drm: Add via unichrome support

Add DRM device driver for VIA Unichrome chipsets

From: Unichrome Project http://unichrome.sf.net, Erdi Chen, Thomas Hellstrom    Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/via_verifier.c b/drivers/char/drm/via_verifier.c
new file mode 100644
index 0000000..07923b0
--- /dev/null
+++ b/drivers/char/drm/via_verifier.c
@@ -0,0 +1,1061 @@
+/*
+ * Copyright 2004 The Unichrome Project. All Rights Reserved.
+ * Copyright 2005 Thomas Hellstrom. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S), AND/OR THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Author: Thomas Hellstrom 2004, 2005.
+ * This code was written using docs obtained under NDA from VIA Inc.
+ *
+ * Don't run this code directly on an AGP buffer. Due to cache problems it will
+ * be very slow.
+ */
+
+
+#include "via_3d_reg.h"
+#include "drmP.h"
+#include "drm.h"
+#include "via_drm.h"
+#include "via_verifier.h"
+#include "via_drv.h"
+
+typedef enum{
+	state_command,
+	state_header2,
+	state_header1,
+	state_vheader5,
+	state_vheader6,
+	state_error
+} verifier_state_t;
+
+
+typedef enum{
+	no_check = 0,
+	check_for_header2,
+	check_for_header1,
+	check_for_header2_err,
+	check_for_header1_err,
+	check_for_fire,
+	check_z_buffer_addr0,
+	check_z_buffer_addr1,
+	check_z_buffer_addr_mode,
+	check_destination_addr0,
+	check_destination_addr1,
+	check_destination_addr_mode,
+	check_for_dummy,
+	check_for_dd,
+	check_texture_addr0,
+	check_texture_addr1,
+	check_texture_addr2,
+	check_texture_addr3,
+	check_texture_addr4,
+	check_texture_addr5,
+	check_texture_addr6,
+	check_texture_addr7,
+	check_texture_addr8,
+	check_texture_addr_mode,
+	check_for_vertex_count,
+	check_number_texunits,
+	forbidden_command
+}hazard_t;
+
+/*
+ * Associates each hazard above with a possible multi-command
+ * sequence. For example an address that is split over multiple
+ * commands and that needs to be checked at the first command 
+ * that does not include any part of the address.
+ */
+
+static drm_via_sequence_t seqs[] = { 
+	no_sequence,
+	no_sequence,
+	no_sequence,
+	no_sequence,
+	no_sequence,
+	no_sequence,
+	z_address,
+	z_address,
+	z_address,
+	dest_address,
+	dest_address,
+	dest_address,
+	no_sequence,
+	no_sequence,
+	tex_address,
+	tex_address,
+	tex_address,
+	tex_address,
+	tex_address,
+	tex_address,
+	tex_address,
+	tex_address,
+	tex_address,
+	tex_address,
+	no_sequence
+};
+    
+typedef struct{
+	unsigned int code;
+	hazard_t hz;
+} hz_init_t;
+
+
+
+static hz_init_t init_table1[] = {
+	{0xf2, check_for_header2_err},
+	{0xf0, check_for_header1_err},
+	{0xee, check_for_fire},
+	{0xcc, check_for_dummy},
+	{0xdd, check_for_dd},
+	{0x00, no_check},
+	{0x10, check_z_buffer_addr0},
+	{0x11, check_z_buffer_addr1},
+	{0x12, check_z_buffer_addr_mode},
+	{0x13, no_check},
+	{0x14, no_check},
+	{0x15, no_check},
+	{0x23, no_check},
+	{0x24, no_check},
+	{0x33, no_check},
+	{0x34, no_check},
+	{0x35, no_check},
+	{0x36, no_check},
+	{0x37, no_check},
+	{0x38, no_check},
+	{0x39, no_check},
+	{0x3A, no_check},
+	{0x3B, no_check},
+	{0x3C, no_check},
+	{0x3D, no_check},
+	{0x3E, no_check},
+	{0x40, check_destination_addr0},
+	{0x41, check_destination_addr1},
+	{0x42, check_destination_addr_mode},
+	{0x43, no_check},
+	{0x44, no_check},
+	{0x50, no_check},
+	{0x51, no_check},
+	{0x52, no_check},
+	{0x53, no_check},
+	{0x54, no_check},
