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-rw-r--r--arch/arm/mm/pmsa-v7.c476
1 files changed, 476 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..59d916ccd
--- /dev/null
+++ b/arch/arm/mm/pmsa-v7.c
@@ -0,0 +1,476 @@
+/*
+ * 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, &region->subreg);
+
+ for (i = 1; i <= sslots; i++)
+ _set_bit(PMSAv7_NR_SUBREGS - i, &region->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, &regions[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;
+ phys_addr_t mem_start;
+ phys_addr_t mem_end;
+ phys_addr_t reg_start, reg_end;
+ unsigned int mem_max_regions;
+ bool first = true;
+ int num;
+ u64 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_mem_range(i, &reg_start, &reg_end) {
+ if (first) {
+ phys_addr_t phys_offset = PHYS_OFFSET;
+
+ /*
+ * Initially only use memory continuous from
+ * PHYS_OFFSET */
+ if (reg_start != phys_offset)
+ panic("First memory bank must be contiguous from PHYS_OFFSET");
+
+ mem_start = reg_start;
+ mem_end = reg_end;
+ specified_mem_size = mem_end - mem_start;
+ 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, &reg_start);
+ memblock_remove(reg_start, 0 - reg_start);
+ 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);
+ }
+}