x86-get-user-pages-kmap-atomic-fix-32bit.patch

From 172f00812bbad3f1730c7718ee60d9d9978436b4 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 3 Jul 2009 08:44:33 -0500
Subject: [PATCH] x86: get user pages kmap atomic fix (32bit)

commit 6c8a72dd4bcd3576b6a2758a9ce7e82cb39461df in tip.

[PG: add paravirt_types.h change from big 33rt merge commit, then
 delete paravirt parts that go away due to upstream dad52fc0116]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index 8391a46..28f471b 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -64,6 +64,7 @@ void kunmap(struct page *page);
 
 void *__kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot);
 void *__kmap_atomic(struct page *page, enum km_type type);
+void *__kmap_atomic_direct(struct page *page, enum km_type type);
 void __kunmap_atomic(void *kvaddr, enum km_type type);
 void *__kmap_atomic_pfn(unsigned long pfn, enum km_type type);
 struct page *__kmap_atomic_to_page(void *ptr);
@@ -76,6 +77,9 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
 void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);
 struct page *kmap_atomic_to_page(void *ptr);
 
+#define kmap_atomic_pte(page, type)		kmap_atomic(page, type)
+#define kmap_atomic_pte_direct(page, type)	kmap_atomic_direct(page, type)
+
 #define flush_cache_kmaps()	do { } while (0)
 
 extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
@@ -90,12 +94,16 @@ extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
 # define kmap_atomic_pfn(pfn, type)	kmap(pfn_to_page(pfn))
 # define kunmap_atomic(kvaddr, type)	do { pagefault_enable(); kunmap_virt(kvaddr); } while(0)
 # define kmap_atomic_to_page(kvaddr)	kmap_to_page(kvaddr)
+# define kmap_atomic_direct(page, type)	__kmap_atomic_direct(page, type)
+# define kunmap_atomic_direct(kvaddr, type)	__kunmap_atomic(kvaddr, type)
 #else
 # define kmap_atomic_prot(page, type, prot)	__kmap_atomic_prot(page, type, prot)
 # define kmap_atomic(page, type)	__kmap_atomic(page, type)
 # define kmap_atomic_pfn(pfn, type)	__kmap_atomic_pfn(pfn, type)
 # define kunmap_atomic(kvaddr, type)	__kunmap_atomic(kvaddr, type)
 # define kmap_atomic_to_page(kvaddr)	__kmap_atomic_to_page(kvaddr)
+# define kmap_atomic_direct(page, type)	__kmap_atomic(page, type)
+# define kunmap_atomic_direct(kvaddr, type)	__kunmap_atomic(kvaddr, type)
 #endif
 
 #endif /* __KERNEL__ */
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index 47339a1..a350daa 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -59,14 +59,20 @@ extern void set_pmd_pfn(unsigned long, unsigned long, pgprot_t);
 #define pte_offset_map_nested(dir, address)				\
 	((pte_t *)kmap_atomic(pmd_page(*(dir)), KM_PTE1) +		\
 	 pte_index((address)))
+#define pte_offset_map_direct(dir, address)				\
+	((pte_t *)kmap_atomic_pte_direct(pmd_page(*(dir)), __KM_PTE) +	\
+	 pte_index((address)))
 #define pte_unmap(pte) kunmap_atomic((pte), __KM_PTE)
 #define pte_unmap_nested(pte) kunmap_atomic((pte), KM_PTE1)
+#define pte_unmap_direct(pte) kunmap_atomic_direct((pte), __KM_PTE)
 #else
 #define pte_offset_map(dir, address)					\
 	((pte_t *)page_address(pmd_page(*(dir))) + pte_index((address)))
 #define pte_offset_map_nested(dir, address) pte_offset_map((dir), (address))
+#define pte_offset_map_direct(dir, address) pte_offset_map((dir), (address))
 #define pte_unmap(pte) do { } while (0)
 #define pte_unmap_nested(pte) do { } while (0)
+#define pte_unmap_direct(pte) do { } while (0)
 #endif
 
 /* Clear a kernel PTE and flush it from the TLB */
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 181be52..3057193 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -126,8 +126,10 @@ static inline int pgd_large(pgd_t pgd) { return 0; }
 /* x86-64 always has all page tables mapped. */
 #define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
 #define pte_offset_map_nested(dir, address) pte_offset_kernel((dir), (address))
-#define pte_unmap(pte) /* NOP */
-#define pte_unmap_nested(pte) /* NOP */
+#define pte_offset_map_direct(dir, address) pte_offset_kernel((dir), (address))
+#define pte_unmap(pte) do { } while (0)
+#define pte_unmap_nested(pte) do { }  while (0)
+#define pte_unmap_direct(pte) do { }  while (0)
 
 #define update_mmu_cache(vma, address, ptep) do { } while (0)
 
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
index 738e659..5aeae53 100644
--- a/arch/x86/mm/gup.c
+++ b/arch/x86/mm/gup.c
@@ -77,13 +77,13 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
 	if (write)
 		mask |= _PAGE_RW;
 
-	ptep = pte_offset_map(&pmd, addr);
+	ptep = pte_offset_map_direct(&pmd, addr);
 	do {
 		pte_t pte = gup_get_pte(ptep);
 		struct page *page;
 
 		if ((pte_flags(pte) & (mask | _PAGE_SPECIAL)) != mask) {
-			pte_unmap(ptep);
+			pte_unmap_direct(ptep);
 			return 0;
 		}
 		VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
@@ -93,7 +93,7 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
 		(*nr)++;
 
 	} while (ptep++, addr += PAGE_SIZE, addr != end);
-	pte_unmap(ptep - 1);
+	pte_unmap_direct(ptep - 1);
 
 	return 1;
 }
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 419d8f6..dcb1899 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -70,6 +70,11 @@ void *__kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
 	return (void *)vaddr;
 }
 
+void *__kmap_atomic_direct(struct page *page, enum km_type type)
+{
+	return __kmap_atomic_prot(page, type, kmap_prot);
+}
+
 void *__kmap_atomic(struct page *page, enum km_type type)
 {
 	return kmap_atomic_prot(page, type, kmap_prot);
@@ -105,6 +110,7 @@ void __kunmap_atomic(void *kvaddr, enum km_type type)
  */
 void *__kmap_atomic_pfn(unsigned long pfn, enum km_type type)
 {
+	preempt_disable();
 	return kmap_atomic_prot_pfn(pfn, type, kmap_prot);
 }
 EXPORT_SYMBOL_GPL(__kmap_atomic_pfn); /* temporarily in use by i915 GEM until vmap */
-- 
1.7.0.4