[PATCH] gfp_t: infrastructure

Beginning of gfp_t annotations:

 - -Wbitwise added to CHECKFLAGS
 - old __bitwise renamed to __bitwise__
 - __bitwise defined to either __bitwise__ or nothing, depending on
   __CHECK_ENDIAN__ being defined
 - gfp_t switched from __nocast to __bitwise__
 - force cast to gfp_t added to __GFP_... constants
 - new helper - gfp_zone(); extracts zone bits out of gfp_t value and casts
   the result to int

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/Makefile b/Makefile
index 1fa7e5343464d69373858c598154da813e66285d..f1d121f23025c664ebd5e6bbebb29c62bce49c5b 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -334,7 +334,7 @@ KALLSYMS    = scripts/kallsyms
 PERL           = perl
 CHECK          = sparse
 
-CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ $(CF)
+CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise $(CF)
 MODFLAGS       = -DMODULE
 CFLAGS_MODULE   = $(MODFLAGS)
 AFLAGS_MODULE   = $(MODFLAGS)

diff --git a/fs/buffer.c b/fs/buffer.c
index 1216c0d3c8ce179adecc466a772d06ea26f4ed8d..9657696fd6d71f23d462a171f3ff1d08f9052027 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -502,7 +502,7 @@ static void free_more_memory(void)
        yield();
 
        for_each_pgdat(pgdat) {
-               zones = pgdat->node_zonelists[GFP_NOFS&GFP_ZONEMASK].zones;
+               zones = pgdat->node_zonelists[gfp_zone(GFP_NOFS)].zones;
                if (*zones)
                        try_to_free_pages(zones, GFP_NOFS);
        }

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 3010e172394dc148539fdb3c5476310d16012769..c3779432a7239b5e2b85494f594d69db3adb6fb8 100644 (file)
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -12,8 +12,8 @@ struct vm_area_struct;
  * GFP bitmasks..
  */
 /* Zone modifiers in GFP_ZONEMASK (see linux/mmzone.h - low two bits) */
-#define __GFP_DMA      0x01u
-#define __GFP_HIGHMEM  0x02u
+#define __GFP_DMA      ((__force gfp_t)0x01u)
+#define __GFP_HIGHMEM  ((__force gfp_t)0x02u)
 
 /*
  * Action modifiers - doesn't change the zoning
@@ -26,24 +26,24 @@ struct vm_area_struct;
  *
  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
  */
-#define __GFP_WAIT     0x10u   /* Can wait and reschedule? */
-#define __GFP_HIGH     0x20u   /* Should access emergency pools? */
-#define __GFP_IO       0x40u   /* Can start physical IO? */
-#define __GFP_FS       0x80u   /* Can call down to low-level FS? */
-#define __GFP_COLD     0x100u  /* Cache-cold page required */
-#define __GFP_NOWARN   0x200u  /* Suppress page allocation failure warning */
-#define __GFP_REPEAT   0x400u  /* Retry the allocation.  Might fail */
-#define __GFP_NOFAIL   0x800u  /* Retry for ever.  Cannot fail */
-#define __GFP_NORETRY  0x1000u /* Do not retry.  Might fail */
-#define __GFP_NO_GROW  0x2000u /* Slab internal usage */
-#define __GFP_COMP     0x4000u /* Add compound page metadata */
-#define __GFP_ZERO     0x8000u /* Return zeroed page on success */
-#define __GFP_NOMEMALLOC 0x10000u /* Don't use emergency reserves */
-#define __GFP_NORECLAIM  0x20000u /* No realy zone reclaim during allocation */
-#define __GFP_HARDWALL   0x40000u /* Enforce hardwall cpuset memory allocs */
+#define __GFP_WAIT     ((__force gfp_t)0x10u)  /* Can wait and reschedule? */
+#define __GFP_HIGH     ((__force gfp_t)0x20u)  /* Should access emergency pools? */
+#define __GFP_IO       ((__force gfp_t)0x40u)  /* Can start physical IO? */
+#define __GFP_FS       ((__force gfp_t)0x80u)  /* Can call down to low-level FS? */
+#define __GFP_COLD     ((__force gfp_t)0x100u) /* Cache-cold page required */
+#define __GFP_NOWARN   ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
+#define __GFP_REPEAT   ((__force gfp_t)0x400u) /* Retry the allocation.  Might fail */
+#define __GFP_NOFAIL   ((__force gfp_t)0x800u) /* Retry for ever.  Cannot fail */
+#define __GFP_NORETRY  ((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
+#define __GFP_NO_GROW  ((__force gfp_t)0x2000u)/* Slab internal usage */
+#define __GFP_COMP     ((__force gfp_t)0x4000u)/* Add compound page metadata */
+#define __GFP_ZERO     ((__force gfp_t)0x8000u)/* Return zeroed page on success */
+#define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
+#define __GFP_NORECLAIM  ((__force gfp_t)0x20000u) /* No realy zone reclaim during allocation */
+#define __GFP_HARDWALL   ((__force gfp_t)0x40000u) /* Enforce hardwall cpuset memory allocs */
 
