[RFC PATCH v2 1/7] ARM: NOMMU: Move out MPU setup in separate module
Vladimir Murzin
vladimir.murzin at arm.com
Fri May 19 02:46:40 PDT 2017
Having MPU handling code in dedicated module makes it easier to
enhance/maintain it.
Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
---
arch/arm/include/asm/mpu.h | 16 ++-
arch/arm/mm/Makefile | 1 +
arch/arm/mm/nommu.c | 254 +------------------------------------------
arch/arm/mm/pmsa-v7.c | 262 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 276 insertions(+), 257 deletions(-)
create mode 100644 arch/arm/mm/pmsa-v7.c
diff --git a/arch/arm/include/asm/mpu.h b/arch/arm/include/asm/mpu.h
index c3247cc..edec5cf 100644
--- a/arch/arm/include/asm/mpu.h
+++ b/arch/arm/include/asm/mpu.h
@@ -1,8 +1,6 @@
#ifndef __ARM_MPU_H
#define __ARM_MPU_H
-#ifdef CONFIG_ARM_MPU
-
/* MPUIR layout */
#define MPUIR_nU 1
#define MPUIR_DREGION 8
@@ -69,8 +67,18 @@ struct mpu_rgn_info {
};
extern struct mpu_rgn_info mpu_rgn_info;
-#endif /* __ASSEMBLY__ */
+#ifdef CONFIG_ARM_MPU
+
+extern void __init adjust_lowmem_bounds_mpu(void);
+extern void __init mpu_setup(void);
-#endif /* CONFIG_ARM_MPU */
+#else
+
+static inline void adjust_lowmem_bounds_mpu(void) {}
+static inline void mpu_setup(void) {}
+
+#endif /* !CONFIG_ARM_MPU */
+
+#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index b3dea80..73f8f3c 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_MMU) += fault-armv.o flush.o idmap.o ioremap.o \
ifneq ($(CONFIG_MMU),y)
obj-y += nommu.o
+obj-$(CONFIG_ARM_MPU) += pmsa-v7.o
endif
obj-$(CONFIG_ARM_PTDUMP) += dump.o
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index 3b8e728..4c56b56 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
diff --git a/arch/arm/mm/pmsa-v7.c b/arch/arm/mm/pmsa-v7.c
new file mode 100644
index 0000000..ee3cf51
--- /dev/null
+++ b/arch/arm/mm/pmsa-v7.c
@@ -0,0 +1,262 @@
+/*
+ * linux/arch/arm/mm/nommu.c
+ *
+ * ARM uCLinux supporting functions.
+ */
+
+#include <linux/memblock.h>
+
+#include <asm/cp15.h>
+#include <asm/cputype.h>
+#include <asm/mpu.h>
+
+#include "mm.h"
+
+/* 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());
+ }
+}
--
2.0.0
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