diff options
| -rw-r--r-- | include/linux/gfp.h | 111 |
1 files changed, 96 insertions, 15 deletions
diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 06b7e8cc80a..412178afd42 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -21,7 +21,8 @@ struct vm_area_struct; #define __GFP_DMA ((__force gfp_t)0x01u) #define __GFP_HIGHMEM ((__force gfp_t)0x02u) #define __GFP_DMA32 ((__force gfp_t)0x04u) - +#define __GFP_MOVABLE ((__force gfp_t)0x08u) /* Page is movable */ +#define GFP_ZONEMASK (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE) /* * Action modifiers - doesn't change the zoning * @@ -51,7 +52,6 @@ struct vm_area_struct; #define __GFP_HARDWALL ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */ #define __GFP_THISNODE ((__force gfp_t)0x40000u)/* No fallback, no policies */ #define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */ -#define __GFP_MOVABLE ((__force gfp_t)0x100000u) /* Page is movable */ #define __GFP_BITS_SHIFT 21 /* Room for 21 __GFP_FOO bits */ #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1)) @@ -116,24 +116,105 @@ static inline int allocflags_to_migratetype(gfp_t gfp_flags) ((gfp_flags & __GFP_RECLAIMABLE) != 0); } -static inline enum zone_type gfp_zone(gfp_t flags) -{ +#ifdef CONFIG_HIGHMEM +#define OPT_ZONE_HIGHMEM ZONE_HIGHMEM +#else +#define OPT_ZONE_HIGHMEM ZONE_NORMAL +#endif + #ifdef CONFIG_ZONE_DMA - if (flags & __GFP_DMA) - return ZONE_DMA; +#define OPT_ZONE_DMA ZONE_DMA +#else +#define OPT_ZONE_DMA ZONE_NORMAL #endif + #ifdef CONFIG_ZONE_DMA32 - if (flags & __GFP_DMA32) - return ZONE_DMA32; +#define OPT_ZONE_DMA32 ZONE_DMA32 +#else +#define OPT_ZONE_DMA32 ZONE_NORMAL #endif - if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) == - (__GFP_HIGHMEM | __GFP_MOVABLE)) - return ZONE_MOVABLE; -#ifdef CONFIG_HIGHMEM - if (flags & __GFP_HIGHMEM) - return ZONE_HIGHMEM; + +/* + * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the + * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long + * and there are 16 of them to cover all possible combinations of + * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM + * + * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA. + * But GFP_MOVABLE is not only a zone specifier but also an allocation + * policy. Therefore __GFP_MOVABLE plus another zone selector is valid. + * Only 1bit of the lowest 3 bit (DMA,DMA32,HIGHMEM) can be set to "1". + * + * bit result + * ================= + * 0x0 => NORMAL + * 0x1 => DMA or NORMAL + * 0x2 => HIGHMEM or NORMAL + * 0x3 => BAD (DMA+HIGHMEM) + * 0x4 => DMA32 or DMA or NORMAL + * 0x5 => BAD (DMA+DMA32) + * 0x6 => BAD (HIGHMEM+DMA32) + * 0x7 => BAD (HIGHMEM+DMA32+DMA) + * 0x8 => NORMAL (MOVABLE+0) + * 0x9 => DMA or NORMAL (MOVABLE+DMA) + * 0xa => MOVABLE (Movable is valid only if HIGHMEM is set too) + * 0xb => BAD (MOVABLE+HIGHMEM+DMA) + * 0xc => DMA32 (MOVABLE+HIGHMEM+DMA32) + * 0xd => BAD (MOVABLE+DMA32+DMA) + * 0xe => BAD (MOVABLE+DMA32+HIGHMEM) + * 0xf => BAD (MOVABLE+DMA32+HIGHMEM+DMA) + * + * ZONES_SHIFT must be <= 2 on 32 bit platforms. + */ + +#if 16 * ZONES_SHIFT > BITS_PER_LONG +#error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer +#endif + +#define GFP_ZONE_TABLE ( \ + (ZONE_NORMAL << 0 * ZONES_SHIFT) \ + | (OPT_ZONE_DMA << __GFP_DMA * ZONES_SHIFT) \ + | (OPT_ZONE_HIGHMEM << __GFP_HIGHMEM * ZONES_SHIFT) \ + | (OPT_ZONE_DMA32 << __GFP_DMA32 * ZONES_SHIFT) \ + | (ZONE_NORMAL << __GFP_MOVABLE * ZONES_SHIFT) \ + | (OPT_ZONE_DMA << (__GFP_MOVABLE | __GFP_DMA) * ZONES_SHIFT) \ + | (ZONE_MOVABLE << (__GFP_MOVABLE | __GFP_HIGHMEM) * ZONES_SHIFT)\ + | (OPT_ZONE_DMA32 << (__GFP_MOVABLE | __GFP_DMA32) * ZONES_SHIFT)\ +) + +/* + * GFP_ZONE_BAD is a bitmap for all combination of __GFP_DMA, __GFP_DMA32 + * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per + * entry starting with bit 0. Bit is set if the combination is not + * allowed. + */ +#define GFP_ZONE_BAD ( \ + 1 << (__GFP_DMA | __GFP_HIGHMEM) \ + | 1 << (__GFP_DMA | __GFP_DMA32) \ + | 1 << (__GFP_DMA32 | __GFP_HIGHMEM) \ + | 1 << (__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM) \ + | 1 << (__GFP_MOVABLE | __GFP_HIGHMEM | __GFP_DMA) \ + | 1 << (__GFP_MOVABLE | __GFP_DMA32 | __GFP_DMA) \ + | 1 << (__GFP_MOVABLE | __GFP_DMA32 | __GFP_HIGHMEM) \ + | 1 << (__GFP_MOVABLE | __GFP_DMA32 | __GFP_DMA | __GFP_HIGHMEM)\ +) + +static inline enum zone_type gfp_zone(gfp_t flags) +{ + enum zone_type z; + int bit = flags & GFP_ZONEMASK; + + z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) & + ((1 << ZONES_SHIFT) - 1); + + if (__builtin_constant_p(bit)) + BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1); + else { +#ifdef CONFIG_DEBUG_VM + BUG_ON((GFP_ZONE_BAD >> bit) & 1); #endif - return ZONE_NORMAL; + } + return z; } /* |