From cbc130f120d5e180a70a0fa4a8b4191e44548a87 Mon Sep 17 00:00:00 2001 From: LEROY Christophe Date: Fri, 19 Sep 2014 10:36:08 +0200 Subject: [PATCH] powerpc/8xx: Use M_TW instead of M_TWB Use M_TW instead of M_TWB for storing Level 1 table address as M_TWB requires 4k aligned tables, which is only the case with 4k pages. Consequently, we have to calculate the level 1 table index by ourselves. Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood --- arch/powerpc/kernel/head_8xx.S | 48 ++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 22 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index c061bc8d9045..c78f7fd342cb 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -278,8 +278,8 @@ SystemCall: . = 0x1100 /* * For the MPC8xx, this is a software tablewalk to load the instruction - * TLB. It is modelled after the example in the Motorola manual. The task - * switch loads the M_TWB register with the pointer to the first level table. + * TLB. The task switch loads the M_TW register with the pointer to the first + * level table. * If we discover there is no second level table (value is zero) or if there * is an invalid pte, we load that into the TLB, which causes another fault * into the TLB Error interrupt where we can handle such problems. @@ -301,7 +301,6 @@ InstructionTLBMiss: #endif DO_8xx_CPU6(0x3780, r3) mtspr SPRN_MD_EPN, r10 /* Have to use MD_EPN for walk, MI_EPN can't */ - mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */ /* If we are faulting a kernel address, we have to use the * kernel page tables. @@ -309,14 +308,17 @@ InstructionTLBMiss: #ifdef CONFIG_MODULES /* Only modules will cause ITLB Misses as we always * pin the first 8MB of kernel memory */ - andi. r11, r10, 0x0800 /* Address >= 0x80000000 */ + andis. r11, r10, 0x8000 /* Address >= 0x80000000 */ +#endif + mfspr r11, SPRN_M_TW /* Get level 1 table base address */ +#ifdef CONFIG_MODULES beq 3f - lis r11, swapper_pg_dir@h - ori r11, r11, swapper_pg_dir@l - rlwimi r10, r11, 0, 2, 19 + lis r11, (swapper_pg_dir-PAGE_OFFSET)@h + ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l 3: #endif - lwz r11, 0(r10) /* Get the level 1 entry */ + rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */ + lwzx r11, r10, r11 /* Get the level 1 entry */ rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */ beq 2f /* If zero, don't try to find a pte */ @@ -377,18 +379,19 @@ DataStoreTLBMiss: #endif EXCEPTION_PROLOG_0 mtspr SPRN_SPRG_SCRATCH2, r10 - mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */ + mfspr r10, SPRN_MD_EPN /* If we are faulting a kernel address, we have to use the * kernel page tables. */ - andi. r11, r10, 0x0800 + andis. r11, r10, 0x8000 + mfspr r11, SPRN_M_TW /* Get level 1 table base address */ beq 3f - lis r11, swapper_pg_dir@h - ori r11, r11, swapper_pg_dir@l - rlwimi r10, r11, 0, 2, 19 + lis r11, (swapper_pg_dir-PAGE_OFFSET)@h + ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l 3: - lwz r11, 0(r10) /* Get the level 1 entry */ + rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */ + lwzx r11, r10, r11 /* Get the level 1 entry */ rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */ beq 2f /* If zero, don't try to find a pte */ @@ -527,12 +530,12 @@ FixupDAR:/* Entry point for dcbx workaround. */ andis. r11, r10, 0x8000 /* Address >= 0x80000000 */ DO_8xx_CPU6(0x3780, r3) mtspr SPRN_MD_EPN, r10 - mfspr r11, SPRN_M_TWB /* Get level 1 table entry address */ + mfspr r11, SPRN_M_TW /* Get level 1 table base address */ beq- 3f /* Branch if user space */ lis r11, (swapper_pg_dir-PAGE_OFFSET)@h ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l - rlwimi r11, r10, 32-20, 0xffc /* r11 = r11&~0xffc|(r10>>20)&0xffc */ -3: lwz r11, 0(r11) /* Get the level 1 entry */ +3: rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */ + lwzx r11, r10, r11 /* Get the level 1 entry */ DO_8xx_CPU6(0x3b80, r3) mtspr SPRN_MD_TWC, r11 /* Load pte table base address */ mfspr r11, SPRN_MD_TWC /* ....and get the pte address */ @@ -541,6 +544,7 @@ FixupDAR:/* Entry point for dcbx workaround. */ lwz r3, 8(r0) /* restore r3 from memory */ #endif /* concat physical page address(r11) and page offset(r10) */ + mfspr r10, SPRN_SRR0 rlwimi r11, r10, 0, 20, 31 lwz r11,0(r11) /* Check if it really is a dcbx instruction. */ @@ -696,11 +700,11 @@ start_here: #ifdef CONFIG_8xx_CPU6 lis r4, cpu6_errata_word@h ori r4, r4, cpu6_errata_word@l - li r3, 0x3980 + li r3, 0x3f80 stw r3, 12(r4) lwz r3, 12(r4) #endif - mtspr SPRN_M_TWB, r6 + mtspr SPRN_M_TW, r6 lis r4,2f@h ori r4,r4,2f@l tophys(r4,r4) @@ -874,10 +878,10 @@ _GLOBAL(set_context) lis r6, cpu6_errata_word@h ori r6, r6, cpu6_errata_word@l tophys (r4, r4) - li r7, 0x3980 + li r7, 0x3f80 stw r7, 12(r6) lwz r7, 12(r6) - mtspr SPRN_M_TWB, r4 /* Update MMU base address */ + mtspr SPRN_M_TW, r4 /* Update MMU base address */ li r7, 0x3380 stw r7, 12(r6) lwz r7, 12(r6) @@ -885,7 +889,7 @@ _GLOBAL(set_context) #else mtspr SPRN_M_CASID,r3 /* Update context */ tophys (r4, r4) - mtspr SPRN_M_TWB, r4 /* and pgd */ + mtspr SPRN_M_TW, r4 /* and pgd */ #endif SYNC blr -- 2.39.2