From 7128039fe2dd3d59da9e4ffa036f3aaa3ba87b9f Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Mon, 21 Jul 2014 22:01:51 +0400 Subject: [PATCH] xtensa: fix TLBTEMP_BASE_2 region handling in fast_second_level_miss Current definition of TLBTEMP_BASE_2 is always 32K above the TLBTEMP_BASE_1, whereas fast_second_level_miss handler for the TLBTEMP region analyzes virtual address bit (PAGE_SHIFT + DCACHE_ALIAS_ORDER) to determine TLBTEMP region where the fault happened. The size of the TLBTEMP region is also checked incorrectly: not 64K, but twice data cache way size (whicht may as well be less than the instruction cache way size). Fix TLBTEMP_BASE_2 to be TLBTEMP_BASE_1 + data cache way size. Provide TLBTEMP_SIZE that is a greater of doubled data cache way size or the instruction cache way size, and use it to determine if the second level TLB miss occured in the TLBTEMP region. Practical occurence of page faults in the TLBTEMP area is extremely rare, this code can be tested by deletion of all w[di]tlb instructions in the tlbtemp_mapping region. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov --- arch/xtensa/include/asm/pgtable.h | 7 ++++++- arch/xtensa/kernel/entry.S | 2 +- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h index 4b0ca35a93b1..b2173e5da601 100644 --- a/arch/xtensa/include/asm/pgtable.h +++ b/arch/xtensa/include/asm/pgtable.h @@ -67,7 +67,12 @@ #define VMALLOC_START 0xC0000000 #define VMALLOC_END 0xC7FEFFFF #define TLBTEMP_BASE_1 0xC7FF0000 -#define TLBTEMP_BASE_2 0xC7FF8000 +#define TLBTEMP_BASE_2 (TLBTEMP_BASE_1 + DCACHE_WAY_SIZE) +#if 2 * DCACHE_WAY_SIZE > ICACHE_WAY_SIZE +#define TLBTEMP_SIZE (2 * DCACHE_WAY_SIZE) +#else +#define TLBTEMP_SIZE ICACHE_WAY_SIZE +#endif /* * For the Xtensa architecture, the PTE layout is as follows: diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index db96acb1362b..21917e5fd53a 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -1565,7 +1565,7 @@ ENTRY(fast_second_level_miss) rsr a0, excvaddr bltu a0, a3, 2f - addi a1, a0, -(2 << (DCACHE_ALIAS_ORDER + PAGE_SHIFT)) + addi a1, a0, -TLBTEMP_SIZE bgeu a1, a3, 2f /* Check if we have to restore an ITLB mapping. */ -- 2.39.5