Changes in kernel/arch/arm32/src/cpu/cpu.c [a000878c:c8a5c8c] in mainline

File:

• kernel/arch/arm32/src/cpu/cpu.c (modified) (2 diffs)

kernel/arch/arm32/src/cpu/cpu.c

@@ -34 +34 @@
  */
 
+#include <arch/cache.h>
 #include <arch/cpu.h>
+#include <arch/cp15.h>
 #include <cpu.h>
 #include <arch.h>
 #include <print.h>
 
-/** Number of indexes left out in the #imp_data array */
-#define IMP_DATA_START_OFFSET 0x40
-
-/** Implementators (vendor) names */
-static const char *imp_data[] = {
-        "?",                                    /* IMP_DATA_START_OFFSET */
-        "ARM Ltd",                              /* 0x41 */
-        "",                                     /* 0x42 */
-        "",                                     /* 0x43 */
-        "Digital Equipment Corporation",        /* 0x44 */
-        "", "", "", "", "", "", "", "", "", "", /* 0x45 - 0x4e */
-        "", "", "", "", "", "", "", "", "", "", /* 0x4f - 0x58 */
-        "", "", "", "", "", "", "", "", "", "", /* 0x59 - 0x62 */
-        "", "", "", "", "", "",                 /* 0x63 - 0x68 */
-        "Intel Corporation"                     /* 0x69 */
-};
-
-/** Length of the #imp_data array */
-static unsigned int imp_data_length = sizeof(imp_data) / sizeof(char *);
+static inline unsigned log2(unsigned val)
+{
+        unsigned log = 0;
+        --val;
+        while (val) {
+                ++log;
+                val >>= 1;
+        }
+        return log;
+}
+
+static unsigned dcache_ways(unsigned level);
+static unsigned dcache_sets(unsigned level);
+static unsigned dcache_linesize_log(unsigned level);
+
+
+/** Implementers (vendor) names */
+static const char * implementer(unsigned id)
+{
+        switch (id)
+        {
+        case 0x41: return "ARM Limited";
+        case 0x44: return "Digital Equipment Corporation";
+        case 0x4d: return "Motorola, Freescale Semiconductor Inc.";
+        case 0x51: return "Qualcomm Inc.";
+        case 0x56: return "Marvell Semiconductor Inc.";
+        case 0x69: return "Intel Corporation";
+        }
+        return "Unknown implementer";
+}
 
 /** Architecture names */
-static const char *arch_data[] = {
-        "?",       /* 0x0 */
-        "4",       /* 0x1 */
-        "4T",      /* 0x2 */
-        "5",       /* 0x3 */
-        "5T",      /* 0x4 */
-        "5TE",     /* 0x5 */
-        "5TEJ",    /* 0x6 */
-        "6"        /* 0x7 */
-};
-
-/** Length of the #arch_data array */
-static unsigned int arch_data_length = sizeof(arch_data) / sizeof(char *);
+static const char * architecture_string(cpu_arch_t *arch)
+{
+        static const char *arch_data[] = {
+                "ARM",       /* 0x0 */
+                "ARMv4",       /* 0x1 */
+                "ARMv4T",      /* 0x2 */
+                "ARMv5",       /* 0x3 */
+                "ARMv5T",      /* 0x4 */
+                "ARMv5TE",     /* 0x5 */
+                "ARMv5TEJ",    /* 0x6 */
+                "ARMv6"        /* 0x7 */
+        };
+        if (arch->arch_num < (sizeof(arch_data) / sizeof(arch_data[0])))
+                return arch_data[arch->arch_num];
+        else
+                return arch_data[0];
+}
 
