mm/gup: change write parameter to flags in fast walk

In order to support more options in the GUP fast walk, change the write
parameter to flags throughout the call stack.

This patch does not change functionality and passes FOLL_WRITE where write
was previously used.

Link: http://lkml.kernel.org/r/20190328084422.29911-3-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190317183438.2057-3-ira.weiny@intel.comSigned-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/gup.c

@@ -1615,7 +1615,7 @@ static inline struct page *try_get_compound_head(struct page *page, int refs)
 
 #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
-			 int write, struct page **pages, int *nr)
+			 unsigned int flags, struct page **pages, int *nr)
 {
 	struct dev_pagemap *pgmap = NULL;
 	int nr_start = *nr, ret = 0;
@@ -1633,7 +1633,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 		if (pte_protnone(pte))
 			goto pte_unmap;
 
-		if (!pte_access_permitted(pte, write))
+		if (!pte_access_permitted(pte, flags & FOLL_WRITE))
 			goto pte_unmap;
 
 		if (pte_devmap(pte)) {
@@ -1685,7 +1685,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
  * useful to have gup_huge_pmd even if we can't operate on ptes.
  */
 static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
-			 int write, struct page **pages, int *nr)
+			 unsigned int flags, struct page **pages, int *nr)
 {
 	return 0;
 }
@@ -1768,12 +1768,12 @@ static int __gup_device_huge_pud(pud_t pud, pud_t *pudp, unsigned long addr,
 #endif
 
 static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
-		unsigned long end, int write, struct page **pages, int *nr)
+		unsigned long end, unsigned int flags, struct page **pages, int *nr)
 {
 	struct page *head, *page;
 	int refs;
 
-	if (!pmd_access_permitted(orig, write))
+	if (!pmd_access_permitted(orig, flags & FOLL_WRITE))
 		return 0;
 
 	if (pmd_devmap(orig))
@@ -1806,12 +1806,12 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
 }
 
 static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
-		unsigned long end, int write, struct page **pages, int *nr)
+		unsigned long end, unsigned int flags, struct page **pages, int *nr)
 {
 	struct page *head, *page;
 	int refs;
 
-	if (!pud_access_permitted(orig, write))
+	if (!pud_access_permitted(orig, flags & FOLL_WRITE))
 		return 0;
 
 	if (pud_devmap(orig))
@@ -1844,13 +1844,13 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
 }
 
 static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr,
-			unsigned long end, int write,
+			unsigned long end, unsigned int flags,
 			struct page **pages, int *nr)
 {
 	int refs;
 	struct page *head, *page;
 
-	if (!pgd_access_permitted(orig, write))
+	if (!pgd_access_permitted(orig, flags & FOLL_WRITE))
 		return 0;
 
 	BUILD_BUG_ON(pgd_devmap(orig));
@@ -1881,7 +1881,7 @@ static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr,
 }
 
 static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
-		int write, struct page **pages, int *nr)
+		unsigned int flags, struct page **pages, int *nr)
 {
 	unsigned long next;
 	pmd_t *pmdp;
@@ -1904,7 +1904,7 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
 			if (pmd_protnone(pmd))
 				return 0;
 
-			if (!gup_huge_pmd(pmd, pmdp, addr, next, write,
+			if (!gup_huge_pmd(pmd, pmdp, addr, next, flags,
 				pages, nr))
 				return 0;
 
@@ -1914,9 +1914,9 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
 			 * pmd format and THP pmd format
 			 */
 			if (!gup_huge_pd(__hugepd(pmd_val(pmd)), addr,
-					 PMD_SHIFT, next, write, pages, nr))
+					 PMD_SHIFT, next, flags, pages, nr))
 				return 0;
-		} else if (!gup_pte_range(pmd, addr, next, write, pages, nr))
+		} else if (!gup_pte_range(pmd, addr, next, flags, pages, nr))
 			return 0;
 	} while (pmdp++, addr = next, addr != end);
 
