forked from KolibriOS/kolibrios
352 lines
14 KiB
C
352 lines
14 KiB
C
#ifndef __LINUX_GFP_H
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#define __LINUX_GFP_H
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#include <linux/mmdebug.h>
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#include <linux/mmzone.h>
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#include <linux/stddef.h>
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#include <linux/linkage.h>
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struct vm_area_struct;
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/*
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* In case of changes, please don't forget to update
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* include/trace/events/mmflags.h and tools/perf/builtin-kmem.c
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*/
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/* Plain integer GFP bitmasks. Do not use this directly. */
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#define ___GFP_DMA 0x01u
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#define ___GFP_HIGHMEM 0x02u
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#define ___GFP_DMA32 0x04u
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#define ___GFP_MOVABLE 0x08u
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#define ___GFP_RECLAIMABLE 0x10u
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#define ___GFP_HIGH 0x20u
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#define ___GFP_IO 0x40u
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#define ___GFP_FS 0x80u
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#define ___GFP_COLD 0x100u
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#define ___GFP_NOWARN 0x200u
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#define ___GFP_REPEAT 0x400u
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#define ___GFP_NOFAIL 0x800u
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#define ___GFP_NORETRY 0x1000u
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#define ___GFP_MEMALLOC 0x2000u
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#define ___GFP_COMP 0x4000u
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#define ___GFP_ZERO 0x8000u
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#define ___GFP_NOMEMALLOC 0x10000u
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#define ___GFP_HARDWALL 0x20000u
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#define ___GFP_THISNODE 0x40000u
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#define ___GFP_ATOMIC 0x80000u
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#define ___GFP_ACCOUNT 0x100000u
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#define ___GFP_NOTRACK 0x200000u
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#define ___GFP_DIRECT_RECLAIM 0x400000u
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#define ___GFP_OTHER_NODE 0x800000u
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#define ___GFP_WRITE 0x1000000u
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#define ___GFP_KSWAPD_RECLAIM 0x2000000u
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/* If the above are modified, __GFP_BITS_SHIFT may need updating */
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/*
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* Physical address zone modifiers (see linux/mmzone.h - low four bits)
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*
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* Do not put any conditional on these. If necessary modify the definitions
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* without the underscores and use them consistently. The definitions here may
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* be used in bit comparisons.
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*/
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#define __GFP_DMA ((__force gfp_t)___GFP_DMA)
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#define __GFP_HIGHMEM ((__force gfp_t)___GFP_HIGHMEM)
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#define __GFP_DMA32 ((__force gfp_t)___GFP_DMA32)
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#define __GFP_MOVABLE ((__force gfp_t)___GFP_MOVABLE) /* ZONE_MOVABLE allowed */
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#define GFP_ZONEMASK (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
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/*
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* Page mobility and placement hints
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*
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* These flags provide hints about how mobile the page is. Pages with similar
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* mobility are placed within the same pageblocks to minimise problems due
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* to external fragmentation.
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*
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* __GFP_MOVABLE (also a zone modifier) indicates that the page can be
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* moved by page migration during memory compaction or can be reclaimed.
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*
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* __GFP_RECLAIMABLE is used for slab allocations that specify
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* SLAB_RECLAIM_ACCOUNT and whose pages can be freed via shrinkers.
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*
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* __GFP_WRITE indicates the caller intends to dirty the page. Where possible,
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* these pages will be spread between local zones to avoid all the dirty
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* pages being in one zone (fair zone allocation policy).
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*
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* __GFP_HARDWALL enforces the cpuset memory allocation policy.
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*
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* __GFP_THISNODE forces the allocation to be satisified from the requested
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* node with no fallbacks or placement policy enforcements.
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*
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* __GFP_ACCOUNT causes the allocation to be accounted to kmemcg (only relevant
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* to kmem allocations).
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*/
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#define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
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#define __GFP_WRITE ((__force gfp_t)___GFP_WRITE)
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#define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL)
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#define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE)
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#define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT)
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/*
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* Watermark modifiers -- controls access to emergency reserves
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*
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* __GFP_HIGH indicates that the caller is high-priority and that granting
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* the request is necessary before the system can make forward progress.
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* For example, creating an IO context to clean pages.
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*
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* __GFP_ATOMIC indicates that the caller cannot reclaim or sleep and is
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* high priority. Users are typically interrupt handlers. This may be
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* used in conjunction with __GFP_HIGH
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*
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* __GFP_MEMALLOC allows access to all memory. This should only be used when
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* the caller guarantees the allocation will allow more memory to be freed
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* very shortly e.g. process exiting or swapping. Users either should
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* be the MM or co-ordinating closely with the VM (e.g. swap over NFS).
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*
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* __GFP_NOMEMALLOC is used to explicitly forbid access to emergency reserves.
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* This takes precedence over the __GFP_MEMALLOC flag if both are set.
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*/
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#define __GFP_ATOMIC ((__force gfp_t)___GFP_ATOMIC)
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#define __GFP_HIGH ((__force gfp_t)___GFP_HIGH)
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#define __GFP_MEMALLOC ((__force gfp_t)___GFP_MEMALLOC)
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#define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC)
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/*
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* Reclaim modifiers
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*
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* __GFP_IO can start physical IO.
