From 4756dcbfd37819a8359d3c69a22be2ee41666d0f Mon Sep 17 00:00:00 2001 From: Cyril Chemparathy Date: Sat, 21 Jul 2012 15:55:04 -0400 Subject: [PATCH] ARM: LPAE: accomodate >32-bit addresses for page table base This patch redefines the early boot time use of the R4 register to steal a few low order bits (ARCH_PGD_SHIFT bits) on LPAE systems. This allows for up to 38-bit physical addresses. Signed-off-by: Cyril Chemparathy Signed-off-by: Vitaly Andrianov Acked-by: Nicolas Pitre Tested-by: Santosh Shilimkar Tested-by: Subash Patel Signed-off-by: Will Deacon --- arch/arm/include/asm/memory.h | 16 ++++++++++++++++ arch/arm/kernel/head.S | 10 ++++------ arch/arm/kernel/smp.c | 11 +++++++++-- arch/arm/mm/proc-v7-3level.S | 8 ++++++++ 4 files changed, 37 insertions(+), 8 deletions(-) diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 57870ab313c5..e506088a7678 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -18,6 +18,8 @@ #include #include +#include + #ifdef CONFIG_NEED_MACH_MEMORY_H #include #endif @@ -141,6 +143,20 @@ #define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page))) #define phys_to_page(phys) (pfn_to_page(__phys_to_pfn(phys))) +/* + * Minimum guaranted alignment in pgd_alloc(). The page table pointers passed + * around in head.S and proc-*.S are shifted by this amount, in order to + * leave spare high bits for systems with physical address extension. This + * does not fully accomodate the 40-bit addressing capability of ARM LPAE, but + * gives us about 38-bits or so. + */ +#ifdef CONFIG_ARM_LPAE +#define ARCH_PGD_SHIFT L1_CACHE_SHIFT +#else +#define ARCH_PGD_SHIFT 0 +#endif +#define ARCH_PGD_MASK ((1 << ARCH_PGD_SHIFT) - 1) + #ifndef __ASSEMBLY__ /* diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 8bac553fe213..45e8935cae4e 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -156,7 +156,7 @@ ENDPROC(stext) * * Returns: * r0, r3, r5-r7 corrupted - * r4 = physical page table address + * r4 = page table (see ARCH_PGD_SHIFT in asm/memory.h) */ __create_page_tables: pgtbl r4, r8 @ page table address @@ -331,6 +331,7 @@ __create_page_tables: #endif #ifdef CONFIG_ARM_LPAE sub r4, r4, #0x1000 @ point to the PGD table + mov r4, r4, lsr #ARCH_PGD_SHIFT #endif mov pc, lr ENDPROC(__create_page_tables) @@ -408,7 +409,7 @@ __secondary_data: * r0 = cp#15 control register * r1 = machine ID * r2 = atags or dtb pointer - * r4 = page table pointer + * r4 = page table (see ARCH_PGD_SHIFT in asm/memory.h) * r9 = processor ID * r13 = *virtual* address to jump to upon completion */ @@ -427,10 +428,7 @@ __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 +#ifndef CONFIG_ARM_LPAE mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \ domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \ diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 550d63cef68e..217b755aadd4 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -78,6 +78,13 @@ void __init smp_set_ops(struct smp_operations *ops) smp_ops = *ops; }; +static unsigned long get_arch_pgd(pgd_t *pgd) +{ + phys_addr_t pgdir = virt_to_phys(pgd); + BUG_ON(pgdir & ARCH_PGD_MASK); + return pgdir >> ARCH_PGD_SHIFT; +} + int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle) { int ret; @@ -87,8 +94,8 @@ int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle) * its stack and the page tables. */ secondary_data.stack = task_stack_page(idle) + THREAD_START_SP; - secondary_data.pgdir = virt_to_phys(idmap_pgd); - secondary_data.swapper_pg_dir = virt_to_phys(swapper_pg_dir); + secondary_data.pgdir = get_arch_pgd(idmap_pgd); + secondary_data.swapper_pg_dir = get_arch_pgd(swapper_pg_dir); __cpuc_flush_dcache_area(&secondary_data, sizeof(secondary_data)); outer_clean_range(__pa(&secondary_data), __pa(&secondary_data + 1)); diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S index 58ab7477bb61..5ffe1956c6d9 100644 --- a/arch/arm/mm/proc-v7-3level.S +++ b/arch/arm/mm/proc-v7-3level.S @@ -114,6 +114,7 @@ ENDPROC(cpu_v7_set_pte_ext) */ .macro v7_ttb_setup, zero, ttbr0, ttbr1, tmp ldr \tmp, =swapper_pg_dir @ swapper_pg_dir virtual address + mov \tmp, \tmp, lsr #ARCH_PGD_SHIFT cmp \ttbr1, \tmp @ PHYS_OFFSET > PAGE_OFFSET? mrc p15, 0, \tmp, c2, c0, 2 @ TTB control register orr \tmp, \tmp, #TTB_EAE @@ -128,8 +129,15 @@ ENDPROC(cpu_v7_set_pte_ext) */ orrls \tmp, \tmp, #TTBR1_SIZE @ TTBCR.T1SZ mcr p15, 0, \tmp, c2, c0, 2 @ TTBCR + mov \tmp, \ttbr1, lsr #(32 - ARCH_PGD_SHIFT) @ upper bits + mov \ttbr1, \ttbr1, lsl #ARCH_PGD_SHIFT @ lower bits addls \ttbr1, \ttbr1, #TTBR1_OFFSET mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1 + mov \tmp, \ttbr0, lsr #(32 - ARCH_PGD_SHIFT) @ upper bits + mov \ttbr0, \ttbr0, lsl #ARCH_PGD_SHIFT @ lower bits + mcrr p15, 0, \ttbr0, \zero, c2 @ load TTBR0 + mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1 + mcrr p15, 0, \ttbr0, \zero, c2 @ load TTBR0 .endm __CPUINIT -- 2.20.1