| Message ID | 20190729162117.832-10-steve.capper@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | 52-bit kernel + user VAs | expand |
On Mon, Jul 29, 2019 at 05:21:15PM +0100, Steve Capper wrote: > In a later patch we will need to have a slightly larger VMEMMAP region > to accommodate boot time selection between 48/52-bit kernel VAs. > > This patch modifies the formula for computing VMEMMAP_SIZE to depend > explicitly on the PAGE_OFFSET and start of kernel addressable memory. > (This allows for a slightly larger direct linear map in future). > > Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 93341f4fe840..aa7186006ee5 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -26,8 +26,15 @@ /* * VMEMMAP_SIZE - allows the whole linear region to be covered by * a struct page array + * + * If we are configured with a 52-bit kernel VA then our VMEMMAP_SIZE + * neads to cover the memory region from the beginning of the 52-bit + * PAGE_OFFSET all the way to VA_START for 48-bit. This allows us to + * keep a constant PAGE_OFFSET and "fallback" to using the higher end + * of the VMEMMAP where 52-bit support is not available in hardware. */ -#define VMEMMAP_SIZE (UL(1) << (VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)) +#define VMEMMAP_SIZE ((_VA_START(VA_BITS_MIN) - PAGE_OFFSET) \ + >> (PAGE_SHIFT - STRUCT_PAGE_MAX_SHIFT)) /* * PAGE_OFFSET - the virtual address of the start of the linear map (top
In a later patch we will need to have a slightly larger VMEMMAP region to accommodate boot time selection between 48/52-bit kernel VAs. This patch modifies the formula for computing VMEMMAP_SIZE to depend explicitly on the PAGE_OFFSET and start of kernel addressable memory. (This allows for a slightly larger direct linear map in future). Signed-off-by: Steve Capper <steve.capper@arm.com> --- arch/arm64/include/asm/memory.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)