+	{0x55, no_check},
+	{0x56, no_check},
+	{0x57, no_check},
+	{0x58, no_check},
+	{0x70, no_check},
+	{0x71, no_check},
+	{0x78, no_check},
+	{0x79, no_check},
+	{0x7A, no_check},
+	{0x7B, no_check},
+	{0x7C, no_check},
+	{0x7D, check_for_vertex_count}
+};
+
+   
+		       
+static hz_init_t init_table2[] = {
+	{0xf2, check_for_header2_err},
+	{0xf0, check_for_header1_err},
+	{0xee, check_for_fire},
+	{0xcc, check_for_dummy},
+	{0x00, check_texture_addr0},
+	{0x01, check_texture_addr0},
+	{0x02, check_texture_addr0},
+	{0x03, check_texture_addr0},
+	{0x04, check_texture_addr0},
+	{0x05, check_texture_addr0},
+	{0x06, check_texture_addr0},
+	{0x07, check_texture_addr0},
+	{0x08, check_texture_addr0},
+	{0x09, check_texture_addr0},
+	{0x20, check_texture_addr1},
+	{0x21, check_texture_addr1},
+	{0x22, check_texture_addr1},
+	{0x23, check_texture_addr4},
+	{0x2B, check_texture_addr3},
+	{0x2C, check_texture_addr3},
+	{0x2D, check_texture_addr3},
+	{0x2E, check_texture_addr3},
+	{0x2F, check_texture_addr3},
+	{0x30, check_texture_addr3},
+	{0x31, check_texture_addr3},
+	{0x32, check_texture_addr3},
+	{0x33, check_texture_addr3},
+	{0x34, check_texture_addr3},
+	{0x4B, check_texture_addr5},
+	{0x4C, check_texture_addr6},
+	{0x51, check_texture_addr7},
+	{0x52, check_texture_addr8},
+	{0x77, check_texture_addr2},
+	{0x78, no_check},
+	{0x79, no_check},
+	{0x7A, no_check},
+	{0x7B, check_texture_addr_mode},
+	{0x7C, no_check},
+	{0x7D, no_check},
+	{0x7E, no_check},
+	{0x7F, no_check},
+	{0x80, no_check},
+	{0x81, no_check},
+	{0x82, no_check},
+	{0x83, no_check},
+	{0x85, no_check},
+	{0x86, no_check},
+	{0x87, no_check},
+	{0x88, no_check},
+	{0x89, no_check},
+	{0x8A, no_check},
+	{0x90, no_check},
+	{0x91, no_check},
+	{0x92, no_check},
+	{0x93, no_check}
+};
+
+static hz_init_t init_table3[] = {
+	{0xf2, check_for_header2_err},
+	{0xf0, check_for_header1_err},
+	{0xcc, check_for_dummy},
+	{0x00, check_number_texunits}
+};
+   
+		       
+static hazard_t table1[256]; 
+static hazard_t table2[256]; 
+static hazard_t table3[256]; 
+
+
+
+static __inline__ int
+eat_words(const uint32_t **buf, const uint32_t *buf_end, unsigned num_words)
+{
+	if ((*buf - buf_end) >= num_words) {
+		*buf += num_words;
+		return 0;
+	} 
+	DRM_ERROR("Illegal termination of DMA command buffer\n");
+	return 1;
+}
+
+
+/*
+ * Partially stolen from drm_memory.h
+ */
+
+static __inline__ drm_map_t *
+via_drm_lookup_agp_map (drm_via_state_t *seq, unsigned long offset, unsigned long size, 
+			drm_device_t *dev)
+{
+	struct list_head *list;
+	drm_map_list_t *r_list;
+	drm_map_t *map = seq->map_cache;
+
+	if (map && map->offset <= offset && (offset + size) <= (map->offset + map->size)) {
+		return map;
+	}
+		
+	list_for_each(list, &dev->maplist->head) {
+		r_list = (drm_map_list_t *) list;
+		map = r_list->map;
+		if (!map)
+			continue;
+		if (map->offset <= offset && (offset + size) <= (map->offset + map->size) && 
+		    !(map->flags & _DRM_RESTRICTED) && (map->type == _DRM_AGP)) {
+			seq->map_cache = map;
+			return map;
+		}
+	}
+	return NULL;
+}
+
+
+/*
+ * Require that all AGP texture levels reside in the same AGP map which should 
+ * be mappable by the client. This is not a big restriction.
+ * FIXME: To actually enforce this security policy strictly, drm_rmmap 
+ * would have to wait for dma quiescent before removing an AGP map. 
