diff options
author | Tony Lindgren <tony@atomide.com> | 2017-11-28 08:12:32 -0800 |
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committer | Tony Lindgren <tony@atomide.com> | 2017-11-28 08:12:32 -0800 |
commit | bc686442f8a601bccac1f22506ecdb4b0d62cadd (patch) | |
tree | b224ab4aa2350b233da640f5850f48bc6bfeb2d0 /arch/arm/mm/nommu.c | |
parent | 60636a5d0fa2f8bc6d0c23c4027100ba20866f9b (diff) | |
parent | ca41e244517d6d3f1600c229ff7ca615049c1e9c (diff) |
Merge branch 'dts-fixes' into omap-for-v4.15/fixes-dt
Diffstat (limited to 'arch/arm/mm/nommu.c')
-rw-r--r-- | arch/arm/mm/nommu.c | 259 |
1 files changed, 6 insertions, 253 deletions
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c index 3b8e728cc944..e4370810f4f1 100644 --- a/arch/arm/mm/nommu.c +++ b/arch/arm/mm/nommu.c @@ -27,259 +27,7 @@ unsigned long vectors_base; #ifdef CONFIG_ARM_MPU struct mpu_rgn_info mpu_rgn_info; - -/* Region number */ -static void rgnr_write(u32 v) -{ - asm("mcr p15, 0, %0, c6, c2, 0" : : "r" (v)); -} - -/* Data-side / unified region attributes */ - -/* Region access control register */ -static void dracr_write(u32 v) -{ - asm("mcr p15, 0, %0, c6, c1, 4" : : "r" (v)); -} - -/* Region size register */ -static void drsr_write(u32 v) -{ - asm("mcr p15, 0, %0, c6, c1, 2" : : "r" (v)); -} - -/* Region base address register */ -static void drbar_write(u32 v) -{ - asm("mcr p15, 0, %0, c6, c1, 0" : : "r" (v)); -} - -static u32 drbar_read(void) -{ - u32 v; - asm("mrc p15, 0, %0, c6, c1, 0" : "=r" (v)); - return v; -} -/* Optional instruction-side region attributes */ - -/* I-side Region access control register */ -static void iracr_write(u32 v) -{ - asm("mcr p15, 0, %0, c6, c1, 5" : : "r" (v)); -} - -/* I-side Region size register */ -static void irsr_write(u32 v) -{ - asm("mcr p15, 0, %0, c6, c1, 3" : : "r" (v)); -} - -/* I-side Region base address register */ -static void irbar_write(u32 v) -{ - asm("mcr p15, 0, %0, c6, c1, 1" : : "r" (v)); -} - -static unsigned long irbar_read(void) -{ - unsigned long v; - asm("mrc p15, 0, %0, c6, c1, 1" : "=r" (v)); - return v; -} - -/* MPU initialisation functions */ -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; - struct memblock_region *reg; - bool first = true; - phys_addr_t mem_start; - phys_addr_t mem_end; - - for_each_memblock(memory, reg) { - if (first) { - /* - * Initially only use memory continuous from - * PHYS_OFFSET */ - if (reg->base != phys_offset) - panic("First memory bank must be contiguous from PHYS_OFFSET"); - - mem_start = reg->base; - mem_end = reg->base + reg->size; - specified_mem_size = reg->size; - first = false; - } else { - /* - * memblock auto merges contiguous blocks, remove - * all blocks afterwards in one go (we can't remove - * blocks separately while iterating) - */ - pr_notice("Ignoring RAM after %pa, memory at %pa ignored\n", - &mem_end, ®->base); - memblock_remove(reg->base, 0 - reg->base); - break; - } - } - - /* - * MPU has curious alignment requirements: Size must be power of 2, and - * region start must be aligned to the region size - */ - if (phys_offset != 0) - pr_info("PHYS_OFFSET != 0 => MPU Region size constrained by alignment requirements\n"); - - /* - * Maximum aligned region might overflow phys_addr_t if phys_offset is - * 0. Hence we keep everything below 4G until we take the smaller of - * the aligned_region_size and rounded_mem_size, one of which is - * guaranteed to be smaller than the maximum physical address. - */ - aligned_region_size = (phys_offset - 1) ^ (phys_offset); - /* Find the max power-of-two sized region that fits inside our bank */ - rounded_mem_size = (1 << __fls(specified_mem_size)) - 1; - - /* The actual region size is the smaller of the two */ - aligned_region_size = aligned_region_size < rounded_mem_size - ? aligned_region_size + 1 - : rounded_mem_size + 1; - - if (aligned_region_size != specified_mem_size) { - pr_warn("Truncating memory from %pa to %pa (MPU region constraints)", - &specified_mem_size, &aligned_region_size); - memblock_remove(mem_start + aligned_region_size, - specified_mem_size - aligned_region_size); - - mem_end = mem_start + aligned_region_size; - } - - pr_debug("MPU Region from %pa size %pa (end %pa))\n", - &phys_offset, &aligned_region_size, &mem_end); - -} - -static int mpu_present(void) -{ - return ((read_cpuid_ext(CPUID_EXT_MMFR0) & MMFR0_PMSA) == MMFR0_PMSAv7); -} - -static int mpu_max_regions(void) -{ - /* - * We don't support a different number of I/D side regions so if we - * have separate instruction and data memory maps then return - * whichever side has a smaller number of supported regions. - */ - u32 dregions, iregions, mpuir; - mpuir = read_cpuid(CPUID_MPUIR); - - dregions = iregions = (mpuir & MPUIR_DREGION_SZMASK) >> MPUIR_DREGION; - - /* Check for separate d-side and i-side memory maps */ - if (mpuir & MPUIR_nU) - iregions = (mpuir & MPUIR_IREGION_SZMASK) >> MPUIR_IREGION; - - /* Use the smallest of the two maxima */ - return min(dregions, iregions); -} - -static int mpu_iside_independent(void) -{ - /* MPUIR.nU specifies whether there is *not* a unified memory map */ - return read_cpuid(CPUID_MPUIR) & MPUIR_nU; -} - -static int mpu_min_region_order(void) -{ - u32 drbar_result, irbar_result; - /* We've kept a region free for this probing */ - rgnr_write(MPU_PROBE_REGION); - isb(); - /* - * As per ARM ARM, write 0xFFFFFFFC to DRBAR to find the minimum - * region order - */ - drbar_write(0xFFFFFFFC); - drbar_result = irbar_result = drbar_read(); - drbar_write(0x0); - /* If the MPU is non-unified, we use the larger of the two minima*/ - if (mpu_iside_independent()) { - irbar_write(0xFFFFFFFC); - irbar_result = irbar_read(); - irbar_write(0x0); - } - isb(); /* Ensure that MPU region operations have completed */ - /* Return whichever result is larger */ - return __ffs(max(drbar_result, irbar_result)); -} - -static int mpu_setup_region(unsigned int number, phys_addr_t start, - unsigned int size_order, unsigned int properties) -{ - u32 size_data; - - /* We kept a region free for probing resolution of MPU regions*/ - if (number > mpu_max_regions() || number == MPU_PROBE_REGION) - return -ENOENT; - - if (size_order > 32) - return -ENOMEM; - - if (size_order < mpu_min_region_order()) - return -ENOMEM; - - /* Writing N to bits 5:1 (RSR_SZ) specifies region size 2^N+1 */ - size_data = ((size_order - 1) << MPU_RSR_SZ) | 1 << MPU_RSR_EN; - - dsb(); /* Ensure all previous data accesses occur with old mappings */ - rgnr_write(number); - isb(); - drbar_write(start); - dracr_write(properties); - isb(); /* Propagate properties before enabling region */ - drsr_write(size_data); - - /* Check for independent I-side registers */ - if (mpu_iside_independent()) { - irbar_write(start); - iracr_write(properties); - isb(); - irsr_write(size_data); - } - isb(); - - /* Store region info (we treat i/d side the same, so only store d) */ - mpu_rgn_info.rgns[number].dracr = properties; - mpu_rgn_info.rgns[number].drbar = start; - mpu_rgn_info.rgns[number].drsr = size_data; - return 0; -} - -/* -* Set up default MPU regions, doing nothing if there is no MPU -*/ -void __init mpu_setup(void) -{ - int region_err; - if (!mpu_present()) - return; - - region_err = mpu_setup_region(MPU_RAM_REGION, PHYS_OFFSET, - ilog2(memblock.memory.regions[0].size), - MPU_AP_PL1RW_PL0RW | MPU_RGN_NORMAL); - if (region_err) { - panic("MPU region initialization failure! %d", region_err); - } else { - pr_info("Using ARMv7 PMSA Compliant MPU. " - "Region independence: %s, Max regions: %d\n", - mpu_iside_independent() ? "Yes" : "No", - mpu_max_regions()); - } -} -#else -static void adjust_lowmem_bounds_mpu(void) {} -static void __init mpu_setup(void) {} -#endif /* CONFIG_ARM_MPU */ +#endif #ifdef CONFIG_CPU_CP15 #ifdef CONFIG_CPU_HIGH_VECTOR @@ -344,6 +92,11 @@ void __init arm_mm_memblock_reserve(void) * reserved here. */ #endif + /* + * In any case, always ensure address 0 is never used as many things + * get very confused if 0 is returned as a legitimate address. + */ + memblock_reserve(0, 1); } void __init adjust_lowmem_bounds(void) |