From eeba1f7c38425cfc0b70ba133ab7e523d5b6d90e Mon Sep 17 00:00:00 2001 From: LEROY Christophe Date: Mon, 20 Apr 2015 07:54:46 +0200 Subject: [PATCH] powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000 By default, TASK_SIZE is set to 0x80000000 for PPC_8xx, which is most likely sufficient for most cases. However, kernel configuration allows to set TASK_SIZE to another value, so the 8xx shall handle it. This patch also takes into account the case of PAGE_OFFSET lower than 0x80000000, allthought most of the time it is equal to 0xC0000000 Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood --- arch/powerpc/kernel/head_8xx.S | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index ba2dc53..c640bbb 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -48,6 +48,19 @@ mtspr spr, reg #endif +/* Macro to test if an address is a kernel address */ +#if CONFIG_TASK_SIZE <= 0x80000000 && CONFIG_PAGE_OFFSET >= 0x80000000 +#define IS_KERNEL(tmp, addr) \ + andis. tmp, addr, 0x8000 /* Address >= 0x80000000 */ +#define BRANCH_UNLESS_KERNEL(label) beq label +#else +#define IS_KERNEL(tmp, addr) \ + rlwinm tmp, addr, 16, 16, 31; \ + cmpli cr0, tmp, PAGE_OFFSET >> 16 +#define BRANCH_UNLESS_KERNEL(label) blt label +#endif + + /* * Value for the bits that have fixed value in RPN entries. * Also used for tagging DAR for DTLBerror. @@ -322,9 +335,9 @@ InstructionTLBMiss: mfspr r11, SPRN_SRR0 /* Get effective address of fault */ INVALIDATE_ADJACENT_PAGES_CPU15(r10, r11) mfcr r10 - andis. r11, r11, 0x8000 /* Address >= 0x80000000 */ + IS_KERNEL(r11, r11) mfspr r11, SPRN_M_TW /* Get level 1 table */ - beq 3f + BRANCH_UNLESS_KERNEL(3f) lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha 3: mtcr r10 @@ -379,9 +392,9 @@ DataStoreTLBMiss: * kernel page tables. */ mfspr r11, SPRN_MD_EPN - andis. r11, r11, 0x8000 + IS_KERNEL(r11, r11) mfspr r11, SPRN_M_TW /* Get level 1 table */ - beq 3f + BRANCH_UNLESS_KERNEL(3f) lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha 3: mtcr r10 @@ -513,9 +526,9 @@ FixupDAR:/* Entry point for dcbx workaround. */ mtspr SPRN_SPRG_SCRATCH2, r10 /* fetch instruction from memory. */ mfspr r10, SPRN_SRR0 - andis. r11, r10, 0x8000 /* Address >= 0x80000000 */ + IS_KERNEL(r11, r10) mfspr r11, SPRN_M_TW /* Get level 1 table */ - beq 3f + BRANCH_UNLESS_KERNEL(3f) lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha /* Insert level 1 index */ 3: rlwimi r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29 -- 2.7.4