+ * The via_drm_lookup_agp_map call in reality seems to take
+ * very little CPU time.
+ */
+
+
+static __inline__ int
+finish_current_sequence(drm_via_state_t *cur_seq) 
+{
+	switch(cur_seq->unfinished) {
+	case z_address:
+		DRM_DEBUG("Z Buffer start address is 0x%x\n", cur_seq->z_addr);
+		break;
+	case dest_address:
+		DRM_DEBUG("Destination start address is 0x%x\n", cur_seq->d_addr);
+		break;
+	case tex_address:
+		if (cur_seq->agp_texture) {			 
+			unsigned start = cur_seq->tex_level_lo[cur_seq->texture];
+			unsigned end = cur_seq->tex_level_hi[cur_seq->texture];
+			unsigned long lo=~0, hi=0, tmp;
+			uint32_t *addr, *pitch, *height, tex;
+			unsigned i;
+
+			if (end > 9) end = 9;
+			if (start > 9) start = 9;
+
+			addr =&(cur_seq->t_addr[tex = cur_seq->texture][start]);
+			pitch = &(cur_seq->pitch[tex][start]);
+			height = &(cur_seq->height[tex][start]);
+
+			for (i=start; i<= end; ++i) {
+				tmp = *addr++;
+				if (tmp < lo) lo = tmp;
+				tmp += (*height++ << *pitch++);
+				if (tmp > hi) hi = tmp;
+			}
+
+			if (! via_drm_lookup_agp_map (cur_seq, lo, hi - lo, cur_seq->dev)) {
+				DRM_ERROR("AGP texture is not in allowed map\n");
+				return 2;
+			}
+		}	
+		break;
+	default:
+		break;
+	}
+	cur_seq->unfinished = no_sequence;
+	return 0;
+}
+
+static __inline__ int 
+investigate_hazard( uint32_t cmd, hazard_t hz, drm_via_state_t *cur_seq)
+{
+	register uint32_t tmp, *tmp_addr;
+
+	if (cur_seq->unfinished && (cur_seq->unfinished != seqs[hz])) {
+		int ret;
+		if ((ret = finish_current_sequence(cur_seq))) return ret;
+	}
+
+	switch(hz) {
+	case check_for_header2:
+		if (cmd == HALCYON_HEADER2) return 1;
+		return 0;
+	case check_for_header1:
+		if ((cmd & HALCYON_HEADER1MASK) == HALCYON_HEADER1) return 1;
+		return 0;
+	case check_for_header2_err:
+		if (cmd == HALCYON_HEADER2) return 1;
+		DRM_ERROR("Illegal DMA HALCYON_HEADER2 command\n");
+		break;
+	case check_for_header1_err:
+		if ((cmd & HALCYON_HEADER1MASK) == HALCYON_HEADER1) return 1;
+		DRM_ERROR("Illegal DMA HALCYON_HEADER1 command\n");
+		break;
+	case check_for_fire:
+		if ((cmd & HALCYON_FIREMASK) == HALCYON_FIRECMD) return 1; 
+		DRM_ERROR("Illegal DMA HALCYON_FIRECMD command\n");
+		break;
+	case check_for_dummy:
+		if (HC_DUMMY == cmd) return 0;
+		DRM_ERROR("Illegal DMA HC_DUMMY command\n");
+		break;
+	case check_for_dd:
+		if (0xdddddddd == cmd) return 0;
+		DRM_ERROR("Illegal DMA 0xdddddddd command\n");
+		break;
+	case check_z_buffer_addr0:
+		cur_seq->unfinished = z_address;
+		cur_seq->z_addr = (cur_seq->z_addr & 0xFF000000) |
+			(cmd & 0x00FFFFFF);
+		return 0;
+	case check_z_buffer_addr1:
+		cur_seq->unfinished = z_address;
+		cur_seq->z_addr = (cur_seq->z_addr & 0x00FFFFFF) |
+			((cmd & 0xFF) << 24);
+		return 0;
+	case check_z_buffer_addr_mode:
+		cur_seq->unfinished = z_address;
+		if ((cmd & 0x0000C000) == 0) return 0;
+		DRM_ERROR("Attempt to place Z buffer in system memory\n");
+		return 2;
+	case check_destination_addr0:
+		cur_seq->unfinished = dest_address;
+		cur_seq->d_addr = (cur_seq->d_addr & 0xFF000000) |
