gpu_neon: some cmd/vram io and dma handling

1 files changed, 267 insertions, 32 deletions

diff --git a/plugins/gpu_neon/gpu.c b/plugins/gpu_neon/gpu.c
index f905f0a..4541b02 100644
--- a/plugins/gpu_neon/gpu.c
+++ b/plugins/gpu_neon/gpu.c
@@ -8,51 +8,63 @@
  * See the COPYING file in the top-level directory.
  */
 
+#include <stdio.h>
 #include <stdint.h>
 #include <string.h>
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#define unlikely(x) __builtin_expect((x), 0)
 
-static struct {
+#define CMD_BUFFER_LEN          1024
+
+static struct __attribute__((aligned(64))) {
   uint16_t vram[1024 * 512];
   uint16_t guard[1024 * 512]; // overdraw guard
+  uint32_t cmd_buffer[CMD_BUFFER_LEN];
   uint32_t regs[16];
   union {
     uint32_t reg;
     struct {
-      uint32_t tx:4;    //  0 texture page
+      uint32_t tx:4;        //  0 texture page
       uint32_t ty:1;
       uint32_t abr:2;
-      uint32_t tp:2;    //  7 t.p. mode (4,8,15bpp)
-      uint32_t dtd:1;   //  9 dither
+      uint32_t tp:2;        //  7 t.p. mode (4,8,15bpp)
+      uint32_t dtd:1;       //  9 dither
       uint32_t dfe:1;
-      uint32_t md:1;    // 11 set mask bit when drawing
-      uint32_t me:1;    // 12 no draw on mask
+      uint32_t md:1;        // 11 set mask bit when drawing
+      uint32_t me:1;        // 12 no draw on mask
       uint32_t unkn:3;
-      uint32_t width1:1;// 16
+      uint32_t width1:1;    // 16
       uint32_t width0:2;
-      uint32_t height:1;
-      uint32_t video:1; // 20 NTSC,PAL
+      uint32_t dheight:1;   // 19 double height
+      uint32_t video:1;     // 20 NTSC,PAL
       uint32_t rgb24:1;
-      uint32_t inter:1; // 22 interlace on
-      uint32_t den:1;   // 23 display not enabled
+      uint32_t interlace:1; // 22 interlace on
+      uint32_t blanking:1;  // 23 display not enabled
       uint32_t unkn2:2;
-      uint32_t busy:1;  // 26 !busy drawing
-      uint32_t img:1;   // 27 ready to DMA
-      uint32_t com:1;   // 28 ready for commands
-      uint32_t dma:2;   // 29 off, ?, to vram, from vram
-      uint32_t lcf:1;   // 21 odd frame/blanking?
+      uint32_t busy:1;      // 26 !busy drawing
+      uint32_t img:1;       // 27 ready to DMA image data
+      uint32_t com:1;       // 28 ready for commands
+      uint32_t dma:2;       // 29 off, ?, to vram, from vram
+      uint32_t lcf:1;       // 31
     };
   } status;
   struct {
     int x, y, w, h;
     int y1, y2;
   } screen;
-  uint32_t blanking;
+  struct {
+    int x, y, w, h;
+    int offset;
+  } dma;
+  int cmd_len;
+  const uint32_t *lcf_hc;
+  uint32_t zero;
 } gpu;
 
 long GPUinit(void)
 {
+  gpu.status.reg = 0x14802000;
   return 0;
 }
 
@@ -61,11 +73,6 @@ long GPUshutdown(void)
   return 0;
 }
 
-uint32_t GPUreadStatus(void)
-{
-  return gpu.status.reg | (gpu.blanking << 31);
-}
-
 void GPUwriteStatus(uint32_t data)
 {
   static const short hres[8] = { 256, 368, 320, 384, 512, 512, 640, 640 };
@@ -74,9 +81,10 @@ void GPUwriteStatus(uint32_t data)
 
   switch (data >> 24) {
     case 0x00:
+      gpu.status.reg = 0x14802000;
       break;
     case 0x03:
-      gpu.status.den = data & 1;
+      gpu.status.blanking = data & 1;
       break;
     case 0x04:
       gpu.status.dma = data & 3;
@@ -100,28 +108,243 @@ void GPUwriteStatus(uint32_t data)
     gpu.regs[cmd] = data;
 }
 
