📄 gfp.h
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#ifndef __LINUX_GFP_H#define __LINUX_GFP_H#include <linux/mmzone.h>#include <linux/stddef.h>#include <linux/linkage.h>struct vm_area_struct;/* * GFP bitmasks.. *//* Zone modifiers in GFP_ZONEMASK (see linux/mmzone.h - low two bits) */#define __GFP_DMA 0x01#define __GFP_HIGHMEM 0x02/* * Action modifiers - doesn't change the zoning * * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt * _might_ fail. This depends upon the particular VM implementation. * * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller * cannot handle allocation failures. * * __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_BITS_SHIFT 20 /* Room for 20 __GFP_FOO bits */#define __GFP_BITS_MASK ((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| \ __GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \ __GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \ __GFP_NOMEMALLOC)#define GFP_ATOMIC (__GFP_HIGH)#define GFP_NOIO (__GFP_WAIT)#define GFP_NOFS (__GFP_WAIT | __GFP_IO)#define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)#define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS)#define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HIGHMEM)/* Flag - indicates that the buffer will be suitable for DMA. Ignored on some platforms, used as appropriate on others */#define GFP_DMA __GFP_DMA/* * There is only one page-allocator function, and two main namespaces to * it. The alloc_page*() variants return 'struct page *' and as such * can allocate highmem pages, the *get*page*() variants return * virtual kernel addresses to the allocated page(s). *//* * We get the zone list from the current node and the gfp_mask. * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones. * * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets * optimized to &contig_page_data at compile-time. */#ifndef HAVE_ARCH_FREE_PAGEstatic inline void arch_free_page(struct page *page, int order) { }#endifextern struct page *FASTCALL(__alloc_pages(unsigned int, unsigned int, struct zonelist *));static inline struct page *alloc_pages_node(int nid, unsigned int gfp_mask, unsigned int order){ if (unlikely(order >= MAX_ORDER)) return NULL; return __alloc_pages(gfp_mask, order, NODE_DATA(nid)->node_zonelists + (gfp_mask & GFP_ZONEMASK));}#ifdef CONFIG_NUMAextern struct page *alloc_pages_current(unsigned int gfp_mask, unsigned order);static inline struct page *alloc_pages(unsigned int gfp_mask, unsigned int order){ if (unlikely(order >= MAX_ORDER)) return NULL; return alloc_pages_current(gfp_mask, order);}extern struct page *alloc_page_vma(unsigned gfp_mask, struct vm_area_struct *vma, unsigned long addr);#else#define alloc_pages(gfp_mask, order) \ alloc_pages_node(numa_node_id(), gfp_mask, order)#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)#endif#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)extern unsigned long FASTCALL(__get_free_pages(unsigned int gfp_mask, unsigned int order));extern unsigned long FASTCALL(get_zeroed_page(unsigned int gfp_mask));#define __get_free_page(gfp_mask) \ __get_free_pages((gfp_mask),0)#define __get_dma_pages(gfp_mask, order) \ __get_free_pages((gfp_mask) | GFP_DMA,(order))extern void FASTCALL(__free_pages(struct page *page, unsigned int order));extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));extern void FASTCALL(free_hot_page(struct page *page));extern void FASTCALL(free_cold_page(struct page *page));#define __free_page(page) __free_pages((page), 0)#define free_page(addr) free_pages((addr),0)void page_alloc_init(void);#endif /* __LINUX_GFP_H */
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