+			(cmd & 0x00FFFFFF);
+		return 0;
+	case check_destination_addr1:
+		cur_seq->unfinished = dest_address;
+		cur_seq->d_addr = (cur_seq->d_addr & 0x00FFFFFF) |
+			((cmd & 0xFF) << 24);
+		return 0;
+	case check_destination_addr_mode:
+		cur_seq->unfinished = dest_address;
+		if ((cmd & 0x0000C000) == 0) return 0;
+		DRM_ERROR("Attempt to place 3D drawing buffer in system memory\n");
+		return 2;	    
+	case check_texture_addr0:
+		cur_seq->unfinished = tex_address;
+		tmp = (cmd >> 24);
+		tmp_addr = &cur_seq->t_addr[cur_seq->texture][tmp];
+		*tmp_addr = (*tmp_addr & 0xFF000000) | (cmd & 0x00FFFFFF);
+		return 0;
+	case check_texture_addr1:
+		cur_seq->unfinished = tex_address;
+		tmp = ((cmd >> 24) - 0x20);
+		tmp += tmp << 1;
+		tmp_addr = &cur_seq->t_addr[cur_seq->texture][tmp];
+		*tmp_addr = (*tmp_addr & 0x00FFFFFF) | ((cmd & 0xFF) << 24);
+		tmp_addr++;
+		*tmp_addr = (*tmp_addr & 0x00FFFFFF) | ((cmd & 0xFF00) << 16);
+		tmp_addr++;
+		*tmp_addr = (*tmp_addr & 0x00FFFFFF) | ((cmd & 0xFF0000) << 8);
+		return 0;
+	case check_texture_addr2:
+		cur_seq->unfinished = tex_address;
+		cur_seq->tex_level_lo[tmp = cur_seq->texture] = cmd & 0x3F;
+		cur_seq->tex_level_hi[tmp] = (cmd & 0xFC0) >> 6;
+		return 0;
+	case check_texture_addr3:
+		cur_seq->unfinished = tex_address;
+		tmp = ((cmd >> 24) - 0x2B);
+		cur_seq->pitch[cur_seq->texture][tmp] = (cmd & 0x00F00000) >> 20;
+		if (!tmp && (cmd & 0x000FFFFF)) {
+			DRM_ERROR("Unimplemented texture level 0 pitch mode.\n");
+			return 2;
+		}
+		return 0;
+	case check_texture_addr4:
+		cur_seq->unfinished = tex_address;
+		tmp_addr = &cur_seq->t_addr[cur_seq->texture][9];
+		*tmp_addr = (*tmp_addr & 0x00FFFFFF) | ((cmd & 0xFF) << 24);
+		return 0;
+	case check_texture_addr5:
+	case check_texture_addr6:
+		cur_seq->unfinished = tex_address;
+		/*
+		 * Texture width. We don't care since we have the pitch.
+		 */  
+		return 0;
+	case check_texture_addr7:
+		cur_seq->unfinished = tex_address;
+		tmp_addr = &(cur_seq->height[cur_seq->texture][0]);
+		tmp_addr[5] = 1 << ((cmd & 0x00F00000) >> 20);
+		tmp_addr[4] = 1 << ((cmd & 0x000F0000) >> 16);
+		tmp_addr[3] = 1 << ((cmd & 0x0000F000) >> 12);
+		tmp_addr[2] = 1 << ((cmd & 0x00000F00) >> 8);
+		tmp_addr[1] = 1 << ((cmd & 0x000000F0) >> 4);
+		tmp_addr[0] = 1 << (cmd & 0x0000000F);
+		return 0;
+	case check_texture_addr8:
+		cur_seq->unfinished = tex_address;
+		tmp_addr = &(cur_seq->height[cur_seq->texture][0]);
+		tmp_addr[9] = 1 << ((cmd & 0x0000F000) >> 12);
+	        tmp_addr[8] = 1 << ((cmd & 0x00000F00) >> 8);
+		tmp_addr[7] = 1 << ((cmd & 0x000000F0) >> 4);
+		tmp_addr[6] = 1 << (cmd & 0x0000000F);
+		return 0;
+	case check_texture_addr_mode:
+		cur_seq->unfinished = tex_address;
+		if ( 2 == (tmp = cmd & 0x00000003)) {
+			DRM_ERROR("Attempt to fetch texture from system memory.\n"); 
+			return 2;
+		}
+		cur_seq->agp_texture = (tmp == 3);
+		cur_seq->tex_palette_size[cur_seq->texture] = 
+			(cmd >> 16) & 0x000000007;
+		return 0;
+	case check_for_vertex_count:
+		cur_seq->vertex_count = cmd & 0x0000FFFF;
