headers/deps: mm: Split <linux/gfp_types.h> out of <linux/gfp.h>

This is a much smaller header.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

1 files changed, 2 insertions, 343 deletions

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 52f2c873a7d4..f314be58fa77 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -2,354 +2,13 @@
 #ifndef __LINUX_GFP_H
 #define __LINUX_GFP_H
 
+#include <linux/gfp_types.h>
+
 #include <linux/mmzone.h>
 #include <linux/topology.h>
 
-/* The typedef is in types.h but we want the documentation here */
-#if 0
-/**
- * typedef gfp_t - Memory allocation flags.
- *
- * GFP flags are commonly used throughout Linux to indicate how memory
- * should be allocated.  The GFP acronym stands for get_free_pages(),
- * the underlying memory allocation function.  Not every GFP flag is
- * supported by every function which may allocate memory.  Most users
- * will want to use a plain ``GFP_KERNEL``.
- */
-typedef unsigned int __bitwise gfp_t;
-#endif
-
 struct vm_area_struct;
 
-/*
- * In case of changes, please don't forget to update
- * include/trace/events/mmflags.h and tools/perf/builtin-kmem.c
- */
-
-/* Plain integer GFP bitmasks. Do not use this directly. */
-#define ___GFP_DMA		0x01u
-#define ___GFP_HIGHMEM		0x02u
-#define ___GFP_DMA32		0x04u
-#define ___GFP_MOVABLE		0x08u
-#define ___GFP_RECLAIMABLE	0x10u
-#define ___GFP_HIGH		0x20u
-#define ___GFP_IO		0x40u
-#define ___GFP_FS		0x80u
-#define ___GFP_ZERO		0x100u
-#define ___GFP_ATOMIC		0x200u
-#define ___GFP_DIRECT_RECLAIM	0x400u
-#define ___GFP_KSWAPD_RECLAIM	0x800u
-#define ___GFP_WRITE		0x1000u
-#define ___GFP_NOWARN		0x2000u
-#define ___GFP_RETRY_MAYFAIL	0x4000u
-#define ___GFP_NOFAIL		0x8000u
-#define ___GFP_NORETRY		0x10000u
-#define ___GFP_MEMALLOC		0x20000u
-#define ___GFP_COMP		0x40000u
-#define ___GFP_NOMEMALLOC	0x80000u
-#define ___GFP_HARDWALL		0x100000u
-#define ___GFP_THISNODE		0x200000u
-#define ___GFP_ACCOUNT		0x400000u
-#define ___GFP_ZEROTAGS		0x800000u
-#ifdef CONFIG_KASAN_HW_TAGS
-#define ___GFP_SKIP_ZERO		0x1000000u
-#define ___GFP_SKIP_KASAN_UNPOISON	0x2000000u
-#define ___GFP_SKIP_KASAN_POISON	0x4000000u
-#else
-#define ___GFP_SKIP_ZERO		0
-#define ___GFP_SKIP_KASAN_UNPOISON	0
-#define ___GFP_SKIP_KASAN_POISON	0
-#endif
-#ifdef CONFIG_LOCKDEP
-#define ___GFP_NOLOCKDEP	0x8000000u
-#else
-#define ___GFP_NOLOCKDEP	0
-#endif
-/* If the above are modified, __GFP_BITS_SHIFT may need updating */
-
-/*
- * Physical address zone modifiers (see linux/mmzone.h - low four bits)
- *
- * Do not put any conditional on these. If necessary modify the definitions
- * without the underscores and use them consistently. The definitions here may
- * be used in bit comparisons.
- */
-#define __GFP_DMA	((__force gfp_t)___GFP_DMA)
-#define __GFP_HIGHMEM	((__force gfp_t)___GFP_HIGHMEM)
-#define __GFP_DMA32	((__force gfp_t)___GFP_DMA32)
-#define __GFP_MOVABLE	((__force gfp_t)___GFP_MOVABLE)  /* ZONE_MOVABLE allowed */
-#define GFP_ZONEMASK	(__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
-
-/**
- * DOC: Page mobility and placement hints
- *
- * Page mobility and placement hints
- * ---------------------------------
- *
- * These flags provide hints about how mobile the page is. Pages with similar
- * mobility are placed within the same pageblocks to minimise problems due
- * to external fragmentation.
- *
- * %__GFP_MOVABLE (also a zone modifier) indicates that the page can be
- * moved by page migration during memory compaction or can be reclaimed.