-void GPUreadDataMem(uint32_t *mem, int count)
+static const unsigned char cmd_lengths[256] =
 {
+	0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	3, 3, 3, 3, 6, 6, 6, 6, 4, 4, 4, 4, 8, 8, 8, 8, // 20
+	5, 5, 5, 5, 8, 8, 8, 8, 7, 7, 7, 7, 11, 11, 11, 11,
+	2, 2, 2, 2, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3, 3, 3, // 40
+	3, 3, 3, 3, 0, 0, 0, 0, 4, 4, 4, 4, 4, 4, 4, 4,
+	2, 2, 2, 2, 3, 3, 3, 3, 1, 1, 1, 1, 2, 2, 2, 2, // 60
+	1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2,
+	3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 80
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // a0
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // c0
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // e0
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+void do_cmd(uint32_t *list, int count)
+{
+  uint32_t *list_end = list + count;
+  int cmd;
+  //printf("do_cmd    %p, %d\n", data, count);
+
+  for (; list < list_end; list += 1 + cmd_lengths[cmd])
+  {
+    cmd = list[0] >> 24;
+    switch (cmd)
+    {
+      case 0xe1:
+        gpu.status.reg &= ~0x7ff;
+        gpu.status.reg |= list[0] & 0x7ff;
+        break;
+      case 0xe6:
+        gpu.status.reg &= ~0x1800;
+        gpu.status.reg |= (list[0] & 3) << 11;
+        break;
+    }
+    if ((cmd & 0xf4) == 0x24) {
+      // flat textured prim
+      gpu.status.reg &= ~0x1ff;
+      gpu.status.reg |= list[4] & 0x1ff;
+    }
+    else if ((cmd & 0xf4) == 0x34) {
+      // shaded textured prim
+      gpu.status.reg &= ~0x1ff;
+      gpu.status.reg |= list[5] & 0x1ff;
+    }
+  }
 }
 
-uint32_t GPUreadData(void)
+#define VRAM_MEM_XY(x, y) &gpu.vram[(y) * 1024 + (x)]
+
+static inline void do_vram_line(int x, int y, uint16_t *mem, int l, int is_read)
 {
-  return 0;
+  uint16_t *vram = VRAM_MEM_XY(x, y);
+  if (is_read)
+    memcpy(mem, vram, l * 2);
+  else
+    memcpy(vram, mem, l * 2);
+}
+
+static int do_vram_io(uint32_t *data, int count, int is_read)
+{
+  int count_initial = count;
+  uint16_t *sdata = (uint16_t *)data;
+  int x = gpu.dma.x, y = gpu.dma.y;
+  int w = gpu.dma.w, h = gpu.dma.h;
+  int l;
+  count *= 2; // operate in 16bpp pixels
+
+  if (gpu.dma.offset) {
+    l = w - gpu.dma.offset;
+    if (l > count)
+      l = count;
+    do_vram_line(x + gpu.dma.offset, y, sdata, l, is_read);
+    sdata += l;
+    count -= l;
+    y++;
+    h--;
+  }
+
+  for (; h > 0 && count >= w; sdata += w, count -= w, y++, h--) {
+    y &= 511;
+    do_vram_line(x, y, sdata, w, is_read);
+  }
+
+  if (h > 0 && count > 0) {
+    y &= 511;
+    do_vram_line(x, y, sdata, count, is_read);
+    gpu.dma.offset = count;
+    count = 0;
+  }
+  else
+    gpu.dma.offset = 0;
+  gpu.dma.y = y;
+  gpu.dma.h = h;
+
+  return count_initial - (count + 1) / 2;
+}
+
+static void start_vram_transfer(uint32_t pos_word, uint32_t size_word, int is_read)
+{
+  gpu.dma.x = pos_word & 1023;
+  gpu.dma.y = (pos_word >> 16) & 511;
+  gpu.dma.w = size_word & 0xffff; // ?
+  gpu.dma.h = size_word >> 16;
+  gpu.dma.offset = 0;
+
+  if (is_read)
+    gpu.status.img = 1;
+
+  //printf("start_vram_transfer %c (%d, %d) %dx%d\n", is_read ? 'r' : 'w',
+  //  gpu.dma.x, gpu.dma.y, gpu.dma.w, gpu.dma.h);
+}
+
+static int check_cmd(uint32_t *data, int count)
+{
+  int len, cmd, start, pos;
+
+  //printf("check_cmd %p, %d\n", data, count);
+
+  // process buffer
+  for (start = pos = 0;; )
+  {
+    cmd = -1;
+    len = 0;
+
+    if (gpu.dma.h) {
+      pos += do_vram_io(data + pos, count - pos, 0);
+      start = pos;
+    }
+
+    while (pos < count) {
+      cmd = data[pos] >> 24;
+      len = 1 + cmd_lengths[cmd];
+      //printf("  %3d: %02x %d\n", pos, cmd, len);
+      if (pos + len > count) {
+        cmd = -1;
+        break; // incomplete cmd
+      }
+      if (cmd == 0xa0 || cmd == 0xc0)
+        break; // image i/o
+      pos += len;
+    }
+
+    if (pos - start > 0) {
+      do_cmd(data + start, pos - start);
+      start = pos;
+    }
+
+    if (cmd == 0xa0 || cmd == 0xc0) {
+      // consume vram write/read cmd
+      start_vram_transfer(data[pos + 1], data[pos + 2], cmd == 0xc0);
+      pos += len;
+    }
+
+    if (pos == count)
+      return 0;
+
+    if (pos + len > count) {
+      //printf("discarding %d words\n", pos + len - count);
+      return pos + len - count;
+    }
+  }
+}
+
+static void flush_cmd_buffer(void)
+{
+  int left = check_cmd(gpu.cmd_buffer, gpu.cmd_len);
+  if (left > 0)
+    memmove(gpu.cmd_buffer, gpu.cmd_buffer + gpu.cmd_len - left, left * 4);
+  gpu.cmd_len = left;
 }
 
