vga: Separate LE and BE conversion functions

Provide different functions for converting from an LE vs a BE
framebuffer. We cannot rely on the simple cases always being
shared surfaces since cirrus will need to always shadow for
cursor emulation, so we need the full set of functions to
be able to later handle runtime switching.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>\
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>

hw/display/vga.c

@@ -1374,10 +1374,14 @@ enum {
     VGA_DRAW_LINE4D2,
     VGA_DRAW_LINE8D2,
     VGA_DRAW_LINE8,
-    VGA_DRAW_LINE15,
-    VGA_DRAW_LINE16,
-    VGA_DRAW_LINE24,
-    VGA_DRAW_LINE32,
+    VGA_DRAW_LINE15_LE,
+    VGA_DRAW_LINE16_LE,
+    VGA_DRAW_LINE24_LE,
+    VGA_DRAW_LINE32_LE,
+    VGA_DRAW_LINE15_BE,
+    VGA_DRAW_LINE16_BE,
+    VGA_DRAW_LINE24_BE,
+    VGA_DRAW_LINE32_BE,
     VGA_DRAW_LINE_NB,
 };
 
@@ -1388,10 +1392,14 @@ static vga_draw_line_func * const vga_draw_line_table[VGA_DRAW_LINE_NB] = {
     vga_draw_line4d2,
     vga_draw_line8d2,
     vga_draw_line8,
-    vga_draw_line15,
-    vga_draw_line16,
-    vga_draw_line24,
-    vga_draw_line32,
+    vga_draw_line15_le,
+    vga_draw_line16_le,
+    vga_draw_line24_le,
+    vga_draw_line32_le,
+    vga_draw_line15_be,
+    vga_draw_line16_be,
+    vga_draw_line24_be,
+    vga_draw_line32_be,
 };
 
 static int vga_get_bpp(VGACommonState *s)
@@ -1464,10 +1472,15 @@ static void vga_draw_graphic(VGACommonState *s, int full_update)
     uint8_t *d;
     uint32_t v, addr1, addr;
     vga_draw_line_func *vga_draw_line;
-#if defined(HOST_WORDS_BIGENDIAN) == defined(TARGET_WORDS_BIGENDIAN)
-    static const bool byteswap = false;
+#if defined(TARGET_WORDS_BIGENDIAN)
+    static const bool big_endian_fb = true;
 #else
-    static const bool byteswap = true;
+    static const bool big_endian_fb = false;
+#endif
+#if defined(HOST_WORDS_BIGENDIAN)
+    static const bool byteswap = !big_endian_fb;
+#else
+    static const bool byteswap = big_endian_fb;
 #endif
 
     full_update |= update_basic_params(s);
@@ -1572,19 +1585,19 @@ static void vga_draw_graphic(VGACommonState *s, int full_update)
             bits = 8;
             break;
         case 15:
-            v = VGA_DRAW_LINE15;
+            v = big_endian_fb ? VGA_DRAW_LINE15_BE : VGA_DRAW_LINE15_LE;
             bits = 16;
             break;
         case 16:
-            v = VGA_DRAW_LINE16;
+            v = big_endian_fb ? VGA_DRAW_LINE16_BE : VGA_DRAW_LINE16_LE;
             bits = 16;
             break;
         case 24:
-            v = VGA_DRAW_LINE24;
+            v = big_endian_fb ? VGA_DRAW_LINE24_BE : VGA_DRAW_LINE24_LE;
             bits = 24;
             break;
         case 32:
-            v = VGA_DRAW_LINE32;
+            v = big_endian_fb ? VGA_DRAW_LINE32_BE : VGA_DRAW_LINE32_LE;
             bits = 32;
             break;
         }

hw/display/vga_template.h

@@ -278,21 +278,36 @@ static void vga_draw_line8(VGACommonState *s1, uint8_t *d,
     }
 }
 
