address(address, &level);
if (!kpte)
@@ -600,7 +644,7 @@ repeat:
return 0;
WARN(1, KERN_WARNING "CPA: called for zero pte. "
"vaddr = %lx cpa->vaddr = %lx\n", address,
- cpa->vaddr);
+ *cpa->vaddr);
return -EINVAL;
}
@@ -626,7 +670,7 @@ repeat:
*/
if (pte_val(old_pte) != pte_val(new_pte)) {
set_pte_atomic(kpte, new_pte);
- cpa->flushtlb = 1;
+ cpa->flags |= CPA_FLUSHTLB;
}
cpa->numpages = 1;
return 0;
@@ -650,7 +694,7 @@ repeat:
*/
err = split_large_page(kpte, address);
if (!err) {
- cpa->flushtlb = 1;
+ cpa->flags |= CPA_FLUSHTLB;
goto repeat;
}
@@ -663,6 +707,7 @@ static int cpa_process_alias(struct cpa_
{
struct cpa_data alias_cpa;
int ret = 0;
+ unsigned long temp_cpa_vaddr, vaddr;
if (cpa->pfn >= max_pfn_mapped)
return 0;
@@ -675,16 +720,24 @@ static int cpa_process_alias(struct cpa_
* No need to redo, when the primary call touched the direct
* mapping already:
*/
- if (!(within(cpa->vaddr, PAGE_OFFSET,
+ if (cpa->flags & CPA_ARRAY)
+ vaddr = cpa->vaddr[cpa->curpage];
+ else
+ vaddr = *cpa->vaddr;
+
+ if (!(within(vaddr, PAGE_OFFSET,
PAGE_OFFSET + (max_low_pfn_mapped << PAGE_SHIFT))
#ifdef CONFIG_X86_64
- || within(cpa->vaddr, PAGE_OFFSET + (1UL<<32),
+ || within(vaddr, PAGE_OFFSET + (1UL<<32),
PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))
#endif
)) {
alias_cpa = *cpa;
- alias_cpa.vaddr = (unsigned long) __va(cpa->pfn << PAGE_SHIFT);
+ temp_cpa_vaddr = (unsigned long) __va(cpa->pfn << PAGE_SHIFT);
+ alias_cpa.vaddr = &temp_cpa_vaddr;
+ alias_cpa.flags &= ~CPA_ARRAY;
+
ret = __change_page_attr_set_clr(&alias_cpa, 0);
}
@@ -696,7 +749,7 @@ static int cpa_process_alias(struct cpa_
* No need to redo, when the primary call touched the high
* mapping already:
*/
- if (within(cpa->vaddr, (unsigned long) _text, (unsigned long) _end))
+ if (within(vaddr, (unsigned long) _text, (unsigned long) _end))
return 0;
/*
@@ -707,8 +760,9 @@ static int cpa_process_alias(struct cpa_
return 0;
alias_cpa = *cpa;
- alias_cpa.vaddr =
- (cpa->pfn << PAGE_SHIFT) + __START_KERNEL_map - phys_base;
+ temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) + __START_KERNEL_map - phys_base;
+ alias_cpa.vaddr = &temp_cpa_vaddr;
+ alias_cpa.flags &= ~CPA_ARRAY;
/*
* The high mapping range is imprecise, so ignore the return value.
@@ -728,6 +782,9 @@ static int __change_page_attr_set_clr(st
* preservation check.