 void GPUwriteDataMem(uint32_t *mem, int count)
 {
+  int left;
+
+  if (unlikely(gpu.cmd_len > 0))
+    flush_cmd_buffer();
+  left = check_cmd(mem, count);
+  if (left)
+    printf("GPUwriteDataMem: discarded %d/%d words\n", left, count);
 }
 
-void GPUwriteData(uint32_t gdata)
+void GPUwriteData(uint32_t data)
 {
+  gpu.cmd_buffer[gpu.cmd_len++] = data;
+  if (gpu.cmd_len >= CMD_BUFFER_LEN)
+    flush_cmd_buffer();
 }
 
 long GPUdmaChain(uint32_t *base, uint32_t addr)
 {
+  uint32_t *list;
+  int len;
+
+  if (unlikely(gpu.cmd_len > 0))
+    flush_cmd_buffer();
+
+  while (addr != 0xffffff) {
+    list = base + (addr & 0x1fffff) / 4;
+    len = list[0] >> 24;
+    addr = list[0] & 0xffffff;
+    if (len)
+      GPUwriteDataMem(list + 1, len);
+  }
+
   return 0;
 }
 
+void GPUreadDataMem(uint32_t *mem, int count)
+{
+  if (unlikely(gpu.cmd_len > 0))
+    flush_cmd_buffer();
+  if (gpu.dma.h)
+    do_vram_io(mem, count, 1);
+}
+
+uint32_t GPUreadData(void)
+{
+  uint32_t v = 0;
+  GPUreadDataMem(&v, 1);
+  return v;
+}
+
+uint32_t GPUreadStatus(void)
+{
+  if (unlikely(gpu.cmd_len > 0))
+    flush_cmd_buffer();
+
+  return gpu.status.reg | (*gpu.lcf_hc << 31);
+}
+
 typedef struct GPUFREEZETAG
 {
   uint32_t ulFreezeVersion;      // should be always 1 for now (set by main emu)
@@ -134,16 +357,16 @@ long GPUfreeze(uint32_t type, GPUFreeze_t *freeze)
 {
   switch (type) {
     case 1: // save
+      if (gpu.cmd_len > 0)
+        flush_cmd_buffer();
       memcpy(freeze->psxVRam, gpu.vram, sizeof(gpu.vram));
       memcpy(freeze->ulControl, gpu.regs, sizeof(gpu.regs));
       freeze->ulStatus = gpu.status.reg;
-      freeze->ulControl[255] = gpu.blanking; // abuse free space
       break;
     case 0: // load
       memcpy(gpu.vram, freeze->psxVRam, sizeof(gpu.vram));
       memcpy(gpu.regs, freeze->ulControl, sizeof(gpu.regs));
       gpu.status.reg = freeze->ulStatus;
-      gpu.blanking = freeze->ulControl[255];
       GPUwriteStatus((5 << 24) | gpu.regs[5]);
       GPUwriteStatus((7 << 24) | gpu.regs[7]);
       GPUwriteStatus((8 << 24) | gpu.regs[8]);
@@ -153,9 +376,18 @@ long GPUfreeze(uint32_t type, GPUFreeze_t *freeze)
   return 1;
 }
 
-void GPUvBlank(int val)
+void GPUvBlank(int val, uint32_t *hcnt)
 {
-  gpu.blanking = !!val;
+  gpu.lcf_hc = &gpu.zero;
+  if (gpu.status.interlace) {
+    if (val)
+      gpu.status.lcf ^= 1;
+  }
+  else {
+    gpu.status.lcf = 0;
+    if (!val)
+      gpu.lcf_hc = hcnt;
+  }
 }
 
 // rearmed specific
@@ -179,6 +411,8 @@ static void blit(void)
   srcs = &gpu.vram[y * 1024 + x];
 
   h = gpu.screen.y2 - gpu.screen.y1;
+  if (gpu.status.dheight)
+    h *= 2;
 
   if (h <= 0)
     return;
@@ -218,7 +452,8 @@ static void blit(void)
 
 void GPUupdateLace(void)
 {
-  blit();
+  if (!gpu.status.blanking)
+    blit();
 }
 
 long GPUopen(void)