[U-Boot] [PATCH] armv8: Fix MMU table page descriptor

Page descriptor uses different format than block descriptor. Both bit 1 and 0 must be set to indicate a valid page.
Signed-off-by: York Sun york.sun@nxp.com CC: Alexander Graf agraf@suse.de --- This issue didn't reveal itself unless we use MMU tables down to page size.
arch/arm/cpu/armv8/cache_v8.c | 2 +- arch/arm/include/asm/armv8/mmu.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c index 6c5630c..afa76c1 100644 --- a/arch/arm/cpu/armv8/cache_v8.c +++ b/arch/arm/cpu/armv8/cache_v8.c @@ -230,7 +230,7 @@ static void add_map(struct mm_region *map) /* Page fits, create block PTE */ debug("Setting PTE %p to block virt=%llx\n", pte, virt); - *pte = phys | attrs; + *pte = phys | attrs | (level == 3 ? PTE_TYPE_PAGE : 0); virt += blocksize; phys += blocksize; size -= blocksize; diff --git a/arch/arm/include/asm/armv8/mmu.h b/arch/arm/include/asm/armv8/mmu.h index aa0f3c4..58aecb9 100644 --- a/arch/arm/include/asm/armv8/mmu.h +++ b/arch/arm/include/asm/armv8/mmu.h @@ -60,6 +60,7 @@ #define PTE_TYPE_MASK (3 << 0) #define PTE_TYPE_FAULT (0 << 0) #define PTE_TYPE_TABLE (3 << 0) +#define PTE_TYPE_PAGE (3 << 0) #define PTE_TYPE_BLOCK (1 << 0)
#define PTE_TABLE_PXN (1UL << 59)

On 02/02/2017 10:58 AM, York Sun wrote:
Page descriptor uses different format than block descriptor. Both bit 1 and 0 must be set to indicate a valid page.
diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
@@ -230,7 +230,7 @@ static void add_map(struct mm_region *map) /* Page fits, create block PTE */ debug("Setting PTE %p to block virt=%llx\n", pte, virt);
*pte = phys | attrs;
*pte = phys | attrs | (level == 3 ? PTE_TYPE_PAGE : 0);
The value of attrs already includes PTE_TYPE_BLOCK. Luckily, the bits set in the value of PTE_TYPE_BLOCK is a strict subset of the bits set in the value of PTE_TYPE_PAGE, so this works fine. Still, it might be clearer to explicitly remove PTE_TYPE_BLOCK before adding in PTE_TYPE_PAGE, or simply add a comment explaining why the code is OK as written.
With one of those fixes, Reviewed-by: Stephen Warren swarren@nvidia.com
participants (2)
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Stephen Warren
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York Sun