diff options
Diffstat (limited to 'arch/arm/mm/pmsa-v7.c')
| -rw-r--r-- | arch/arm/mm/pmsa-v7.c | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/arch/arm/mm/pmsa-v7.c b/arch/arm/mm/pmsa-v7.c new file mode 100644 index 000000000..699fa2e88 --- /dev/null +++ b/arch/arm/mm/pmsa-v7.c @@ -0,0 +1,475 @@ +/* + * Based on linux/arch/arm/mm/nommu.c + * + * ARM PMSAv7 supporting functions. + */ + +#include <linux/bitops.h> +#include <linux/memblock.h> +#include <linux/string.h> + +#include <asm/cacheflush.h> +#include <asm/cp15.h> +#include <asm/cputype.h> +#include <asm/mpu.h> +#include <asm/sections.h> + +#include "mm.h" + +struct region { + phys_addr_t base; + phys_addr_t size; + unsigned long subreg; +}; + +static struct region __initdata mem[MPU_MAX_REGIONS]; +#ifdef CONFIG_XIP_KERNEL +static struct region __initdata xip[MPU_MAX_REGIONS]; +#endif + +static unsigned int __initdata mpu_min_region_order; +static unsigned int __initdata mpu_max_regions; + +static int __init __mpu_min_region_order(void); +static int __init __mpu_max_regions(void); + +#ifndef CONFIG_CPU_V7M + +#define DRBAR __ACCESS_CP15(c6, 0, c1, 0) +#define IRBAR __ACCESS_CP15(c6, 0, c1, 1) +#define DRSR __ACCESS_CP15(c6, 0, c1, 2) +#define IRSR __ACCESS_CP15(c6, 0, c1, 3) +#define DRACR __ACCESS_CP15(c6, 0, c1, 4) +#define IRACR __ACCESS_CP15(c6, 0, c1, 5) +#define RNGNR __ACCESS_CP15(c6, 0, c2, 0) + +/* Region number */ +static inline void rgnr_write(u32 v) +{ + write_sysreg(v, RNGNR); +} + +/* Data-side / unified region attributes */ + +/* Region access control register */ +static inline void dracr_write(u32 v) +{ + write_sysreg(v, DRACR); +} + +/* Region size register */ +static inline void drsr_write(u32 v) +{ + write_sysreg(v, DRSR); +} + +/* Region base address register */ +static inline void drbar_write(u32 v) +{ + write_sysreg(v, DRBAR); +} + +static inline u32 drbar_read(void) +{ + return read_sysreg(DRBAR); +} +/* Optional instruction-side region attributes */ + +/* I-side Region access control register */ +static inline void iracr_write(u32 v) +{ + write_sysreg(v, IRACR); +} + +/* I-side Region size register */ +static inline void irsr_write(u32 v) +{ + write_sysreg(v, IRSR); +} + +/* I-side Region base address register */ +static inline void irbar_write(u32 v) +{ + write_sysreg(v, IRBAR); +} + +static inline u32 irbar_read(void) +{ + return read_sysreg(IRBAR); +} + +#else + +static inline void rgnr_write(u32 v) +{ + writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv7_RNR); +} + +/* Data-side / unified region attributes */ + +/* Region access control register */ +static inline void dracr_write(u32 v) +{ + u32 rsr = readl_relaxed(BASEADDR_V7M_SCB + PMSAv7_RASR) & GENMASK(15, 0); + + writel_relaxed((v << 16) | rsr, BASEADDR_V7M_SCB + PMSAv7_RASR); +} + +/* Region size register */ +static inline void drsr_write(u32 v) +{ + u32 racr = readl_relaxed(BASEADDR_V7M_SCB + PMSAv7_RASR) & GENMASK(31, 16); + + writel_relaxed(v | racr, BASEADDR_V7M_SCB + PMSAv7_RASR); +} + +/* Region base address register */ +static inline void drbar_write(u32 v) +{ + writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv7_RBAR); +} + +static inline u32 drbar_read(void) +{ + return readl_relaxed(BASEADDR_V7M_SCB + PMSAv7_RBAR); +} + +/* ARMv7-M only supports a