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*
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* __GFP_FS can call down to the low-level FS. Clearing the flag avoids the
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* allocator recursing into the filesystem which might already be holding
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* locks.
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*
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* __GFP_DIRECT_RECLAIM indicates that the caller may enter direct reclaim.
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* This flag can be cleared to avoid unnecessary delays when a fallback
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* option is available.
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*
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* __GFP_KSWAPD_RECLAIM indicates that the caller wants to wake kswapd when
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* the low watermark is reached and have it reclaim pages until the high
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* watermark is reached. A caller may wish to clear this flag when fallback
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* options are available and the reclaim is likely to disrupt the system. The
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* canonical example is THP allocation where a fallback is cheap but
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* reclaim/compaction may cause indirect stalls.
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*
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* __GFP_RECLAIM is shorthand to allow/forbid both direct and kswapd reclaim.
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*
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* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
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* _might_ fail. This depends upon the particular VM implementation.
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*
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* __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
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* cannot handle allocation failures. New users should be evaluated carefully
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* (and the flag should be used only when there is no reasonable failure
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* policy) but it is definitely preferable to use the flag rather than
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* opencode endless loop around allocator.
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*
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* __GFP_NORETRY: The VM implementation must not retry indefinitely and will
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* return NULL when direct reclaim and memory compaction have failed to allow
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* the allocation to succeed. The OOM killer is not called with the current
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* implementation.
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*/
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#define __GFP_IO ((__force gfp_t)___GFP_IO)
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#define __GFP_FS ((__force gfp_t)___GFP_FS)
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#define __GFP_DIRECT_RECLAIM ((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
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#define __GFP_KSWAPD_RECLAIM ((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */
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#define __GFP_RECLAIM ((__force gfp_t)(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM))
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#define __GFP_REPEAT ((__force gfp_t)___GFP_REPEAT)
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#define __GFP_NOFAIL ((__force gfp_t)___GFP_NOFAIL)
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#define __GFP_NORETRY ((__force gfp_t)___GFP_NORETRY)
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/*
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* Action modifiers
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*
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* __GFP_COLD indicates that the caller does not expect to be used in the near
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* future. Where possible, a cache-cold page will be returned.
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*
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* __GFP_NOWARN suppresses allocation failure reports.
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*
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* __GFP_COMP address compound page metadata.
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*
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* __GFP_ZERO returns a zeroed page on success.
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*
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* __GFP_NOTRACK avoids tracking with kmemcheck.
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*
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* __GFP_NOTRACK_FALSE_POSITIVE is an alias of __GFP_NOTRACK. It's a means of
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* distinguishing in the source between false positives and allocations that
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* cannot be supported (e.g. page tables).
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*
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* __GFP_OTHER_NODE is for allocations that are on a remote node but that
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* should not be accounted for as a remote allocation in vmstat. A
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* typical user would be khugepaged collapsing a huge page on a remote
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* node.
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*/
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#define __GFP_COLD ((__force gfp_t)___GFP_COLD)
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#define __GFP_NOWARN ((__force gfp_t)___GFP_NOWARN)
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#define __GFP_COMP ((__force gfp_t)___GFP_COMP)
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#define __GFP_ZERO ((__force gfp_t)___GFP_ZERO)
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#define __GFP_NOTRACK ((__force gfp_t)___GFP_NOTRACK)
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#define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
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#define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE)
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/* Room for N __GFP_FOO bits */
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#define __GFP_BITS_SHIFT 26
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#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
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/*
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* Useful GFP flag combinations that are commonly used. It is recommended
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* that subsystems start with one of these combinations and then set/clear
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* __GFP_FOO flags as necessary.
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*
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* GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower
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* watermark is applied to allow access to "atomic reserves"
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*
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* GFP_KERNEL is typical for kernel-internal allocations. The caller requires
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* ZONE_NORMAL or a lower zone for direct access but can direct reclaim.
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*
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* GFP_KERNEL_ACCOUNT is the same as GFP_KERNEL, except the allocation is
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* accounted to kmemcg.
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*
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* GFP_NOWAIT is for kernel allocations that should not stall for direct
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* reclaim, start physical IO or use any filesystem callback.
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*
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* GFP_NOIO will use direct reclaim to discard clean pages or slab pages
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* that do not require the starting of any physical IO.
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*
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* GFP_NOFS will use direct reclaim but will not use any filesystem interfaces.
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*
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* GFP_USER is for userspace allocations that also need to be directly
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* accessibly by the kernel or hardware. It is typically used by hardware
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* for buffers that are mapped to userspace (e.g. graphics) that hardware
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* still must DMA to. cpuset limits are enforced for these allocations.
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*
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* GFP_DMA exists for historical reasons and should be avoided where possible.
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* The flags indicates that the caller requires that the lowest zone be
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* used (ZONE_DMA or 16M on x86-64). Ideally, this would be removed but
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* it would require careful auditing as some users really require it and
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* others use the flag to avoid lowmem reserves in ZONE_DMA and treat the
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* lowest zone as a type of emergency reserve.
