From a7761fe48993f103d6deac6037bf786bd1db0501 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 9 Feb 2016 17:08:18 +0100 Subject: [PATCH] powerpc/8xx: rewrite set_context() in C There is no real need to have set_context() in assembly. Now that we have mtspr() handling CPU6 ERRATA directly, we can rewrite set_context() in C language for easier maintenance. Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood --- arch/powerpc/kernel/head_8xx.S | 44 ------------------------------------------ arch/powerpc/mm/8xx_mmu.c | 34 ++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 44 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 4a5e56d..80c6947 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -883,50 +883,6 @@ initial_mmu: /* - * Set up to use a given MMU context. - * r3 is context number, r4 is PGD pointer. - * - * We place the physical address of the new task page directory loaded - * into the MMU base register, and set the ASID compare register with - * the new "context." - */ -_GLOBAL(set_context) - -#ifdef CONFIG_BDI_SWITCH - /* Context switch the PTE pointer for the Abatron BDI2000. - * The PGDIR is passed as second argument. - */ - lis r5, KERNELBASE@h - lwz r5, 0xf0(r5) - stw r4, 0x4(r5) -#endif - - /* Register M_TW will contain base address of level 1 table minus the - * lower part of the kernel PGDIR base address, so that all accesses to - * level 1 table are done relative to lower part of kernel PGDIR base - * address. - */ - li r5, (swapper_pg_dir-PAGE_OFFSET)@l - sub r4, r4, r5 - tophys (r4, r4) -#ifdef CONFIG_8xx_CPU6 - lis r6, cpu6_errata_word@h - ori r6, r6, cpu6_errata_word@l - li r7, 0x3f80 - stw r7, 12(r6) - lwz r7, 12(r6) -#endif - mtspr SPRN_M_TW, r4 /* Update pointeur to level 1 table */ -#ifdef CONFIG_8xx_CPU6 - li r7, 0x3380 - stw r7, 12(r6) - lwz r7, 12(r6) -#endif - mtspr SPRN_M_CASID, r3 /* Update context */ - SYNC - blr - -/* * We put a few things here that have to be page-aligned. * This stuff goes at the beginning of the data segment, * which is page-aligned. diff --git a/arch/powerpc/mm/8xx_mmu.c b/arch/powerpc/mm/8xx_mmu.c index a84f5eb..606d231 100644 --- a/arch/powerpc/mm/8xx_mmu.c +++ b/arch/powerpc/mm/8xx_mmu.c @@ -98,3 +98,37 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base, memblock_set_current_limit(min_t(u64, first_memblock_size, 0x00800000)); #endif } + +/* + * Set up to use a given MMU context. + * id is context number, pgd is PGD pointer. + * + * We place the physical address of the new task page directory loaded + * into the MMU base register, and set the ASID compare register with + * the new "context." + */ +void set_context(unsigned long id, pgd_t *pgd) +{ + s16 offset = (s16)(__pa(swapper_pg_dir)); + +#ifdef CONFIG_BDI_SWITCH + pgd_t **ptr = *(pgd_t ***)(KERNELBASE + 0xf0); + + /* Context switch the PTE pointer for the Abatron BDI2000. + * The PGDIR is passed as second argument. + */ + *(ptr + 1) = pgd; +#endif + + /* Register M_TW will contain base address of level 1 table minus the + * lower part of the kernel PGDIR base address, so that all accesses to + * level 1 table are done relative to lower part of kernel PGDIR base + * address. + */ + mtspr(SPRN_M_TW, __pa(pgd) - offset); + + /* Update context */ + mtspr(SPRN_M_CASID, id); + /* sync */ + mb(); +} -- 2.7.4