58 lines
1.6 KiB
C
58 lines
1.6 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include <linux/efi.h>
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#include <asm/efi.h>
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#include "efistub.h"
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/**
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* efi_allocate_pages_aligned() - Allocate memory pages
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* @size: minimum number of bytes to allocate
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* @addr: On return the address of the first allocated page. The first
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* allocated page has alignment EFI_ALLOC_ALIGN which is an
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* architecture dependent multiple of the page size.
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* @max: the address that the last allocated memory page shall not
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* exceed
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* @align: minimum alignment of the base of the allocation
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*
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* Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according
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* to @align, which should be >= EFI_ALLOC_ALIGN. The last allocated page will
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* not exceed the address given by @max.
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*
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* Return: status code
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*/
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efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr,
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unsigned long max, unsigned long align)
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{
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efi_physical_addr_t alloc_addr;
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efi_status_t status;
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int slack;
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if (align < EFI_ALLOC_ALIGN)
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align = EFI_ALLOC_ALIGN;
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alloc_addr = ALIGN_DOWN(max + 1, align) - 1;
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size = round_up(size, EFI_ALLOC_ALIGN);
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slack = align / EFI_PAGE_SIZE - 1;
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status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS,
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EFI_LOADER_DATA, size / EFI_PAGE_SIZE + slack,
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&alloc_addr);
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if (status != EFI_SUCCESS)
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return status;
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*addr = ALIGN((unsigned long)alloc_addr, align);
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if (slack > 0) {
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int l = (alloc_addr & (align - 1)) / EFI_PAGE_SIZE;
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if (l) {
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efi_bs_call(free_pages, alloc_addr, slack - l + 1);
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slack = l - 1;
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}
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if (slack)
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efi_bs_call(free_pages, *addr + size, slack);
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}
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return EFI_SUCCESS;
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}
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