drm: Add general-purpose packet for manipulating scratch registers (r300)

From: Aapo Tahkola (via DRM CVS)
Signed-off-by: Dave Airlie <airlied@linux.ie>

drivers/char/drm/r300_cmdbuf.c

@@ -704,6 +704,64 @@ static void r300_discard_buffer(drm_device_t * dev, drm_buf_t * buf)
 	buf->used = 0;
 }
 
+static int r300_scratch(drm_radeon_private_t *dev_priv,
+			drm_radeon_kcmd_buffer_t *cmdbuf,
+			drm_r300_cmd_header_t header)
+{
+	u32 *ref_age_base;
+	u32 i, buf_idx, h_pending;
+	RING_LOCALS;
+	
+	if (cmdbuf->bufsz < 
+	    (sizeof(u64) + header.scratch.n_bufs * sizeof(buf_idx))) {
+		return DRM_ERR(EINVAL);
+	}
+	
+	if (header.scratch.reg >= 5) {
+		return DRM_ERR(EINVAL);
+	}
+	
+	dev_priv->scratch_ages[header.scratch.reg]++;
+	
+	ref_age_base = *(u32 **)cmdbuf->buf;
+	
+	cmdbuf->buf += sizeof(u64);
+	cmdbuf->bufsz -= sizeof(u64);
+	
+	for (i=0; i < header.scratch.n_bufs; i++) {
+		buf_idx = *(u32 *)cmdbuf->buf;
+		buf_idx *= 2; /* 8 bytes per buf */
+		
+		if (DRM_COPY_TO_USER(ref_age_base + buf_idx, &dev_priv->scratch_ages[header.scratch.reg], sizeof(u32))) {
+			return DRM_ERR(EINVAL);
+		}
+					
+		if (DRM_COPY_FROM_USER(&h_pending, ref_age_base + buf_idx + 1, sizeof(u32))) {
+			return DRM_ERR(EINVAL);
+		}
+					
+		if (h_pending == 0) {
+			return DRM_ERR(EINVAL);
+		}
+					
+		h_pending--;
+						
+		if (DRM_COPY_TO_USER(ref_age_base + buf_idx + 1, &h_pending, sizeof(u32))) {
+			return DRM_ERR(EINVAL);
+		}
+					
+		cmdbuf->buf += sizeof(buf_idx);
+		cmdbuf->bufsz -= sizeof(buf_idx);
+	}
+	
+	BEGIN_RING(2);
+	OUT_RING(CP_PACKET0(RADEON_SCRATCH_REG0 + header.scratch.reg * 4, 0));
+	OUT_RING(dev_priv->scratch_ages[header.scratch.reg]);
+	ADVANCE_RING();
+	
+	return 0;
+}
+
 /**
  * Parses and validates a user-supplied command buffer and emits appropriate
  * commands on the DMA ring buffer.
@@ -841,6 +899,15 @@ int r300_do_cp_cmdbuf(drm_device_t *dev,
 			}
 			break;
 
+		case R300_CMD_SCRATCH:
+			DRM_DEBUG("R300_CMD_SCRATCH\n");
+			ret = r300_scratch(dev_priv, cmdbuf, header);
+			if (ret) {
+				DRM_ERROR("r300_scratch failed\n");
+				goto cleanup;
+			}
+			break;
+			
 		default:
 			DRM_ERROR("bad cmd_type %i at %p\n",
 				  header.header.cmd_type,

drivers/char/drm/radeon_drm.h

@@ -222,6 +222,7 @@ typedef union {
 #	define R300_WAIT_3D  		0x2
 #	define R300_WAIT_2D_CLEAN  	0x3
 #	define R300_WAIT_3D_CLEAN  	0x4
+#define R300_CMD_SCRATCH		8
 
 typedef union {
 	unsigned int u;
@@ -247,6 +248,9 @@ typedef union {
 	struct {
 		unsigned char cmd_type, flags, pad0, pad1;
 	} wait;
+	struct {
+		unsigned char cmd_type, reg, n_bufs, flags;
+	} scratch;
 } drm_r300_cmd_header_t;
 
 #define RADEON_FRONT			0x1

drivers/char/drm/radeon_drv.h

@@ -92,9 +92,10 @@
  * 1.21- Add support for card type getparam
  * 1.22- Add support for texture cache flushes (R300_TX_CNTL)
  * 1.23- Add new radeon memory map work from benh
+ * 1.24- Add general-purpose packet for manipulating scratch registers (r300)
  */
 #define DRIVER_MAJOR		1
-#define DRIVER_MINOR		23
+#define DRIVER_MINOR		24
 #define DRIVER_PATCHLEVEL	0
 
 /*
@@ -276,6 +277,8 @@ typedef struct drm_radeon_private {
 	unsigned long pcigart_offset;
 	drm_ati_pcigart_info gart_info;
 
+	u32 scratch_ages[5];
+
 	/* starting from here on, data is preserved accross an open */
 	uint32_t flags;		/* see radeon_chip_flags */
 } drm_radeon_private_t;