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#include "efi.h"
#include <xen/init.h>
#include <xen/mm.h>
#ifdef CONFIG_ARM
/*
* TODO: Enable EFI boot allocator on ARM.
* This code can be common for x86 and ARM.
* Things TODO on ARM before enabling ebmalloc:
* - estimate required EBMALLOC_SIZE value,
* - where (in which section) ebmalloc_mem[] should live; if in
* .bss.page_aligned, as it is right now, then whole BSS zeroing
* have to be disabled in xen/arch/arm/arm64/head.S; though BSS
* should be initialized somehow before use of variables living there,
* - use ebmalloc() in ARM/common EFI boot code,
* - call free_ebmalloc_unused_mem() somewhere in init code.
*/
#define EBMALLOC_SIZE MB(0)
#else
#define EBMALLOC_SIZE MB(1)
#endif
static char __section(".bss.page_aligned") __aligned(PAGE_SIZE)
ebmalloc_mem[EBMALLOC_SIZE];
static unsigned long __read_mostly ebmalloc_allocated;
/* EFI boot allocator. */
void __init *ebmalloc(size_t size)
{
void *ptr = ebmalloc_mem + ebmalloc_allocated;
ebmalloc_allocated += ROUNDUP(size, sizeof(void *));
if ( ebmalloc_allocated > sizeof(ebmalloc_mem) )
blexit(L"Out of static memory\r\n");
return ptr;
}
bool efi_boot_mem_unused(unsigned long *start, unsigned long *end)
{
if ( !start && !end )
{
ebmalloc_allocated = sizeof(ebmalloc_mem);
return false;
}
*start = (unsigned long)ebmalloc_mem + PAGE_ALIGN(ebmalloc_allocated);
*end = (unsigned long)ebmalloc_mem + sizeof(ebmalloc_mem);
return *start < *end;
}
void __init free_ebmalloc_unused_mem(void)
{
unsigned long start, end;
if ( !efi_boot_mem_unused(&start, &end) )
return;
destroy_xen_mappings(start, end);
#ifdef CONFIG_X86
/*
* By reserving the space early in the E820 map, it gets freed way before
* we make it here. Don't free the range a 2nd time.
*/
#else
init_xenheap_pages(__pa(start), __pa(end));
#endif
printk(XENLOG_INFO "Freed %lukB unused BSS memory\n", (end - start) >> 10);
}
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