efi/memreserve: deal with memreserve entries in unmapped memory (18df7577) · Commits · 戴 / test

drivers/firmware/efi/efi.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -1009,14 +1009,16 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)

		/* first try to find a slot in an existing linked list entry */
		for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
		rsv = __va(prsv);
		rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
		index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
		if (index < rsv->size) {
		rsv->entry[index].base = addr;
		rsv->entry[index].size = size;

		memunmap(rsv);
		return 0;
		}
		memunmap(rsv);
		}

		/* no slot found - allocate a new linked list entry */
		@@ -1024,7 +1026,13 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
		if (!rsv)
		return -ENOMEM;

		rsv->size = EFI_MEMRESERVE_COUNT(PAGE_SIZE);
		/*
		* The memremap() call above assumes that a linux_efi_memreserve entry
		* never crosses a page boundary, so let's ensure that this remains true
		* even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
		* using SZ_4K explicitly in the size calculation below.
		*/
		rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
		atomic_set(&rsv->count, 1);
		rsv->entry[0].base = addr;
		rsv->entry[0].size = size;