+		return 0;
+	case check_number_texunits:
+	        cur_seq->multitex = (cmd >> 3) & 1;
+		return 0;
+	default:
+		DRM_ERROR("Illegal DMA data: 0x%x\n", cmd);
+		return 2;
+	}
+	return 2;
+}
+
+
+static __inline__ int
+via_check_prim_list(uint32_t const **buffer, const uint32_t *buf_end,
+		    drm_via_state_t *cur_seq)
+{
+	drm_via_private_t *dev_priv = (drm_via_private_t *) cur_seq->dev->dev_private;
+	uint32_t a_fire, bcmd , dw_count;
+	int ret = 0;
+	int have_fire;
+	const uint32_t *buf = *buffer;
+
+	while(buf < buf_end) {
+	        have_fire = 0;
+		if ((buf_end - buf) < 2) {
+			DRM_ERROR("Unexpected termination of primitive list.\n");
+			ret = 1;
+			break;
+		}
+		if ((*buf & HC_ACMD_MASK) != HC_ACMD_HCmdB) break;
+		bcmd = *buf++;
+		if ((*buf & HC_ACMD_MASK) != HC_ACMD_HCmdA) {
+			DRM_ERROR("Expected Vertex List A command, got 0x%x\n",
+				  *buf);
+			ret = 1;
+			break;
+		}
+		a_fire = *buf++ | HC_HPLEND_MASK | HC_HPMValidN_MASK | HC_HE3Fire_MASK;	
+	
+		/*
+		 * How many dwords per vertex ?
+		 */ 
+		
+		if (cur_seq->agp && ((bcmd & (0xF << 11)) == 0)) {
+			DRM_ERROR("Illegal B command vertex data for AGP.\n");
+			ret = 1;
+			break;
+		} 
+
+		dw_count = 0;
+		if (bcmd & (1 << 7)) dw_count += (cur_seq->multitex) ? 2:1;
+		if (bcmd & (1 << 8)) dw_count += (cur_seq->multitex) ? 2:1;
+		if (bcmd & (1 << 9)) dw_count++;
+		if (bcmd & (1 << 10)) dw_count++;
+		if (bcmd & (1 << 11)) dw_count++;
+		if (bcmd & (1 << 12)) dw_count++;
+		if (bcmd & (1 << 13)) dw_count++;
+		if (bcmd & (1 << 14)) dw_count++;
+
+		while(buf < buf_end) {
+			if (*buf == a_fire) {
+				if (dev_priv->num_fire_offsets >= VIA_FIRE_BUF_SIZE) {
+					DRM_ERROR("Fire offset buffer full.\n");
+					ret = 1;
+					break;
+				}
+				dev_priv->fire_offsets[dev_priv->num_fire_offsets++] = buf;
+			        have_fire = 1;
+				buf++;
+				if (buf < buf_end && *buf == a_fire) 
+					buf++;
+				break;
+			}
+			if ((*buf == HALCYON_HEADER2) || 
+			    ((*buf & HALCYON_FIREMASK) == HALCYON_FIRECMD)) {
+				DRM_ERROR("Missing Vertex Fire command, "
+					  "Stray Vertex Fire command  or verifier "
+					  "lost sync.\n");
+				ret = 1;
+				break;
+			}
+			if ((ret = eat_words(&buf, buf_end, dw_count)))
+				break;
+		}
+		if (buf >= buf_end && !have_fire) {
+			DRM_ERROR("Missing Vertex Fire command or verifier "
+				  "lost sync.\n");
+			ret = 1;
+			break;
+		}
+		if (cur_seq->agp && ((buf - cur_seq->buf_start) & 0x01)) {
+			DRM_ERROR("AGP Primitive list end misaligned.\n");
+			ret = 1;
+			break;
+		}
+	} 
+	*buffer = buf;
+	return ret;
+}
+
+
+		       
+
+
+static __inline__ verifier_state_t
+via_check_header2( uint32_t const **buffer, const uint32_t *buf_end, 
+		   drm_via_state_t *hc_state)
+{
+	uint32_t cmd;
+	int hz_mode;
+	hazard_t hz;
+	const uint32_t *buf = *buffer;
+	const hazard_t *hz_table;
+
+
+	if ((buf_end - buf) < 2) {
+		DRM_ERROR("Illegal termination of DMA HALCYON_HEADER2 sequence.\n");
+		return state_error;
+	}
+	buf++;
+	cmd = (*buf++ & 0xFFFF0000) >> 16;
+
+	switch(cmd) {
