VR4300: Start adding data cache support.

vr4300/cpu.c

@@ -33,6 +33,7 @@ int vr4300_init(struct vr4300 *vr4300, struct bus_controller *bus) {
   vr4300_connect_bus(vr4300, bus);
 
   vr4300_cp0_init(vr4300);
+  vr4300_dcache_init(&vr4300->dcache);
   vr4300_icache_init(&vr4300->icache);
   vr4300_pipeline_init(&vr4300->pipeline);
 

vr4300/cpu.h

@@ -12,6 +12,7 @@
 #define __vr4300_cpu_h__
 #include "common.h"
 #include "vr4300/cp0.h"
+#include "vr4300/dcache.h"
 #include "vr4300/icache.h"
 #include "vr4300/pipeline.h"
 
@@ -81,6 +82,7 @@ struct vr4300 {
   uint64_t regs[NUM_VR4300_REGISTERS];
   uint32_t mi_regs[NUM_MI_REGISTERS];
 
+  struct vr4300_dcache dcache;
   struct vr4300_icache icache;
   struct vr4300_pipeline pipeline;
 

vr4300/dcache.c

@@ -0,0 +1,138 @@
+//
+// vr4300/dcache.c: VR4300 instruction cache.
+//
+// CEN64: Cycle-Accurate Nintendo 64 Simulator.
+// Copyright (C) 2014, Tyler J. Stachecki.
+//
+// This file is subject to the terms and conditions defined in
+// 'LICENSE', which is part of this source code package.
+//
+
+#include "common.h"
+#include "vr4300/dcache.h"
+
+static inline struct vr4300_dcache_line* get_line(
+  struct vr4300_dcache *dcache, uint64_t vaddr);
+static inline const struct vr4300_dcache_line* get_line_const(
+  const struct vr4300_dcache *dcache, uint64_t vaddr);
+
+static inline uint32_t get_tag(const struct vr4300_dcache_line *line);
+static void invalidate_line(struct vr4300_dcache_line *line);
+static bool is_dirty(const struct vr4300_dcache_line *line);
+static bool is_valid(const struct vr4300_dcache_line *line);
+static void set_clean(struct vr4300_dcache_line *line);
+static void set_dirty(struct vr4300_dcache_line *line);
+static void set_tag(struct vr4300_dcache_line *line, uint32_t tag);
+static void validate_line(struct vr4300_dcache_line *line, uint32_t tag);
+
+// Returns the line for a given virtual address.
+struct vr4300_dcache_line* get_line(
+  struct vr4300_dcache *dcache, uint64_t vaddr) {
+  return dcache->lines + (vaddr >> 4 & 0x1FF);
+}
+
+// Returns the line for a given virtual address.
+const struct vr4300_dcache_line* get_line_const(
+  const struct vr4300_dcache *dcache, uint64_t vaddr) {
+  return dcache->lines + (vaddr >> 4 & 0x1FF);
+}
+
+// Returns the physical tag associated with the line.
+uint32_t get_tag(const struct vr4300_dcache_line *line) {
+  return line->metadata >> 12;
+}
+
+// Invalidates the line, but leaves the physical tag untouched.
+void invalidate_line(struct vr4300_dcache_line *line) {
+  line->metadata &= ~0x1;
+}
+
+// Returns true if the line is valid, otherwise returns false.
+bool is_dirty(const struct vr4300_dcache_line *line) {
+  return (line->metadata & 0x2) == 0x2;
+}
+
+// Returns true if the line is valid, otherwise returns false.
+bool is_valid(const struct vr4300_dcache_line *line) {
+  return (line->metadata & 0x1) == 0x1;
+}
+
+// Sets the state of the line to clean.
+void set_clean(struct vr4300_dcache_line *line) {
+  line->metadata &= ~0x2;
+}
+
+// Sets the state of the line to dirty.
+void set_dirty(struct vr4300_dcache_line *line) {
+  line->metadata |= 0x2;
+}
+
+// Sets the tag of the specified line, retaining current valid bit.
+void set_tag(struct vr4300_dcache_line *line, uint32_t tag) {
+  line->metadata = (tag << 12) | (line->metadata & 0x1);
+}
+
+// Sets the line's physical tag and validates the line.
+static void validate_line(struct vr4300_dcache_line *line, uint32_t tag) {
+  line->metadata = (tag << 12) | 0x1;
+}
+
+// Fills an instruction cache line with data.
+void vr4300_dcache_fill(struct vr4300_dcache *dcache,
+  uint64_t vaddr, uint32_t paddr, const void *data) {
+  struct vr4300_dcache_line *line = get_line(dcache, vaddr);
+
+  memcpy(line->data, data, sizeof(line->data));
+  validate_line(line, paddr >> 4);
+}
+
+// Returns the tag of the line associated with vaddr.
+uint32_t vr4300_dcache_get_tag(const struct vr4300_dcache *dcache,
+  uint64_t vaddr) {
+  const struct vr4300_dcache_line *line = get_line_const(dcache, vaddr);
+
+  return get_tag(line);
+}
+
+// Initializes the instruction cache.
+void vr4300_dcache_init(struct vr4300_dcache *dcache) {
+  memset(dcache->lines, 0, sizeof(dcache->lines));
+}
+
+// Invalidates an instruction cache line (regardless if hit or miss).
+void vr4300_dcache_invalidate(struct vr4300_dcache *dcache, uint64_t vaddr) {
+  struct vr4300_dcache_line *line = get_line(dcache, vaddr);
+
+  invalidate_line(line);
+}
+
+// Invalidates an instruction cache line (only on a hit).
+void vr4300_dcache_invalidate_hit(struct vr4300_dcache *dcache,
+  uint64_t vaddr, uint32_t paddr) {
+  struct vr4300_dcache_line *line = get_line(dcache, vaddr);
+  uint32_t ptag = get_tag(line);
+
+  if (ptag == (paddr >> 4) && is_valid(line))
+    invalidate_line(line);
+}
+
+// Probes the instruction cache for a matching line.
+const struct vr4300_dcache_line* vr4300_dcache_probe(
+  const struct vr4300_dcache *dcache, uint64_t vaddr, uint32_t paddr) {
+  const struct vr4300_dcache_line *line = get_line_const(dcache, vaddr);
+  uint32_t ptag = get_tag(line);
+
+  // Virtually index, and physically tagged.
+  return (ptag == (paddr >> 4) && is_valid(line))
+    ? line
+    : NULL;
+}
+
+// Sets the physical tag associated with the line.
+void vr4300_dcache_set_tag(struct vr4300_dcache *dcache,
+  uint64_t vaddr, uint32_t tag) {
+  struct vr4300_dcache_line *line = get_line(dcache, vaddr);
+
+  set_tag(line, tag);
+}
+