 
 /** Retrieves processor identification from CP15 register 0.
- * 
+ *
  * @param cpu Structure for storing CPU identification.
+ * See page B4-1630 of ARM Architecture Reference Manual.
  */
 static void arch_cpu_identify(cpu_arch_t *cpu)
 {
-        uint32_t ident;
-        asm volatile (
-                "mrc p15, 0, %[ident], c0, c0, 0\n"
-                : [ident] "=r" (ident)
-        );
+        const uint32_t ident = MIDR_read();
+
+        cpu->imp_num = (ident >> MIDR_IMPLEMENTER_SHIFT) & MIDR_IMPLEMENTER_MASK;
+        cpu->variant_num = (ident >> MIDR_VARIANT_SHIFT) & MIDR_VARIANT_MASK;
+        cpu->arch_num = (ident >> MIDR_ARCHITECTURE_SHIFT) & MIDR_ARCHITECTURE_MASK;
+        cpu->prim_part_num = (ident >> MIDR_PART_NUMBER_SHIFT) & MIDR_PART_NUMBER_MASK;
+        cpu->rev_num = (ident >> MIDR_REVISION_SHIFT) & MIDR_REVISION_MASK;
+
+        // TODO CPUs with arch_num == 0xf use CPUID scheme for identification
+        cpu->dcache_levels = dcache_levels();
+
+        for (unsigned i = 0; i < cpu->dcache_levels; ++i) {
+                cpu->dcache[i].ways = dcache_ways(i);
+                cpu->dcache[i].sets = dcache_sets(i);
+                cpu->dcache[i].way_shift = 31 - log2(cpu->dcache[i].ways);
+                cpu->dcache[i].set_shift = dcache_linesize_log(i);
+                cpu->dcache[i].line_size = 1 << dcache_linesize_log(i);
+                printf("Found DCache L%u: %u-way, %u sets, %u byte lines "
+                    "(shifts: w%u, s%u)\n", i + 1, cpu->dcache[i].ways,
+                    cpu->dcache[i].sets, cpu->dcache[i].line_size,
+                    cpu->dcache[i].way_shift, cpu->dcache[i].set_shift);
+        }
+}
+
+/** Enables unaligned access and caching for armv6+ */
+void cpu_arch_init(void)
+{
+        uint32_t control_reg = SCTLR_read();
         
-        cpu->imp_num = ident >> 24;
-        cpu->variant_num = (ident << 8) >> 28;
-        cpu->arch_num = (ident << 12) >> 28;
-        cpu->prim_part_num = (ident << 16) >> 20;
-        cpu->rev_num = (ident << 28) >> 28;
-}
-
-/** Does nothing on ARM. */
-void cpu_arch_init(void)
-{
+        /* Turn off tex remap, RAZ/WI prior to armv7 */
+        control_reg &= ~SCTLR_TEX_REMAP_EN_FLAG;
+        /* Turn off accessed flag, RAZ/WI prior to armv7 */
+        control_reg &= ~(SCTLR_ACCESS_FLAG_EN_FLAG | SCTLR_HW_ACCESS_FLAG_EN_FLAG);
+
+        /* Unaligned access is supported on armv6+ */
+#if defined(PROCESSOR_ARCH_armv7_a) | defined(PROCESSOR_ARCH_armv6)
+        /* Enable unaligned access, RAZ/WI prior to armv6
+         * switchable on armv6, RAO/WI writes on armv7,
+         * see ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition
+         * L.3.1 (p. 2456) */
+        control_reg |= SCTLR_UNALIGNED_EN_FLAG;
+        /* Disable alignment checks, this turns unaligned access to undefined,
+         * unless U bit is set. */
+        control_reg &= ~SCTLR_ALIGN_CHECK_EN_FLAG;
+        /* Enable caching, On arm prior to armv7 there is only one level
+         * of caches. Data cache is coherent.
+         * "This means that the behavior of accesses from the same observer to
+         * different VAs, that are translated to the same PA
+         * with the same memory attributes, is fully coherent."
+         *    ARM Architecture Reference Manual ARMv7-A and ARMv7-R Edition
+         *    B3.11.1 (p. 1383)
+         * We are safe to turn this on. For arm v6 see ch L.6.2 (p. 2469)
+         * L2 Cache for armv7 is enabled by default (i.e. controlled by
+         * this flag).
+         */
+        control_reg |= SCTLR_CACHE_EN_FLAG;
+#endif
+#ifdef PROCESSOR_ARCH_armv7_a
+         /* ICache coherency is elaborate on in barrier.h.
+          * VIPT and PIPT caches need maintenance only on code modify,
+          * so it should be safe for general use.
+          * Enable branch predictors too as they follow the same rules
+          * as ICache and they can be flushed together
+          */
+        if ((CTR_read() & CTR_L1I_POLICY_MASK) != CTR_L1I_POLICY_AIVIVT) {
+                control_reg |=
+                    SCTLR_INST_CACHE_EN_FLAG | SCTLR_BRANCH_PREDICT_EN_FLAG;
+        }
+#endif
+        SCTLR_write(control_reg);
+
+#ifdef CONFIG_FPU
+        fpu_setup();
+#endif
+
+#ifdef PROCESSOR_ARCH_armv7_a
+        if ((ID_PFR1_read() & ID_PFR1_GEN_TIMER_EXT_MASK) !=
+            ID_PFR1_GEN_TIMER_EXT) {
+                PMCR_write(PMCR_read() | PMCR_E_FLAG | PMCR_D_FLAG);
+                PMCNTENSET_write(PMCNTENSET_CYCLE_COUNTER_EN_FLAG);
+        }
+#endif
 }
 