+	case HC_ParaType_CmdVdata:
+		if (via_check_prim_list(&buf, buf_end, hc_state )) 
+			return state_error;
+		*buffer = buf;
+		return state_command;
+	case HC_ParaType_NotTex:
+		hz_table = table1;
+		break;
+	case HC_ParaType_Tex:
+		hc_state->texture = 0;
+		hz_table = table2;
+		break;
+	case (HC_ParaType_Tex | (HC_SubType_Tex1 << 8)):
+		hc_state->texture = 1;
+		hz_table = table2;
+		break;
+	case (HC_ParaType_Tex | (HC_SubType_TexGeneral << 8)):
+		hz_table = table3;
+		break;
+	case HC_ParaType_Auto:
+		if (eat_words(&buf, buf_end, 2))
+			return state_error;
+		*buffer = buf;
+		return state_command;
+	case (HC_ParaType_Palette | (HC_SubType_Stipple << 8)):
+		if (eat_words(&buf, buf_end, 32))
+			return state_error;
+		*buffer = buf;
+		return state_command;
+	case (HC_ParaType_Palette | (HC_SubType_TexPalette0 << 8)):
+	case (HC_ParaType_Palette | (HC_SubType_TexPalette1 << 8)):
+		DRM_ERROR("Texture palettes are rejected because of "
+			  "lack of info how to determine their size.\n");
+		return state_error;
+	case (HC_ParaType_Palette | (HC_SubType_FogTable << 8)):
+		DRM_ERROR("Fog factor palettes are rejected because of "
+			  "lack of info how to determine their size.\n");
+		return state_error;
+	default:
+
+		/*
+		 * There are some unimplemented HC_ParaTypes here, that
+		 * need to be implemented if the Mesa driver is extended.
+		 */
+
+		DRM_ERROR("Invalid or unimplemented HALCYON_HEADER2 "
+			  "DMA subcommand: 0x%x. Previous dword: 0x%x\n", 
+			  cmd, *(buf -2));
+		*buffer = buf;
+		return state_error;
+	}
+
+	while(buf < buf_end) {
+		cmd = *buf++;
+		if ((hz = hz_table[cmd >> 24])) {
+			if ((hz_mode = investigate_hazard(cmd, hz, hc_state))) {
+				if (hz_mode == 1) {
+					buf--;
+					break;
+				}
+				return state_error;
+			}
+		} else if (hc_state->unfinished && 
+			   finish_current_sequence(hc_state)) {
+			return state_error;
+		}
+	}
+	if (hc_state->unfinished && finish_current_sequence(hc_state)) {
+		return state_error;
+	}
+	*buffer = buf;
+	return state_command;
+}
+
+static __inline__ verifier_state_t
+via_parse_header2( drm_via_private_t *dev_priv, uint32_t const **buffer, const uint32_t *buf_end,
+		   int *fire_count)
+{
+	uint32_t cmd;
+	const uint32_t *buf = *buffer;
+	const uint32_t *next_fire; 
+	int burst = 0;
+
+	next_fire = dev_priv->fire_offsets[*fire_count];
+	buf++;
+	cmd = (*buf & 0xFFFF0000) >> 16;
+	VIA_WRITE(HC_REG_TRANS_SET + HC_REG_BASE, *buf++);
+	switch(cmd) {
+	case HC_ParaType_CmdVdata:
+		while ((buf < buf_end) &&
+		       (*fire_count < dev_priv->num_fire_offsets) && 
+		       (*buf & HC_ACMD_MASK) == HC_ACMD_HCmdB ) {
+			while(buf <= next_fire) {
+				VIA_WRITE(HC_REG_TRANS_SPACE + HC_REG_BASE + (burst & 63), *buf++);
+				burst += 4;
+			}
+			if ( ( buf < buf_end ) && ((*buf & HALCYON_FIREMASK) == HALCYON_FIRECMD))
+				buf++;
+
+			if (++(*fire_count) < dev_priv->num_fire_offsets) 
+				next_fire = dev_priv->fire_offsets[*fire_count];
+		}
+		break;
+	default:
+		while(buf < buf_end) {
+			
+			if ( *buf == HC_HEADER2 ||