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*
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* GFP_DMA32 is similar to GFP_DMA except that the caller requires a 32-bit
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* address.
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*
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* GFP_HIGHUSER is for userspace allocations that may be mapped to userspace,
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* do not need to be directly accessible by the kernel but that cannot
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* move once in use. An example may be a hardware allocation that maps
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* data directly into userspace but has no addressing limitations.
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*
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* GFP_HIGHUSER_MOVABLE is for userspace allocations that the kernel does not
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* need direct access to but can use kmap() when access is required. They
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* are expected to be movable via page reclaim or page migration. Typically,
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* pages on the LRU would also be allocated with GFP_HIGHUSER_MOVABLE.
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*
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* GFP_TRANSHUGE is used for THP allocations. They are compound allocations
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* that will fail quickly if memory is not available and will not wake
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* kswapd on failure.
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*/
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#define GFP_ATOMIC (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
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#define GFP_KERNEL (__GFP_RECLAIM | __GFP_IO | __GFP_FS)
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#define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
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#define GFP_NOWAIT (__GFP_KSWAPD_RECLAIM)
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#define GFP_NOIO (__GFP_RECLAIM)
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#define GFP_NOFS (__GFP_RECLAIM | __GFP_IO)
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#define GFP_TEMPORARY (__GFP_RECLAIM | __GFP_IO | __GFP_FS | \
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__GFP_RECLAIMABLE)
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#define GFP_USER (__GFP_RECLAIM | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
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#define GFP_DMA __GFP_DMA
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#define GFP_DMA32 __GFP_DMA32
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#define GFP_HIGHUSER (GFP_USER | __GFP_HIGHMEM)
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#define GFP_HIGHUSER_MOVABLE (GFP_HIGHUSER | __GFP_MOVABLE)
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#define GFP_TRANSHUGE ((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
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__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN) & \
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~__GFP_RECLAIM)
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static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
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{
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return !!(gfp_flags & __GFP_DIRECT_RECLAIM);
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}
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#ifdef CONFIG_HIGHMEM
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#define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
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#else
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#define OPT_ZONE_HIGHMEM ZONE_NORMAL
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#endif
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#ifdef CONFIG_ZONE_DMA
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#define OPT_ZONE_DMA ZONE_DMA
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#else
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#define OPT_ZONE_DMA ZONE_NORMAL
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#endif
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#ifdef CONFIG_ZONE_DMA32
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#define OPT_ZONE_DMA32 ZONE_DMA32
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#else
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#define OPT_ZONE_DMA32 ZONE_NORMAL
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#endif
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/*
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* GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
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* zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
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* and there are 16 of them to cover all possible combinations of
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* __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
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*
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* The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
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* But GFP_MOVABLE is not only a zone specifier but also an allocation
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* policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
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* Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
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*
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* bit result
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* =================
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* 0x0 => NORMAL
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* 0x1 => DMA or NORMAL
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* 0x2 => HIGHMEM or NORMAL
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* 0x3 => BAD (DMA+HIGHMEM)
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* 0x4 => DMA32 or DMA or NORMAL
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* 0x5 => BAD (DMA+DMA32)
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* 0x6 => BAD (HIGHMEM+DMA32)
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* 0x7 => BAD (HIGHMEM+DMA32+DMA)
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* 0x8 => NORMAL (MOVABLE+0)
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* 0x9 => DMA or NORMAL (MOVABLE+DMA)
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* 0xa => MOVABLE (Movable is valid only if HIGHMEM is set too)
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* 0xb => BAD (MOVABLE+HIGHMEM+DMA)
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* 0xc => DMA32 (MOVABLE+DMA32)
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* 0xd => BAD (MOVABLE+DMA32+DMA)
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* 0xe => BAD (MOVABLE+DMA32+HIGHMEM)
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* 0xf => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
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*
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* GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.
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*/
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#if 16 * ZONES_SHIFT > BITS_PER_LONG
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#error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
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#endif
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#define GFP_ZONE_TABLE ( \
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(ZONE_NORMAL << 0 * ZONES_SHIFT) \
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| (OPT_ZONE_DMA << ___GFP_DMA * ZONES_SHIFT) \
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| (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * ZONES_SHIFT) \
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| (OPT_ZONE_DMA32 << ___GFP_DMA32 * ZONES_SHIFT) \
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| (ZONE_NORMAL << ___GFP_MOVABLE * ZONES_SHIFT) \
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| (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * ZONES_SHIFT) \
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| (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * ZONES_SHIFT) \
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| (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * ZONES_SHIFT) \
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)
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/*
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* GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
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* __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
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* entry starting with bit 0. Bit is set if the combination is not
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* allowed.
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*/
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#define GFP_ZONE_BAD ( \
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1 << (___GFP_DMA | ___GFP_HIGHMEM) \
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| 1 << (___GFP_DMA | ___GFP_DMA32) \
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| 1 << (___GFP_DMA32 | ___GFP_HIGHMEM) \
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| 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM) \
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| 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA) \
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| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA) \
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| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM) \
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| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM) \
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)
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#endif /* __LINUX_GFP_H */
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