- *
- * %__GFP_RECLAIMABLE is used for slab allocations that specify
- * SLAB_RECLAIM_ACCOUNT and whose pages can be freed via shrinkers.
- *
- * %__GFP_WRITE indicates the caller intends to dirty the page. Where possible,
- * these pages will be spread between local zones to avoid all the dirty
- * pages being in one zone (fair zone allocation policy).
- *
- * %__GFP_HARDWALL enforces the cpuset memory allocation policy.
- *
- * %__GFP_THISNODE forces the allocation to be satisfied from the requested
- * node with no fallbacks or placement policy enforcements.
- *
- * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg.
- */
-#define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
-#define __GFP_WRITE	((__force gfp_t)___GFP_WRITE)
-#define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL)
-#define __GFP_THISNODE	((__force gfp_t)___GFP_THISNODE)
-#define __GFP_ACCOUNT	((__force gfp_t)___GFP_ACCOUNT)
-
-/**
- * DOC: Watermark modifiers
- *
- * Watermark modifiers -- controls access to emergency reserves
- * ------------------------------------------------------------
- *
- * %__GFP_HIGH indicates that the caller is high-priority and that granting
- * the request is necessary before the system can make forward progress.
- * For example, creating an IO context to clean pages.
- *
- * %__GFP_ATOMIC indicates that the caller cannot reclaim or sleep and is
- * high priority. Users are typically interrupt handlers. This may be
- * used in conjunction with %__GFP_HIGH
- *
- * %__GFP_MEMALLOC allows access to all memory. This should only be used when
- * the caller guarantees the allocation will allow more memory to be freed
- * very shortly e.g. process exiting or swapping. Users either should
- * be the MM or co-ordinating closely with the VM (e.g. swap over NFS).
- * Users of this flag have to be extremely careful to not deplete the reserve
- * completely and implement a throttling mechanism which controls the
- * consumption of the reserve based on the amount of freed memory.
- * Usage of a pre-allocated pool (e.g. mempool) should be always considered
- * before using this flag.
- *
- * %__GFP_NOMEMALLOC is used to explicitly forbid access to emergency reserves.
- * This takes precedence over the %__GFP_MEMALLOC flag if both are set.
- */
-#define __GFP_ATOMIC	((__force gfp_t)___GFP_ATOMIC)
-#define __GFP_HIGH	((__force gfp_t)___GFP_HIGH)
-#define __GFP_MEMALLOC	((__force gfp_t)___GFP_MEMALLOC)
-#define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC)
-
-/**
- * DOC: Reclaim modifiers
- *
- * Reclaim modifiers
- * -----------------
- * Please note that all the following flags are only applicable to sleepable
- * allocations (e.g. %GFP_NOWAIT and %GFP_ATOMIC will ignore them).
- *
- * %__GFP_IO can start physical IO.
- *
- * %__GFP_FS can call down to the low-level FS. Clearing the flag avoids the
- * allocator recursing into the filesystem which might already be holding
- * locks.
- *
- * %__GFP_DIRECT_RECLAIM indicates that the caller may enter direct reclaim.
- * This flag can be cleared to avoid unnecessary delays when a fallback
- * option is available.
- *
- * %__GFP_KSWAPD_RECLAIM indicates that the caller wants to wake kswapd when
- * the low watermark is reached and have it reclaim pages until the high
- * watermark is reached. A caller may wish to clear this flag when fallback
- * options are available and the reclaim is likely to disrupt the system. The
- * canonical example is THP allocation where a fallback is cheap but
- * reclaim/compaction may cause indirect stalls.
- *
- * %__GFP_RECLAIM is shorthand to allow/forbid both direct and kswapd reclaim.
- *
- * The default allocator behavior depends on the request size. We have a concept
- * of so called costly allocations (with order > %PAGE_ALLOC_COSTLY_ORDER).
- * !costly allocations are too essential to fail so they are implicitly
- * non-failing by default (with some exceptions like OOM victims might fail so
- * the caller still has to check for failures) while costly requests try to be
- * not disruptive and back off even without invoking the OOM killer.
- * The following three modifiers might be used to override some of these
- * implicit rules
- *
- * %__GFP_NORETRY: The VM implementation will try only very lightweight
- * memory direct reclaim to get some memory under memory pressure (thus
- * it can sleep). It will avoid disruptive actions like OOM killer. The
- * caller must handle the failure which is quite likely to happen under
- * heavy memory pressure. The flag is suitable when failure can easily be
- * handled at small cost, such as reduced throughput
- *
- * %__GFP_RETRY_MAYFAIL: The VM implementation will retry memory reclaim
- * procedures that have previously failed if there is some indication
- * that progress has been made else where.  It can wait for other
- * tasks to attempt high level approaches to freeing memory such as
- * compaction (which removes fragmentation) and page-out.
