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/*
* This work is licensed under the terms of the GNU LGPL, version 2.
*
* This is a simple allocator that provides contiguous physical addresses
* with byte granularity.
*/
#ifndef _ALLOC_PAGE_H_
#define _ALLOC_PAGE_H_
#include <stdbool.h>
#include <asm/memory_areas.h>
#define AREA_ANY_NUMBER 0xff
#define AREA_ANY 0x00000
#define AREA_MASK 0x0ffff
#define FLAG_DONTZERO 0x10000
#define FLAG_FRESH 0x20000
/* Returns true if the page allocator has been initialized */
bool page_alloc_initialized(void);
/*
* Initializes a memory area.
* n is the number of the area to initialize
* base_pfn is the physical frame number of the start of the area to initialize
* top_pfn is the physical frame number of the first page immediately after
* the end of the area to initialize
*/
void page_alloc_init_area(u8 n, phys_addr_t base_pfn, phys_addr_t top_pfn);
/* Enables the page allocator. At least one area must have been initialized */
void page_alloc_ops_enable(void);
/*
* Allocate aligned memory with the specified flags.
* flags is a bitmap of allowed areas and flags.
* alignment must be a power of 2
*/
void *memalign_pages_flags(size_t alignment, size_t size, unsigned int flags);
/*
* Allocate aligned memory from any area and with default flags.
* Equivalent to memalign_pages_flags(alignment, size, AREA_ANY).
*/
static inline void *memalign_pages(size_t alignment, size_t size)
{
return memalign_pages_flags(alignment, size, AREA_ANY);
}
/*
* Allocate 1ull << order naturally aligned pages with the specified flags.
* Equivalent to memalign_pages_flags(1ull << order, 1ull << order, flags).
*/
void *alloc_pages_flags(unsigned int order, unsigned int flags);
/*
* Allocate 1ull << order naturally aligned pages from any area and with
* default flags.
* Equivalent to alloc_pages_flags(order, AREA_ANY);
*/
static inline void *alloc_pages(unsigned int order)
{
return alloc_pages_flags(order, AREA_ANY);
}
/*
* Allocate one page from any area and with default flags.
* Equivalent to alloc_pages(0);
*/
static inline void *alloc_page(void)
{
return alloc_pages(0);
}
/*
* Frees a memory block allocated with any of the memalign_pages* or
* alloc_pages* functions.
* The pointer must point to the start of the block.
*/
void free_pages(void *mem);
/*
* Free one page.
* Equivalent to free_pages(mem).
*/
static inline void free_page(void *mem)
{
free_pages(mem);
}
/*
* Free pages by order.
* Equivalent to free_pages(mem).
*/
static inline void free_pages_by_order(void *mem, unsigned int order)
{
free_pages(mem);
}
/*
* Reserves the specified physical memory range if possible.
* If the specified range cannot be reserved in its entirety, no action is
* performed and -1 is returned.
*
* Returns 0 in case of success, -1 otherwise.
*/
int reserve_pages(phys_addr_t addr, size_t npages);
/*
* Frees a reserved memory range that had been reserved with
* reserve_pages.
* The memory range does not need to match a previous allocation
* exactly, it can also be a subset, in which case only the specified
* pages will be freed and unreserved.
*/
void unreserve_pages(phys_addr_t addr, size_t npages);
#endif