From 481f75c043cf44ec11c7fbdbbf37d43463f1e719 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Fri, 20 Dec 2013 18:02:16 +0800 Subject: [PATCH] x86/efi: Cleanup efi_enter_virtual_mode() function Add two small functions: efi_merge_regions() and efi_map_regions(), efi_enter_virtual_mode() calls them instead of embedding two long for loop. Signed-off-by: Dave Young Acked-by: Borislav Petkov Tested-by: Toshi Kani Signed-off-by: Matt Fleming --- arch/x86/platform/efi/efi.c | 132 +++++++++++++++++++++--------------- 1 file changed, 79 insertions(+), 53 deletions(-) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 15e3b5ea31b5..4694632ef581 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -773,44 +773,12 @@ void __init old_map_region(efi_memory_desc_t *md) (unsigned long long)md->phys_addr); } -/* - * This function will switch the EFI runtime services to virtual mode. - * Essentially, we look through the EFI memmap and map every region that - * has the runtime attribute bit set in its memory descriptor into the - * ->trampoline_pgd page table using a top-down VA allocation scheme. - * - * The old method which used to update that memory descriptor with the - * virtual address obtained from ioremap() is still supported when the - * kernel is booted with efi=old_map on its command line. Same old - * method enabled the runtime services to be called without having to - * thunk back into physical mode for every invocation. - * - * The new method does a pagetable switch in a preemption-safe manner - * so that we're in a different address space when calling a runtime - * function. For function arguments passing we do copy the PGDs of the - * kernel page table into ->trampoline_pgd prior to each call. - */ -void __init efi_enter_virtual_mode(void) +/* Merge contiguous regions of the same type and attribute */ +static void __init efi_merge_regions(void) { + void *p; efi_memory_desc_t *md, *prev_md = NULL; - void *p, *new_memmap = NULL; - unsigned long size; - efi_status_t status; - u64 end, systab; - int count = 0; - - efi.systab = NULL; - /* - * We don't do virtual mode, since we don't do runtime services, on - * non-native EFI - */ - if (!efi_is_native()) { - efi_unmap_memmap(); - return; - } - - /* Merge contiguous regions of the same type and attribute */ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { u64 prev_size; md = p; @@ -835,8 +803,31 @@ void __init efi_enter_virtual_mode(void) continue; } prev_md = md; + } +} + +static void __init get_systab_virt_addr(efi_memory_desc_t *md) +{ + unsigned long size; + u64 end, systab; + size = md->num_pages << EFI_PAGE_SHIFT; + end = md->phys_addr + size; + systab = (u64)(unsigned long)efi_phys.systab; + if (md->phys_addr <= systab && systab < end) { + systab += md->virt_addr - md->phys_addr; + efi.systab = (efi_system_table_t *)(unsigned long)systab; } +} + +/* + * Map efi memory ranges for runtime serivce and update new_memmap with virtual + * addresses. + */ +static void * __init efi_map_regions(int *count) +{ + efi_memory_desc_t *md; + void *p, *tmp, *new_memmap = NULL; for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { md = p; @@ -849,26 +840,64 @@ void __init efi_enter_virtual_mode(void) } efi_map_region(md); + get_systab_virt_addr(md); + + tmp = krealloc(new_memmap, (*count + 1) * memmap.desc_size, + GFP_KERNEL); + if (!tmp) + goto out_krealloc; + new_memmap = tmp; + memcpy(new_memmap + (*count * memmap.desc_size), md, + memmap.desc_size); + (*count)++; + } - size = md->num_pages << EFI_PAGE_SHIFT; - end = md->phys_addr + size; + return new_memmap; +out_krealloc: + kfree(new_memmap); + return NULL; +} + +/* + * This function will switch the EFI runtime services to virtual mode. + * Essentially, we look through the EFI memmap and map every region that + * has the runtime attribute bit set in its memory descriptor into the + * ->trampoline_pgd page table using a top-down VA allocation scheme. + * + * The old method which used to update that memory descriptor with the + * virtual address obtained from ioremap() is still supported when the + * kernel is booted with efi=old_map on its command line. Same old + * method enabled the runtime services to be called without having to + * thunk back into physical mode for every invocation. + * + * The new method does a pagetable switch in a preemption-safe manner + * so that we're in a different address space when calling a runtime + * function. For function arguments passing we do copy the PGDs of the + * kernel page table into ->trampoline_pgd prior to each call. + */ +void __init efi_enter_virtual_mode(void) +{ + efi_status_t status; + void *new_memmap = NULL; + int count = 0; - systab = (u64) (unsigned long) efi_phys.systab; - if (md->phys_addr <= systab && systab < end) { - systab += md->virt_addr - md->phys_addr; + efi.systab = NULL; - efi.systab = (efi_system_table_t *) (unsigned long) systab; - } + /* + * We don't do virtual mode, since we don't do runtime services, on + * non-native EFI + */ + if (!efi_is_native()) { + efi_unmap_memmap(); + return; + } - new_memmap = krealloc(new_memmap, - (count + 1) * memmap.desc_size, - GFP_KERNEL); - if (!new_memmap) - goto err_out; + efi_merge_regions(); - memcpy(new_memmap + (count * memmap.desc_size), md, - memmap.desc_size); - count++; + new_memmap = efi_map_regions(&count); + if (!new_memmap) { + pr_err("Error reallocating memory, EFI runtime non-functional!\n"); + return; } BUG_ON(!efi.systab); @@ -922,9 +951,6 @@ void __init efi_enter_virtual_mode(void) 0, NULL); return; - - err_out: - pr_err("Error reallocating memory, EFI runtime non-functional!\n"); } /* -- 2.39.2