From: BALATON Zoltan <balaton@eik.bme.hu>

Rewrite reading of mouse pointer image. I am not sure this is entirely
correct but appears to work at least on little endian host with PPC
guests using little or big endian frame buffer (MorphOS and MacOS) but
still produces broken pointer image with Linux where I am not sure if
it is a guest driver bug or still missing something.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-ID: <b9de530074b954d661a0eb9b8b4ad82a66085456.1774110169.git.balaton@eik.bme.hu>
[PMD: Replaced BIT() -> BIT_ULL() in ati_cursor_draw_line()]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/display/ati.c | 57 ++++++++++++++++++++++--------------------------
 1 file changed, 26 insertions(+), 31 deletions(-)

diff --git a/hw/display/ati.c b/hw/display/ati.c
index f74dd1efc0b..c054c9aa7a2 100644
--- a/hw/display/ati.c
+++ b/hw/display/ati.c
@@ -141,27 +141,24 @@ static void ati_vga_switch_mode(ATIVGAState *s)
 /* Used by host side hardware cursor */
 static void ati_cursor_define(ATIVGAState *s)
 {
-    uint8_t data[1024];
+    uint64_t data[128];
     uint32_t srcoff;
-    int i, j, idx = 0;
 
     if ((s->regs.cur_offset & BIT(31)) || s->cursor_guest_mode) {
         return; /* Do not update cursor if locked or rendered by guest */
     }
     /* FIXME handle cur_hv_offs correctly */
-    srcoff = s->regs.cur_offset -
-        (s->regs.cur_hv_offs >> 16) - (s->regs.cur_hv_offs & 0xffff) * 16;
-    for (i = 0; i < 64; i++) {
-        for (j = 0; j < 8; j++, idx++) {
-            data[idx] = vga_read_byte(&s->vga, srcoff + i * 16 + j);
-            data[512 + idx] = vga_read_byte(&s->vga, srcoff + i * 16 + j + 8);
-        }
+    srcoff = s->regs.cur_offset - (s->regs.cur_hv_offs >> 16) -
+             (s->regs.cur_hv_offs & 0xffff) * 16;
+    for (int i = 0; i < 64; i++, srcoff += 16) {
+        data[i] = ldq_le_p(&s->vga.vram_ptr[srcoff]);
+        data[i + 64] = ldq_le_p(&s->vga.vram_ptr[srcoff + 8]);
     }
     if (!s->cursor) {
         s->cursor = cursor_alloc(64, 64);
     }
     cursor_set_mono(s->cursor, s->regs.cur_color1, s->regs.cur_color0,
-                    &data[512], 1, &data[0]);
+                    (uint8_t *)&data[64], 1, (uint8_t *)&data[0]);
     dpy_cursor_define(s->vga.con, s->cursor);
 }
 
@@ -196,9 +193,9 @@ static void ati_cursor_invalidate(VGACommonState *vga)
 static void ati_cursor_draw_line(VGACommonState *vga, uint8_t *d, int scr_y)
 {
     ATIVGAState *s = container_of(vga, ATIVGAState, vga);
-    uint32_t srcoff;
+    uint32_t h, srcoff, color;
+    uint64_t abits, xbits, mask;
     uint32_t *dp = (uint32_t *)d;
-    int i, j, h, idx = 0;
 
     if (!(s->regs.crtc_gen_cntl & CRTC2_CUR_EN) ||
         scr_y < vga->hw_cursor_y || scr_y >= vga->hw_cursor_y + 64 ||
@@ -209,26 +206,24 @@ static void ati_cursor_draw_line(VGACommonState *vga, uint8_t *d, int scr_y)
     srcoff = s->cursor_offset + (scr_y - vga->hw_cursor_y) * 16;
     dp = &dp[vga->hw_cursor_x];
     h = ((s->regs.crtc_h_total_disp >> 16) + 1) * 8;
-    for (i = 0; i < 8; i++) {
-        uint32_t color;
-        uint8_t abits = vga_read_byte(vga, srcoff + i);
-        uint8_t xbits = vga_read_byte(vga, srcoff + i + 8);
-        for (j = 0; j < 8; j++, abits <<= 1, xbits <<= 1, idx++) {
-            if (vga->hw_cursor_x + idx >= h) {
-                return; /* end of screen, don't span to next line */
-            }
-            if (abits & BIT(7)) {
-                if (xbits & BIT(7)) {
-                    color = dp[idx] ^ 0xffffffff; /* complement */
-                } else {
-                    continue; /* transparent, no change */
-                }
-            } else {
-                color = (xbits & BIT(7) ? s->regs.cur_color1 :
-                                          s->regs.cur_color0) | 0xff000000;
-            }
-            dp[idx] = color;
+    abits = ldq_be_p(&vga->vram_ptr[srcoff]);
+    xbits = ldq_be_p(&vga->vram_ptr[srcoff + 8]);
+    mask = BIT_ULL(63);
+    for (int i = 0; i < 64; i++, mask >>= 1) {
+        if (vga->hw_cursor_x + i >= h) {
+            return; /* end of screen, don't span to next line */
         }
+        if (abits & mask) {
+            if (xbits & mask) {
+                color = dp[i] ^ 0xffffffff; /* complement */
+            } else {
+                continue; /* transparent, no change */
+            }
+        } else {
+            color = (xbits & mask ? s->regs.cur_color1 :
+                                    s->regs.cur_color0) | 0xff000000;
+        }
+        dp[i] = color;
     }
 }
 
-- 
2.53.0