- * There is still a definite limit to the number of retries, but it is
- * a larger limit than with %__GFP_NORETRY.
- * Allocations with this flag may fail, but only when there is
- * genuinely little unused memory. While these allocations do not
- * directly trigger the OOM killer, their failure indicates that
- * the system is likely to need to use the OOM killer soon.  The
- * caller must handle failure, but can reasonably do so by failing
- * a higher-level request, or completing it only in a much less
- * efficient manner.
- * If the allocation does fail, and the caller is in a position to
- * free some non-essential memory, doing so could benefit the system
- * as a whole.
- *
- * %__GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
- * cannot handle allocation failures. The allocation could block
- * indefinitely but will never return with failure. Testing for
- * failure is pointless.
- * New users should be evaluated carefully (and the flag should be
- * used only when there is no reasonable failure policy) but it is
- * definitely preferable to use the flag rather than opencode endless
- * loop around allocator.
- * Using this flag for costly allocations is _highly_ discouraged.
- */
-#define __GFP_IO	((__force gfp_t)___GFP_IO)
-#define __GFP_FS	((__force gfp_t)___GFP_FS)
-#define __GFP_DIRECT_RECLAIM	((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
-#define __GFP_KSWAPD_RECLAIM	((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */
-#define __GFP_RECLAIM ((__force gfp_t)(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM))
-#define __GFP_RETRY_MAYFAIL	((__force gfp_t)___GFP_RETRY_MAYFAIL)
-#define __GFP_NOFAIL	((__force gfp_t)___GFP_NOFAIL)
-#define __GFP_NORETRY	((__force gfp_t)___GFP_NORETRY)
-
-/**
- * DOC: Action modifiers
- *
- * Action modifiers
- * ----------------
- *
- * %__GFP_NOWARN suppresses allocation failure reports.
- *
- * %__GFP_COMP address compound page metadata.
- *
- * %__GFP_ZERO returns a zeroed page on success.
- *
- * %__GFP_ZEROTAGS zeroes memory tags at allocation time if the memory itself
- * is being zeroed (either via __GFP_ZERO or via init_on_alloc, provided that
- * __GFP_SKIP_ZERO is not set). This flag is intended for optimization: setting
- * memory tags at the same time as zeroing memory has minimal additional
- * performace impact.
- *
- * %__GFP_SKIP_KASAN_UNPOISON makes KASAN skip unpoisoning on page allocation.
- * Only effective in HW_TAGS mode.
- *
- * %__GFP_SKIP_KASAN_POISON makes KASAN skip poisoning on page deallocation.
- * Typically, used for userspace pages. Only effective in HW_TAGS mode.
- */
-#define __GFP_NOWARN	((__force gfp_t)___GFP_NOWARN)
-#define __GFP_COMP	((__force gfp_t)___GFP_COMP)
-#define __GFP_ZERO	((__force gfp_t)___GFP_ZERO)
-#define __GFP_ZEROTAGS	((__force gfp_t)___GFP_ZEROTAGS)
-#define __GFP_SKIP_ZERO ((__force gfp_t)___GFP_SKIP_ZERO)
-#define __GFP_SKIP_KASAN_UNPOISON ((__force gfp_t)___GFP_SKIP_KASAN_UNPOISON)
-#define __GFP_SKIP_KASAN_POISON   ((__force gfp_t)___GFP_SKIP_KASAN_POISON)
-
-/* Disable lockdep for GFP context tracking */
-#define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP)
-
-/* Room for N __GFP_FOO bits */
-#define __GFP_BITS_SHIFT (27 + IS_ENABLED(CONFIG_LOCKDEP))
-#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
-
-/**
- * DOC: Useful GFP flag combinations
- *
- * Useful GFP flag combinations
- * ----------------------------
- *
- * Useful GFP flag combinations that are commonly used. It is recommended
- * that subsystems start with one of these combinations and then set/clear
- * %__GFP_FOO flags as necessary.
- *
- * %GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower
- * watermark is applied to allow access to "atomic reserves".
- * The current implementation doesn't support NMI and few other strict
- * non-preemptive contexts (e.g. raw_spin_lock). The same applies to %GFP_NOWAIT.