vr4300/dcache.h

@@ -0,0 +1,39 @@
+//
+// vr4300/dcache.h: VR4300 instruction cache.
+//
+// CEN64: Cycle-Accurate Nintendo 64 Simulator.
+// Copyright (C) 2014, Tyler J. Stachecki.
+//
+// This file is subject to the terms and conditions defined in
+// 'LICENSE', which is part of this source code package.
+//
+
+#ifndef __vr4300_dcache_h__
+#define __vr4300_dcache_h__
+#include "common.h"
+
+struct vr4300_dcache_line {
+  uint8_t data[4 * 4];
+  uint32_t metadata;
+};
+
+struct vr4300_dcache {
+  struct vr4300_dcache_line lines[512];
+};
+
+void vr4300_dcache_init(struct vr4300_dcache *dcache);
+
+void vr4300_dcache_fill(struct vr4300_dcache *dcache,
+  uint64_t vaddr, uint32_t paddr, const void *data);
+uint32_t vr4300_dcache_get_tag(const struct vr4300_dcache *dcache,
+  uint64_t vaddr);
+void vr4300_dcache_invalidate(struct vr4300_dcache *dcache, uint64_t vaddr);
+void vr4300_dcache_invalidate_hit(struct vr4300_dcache *dcache,
+  uint64_t vaddr, uint32_t paddr);
+const struct vr4300_dcache_line* vr4300_dcache_probe(
+  const struct vr4300_dcache *dcache, uint64_t vaddr, uint32_t paddr);
+void vr4300_dcache_set_tag(struct vr4300_dcache *dcache,
+  uint64_t vaddr, uint32_t tag);
+
+#endif
+