summaryrefslogtreecommitdiffstats
path: root/drivers/firmware
diff options
context:
space:
mode:
authorSteve Capper <steve.capper@arm.com>2018-12-06 22:50:37 +0000
committerWill Deacon <will.deacon@arm.com>2018-12-10 18:42:17 +0000
commit363524d2b12270d86677e1154ecc1c5061f43219 (patch)
tree1b4653ee1c9509e7233e8d3a75a2f8cb8c66f62b /drivers/firmware
parentf6795053dac8d4d2f90d4a98842dd6d2ccd544ad (diff)
downloadlinux-363524d2b12270d86677e1154ecc1c5061f43219.tar.bz2
arm64: mm: Introduce DEFAULT_MAP_WINDOW
We wish to introduce a 52-bit virtual address space for userspace but maintain compatibility with software that assumes the maximum VA space size is 48 bit. In order to achieve this, on 52-bit VA systems, we make mmap behave as if it were running on a 48-bit VA system (unless userspace explicitly requests a VA where addr[51:48] != 0). On a system running a 52-bit userspace we need TASK_SIZE to represent the 52-bit limit as it is used in various places to distinguish between kernelspace and userspace addresses. Thus we need a new limit for mmap, stack, ELF loader and EFI (which uses TTBR0) to represent the non-extended VA space. This patch introduces DEFAULT_MAP_WINDOW and DEFAULT_MAP_WINDOW_64 and switches the appropriate logic to use that instead of TASK_SIZE. Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/arm-runtime.c2
-rw-r--r--drivers/firmware/efi/libstub/arm-stub.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c
index a00934d263c5..23ea1ed409d1 100644
--- a/drivers/firmware/efi/arm-runtime.c
+++ b/drivers/firmware/efi/arm-runtime.c
@@ -38,7 +38,7 @@ static struct ptdump_info efi_ptdump_info = {
.mm = &efi_mm,
.markers = (struct addr_marker[]){
{ 0, "UEFI runtime start" },
- { TASK_SIZE_64, "UEFI runtime end" }
+ { DEFAULT_MAP_WINDOW_64, "UEFI runtime end" }
},
.base_addr = 0,
};
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index 3d36142cf812..6640942a1c0d 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -33,7 +33,7 @@
#define EFI_RT_VIRTUAL_SIZE SZ_512M
#ifdef CONFIG_ARM64
-# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE_64
+# define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64
#else
# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE
#endif