- *
- * %GFP_KERNEL is typical for kernel-internal allocations. The caller requires
- * %ZONE_NORMAL or a lower zone for direct access but can direct reclaim.
- *
- * %GFP_KERNEL_ACCOUNT is the same as GFP_KERNEL, except the allocation is
- * accounted to kmemcg.
- *
- * %GFP_NOWAIT is for kernel allocations that should not stall for direct
- * reclaim, start physical IO or use any filesystem callback.
- *
- * %GFP_NOIO will use direct reclaim to discard clean pages or slab pages
- * that do not require the starting of any physical IO.
- * Please try to avoid using this flag directly and instead use
- * memalloc_noio_{save,restore} to mark the whole scope which cannot
- * perform any IO with a short explanation why. All allocation requests
- * will inherit GFP_NOIO implicitly.
- *
- * %GFP_NOFS will use direct reclaim but will not use any filesystem interfaces.
- * Please try to avoid using this flag directly and instead use
- * memalloc_nofs_{save,restore} to mark the whole scope which cannot/shouldn't
- * recurse into the FS layer with a short explanation why. All allocation
- * requests will inherit GFP_NOFS implicitly.
- *
- * %GFP_USER is for userspace allocations that also need to be directly
- * accessibly by the kernel or hardware. It is typically used by hardware
- * for buffers that are mapped to userspace (e.g. graphics) that hardware
- * still must DMA to. cpuset limits are enforced for these allocations.
- *
- * %GFP_DMA exists for historical reasons and should be avoided where possible.
- * The flags indicates that the caller requires that the lowest zone be
- * used (%ZONE_DMA or 16M on x86-64). Ideally, this would be removed but
- * it would require careful auditing as some users really require it and
- * others use the flag to avoid lowmem reserves in %ZONE_DMA and treat the
- * lowest zone as a type of emergency reserve.
- *
- * %GFP_DMA32 is similar to %GFP_DMA except that the caller requires a 32-bit
- * address. Note that kmalloc(..., GFP_DMA32) does not return DMA32 memory
- * because the DMA32 kmalloc cache array is not implemented.
- * (Reason: there is no such user in kernel).
- *
- * %GFP_HIGHUSER is for userspace allocations that may be mapped to userspace,
- * do not need to be directly accessible by the kernel but that cannot
- * move once in use. An example may be a hardware allocation that maps
- * data directly into userspace but has no addressing limitations.
- *
- * %GFP_HIGHUSER_MOVABLE is for userspace allocations that the kernel does not
- * need direct access to but can use kmap() when access is required. They
- * are expected to be movable via page reclaim or page migration. Typically,
- * pages on the LRU would also be allocated with %GFP_HIGHUSER_MOVABLE.
- *
- * %GFP_TRANSHUGE and %GFP_TRANSHUGE_LIGHT are used for THP allocations. They
- * are compound allocations that will generally fail quickly if memory is not
- * available and will not wake kswapd/kcompactd on failure. The _LIGHT
- * version does not attempt reclaim/compaction at all and is by default used
- * in page fault path, while the non-light is used by khugepaged.
- */
-#define GFP_ATOMIC	(__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
-#define GFP_KERNEL	(__GFP_RECLAIM | __GFP_IO | __GFP_FS)
-#define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
-#define GFP_NOWAIT	(__GFP_KSWAPD_RECLAIM)
-#define GFP_NOIO	(__GFP_RECLAIM)
-#define GFP_NOFS	(__GFP_RECLAIM | __GFP_IO)
-#define GFP_USER	(__GFP_RECLAIM | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
-#define GFP_DMA		__GFP_DMA
-#define GFP_DMA32	__GFP_DMA32
-#define GFP_HIGHUSER	(GFP_USER | __GFP_HIGHMEM)
-#define GFP_HIGHUSER_MOVABLE	(GFP_HIGHUSER | __GFP_MOVABLE | \
-			 __GFP_SKIP_KASAN_POISON)
-#define GFP_TRANSHUGE_LIGHT	((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
-			 __GFP_NOMEMALLOC | __GFP_NOWARN) & ~__GFP_RECLAIM)
-#define GFP_TRANSHUGE	(GFP_TRANSHUGE_LIGHT | __GFP_DIRECT_RECLAIM)
-
 /* Convert GFP flags to their corresponding migrate type */
 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
 #define GFP_MOVABLE_SHIFT 3