x86, pageattr: introduce APIs to change pageattr of a page array

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@gmail.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 166 insertions, 50 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 5c06469a0653..041e81ef673a 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -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];
 
@@ -184,6 +188,41 @@ static void cpa_flush_range(unsigned long start, int numpages, int cache)
         }
 }
 
+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
@@ -392,7 +431,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
                  */
                 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;
         }
 
@@ -578,11 +617,16 @@ 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)
@@ -594,8 +638,8 @@ repeat:
                         return 0;
                 printk(KERN_WARNING "CPA: called for zero pte. "
                        "vaddr = %lx cpa->vaddr = %lx\n", address,
-                       cpa->vaddr);
                 WARN_ON(1);
+                       *cpa->vaddr);
                 return -EINVAL;
         }
 
@@ -621,7 +665,7 @@ 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;
@@ -645,7 +689,7 @@ repeat:
          */
         err = split_large_page(kpte, address);
         if (!err) {
-                cpa->flushtlb = 1;
+                cpa->flags |= CPA_FLUSHTLB;
                 goto repeat;
         }
 
@@ -658,6 +702,7 @@ static int cpa_process_alias(struct cpa_data *cpa)
 {
         struct cpa_data alias_cpa;
         int ret = 0;
+        unsigned long temp_cpa_vaddr, vaddr;
 
         if (cpa->pfn >= max_pfn_mapped)
                 return 0;
@@ -670,16 +715,24 @@ static int cpa_process_alias(struct cpa_data *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);
         }
@@ -691,7 +744,7 @@ static int cpa_process_alias(struct cpa_data *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;
 
         /*
@@ -702,8 +755,9 @@ static int cpa_process_alias(struct cpa_data *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.
@@ -723,6 +777,9 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
                  * 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)
@@ -741,7 +798,11 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
                  */
                 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;
 }
@@ -752,9 +813,9 @@ static inline int cache_attr(pgprot_t attr)
                 (_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;
@@ -769,12 +830,22 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
                 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 */
@@ -784,9 +855,13 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
         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;
 
@@ -795,7 +870,7 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
         /*
          * Check whether we really changed something:
          */
-        if (!cpa.flushtlb)
+        if (!(cpa.flags & CPA_FLUSHTLB))
                 goto out;
 
         /*
@@ -810,9 +885,12 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
          * 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:
@@ -821,16 +899,18 @@ 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)
@@ -838,8 +918,8 @@ int _set_memory_uc(unsigned long addr, int numpages)
         /*
          * 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)
@@ -855,10 +935,31 @@ int set_memory_uc(unsigned long addr, int numpages)
 }
 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)
@@ -876,8 +977,8 @@ 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)
@@ -888,37 +989,48 @@ int set_memory_wb(unsigned long addr, int numpages)
 }
 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)
@@ -971,20 +1083,24 @@ int set_pages_rw(struct page *page, int numpages)
 
 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);
 }