diff options
Diffstat (limited to 'arch/arm/mm/nommu.c')
| -rw-r--r-- | arch/arm/mm/nommu.c | 60 |
1 files changed, 54 insertions, 6 deletions
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c index 2740967727e2..3b5c7aaf9c76 100644 --- a/arch/arm/mm/nommu.c +++ b/arch/arm/mm/nommu.c @@ -11,6 +11,7 @@ #include <linux/kernel.h> #include <asm/cacheflush.h> +#include <asm/cp15.h> #include <asm/sections.h> #include <asm/page.h> #include <asm/setup.h> @@ -22,6 +23,8 @@ #include "mm.h" +unsigned long vectors_base; + #ifdef CONFIG_ARM_MPU struct mpu_rgn_info mpu_rgn_info; @@ -85,7 +88,7 @@ static unsigned long irbar_read(void) } /* MPU initialisation functions */ -void __init sanity_check_meminfo_mpu(void) +void __init adjust_lowmem_bounds_mpu(void) { phys_addr_t phys_offset = PHYS_OFFSET; phys_addr_t aligned_region_size, specified_mem_size, rounded_mem_size; @@ -274,19 +277,64 @@ void __init mpu_setup(void) } } #else -static void sanity_check_meminfo_mpu(void) {} +static void adjust_lowmem_bounds_mpu(void) {} static void __init mpu_setup(void) {} #endif /* CONFIG_ARM_MPU */ +#ifdef CONFIG_CPU_CP15 +#ifdef CONFIG_CPU_HIGH_VECTOR +static unsigned long __init setup_vectors_base(void) +{ + unsigned long reg = get_cr(); + + set_cr(reg | CR_V); + return 0xffff0000; +} +#else /* CONFIG_CPU_HIGH_VECTOR */ +/* Write exception base address to VBAR */ +static inline void set_vbar(unsigned long val) +{ + asm("mcr p15, 0, %0, c12, c0, 0" : : "r" (val) : "cc"); +} + +/* + * Security extensions, bits[7:4], permitted values, + * 0b0000 - not implemented, 0b0001/0b0010 - implemented + */ +static inline bool security_extensions_enabled(void) +{ + return !!cpuid_feature_extract(CPUID_EXT_PFR1, 4); +} + +static unsigned long __init setup_vectors_base(void) +{ + unsigned long base = 0, reg = get_cr(); + + set_cr(reg & ~CR_V); + if (security_extensions_enabled()) { + if (IS_ENABLED(CONFIG_REMAP_VECTORS_TO_RAM)) + base = CONFIG_DRAM_BASE; + set_vbar(base); + } else if (IS_ENABLED(CONFIG_REMAP_VECTORS_TO_RAM)) { + if (CONFIG_DRAM_BASE != 0) + pr_err("Security extensions not enabled, vectors cannot be remapped to RAM, vectors base will be 0x00000000\n"); + } + + return base; +} +#endif /* CONFIG_CPU_HIGH_VECTOR */ +#endif /* CONFIG_CPU_CP15 */ + void __init arm_mm_memblock_reserve(void) { #ifndef CONFIG_CPU_V7M + vectors_base = IS_ENABLED(CONFIG_CPU_CP15) ? setup_vectors_base() : 0; /* * Register the exception vector page. * some architectures which the DRAM is the exception vector to trap, * alloc_page breaks with error, although it is not NULL, but "0." */ - memblock_reserve(CONFIG_VECTORS_BASE, 2 * PAGE_SIZE); + memblock_reserve(vectors_base, 2 * PAGE_SIZE); #else /* ifndef CONFIG_CPU_V7M */ /* * There is no dedicated vector page on V7-M. So nothing needs to be @@ -295,10 +343,10 @@ void __init arm_mm_memblock_reserve(void) #endif } -void __init sanity_check_meminfo(void) +void __init adjust_lowmem_bounds(void) { phys_addr_t end; - sanity_check_meminfo_mpu(); + adjust_lowmem_bounds_mpu(); end = memblock_end_of_DRAM(); high_memory = __va(end - 1) + 1; memblock_set_current_limit(end); @@ -310,7 +358,7 @@ void __init sanity_check_meminfo(void) */ void __init paging_init(const struct machine_desc *mdesc) { - early_trap_init((void *)CONFIG_VECTORS_BASE); + early_trap_init((void *)vectors_base); mpu_setup(); bootmem_init(); } |