From d675d0bc47f28c5414fbbe17fcc801f69c45b960 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 22 Nov 2011 17:30:28 +0000 Subject: ARM: LPAE: add ISBs around MMU enabling code Before we enable the MMU, we must ensure that the TTBR registers contain sane values. After the MMU has been enabled, we jump to the *virtual* address of the following function, so we also need to ensure that the SCTLR write has taken effect. This patch adds ISB instructions around the SCTLR write to ensure the visibility of the above. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm/kernel/head.S | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arm/kernel/head.S') diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 64e9943ea4f0..54eb94aff6cd 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -401,8 +401,10 @@ ENDPROC(__enable_mmu) .pushsection .idmap.text, "ax" ENTRY(__turn_mmu_on) mov r0, r0 + instr_sync mcr p15, 0, r0, c1, c0, 0 @ write control reg mrc p15, 0, r3, c0, c0, 0 @ read id reg + instr_sync mov r3, r3 mov r3, r13 mov pc, r3 -- cgit v1.2.1 From 1b6ba46b7efa31055eb993a6f2c6bbcb8b35b001 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 22 Nov 2011 17:30:29 +0000 Subject: ARM: LPAE: MMU setup for the 3-level page table format This patch adds the MMU initialisation for the LPAE page table format. The swapper_pg_dir size with LPAE is 5 rather than 4 pages. A new proc-v7-3level.S file contains the TTB initialisation, context switch and PTE setting code with the LPAE. The TTBRx split is based on the PAGE_OFFSET with TTBR1 used for the kernel mappings. The 36-bit mappings (supersections) and a few other memory types in mmu.c are conditionally compiled. Signed-off-by: Catalin Marinas --- arch/arm/kernel/head.S | 45 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 43 insertions(+), 2 deletions(-) (limited to 'arch/arm/kernel/head.S') diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 54eb94aff6cd..c8e797baaf55 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -39,8 +39,14 @@ #error KERNEL_RAM_VADDR must start at 0xXXXX8000 #endif +#ifdef CONFIG_ARM_LPAE + /* LPAE requires an additional page for the PGD */ +#define PG_DIR_SIZE 0x5000 +#define PMD_ORDER 3 +#else #define PG_DIR_SIZE 0x4000 #define PMD_ORDER 2 +#endif .globl swapper_pg_dir .equ swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE @@ -164,6 +170,25 @@ __create_page_tables: teq r0, r6 bne 1b +#ifdef CONFIG_ARM_LPAE + /* + * Build the PGD table (first level) to point to the PMD table. A PGD + * entry is 64-bit wide. + */ + mov r0, r4 + add r3, r4, #0x1000 @ first PMD table address + orr r3, r3, #3 @ PGD block type + mov r6, #4 @ PTRS_PER_PGD + mov r7, #1 << (55 - 32) @ L_PGD_SWAPPER +1: str r3, [r0], #4 @ set bottom PGD entry bits + str r7, [r0], #4 @ set top PGD entry bits + add r3, r3, #0x1000 @ next PMD table + subs r6, r6, #1 + bne 1b + + add r4, r4, #0x1000 @ point to the PMD tables +#endif + ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags /* @@ -219,8 +244,8 @@ __create_page_tables: #endif /* - * Then map boot params address in r2 or - * the first 1MB of ram if boot params address is not specified. + * Then map boot params address in r2 or the first 1MB (2MB with LPAE) + * of ram if boot params address is not specified. */ mov r0, r2, lsr #SECTION_SHIFT movs r0, r0, lsl #SECTION_SHIFT @@ -251,7 +276,15 @@ __create_page_tables: mov r3, r7, lsr #SECTION_SHIFT ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags orr r3, r7, r3, lsl #SECTION_SHIFT +#ifdef CONFIG_ARM_LPAE + mov r7, #1 << (54 - 32) @ XN +#else + orr r3, r3, #PMD_SECT_XN +#endif 1: str r3, [r0], #4 +#ifdef CONFIG_ARM_LPAE + str r7, [r0], #4 +#endif add r3, r3, #1 << SECTION_SHIFT cmp r0, r6 blo 1b @@ -282,6 +315,9 @@ __create_page_tables: add r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_ORDER) str r3, [r0] #endif +#endif +#ifdef CONFIG_ARM_LPAE + sub r4, r4, #0x1000 @ point to the PGD table #endif mov pc, lr ENDPROC(__create_page_tables) @@ -374,12 +410,17 @@ __enable_mmu: #ifdef CONFIG_CPU_ICACHE_DISABLE bic r0, r0, #CR_I #endif +#ifdef CONFIG_ARM_LPAE + mov r5, #0 + mcrr p15, 0, r4, r5, c2 @ load TTBR0 +#else mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \ domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \ domain_val(DOMAIN_IO, DOMAIN_CLIENT)) mcr p15, 0, r5, c3, c0, 0 @ load domain access register mcr p15, 0, r4, c2, c0, 0 @ load page table pointer +#endif b __turn_mmu_on ENDPROC(__enable_mmu) -- cgit v1.2.1