*/
cpa->numpages = numpages;
+ /* for array changes, we can't use large page */
+ if (cpa->flags & CPA_ARRAY)
+ cpa->numpages = 1;
ret = __change_page_attr(cpa, checkalias);
if (ret)
@@ -746,7 +803,11 @@ static int __change_page_attr_set_clr(st
*/
BUG_ON(cpa->numpages > numpages);
numpages -= cpa->numpages;
- cpa->vaddr += cpa->numpages * PAGE_SIZE;
+ if (cpa->flags & CPA_ARRAY)
+ cpa->curpage++;
+ else
+ *cpa->vaddr += cpa->numpages * PAGE_SIZE;
+
}
return 0;
}
@@ -757,9 +818,9 @@ static inline int cache_attr(pgprot_t at
(_PAGE_PAT | _PAGE_PAT_LARGE | _PAGE_PWT | _PAGE_PCD);
}
-static int change_page_attr_set_clr(unsigned long addr, int numpages,
+static int change_page_attr_set_clr(unsigned long *addr, int numpages,
pgprot_t mask_set, pgprot_t mask_clr,
- int force_split)
+ int force_split, int array)
{
struct cpa_data cpa;
int ret, cache, checkalias;
@@ -774,12 +835,22 @@ static int change_page_attr_set_clr(unsi
return 0;
/* Ensure we are PAGE_SIZE aligned */
- if (addr & ~PAGE_MASK) {
- addr &= PAGE_MASK;
- /*
- * People should not be passing in unaligned addresses:
- */
- WARN_ON_ONCE(1);
+ if (!array) {
+ if (*addr & ~PAGE_MASK) {
+ *addr &= PAGE_MASK;
+ /*
+ * People should not be passing in unaligned addresses:
+ */
+ WARN_ON_ONCE(1);
+ }
+ } else {
+ int i;
+ for (i = 0; i < numpages; i++) {
+ if (addr[i] & ~PAGE_MASK) {
+ addr[i] &= PAGE_MASK;
+ WARN_ON_ONCE(1);
+ }
+ }
}
/* Must avoid aliasing mappings in the highmem code */
@@ -789,9 +860,13 @@ static int change_page_attr_set_clr(unsi
cpa.numpages = numpages;
cpa.mask_set = mask_set;
cpa.mask_clr = mask_clr;
- cpa.flushtlb = 0;
+ cpa.flags = 0;
+ cpa.curpage = 0;
cpa.force_split = force_split;
+ if (array)
+ cpa.flags |= CPA_ARRAY;
+
/* No alias checking for _NX bit modifications */
checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX;
@@ -800,7 +875,7 @@ static int change_page_attr_set_clr(unsi
/*
* Check whether we really changed something:
*/
- if (!cpa.flushtlb)
+ if (!(cpa.flags & CPA_FLUSHTLB))
goto out;
/*
@@ -815,9 +890,12 @@ static int change_page_attr_set_clr(unsi
* error case we fall back to cpa_flush_all (which uses
* wbindv):
*/
- if (!ret && cpu_has_clflush)
- cpa_flush_range(addr, numpages, cache);
- else
+ if (!ret && cpu_has_clflush) {
+ if (cpa.flags & CPA_ARRAY)
+ cpa_flush_array(addr, numpages, cache);
+ else
+ cpa_flush_range(*addr, numpages, cache);
+ } else
cpa_flush_all(cache);
out:
@@ -826,16 +904,18 @@ out:
return ret;
}
-static inline int change_page_attr_set(unsigned long addr, int numpages,
- pgprot_t mask)
+static inline int change_page_attr_set(unsigned long *addr, int numpages,
+ pgprot_t mask, int array)
{
- return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0);
+ return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0,
+ array);
}
-static inline int change_page_attr_clear(unsigned long addr, int numpages,
- pgprot_t mask)
+static inline int change_page_attr_clear(unsigned long *addr, int numpages,
+ pgprot_t mask, int array)
{
- return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0);
+ return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0,
+ array);
}
int _set_memory_uc(unsigned long addr, int numpages)
@@ -843,8 +923,8 @@ int _set_memory_uc(unsigned long addr, i
/*
* for now UC MINUS. see comments in ioremap_nocache()
*/
- return change_page_attr_set(addr, numpages,
- __pgprot(_PAGE_CACHE_UC_MINUS));
+ return change_page_attr_set(&addr, numpages,
+ __pgprot(_PAGE_CACHE_UC_MINUS), 0);
}
int set_memory_uc(unsigned long addr, int numpages)
@@ -860,10 +940,31 @@ int set_memory_uc(unsigned long addr, in
}
EXPORT_SYMBOL(set_memory_uc);
+int set_memory_array_uc(unsigned long *addr, int addrinarray)
+{
+ int i;
+ /*
+ * for now UC MINUS. see comments in ioremap_nocache()
+ */
+ for (i = 0; i < addrinarray; i++) {
+ if (reserve_memtype(addr[i], addr[i] + PAGE_SIZE,
+ _PAGE_CACHE_UC_MINUS, NULL))
+ goto out;
+ }
+
+ return change_page_attr_set(addr, addrinarray,
+ __pgprot(_PAGE_CACHE_UC_MINUS), 1);
+out:
+ while (--i >= 0)