 #define __GFP_BITS_SHIFT 20    /* Room for 20 __GFP_FOO bits */
-#define __GFP_BITS_MASK ((1 << __GFP_BITS_SHIFT) - 1)
+#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
 
 /* if you forget to add the bitmask here kernel will crash, period */
 #define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
@@ -64,6 +64,7 @@ struct vm_area_struct;
 
 #define GFP_DMA                __GFP_DMA
 
+#define gfp_zone(mask) ((__force int)((mask) & (__force gfp_t)GFP_ZONEMASK))
 
 /*
  * There is only one page-allocator function, and two main namespaces to
@@ -94,7 +95,7 @@ static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
                return NULL;
 
        return __alloc_pages(gfp_mask, order,
-               NODE_DATA(nid)->node_zonelists + (gfp_mask & GFP_ZONEMASK));
+               NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
 }
 
 #ifdef CONFIG_NUMA

diff --git a/include/linux/types.h b/include/linux/types.h
index 0aee34f9da9f8bf7f267d957d5be7ba9faf281f5..21b9ce80364429abd04e9ef718834d0a6427eb15 100644 (file)
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -151,7 +151,12 @@ typedef unsigned long sector_t;
  */
 
 #ifdef __CHECKER__
-#define __bitwise __attribute__((bitwise))
+#define __bitwise__ __attribute__((bitwise))
+#else
+#define __bitwise__
+#endif
+#ifdef __CHECK_ENDIAN__
+#define __bitwise __bitwise__
 #else
 #define __bitwise
 #endif
@@ -166,7 +171,7 @@ typedef __u64 __bitwise __be64;
 #endif
 
 #ifdef __KERNEL__
-typedef unsigned __nocast gfp_t;
+typedef unsigned __bitwise__ gfp_t;
 #endif
 
 struct ustat {

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 37af443eb0944e5e81b4094bf5b7312540ce170d..1d5c64df1653bf6f1c4a232477099ae4fd1112e3 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -700,7 +700,7 @@ static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy)
        case MPOL_BIND:
                /* Lower zones don't get a policy applied */
                /* Careful: current->mems_allowed might have moved */
-               if ((gfp & GFP_ZONEMASK) >= policy_zone)
+               if (gfp_zone(gfp) >= policy_zone)
                        if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist))
                                return policy->v.zonelist;
                /*FALL THROUGH*/
@@ -712,7 +712,7 @@ static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy)
                nd = 0;
                BUG();
        }
-       return NODE_DATA(nd)->node_zonelists + (gfp & GFP_ZONEMASK);
+       return NODE_DATA(nd)->node_zonelists + gfp_zone(gfp);
 }
 
 /* Do dynamic interleaving for a process */
@@ -757,7 +757,7 @@ static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, unsigned ni
        struct page *page;
 
        BUG_ON(!node_online(nid));
-       zl = NODE_DATA(nid)->node_zonelists + (gfp & GFP_ZONEMASK);
+       zl = NODE_DATA(nid)->node_zonelists + gfp_zone(gfp);
        page = __alloc_pages(gfp, order, zl);
        if (page && page_zone(page) == zl->zones[0]) {
                zone_pcp(zl->zones[0],get_cpu())->interleave_hit++;

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e1d3d77f4aeef89259d9e3b09e500042a42d7a87..aa43ae3ab8c921f10262b5a1f399d248049c03fd 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1089,7 +1089,7 @@ static unsigned int nr_free_zone_pages(int offset)
  */
 unsigned int nr_free_buffer_pages(void)
 {
-       return nr_free_zone_pages(GFP_USER & GFP_ZONEMASK);
+       return nr_free_zone_pages(gfp_zone(GFP_USER));
 }
 
 /*
@@ -1097,7 +1097,7 @@ unsigned int nr_free_buffer_pages(void)
  */
 unsigned int nr_free_pagecache_pages(void)
 {
-       return nr_free_zone_pages(GFP_HIGHUSER & GFP_ZONEMASK);
+       return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER));
 }
 
 #ifdef CONFIG_HIGHMEM