 /** Retrieves processor identification and stores it to #CPU.arch */
-void cpu_identify(void) 
+void cpu_identify(void)
 {
         arch_cpu_identify(&CPU->arch);
@@ -108 +192 @@
 void cpu_print_report(cpu_t *m)
 {
-        const char *vendor = imp_data[0];
-        const char *architecture = arch_data[0];
-        cpu_arch_t * cpu_arch = &m->arch;
-
-        if ((cpu_arch->imp_num) > 0 &&
-            (cpu_arch->imp_num < (imp_data_length + IMP_DATA_START_OFFSET))) {
-                vendor = imp_data[cpu_arch->imp_num - IMP_DATA_START_OFFSET];
-        }
-
-        if ((cpu_arch->arch_num) > 0 &&
-            (cpu_arch->arch_num < arch_data_length)) {
-                architecture = arch_data[cpu_arch->arch_num];
-        }
-
-        printf("cpu%d: vendor=%s, architecture=ARM%s, part number=%x, "
+        printf("cpu%d: vendor=%s, architecture=%s, part number=%x, "
             "variant=%x, revision=%x\n",
-            m->id, vendor, architecture, cpu_arch->prim_part_num,
-            cpu_arch->variant_num, cpu_arch->rev_num);
+            m->id, implementer(m->arch.imp_num),
+            architecture_string(&m->arch), m->arch.prim_part_num,
+            m->arch.variant_num, m->arch.rev_num);
+}
+
+/** See chapter B4.1.19 of ARM Architecture Reference Manual */
+static unsigned dcache_linesize_log(unsigned level)
+{
+#ifdef PROCESSOR_ARCH_armv7_a
+        CSSELR_write((level & CCSELR_LEVEL_MASK) << CCSELR_LEVEL_SHIFT);
+        const unsigned ls_log = 2 +
+            ((CCSIDR_read() >> CCSIDR_LINESIZE_SHIFT) & CCSIDR_LINESIZE_MASK);
+        return ls_log + 2; //return log2(bytes)
+#endif
+        return 0;
+
+}
+
+/** See chapter B4.1.19 of ARM Architecture Reference Manual */
+static unsigned dcache_ways(unsigned level)
+{
+#ifdef PROCESSOR_ARCH_armv7_a
+        CSSELR_write((level & CCSELR_LEVEL_MASK) << CCSELR_LEVEL_SHIFT);
+        const unsigned ways = 1 +
+            ((CCSIDR_read() >> CCSIDR_ASSOC_SHIFT) & CCSIDR_ASSOC_MASK);
+        return ways;
+#endif
+        return 0;
+}
+
+/** See chapter B4.1.19 of ARM Architecture Reference Manual */
+static unsigned dcache_sets(unsigned level)
+{
+#ifdef PROCESSOR_ARCH_armv7_a
+        CSSELR_write((level & CCSELR_LEVEL_MASK) << CCSELR_LEVEL_SHIFT);
+        const unsigned sets = 1 +
+            ((CCSIDR_read() >> CCSIDR_NUMSETS_SHIFT) & CCSIDR_NUMSETS_MASK);
+        return sets;
+#endif
+        return 0;
+}
+
+unsigned dcache_levels(void)
+{
+        unsigned levels = 0;
+#ifdef PROCESSOR_ARCH_armv7_a
+        const uint32_t val = CLIDR_read();
+        for (unsigned i = 1; i <= 7; ++i) {
+                const unsigned ctype = CLIDR_CACHE(i, val);
+                switch (ctype) {