+ free_memtype(addr[i], addr[i] + PAGE_SIZE);
+ return -EINVAL;
+}
+EXPORT_SYMBOL(set_memory_array_uc);
+
int _set_memory_wc(unsigned long addr, int numpages)
{
- return change_page_attr_set(addr, numpages,
- __pgprot(_PAGE_CACHE_WC));
+ return change_page_attr_set(&addr, numpages,
+ __pgprot(_PAGE_CACHE_WC), 0);
}
int set_memory_wc(unsigned long addr, int numpages)
@@ -881,8 +982,8 @@ EXPORT_SYMBOL(set_memory_wc);
int _set_memory_wb(unsigned long addr, int numpages)
{
- return change_page_attr_clear(addr, numpages,
- __pgprot(_PAGE_CACHE_MASK));
+ return change_page_attr_clear(&addr, numpages,
+ __pgprot(_PAGE_CACHE_MASK), 0);
}
int set_memory_wb(unsigned long addr, int numpages)
@@ -893,37 +994,48 @@ int set_memory_wb(unsigned long addr, in
}
EXPORT_SYMBOL(set_memory_wb);
+int set_memory_array_wb(unsigned long *addr, int addrinarray)
+{
+ int i;
+ for (i = 0; i < addrinarray; i++)
+ free_memtype(addr[i], addr[i] + PAGE_SIZE);
+
+ return change_page_attr_clear(addr, addrinarray,
+ __pgprot(_PAGE_CACHE_MASK), 1);
+}
+EXPORT_SYMBOL(set_memory_array_wb);
+
int set_memory_x(unsigned long addr, int numpages)
{
- return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_NX));
+ return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0);
}
EXPORT_SYMBOL(set_memory_x);
int set_memory_nx(unsigned long addr, int numpages)
{
- return change_page_attr_set(addr, numpages, __pgprot(_PAGE_NX));
+ return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0);
}
EXPORT_SYMBOL(set_memory_nx);
int set_memory_ro(unsigned long addr, int numpages)
{
- return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_RW));
+ return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW), 0);
}
int set_memory_rw(unsigned long addr, int numpages)
{
- return change_page_attr_set(addr, numpages, __pgprot(_PAGE_RW));
+ return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0);
}
int set_memory_np(unsigned long addr, int numpages)
{
- return change_page_attr_clear(addr, numpages, __pgprot(_PAGE_PRESENT));
+ return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_PRESENT), 0);
}
int set_memory_4k(unsigned long addr, int numpages)
{
- return change_page_attr_set_clr(addr, numpages, __pgprot(0),
- __pgprot(0), 1);
+ return change_page_attr_set_clr(&addr, numpages, __pgprot(0),
+ __pgprot(0), 1, 0);
}
int set_pages_uc(struct page *page, int numpages)
@@ -976,20 +1088,24 @@ int set_pages_rw(struct page *page, int
static int __set_pages_p(struct page *page, int numpages)
{
- struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
+ unsigned long tempaddr = (unsigned long) page_address(page);
+ struct cpa_data cpa = { .vaddr = &tempaddr,
.numpages = numpages,
.mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
- .mask_clr = __pgprot(0)};
+ .mask_clr = __pgprot(0),
+ .flags = 0};
return __change_page_attr_set_clr(&cpa, 1);
}
static int __set_pages_np(struct page *page, int numpages)
{
- struct cpa_data cpa = { .vaddr = (unsigned long) page_address(page),
+ unsigned long tempaddr = (unsigned long) page_address(page);
+ struct cpa_data cpa = { .vaddr = &tempaddr,
.numpages = numpages,
.mask_set = __pgprot(0),
- .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW)};
+ .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW),
+ .flags = 0};
return __change_page_attr_set_clr(&cpa, 1);
}
Index: linux/include/asm-x86/cacheflush.h
===================================================================
--- linux.orig/include/asm-x86/cacheflush.h 2008-08-20 15:34:46.000000000 +0800
+++ linux/include/asm-x86/cacheflush.h 2008-08-20 15:58:40.000000000 +0800
@@ -66,6 +66,9 @@ int set_memory_rw(unsigned long addr, in
int set_memory_np(unsigned long addr, int numpages);
int set_memory_4k(unsigned long addr, int numpages);
+int set_memory_array_uc(unsigned long *addr, int addrinarray);
+int set_memory_array_wb(unsigned long *addr, int addrinarray);
+
/*
* For legacy compatibility with the old APIs, a few functions
* are provided that work on a "struct page".
--
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