@@ -1924,7 +1924,7 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
 }
 
 static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
-			 int write, struct page **pages, int *nr)
+			 unsigned int flags, struct page **pages, int *nr)
 {
 	unsigned long next;
 	pud_t *pudp;
@@ -1937,14 +1937,14 @@ static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
 		if (pud_none(pud))
 			return 0;
 		if (unlikely(pud_huge(pud))) {
-			if (!gup_huge_pud(pud, pudp, addr, next, write,
+			if (!gup_huge_pud(pud, pudp, addr, next, flags,
 					  pages, nr))
 				return 0;
 		} else if (unlikely(is_hugepd(__hugepd(pud_val(pud))))) {
 			if (!gup_huge_pd(__hugepd(pud_val(pud)), addr,
-					 PUD_SHIFT, next, write, pages, nr))
+					 PUD_SHIFT, next, flags, pages, nr))
 				return 0;
-		} else if (!gup_pmd_range(pud, addr, next, write, pages, nr))
+		} else if (!gup_pmd_range(pud, addr, next, flags, pages, nr))
 			return 0;
 	} while (pudp++, addr = next, addr != end);
 
@@ -1952,7 +1952,7 @@ static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
 }
 
 static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end,
-			 int write, struct page **pages, int *nr)
+			 unsigned int flags, struct page **pages, int *nr)
 {
 	unsigned long next;
 	p4d_t *p4dp;
@@ -1967,9 +1967,9 @@ static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end,
 		BUILD_BUG_ON(p4d_huge(p4d));
 		if (unlikely(is_hugepd(__hugepd(p4d_val(p4d))))) {
 			if (!gup_huge_pd(__hugepd(p4d_val(p4d)), addr,
-					 P4D_SHIFT, next, write, pages, nr))
+					 P4D_SHIFT, next, flags, pages, nr))
 				return 0;
-		} else if (!gup_pud_range(p4d, addr, next, write, pages, nr))
+		} else if (!gup_pud_range(p4d, addr, next, flags, pages, nr))
 			return 0;
 	} while (p4dp++, addr = next, addr != end);
 
@@ -1977,7 +1977,7 @@ static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end,
 }
 
 static void gup_pgd_range(unsigned long addr, unsigned long end,
-		int write, struct page **pages, int *nr)
+		unsigned int flags, struct page **pages, int *nr)
 {
 	unsigned long next;
 	pgd_t *pgdp;
@@ -1990,14 +1990,14 @@ static void gup_pgd_range(unsigned long addr, unsigned long end,
 		if (pgd_none(pgd))
 			return;
 		if (unlikely(pgd_huge(pgd))) {
-			if (!gup_huge_pgd(pgd, pgdp, addr, next, write,
+			if (!gup_huge_pgd(pgd, pgdp, addr, next, flags,
 					  pages, nr))
 				return;
 		} else if (unlikely(is_hugepd(__hugepd(pgd_val(pgd))))) {
 			if (!gup_huge_pd(__hugepd(pgd_val(pgd)), addr,
-					 PGDIR_SHIFT, next, write, pages, nr))
+					 PGDIR_SHIFT, next, flags, pages, nr))
 				return;
-		} else if (!gup_p4d_range(pgd, addr, next, write, pages, nr))
+		} else if (!gup_p4d_range(pgd, addr, next, flags, pages, nr))
 			return;
 	} while (pgdp++, addr = next, addr != end);
 }
@@ -2051,7 +2051,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
 
 	if (gup_fast_permitted(start, nr_pages)) {
 		local_irq_save(flags);
-		gup_pgd_range(start, end, write, pages, &nr);
+		gup_pgd_range(start, end, write ? FOLL_WRITE : 0, pages, &nr);
 		local_irq_restore(flags);
 	}
 
@@ -2093,7 +2093,7 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 
 	if (gup_fast_permitted(start, nr_pages)) {
 		local_irq_disable();
-		gup_pgd_range(addr, end, write, pages, &nr);
+		gup_pgd_range(addr, end, write ? FOLL_WRITE : 0, pages, &nr);
 		local_irq_enable();
 		ret = nr;
 	}