unified MPU, so I-side operations are nop */ + +static inline void iracr_write(u32 v) {} +static inline void irsr_write(u32 v) {} +static inline void irbar_write(u32 v) {} +static inline unsigned long irbar_read(void) {return 0;} + +#endif + +static bool __init try_split_region(phys_addr_t base, phys_addr_t size, struct region *region) +{ + unsigned long subreg, bslots, sslots; + phys_addr_t abase = base & ~(size - 1); + phys_addr_t asize = base + size - abase; + phys_addr_t p2size = 1 << __fls(asize); + phys_addr_t bdiff, sdiff; + + if (p2size != asize) + p2size *= 2; + + bdiff = base - abase; + sdiff = p2size - asize; + subreg = p2size / PMSAv7_NR_SUBREGS; + + if ((bdiff % subreg) || (sdiff % subreg)) + return false; + + bslots = bdiff / subreg; + sslots = sdiff / subreg; + + if (bslots || sslots) { + int i; + + if (subreg < PMSAv7_MIN_SUBREG_SIZE) + return false; + + if (bslots + sslots > PMSAv7_NR_SUBREGS) + return false; + + for (i = 0; i < bslots; i++) + _set_bit(i, ®ion->subreg); + + for (i = 1; i <= sslots; i++) + _set_bit(PMSAv7_NR_SUBREGS - i, ®ion->subreg); + } + + region->base = abase; + region->size = p2size; + + return true; +} + +static int __init allocate_region(phys_addr_t base, phys_addr_t size, + unsigned int limit, struct region *regions) +{ + int count = 0; + phys_addr_t diff = size; + int attempts = MPU_MAX_REGIONS; + + while (diff) { + /* Try cover region as is (maybe with help of subregions) */ + if (try_split_region(base, size, ®ions[count])) { + count++; + base += size; + diff -= size; + size = diff; + } else { + /* + * Maximum aligned region might overflow phys_addr_t + * if "base" is 0. Hence we keep everything below 4G + * until we take the smaller of the aligned region + * size ("asize") and rounded region size ("p2size"), + * one of which is guaranteed to be smaller than the + * maximum physical address. + */ + phys_addr_t asize = (base - 1) ^ base; + phys_addr_t p2size = (1 << __fls(diff)) - 1; + + size = asize < p2size ? asize + 1 : p2size + 1; + } + + if (count > limit) + break; + + if (!attempts) + break; + + attempts--; + } + + return count; +} + +/* MPU initialisation functions */ +void __init pmsav7_adjust_lowmem_bounds(void) +{ + phys_addr_t specified_mem_size = 0, total_mem_size = 0; + struct memblock_region *reg; + bool first = true; + phys_addr_t mem_start; + phys_addr_t mem_end; + unsigned int mem_max_regions; + int num, i; + + /* Free-up PMSAv7_PROBE_REGION */ + mpu_min_region_order = __mpu_min_region_order(); + + /* How many regions are supported */ + mpu_max_regions = __mpu_max_regions(); + + mem_max_regions = min((unsigned int)MPU_MAX_REGIONS, mpu_max_regions); + + /* We need to keep one slot for background region */ + mem_max_regions--; + +#ifndef CONFIG_CPU_V7M + /* ... and one for vectors */ + mem_max_regions--; +#endif + +#ifdef CONFIG_XIP_KERNEL + /* plus some regions to cover XIP ROM */ + num = allocate_region(CONFIG_XIP_PHYS_ADDR, __pa(_exiprom) - CONFIG_XIP_PHYS_ADDR, + mem_max_regions, xip); + + mem_max_regions -= num; +#endif + + for_each_memblock(memory, reg) { + if (first) { + phys_addr_t phys_offset = PHYS_OFFSET; + + /* + * 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; + } + } + + memset(mem, 0, sizeof(mem)); + num = allocate_region(mem_start, specified_mem_size, mem_max_regions, mem); + + for (i = 0; i < num; i++) { + unsigned long subreg = mem[i].size / PMSAv7_NR_SUBREGS; + + total_mem_size += mem[i].size - subreg * hweight_long(mem[i].subreg); + + pr_debug("MPU: base %pa size %pa disable subregions: %*pbl\n", + &mem[i].base, &mem[i].size, PMSAv7_NR_SUBREGS, &mem[i].subreg); + } + + if (total_mem_size != specified_mem_size) { + pr_warn("Truncating memory from %pa to %pa (MPU region constraints)", + &specified_mem_size, &total_mem_size); + memblock_remove(mem_start + total_mem_size, + specified_mem_size - total_mem_size); + } +} + +static int __init __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_mputype(); + + 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 __init mpu_iside_independent(void) +{ + /* MPUIR.nU specifies whether there is *not* a unified memory map */ + return read_cpuid_mputype() & MPUIR_nU; +} + +static int __init __mpu_min_region_order(void) +{ + u32 drbar_result, irbar_result; + + /* We've kept a region free for this probing */ + rgnr_write(PMSAv7_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 __init mpu_setup_region(unsigned int number, phys_addr_t start, + unsigned int size_order, unsigned int properties, + unsigned int subregions, bool need_flush) +{ + u32 size_data; + + /* We kept a region free for probing resolution of MPU regions*/ + if (number > mpu_max_regions + || number >= MPU_MAX_REGIONS) + 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) << PMSAv7_RSR_SZ) | 1 << PMSAv7_RSR_EN; + size_data |= subregions << PMSAv7_RSR_SD; + + if (need_flush) + flush_cache_all(); + + 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; + + mpu_rgn_info.used++; + + return 0; +} + +/* +* Set up default MPU regions, doing nothing if there is no MPU +*/ +void __init pmsav7_setup(void) +{ + int i, region = 0, err = 0; + + /* Setup MPU (order is important) */ + + /* Background */ + err |= mpu_setup_region(region++, 0, 32, + PMSAv7_ACR_XN | PMSAv7_RGN_STRONGLY_ORDERED | PMSAv7_AP_PL1RW_PL0RW, + 0, false); + +#ifdef CONFIG_XIP_KERNEL + /* ROM */ + for (i = 0; i < ARRAY_SIZE(xip); i++) { + /* + * In case we overwrite RAM region we set earlier in + * head-nommu.S (which is cachable) all subsequent + * data access till we setup RAM bellow would be done + * with BG region (which is uncachable), thus we need + * to clean and invalidate cache. + */ + bool need_flush = region == PMSAv7_RAM_REGION; + + if (!xip[i].size) + continue; + + err |= mpu_setup_region(region++, xip[i].base, ilog2(xip[i].size), + PMSAv7_AP_PL1RO_PL0NA | PMSAv7_RGN_NORMAL, + xip[i].subreg, need_flush); + } +#endif + + /* RAM */ + for (i = 0; i < ARRAY_SIZE(mem); i++) { + if (!mem[i].size) + continue; + + err |= mpu_setup_region(region++, mem[i].base, ilog2(mem[i].size), + PMSAv7_AP_PL1RW_PL0RW | PMSAv7_RGN_NORMAL, + mem[i].subreg, false); + } + + /* Vectors */ +#ifndef CONFIG_CPU_V7M + err |= mpu_setup_region(region++, vectors_base, ilog2(2 * PAGE_SIZE), + PMSAv7_AP_PL1RW_PL0NA | PMSAv7_RGN_NORMAL, + 0, false); +#endif + if (err) { + panic("MPU region initialization failure! %d", err); + } else { + pr_info("Using ARMv7 PMSA Compliant MPU. " + "Region independence: %s, Used %d of %d regions\n", + mpu_iside_independent() ? "Yes" : "No", + mpu_rgn_info.used, mpu_max_regions); + } +} |