-
-/* XXX: optimize */
-
 /*
  * 15 bit color
  */
-static void vga_draw_line15(VGACommonState *s1, uint8_t *d,
-                            const uint8_t *s, int width)
+static void vga_draw_line15_le(VGACommonState *s1, uint8_t *d,
+                               const uint8_t *s, int width)
 {
     int w;
     uint32_t v, r, g, b;
 
     w = width;
     do {
-        v = lduw_p((void *)s);
+        v = lduw_le_p((void *)s);
+        r = (v >> 7) & 0xf8;
+        g = (v >> 2) & 0xf8;
+        b = (v << 3) & 0xf8;
+        ((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
+        s += 2;
+        d += 4;
+    } while (--w != 0);
+}
+
+static void vga_draw_line15_be(VGACommonState *s1, uint8_t *d,
+                               const uint8_t *s, int width)
+{
+    int w;
+    uint32_t v, r, g, b;
+
+    w = width;
+    do {
+        v = lduw_be_p((void *)s);
         r = (v >> 7) & 0xf8;
         g = (v >> 2) & 0xf8;
         b = (v << 3) & 0xf8;
@@ -305,15 +320,33 @@ static void vga_draw_line15(VGACommonState *s1, uint8_t *d,
 /*
  * 16 bit color
  */
-static void vga_draw_line16(VGACommonState *s1, uint8_t *d,
-                            const uint8_t *s, int width)
+static void vga_draw_line16_le(VGACommonState *s1, uint8_t *d,
+                               const uint8_t *s, int width)
 {
     int w;
     uint32_t v, r, g, b;
 
     w = width;
     do {
-        v = lduw_p((void *)s);
+        v = lduw_le_p((void *)s);
+        r = (v >> 8) & 0xf8;
+        g = (v >> 3) & 0xfc;
+        b = (v << 3) & 0xf8;
+        ((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
+        s += 2;
+        d += 4;
+    } while (--w != 0);
+}
+
+static void vga_draw_line16_be(VGACommonState *s1, uint8_t *d,
+                               const uint8_t *s, int width)
+{
+    int w;
+    uint32_t v, r, g, b;
+
+    w = width;
+    do {
+        v = lduw_be_p((void *)s);
         r = (v >> 8) & 0xf8;
         g = (v >> 3) & 0xfc;
         b = (v << 3) & 0xf8;
@@ -326,23 +359,34 @@ static void vga_draw_line16(VGACommonState *s1, uint8_t *d,
 /*
  * 24 bit color
  */
-static void vga_draw_line24(VGACommonState *s1, uint8_t *d,
-                            const uint8_t *s, int width)
+static void vga_draw_line24_le(VGACommonState *s1, uint8_t *d,
+                               const uint8_t *s, int width)
 {
     int w;
     uint32_t r, g, b;
 
     w = width;
     do {
-#if defined(TARGET_WORDS_BIGENDIAN)
-        r = s[0];
-        g = s[1];
-        b = s[2];
-#else
         b = s[0];
         g = s[1];
         r = s[2];
-#endif
+        ((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
+        s += 3;
+        d += 4;
+    } while (--w != 0);
+}
+
+static void vga_draw_line24_be(VGACommonState *s1, uint8_t *d,
+                               const uint8_t *s, int width)
+{
+    int w;
+    uint32_t r, g, b;
+
+    w = width;
+    do {
+        r = s[0];
+        g = s[1];
+        b = s[2];
         ((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
         s += 3;
         d += 4;
@@ -352,10 +396,10 @@ static void vga_draw_line24(VGACommonState *s1, uint8_t *d,
 /*
  * 32 bit color
  */
-static void vga_draw_line32(VGACommonState *s1, uint8_t *d,
-                            const uint8_t *s, int width)
+static void vga_draw_line32_le(VGACommonState *s1, uint8_t *d,
+                               const uint8_t *s, int width)
 {
-#if defined(HOST_WORDS_BIGENDIAN) == defined(TARGET_WORDS_BIGENDIAN)
+#ifndef HOST_WORDS_BIGENDIAN
     memcpy(d, s, width * 4);
 #else
     int w;
@@ -363,15 +407,30 @@ static void vga_draw_line32(VGACommonState *s1, uint8_t *d,
 
     w = width;
     do {
-#if defined(TARGET_WORDS_BIGENDIAN)
-        r = s[1];
-        g = s[2];
-        b = s[3];
-#else
         b = s[0];
         g = s[1];
         r = s[2];
+        ((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
+        s += 4;
+        d += 4;
+    } while (--w != 0);
 #endif
+}
+
+static void vga_draw_line32_be(VGACommonState *s1, uint8_t *d,
+                               const uint8_t *s, int width)
+{
+#ifdef HOST_WORDS_BIGENDIAN
+    memcpy(d, s, width * 4);
+#else
+    int w;
+    uint32_t r, g, b;
+
+    w = width;
+    do {
+        r = s[1];
+        g = s[2];
+        b = s[3];
         ((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
         s += 4;
         d += 4;