Changeset 8ff9484 in mainline

Timestamp:

2012-11-24T18:50:02Z (12 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

435c33b

Parents:

04cb6957

Message:

arm32: Implement all variants of FPU context save/restore.

Location:

kernel/arch/arm32

Files:

• Makefile.inc (modified) (2 diffs)
• include/cpu.h (modified) (1 diff)
• src/cpu/cpu.c (modified) (5 diffs)
• src/fpu_context.c (added)

kernel/arch/arm32/Makefile.inc

@@ -37 +37 @@
 ifeq ($(CONFIG_FPU),y)
 # This is necessary to allow vmsr insn and fpexc manipulation
-GCC_CFLAGS += -mfloat-abi=hard 
+# Use vfp32 to allow context save/restore of d16-d31 regs.
+GCC_CFLAGS += -mfloat-abi=hard -mfpu=vfp3
 endif
 
@@ -51 +52 @@
         arch/$(KARCH)/src/machine_func.c \
         arch/$(KARCH)/src/context.S \
+        arch/$(KARCH)/src/fpu_context.c \
         arch/$(KARCH)/src/dummy.S \
         arch/$(KARCH)/src/cpu/cpu.c \

kernel/arch/arm32/include/cpu.h

@@ -43 +43 @@
 /** Struct representing ARM CPU identification. */
 typedef struct {
-        /** Implementator (vendor) number. */
+        /** Implementor (vendor) number. */
         uint32_t imp_num;
 

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

@@ -38 +38 @@
 #include <arch.h>
 #include <print.h>
-#include <fpu_context.h>
 
-/** Number of indexes left out in the #imp_data array */
-#define IMP_DATA_START_OFFSET 0x40
-
-/** Implementors (vendor) names */
-static const char *imp_data[] = {
-        "?",                                     /* IMP_DATA_START_OFFSET */
-        "ARM Limited",                           /* 0x41 */
-        "", "",                                  /* 0x42 - 0x43 */
-        "Digital Equipment Corporation",         /* 0x44 */
-        "", "", "", "", "", "", "", "",          /* 0x45 - 0x4c */
-        "Motorola, Freescale Semicondutor Inc.", /* 0x4d */
-        "", "", "",                              /* 0x4e - 0x50 */
-        "Qualcomm Inc.",                         /* 0x51 */
-        "", "", "", "",                          /* 0x52 - 0x55 */
-        "Marvell Semiconductor",                 /* 0x56 */
-        "", "", "", "", "", "", "", "", "", "",  /* 0x57 - 0x60 */
-        "", "", "", "", "", "", "", "",          /* 0x61 - 0x68 */
-        "Intel Corporation"                      /* 0x69 */
-};
-
-/** Length of the #imp_data array */
-static const unsigned int imp_data_length = sizeof(imp_data) / sizeof(char *);
+/** 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 const 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];
+}
 
 
@@ -82 +77 @@
  *
  * @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)
@@ -96 +92 @@
         cpu->prim_part_num = (ident << 16) >> 20;
         cpu->rev_num = (ident << 28) >> 28;
+        // TODO CPUs with arch_num == 0xf use CPUID scheme for identification
 }
 
@@ -139 +136 @@
 }
 
-void fpu_init(void)
-{
-        //TODO: Identify FPU unit
-        //and set correct functions to save/restore ctx
-}
-
-void fpu_enable(void)
-{
-        /* Enable FPU instructions */
-        asm volatile (
-                "ldr r1, =0x40000000\n"
-                "vmsr fpexc, r1\n"
-                ::: "r1"
-        );
-}
-
-void fpu_disable(void)
-{
-        /* Disable FPU instructions */
-        asm volatile (
-                "ldr r1, =0x00000000\n"
-                "vmsr fpexc, r1\n"
-                ::: "r1"
-        );
-}
-
-void fpu_context_save(fpu_context_t *ctx)
-{
-        // TODO check and complete. What about fpexc?
-        asm volatile (
-                "vmrs r1, fpscr\n"
-//              "vmrs r2, fpexc\n"
-                "stm %0, {r1, r2}\n"
-                "vstm %0, {d0-d15}\n"
-                ::"r" (ctx): "r1","r2","memory"
-        );
-}
-
-void fpu_context_restore(fpu_context_t *ctx)
-{
-        // TODO check and complete. What about fpexc?
-        asm volatile (
-                "ldm %0, {r1, r2}\n"
-                "vmsr fpscr, r1\n"
-//              "vmsr fpexc, r2\n"
-                "vldm %0, {d0-d15}\n"
-                ::"r" (ctx): "r1","r2"
-        );
-}
-
 /** Retrieves processor identification and stores it to #CPU.arch */
 void cpu_identify(void)
@@ -198 +145 @@
 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;
-
-        const unsigned imp_offset = cpu_arch->imp_num - IMP_DATA_START_OFFSET;
-
-        if (imp_offset < imp_data_length) {
-                vendor = imp_data[cpu_arch->imp_num - IMP_DATA_START_OFFSET];
-        }
-
-        // TODO CPUs with arch_num == 0xf use CPUID scheme for identification
-        if (cpu_arch->arch_num < arch_data_length) {
-                architecture = arch_data[cpu_arch->arch_num];
-        }
-
-        printf("cpu%d: vendor=%s, architecture=ARMv%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);
 }