powerpc/8xx: Add support for TASK_SIZE greater than 0x80000000
PATCH 11/11 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.
Signed-off-by Christophe Leroy <[email protected]>
--- arch/powerpc/kernel/head_8xx.S | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-)
arch/powerpc/kernel/head_8xx.S +21 -8
@@ -48,6 +48,19 @@ mtspr spr, reg #endif +/* Macro to test if an address is a kernel address */ +#if CONFIG_TASK_SIZE <= 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.
@@ -323,15 +336,15 @@ InstructionTLBMiss: mfspr r10, SPRN_SRR0 /* Get effective address of fault */ DO_8xx_CPU15(r11, r10) mfcr r3 - andis. r11, r10, 0x8000 /* Address >= 0x80000000 */ + IS_KERNEL(r11, r10) #else mfspr r11, SPRN_SRR0 /* Get effective address of fault */ DO_8xx_CPU15(r10, r11) mfcr r10 - andis. r11, r11, 0x8000 /* Address >= 0x80000000 */ + IS_KERNEL(r11, r11) #endif mfspr r11, SPRN_M_TW /* Get level 1 table base address */ - beq 3f + BRANCH_UNLESS_KERNEL(3f) lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha 3: #ifdef CONFIG_8xx_CPU6
@@ -390,14 +403,14 @@ DataStoreTLBMiss: mtspr SPRN_SPRG_SCRATCH2, r3 mfcr r3 mfspr r10, SPRN_MD_EPN - andis. r11, r10, 0x8000 + IS_KERNEL(r11, r10) #else mfcr r10 mfspr r11, SPRN_MD_EPN - andis. r11, r11, 0x8000 + IS_KERNEL(r11, r11) #endif mfspr r11, SPRN_M_TW /* Get level 1 table base address */ - beq 3f + BRANCH_UNLESS_KERNEL(3f) lis r11, (swapper_pg_dir-PAGE_OFFSET)@ha 3: #ifdef CONFIG_8xx_CPU6
@@ -536,9 +549,9 @@ 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 base address */ - 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
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2.1.0