ati-vga: Split ati_2d_do_blt from ati_2d_blt

ati_2d_blt remains the public interface to the blitter but the bulk of
the implementation is moved down into ati_2d_do_blt which is passed an
ATI2DCtx.

ati_2d_do_blt returns a bool that is true when the blit succeeded, which
means that a screen region will need to be set dirty. Otherwise false is
returned.

Signed-off-by: Chad Jablonski <chad@jablonski.xyz>
Reviewed-by: BALATON Zoltan <balaton@eik.bme.hu>
[balaton: Fix build without pixman]
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-ID: <367949c50ca140a2d18ae66234dafbbc586b553c.1773020351.git.balaton@eik.bme.hu>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

hw/display/ati_2d.c

@@ -123,24 +123,21 @@ static void setup_2d_blt_ctx(const ATIVGAState *s, ATI2DCtx *ctx)
             (ctx->top_to_bottom ? 'v' : '^'));
 }
 
-void ati_2d_blt(ATIVGAState *s)
+static bool ati_2d_do_blt(ATIVGAState *s, ATI2DCtx *ctx)
 {
-    ATI2DCtx ctx_;
-    ATI2DCtx *ctx = &ctx_;
-    setup_2d_blt_ctx(s, ctx);
     if (!ctx->bpp) {
         qemu_log_mask(LOG_GUEST_ERROR, "Invalid bpp\n");
-        return;
+        return false;
     }
     if (!ctx->dst_stride) {
         qemu_log_mask(LOG_GUEST_ERROR, "Zero dest pitch\n");
-        return;
+        return false;
     }
     if (ctx->dst.x > 0x3fff || ctx->dst.y > 0x3fff ||
         ctx->dst_bits >= ctx->vram_end || ctx->dst_bits + ctx->dst.x +
         (ctx->dst.y + ctx->dst.height) * ctx->dst_stride >= ctx->vram_end) {
         qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n");
-        return;
+        return false;
     }
     switch (ctx->rop3) {
     case ROP3_SRCCOPY:
@@ -148,14 +145,14 @@ void ati_2d_blt(ATIVGAState *s)
         bool fallback = false;
         if (!ctx->src_stride) {
             qemu_log_mask(LOG_GUEST_ERROR, "Zero source pitch\n");
-            return;
+            return false;
         }
         if (ctx->src.x > 0x3fff || ctx->src.y > 0x3fff ||
             ctx->src_bits >= ctx->vram_end ||
             ctx->src_bits + ctx->src.x + (ctx->src.y + ctx->dst.height) *
             ctx->src_stride >= ctx->vram_end) {
             qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n");
-            return;
+            return false;
         }
 
         DPRINTF("pixman_blt(%p, %p, %ld, %ld, %d, %d, %d, %d, %d, %d, %d, %d)\n",
@@ -265,8 +262,17 @@ void ati_2d_blt(ATIVGAState *s)
     default:
         qemu_log_mask(LOG_UNIMP, "Unimplemented ati_2d blt op %x\n",
                       ctx->rop3 >> 16);
-        return;
+        return false;
     }
 
-    ati_set_dirty(&s->vga, ctx);
+    return true;
+}
+
+void ati_2d_blt(ATIVGAState *s)
+{
+    ATI2DCtx ctx;
+    setup_2d_blt_ctx(s, &ctx);
+    if (ati_2d_do_blt(s, &ctx)) {
+        ati_set_dirty(&s->vga, &ctx);
+    }
 }