+                case CLIDR_DCACHE_ONLY:
+                case CLIDR_SEP_CACHE:
+                case CLIDR_UNI_CACHE:
+                        ++levels;
+                default:
+                        (void)0;
+                }
+        }
+#endif
+        return levels;
+}
+
+static void dcache_clean_manual(unsigned level, bool invalidate,
+    unsigned ways, unsigned sets, unsigned way_shift, unsigned set_shift)
+{
+
+        for (unsigned i = 0; i < ways; ++i) {
+                for (unsigned j = 0; j < sets; ++j) {
+                        const uint32_t val =
+                            ((level & 0x7) << 1) |
+                            (j << set_shift) | (i << way_shift);
+                        if (invalidate)
+                                DCCISW_write(val);
+                        else
+                                DCCSW_write(val);
+                }
+        }
+}
+
+void dcache_flush(void)
+{
+        /* See ARM Architecture Reference Manual ch. B4.2.1 p. B4-1724 */
+        const unsigned levels = dcache_levels();
+        for (unsigned i = 0; i < levels; ++i) {
+                const unsigned ways = dcache_ways(i);
+                const unsigned sets = dcache_sets(i);
+                const unsigned way_shift =  31 - log2(ways);
+                const unsigned set_shift = dcache_linesize_log(i);
+                dcache_clean_manual(i, false, ways, sets, way_shift, set_shift);
+        }
+}
+
+void dcache_flush_invalidate(void)
+{
+        /* See ARM Architecture Reference Manual ch. B4.2.1 p. B4-1724 */
+        const unsigned levels = dcache_levels();
+        for (unsigned i = 0; i < levels; ++i) {
+                const unsigned ways = dcache_ways(i);
+                const unsigned sets = dcache_sets(i);
+                const unsigned way_shift =  31 - log2(ways);
+                const unsigned set_shift = dcache_linesize_log(i);
+                dcache_clean_manual(i, true, ways, sets, way_shift, set_shift);
+        }
+}
+
+
+void cpu_dcache_flush(void)
+{
+        for (unsigned i = 0; i < CPU->arch.dcache_levels; ++i)
+                dcache_clean_manual(i, false,
+                    CPU->arch.dcache[i].ways, CPU->arch.dcache[i].sets,
+                    CPU->arch.dcache[i].way_shift, CPU->arch.dcache[i].set_shift);
+}
+
+void cpu_dcache_flush_invalidate(void)
+{
+        const unsigned levels =  dcache_levels();
+        for (unsigned i = 0; i < levels; ++i)
+                dcache_clean_manual(i, true,
+                    CPU->arch.dcache[i].ways, CPU->arch.dcache[i].sets,
+                    CPU->arch.dcache[i].way_shift, CPU->arch.dcache[i].set_shift);
+}
+
+void icache_invalidate(void)
+{
+        ICIALLU_write(0);
 }