+			     (*buf & HALCYON_HEADER1MASK) == HALCYON_HEADER1  ||
+			     (*buf & VIA_VIDEOMASK) == VIA_VIDEO_HEADER5 ||
+			     (*buf & VIA_VIDEOMASK) == VIA_VIDEO_HEADER6 ) break;
+			
+			VIA_WRITE(HC_REG_TRANS_SPACE + HC_REG_BASE + (burst & 63), *buf++);
+			burst +=4;
+		}
+	}
+	*buffer = buf;
+	return state_command;
+}
+
+
+
+static __inline__ int
+verify_mmio_address( uint32_t address)
+{
+	if ((address > 0x3FF) && (address < 0xC00 )) {
+		DRM_ERROR("Invalid VIDEO DMA command. "
+			  "Attempt to access 3D- or command burst area.\n");
+		return 1;
+	} else if ((address > 0xCFF) && (address < 0x1300)) {
+		DRM_ERROR("Invalid VIDEO DMA command. "
+			  "Attempt to access PCI DMA area.\n");
+		return 1;		
+	} else if (address > 0x13FF ) {
+		DRM_ERROR("Invalid VIDEO DMA command. "
+			  "Attempt to access VGA registers.\n");
+		return 1;
+	}
+	return 0;
+}
+
+static __inline__ int
+verify_video_tail( uint32_t const **buffer, const uint32_t *buf_end, uint32_t dwords) 
+{
+	const uint32_t *buf = *buffer;
+
+	if (buf_end - buf < dwords) {
+		DRM_ERROR("Illegal termination of video command.\n");
+		return 1;
+	}
+	while (dwords--) {
+		if (*buf++) {
+			DRM_ERROR("Illegal video command tail.\n");
+			return 1;
+		}
+	}
+	*buffer = buf;
+	return 0;
+}
+		
+
+static __inline__ verifier_state_t
+via_check_header1( uint32_t const **buffer, const uint32_t *buf_end )
+{
+	uint32_t cmd;
+	const uint32_t *buf = *buffer;
+	verifier_state_t ret = state_command;
+
+	while (buf < buf_end) {
+		cmd = *buf;
+		if ((cmd > ((0x3FF >> 2) | HALCYON_HEADER1)) &&
+		    (cmd < ((0xC00 >> 2) | HALCYON_HEADER1))) {			
+			if ((cmd & HALCYON_HEADER1MASK) != HALCYON_HEADER1) 
+				break;
+			DRM_ERROR("Invalid HALCYON_HEADER1 command. "
+				  "Attempt to access 3D- or command burst area.\n");
+			ret = state_error;
+			break;
+		} else if (cmd > ((0xCFF >> 2) | HALCYON_HEADER1)) {
+			if ((cmd & HALCYON_HEADER1MASK) != HALCYON_HEADER1) 
+				break;
+			DRM_ERROR("Invalid HALCYON_HEADER1 command. "
+				  "Attempt to access VGA registers.\n");
+			ret = state_error;
+			break;			
+		} else {			
+			buf += 2;
+		}
+	}
+	*buffer = buf;
+	return ret;
+}
+
+static __inline__ verifier_state_t
+via_parse_header1( drm_via_private_t *dev_priv, uint32_t const **buffer, const uint32_t *buf_end )
+{
+	register uint32_t cmd;
+	const uint32_t *buf = *buffer;
+
+	while (buf < buf_end) {
+		cmd = *buf;
+		if ((cmd & HALCYON_HEADER1MASK) != HALCYON_HEADER1) break;
+		VIA_WRITE( (cmd & ~HALCYON_HEADER1MASK) << 2, *++buf); 
+		buf++;
+	}
+	*buffer = buf;
+	return state_command;
+}
+
+static __inline__ verifier_state_t
+via_check_vheader5( uint32_t const **buffer, const uint32_t *buf_end )
+{
+	uint32_t data;
+	const uint32_t *buf = *buffer;
+
+	if (buf_end - buf < 4) {
+		DRM_ERROR("Illegal termination of video header5 command\n");
+		return state_error;
+	}
+
+	data = *buf++ & ~VIA_VIDEOMASK;
+	if (verify_mmio_address(data))
+		return state_error;
+
+	data = *buf++;
+	if (*buf++ != 0x00F50000) {
+		DRM_ERROR("Illegal header5 header data\n");
+		return state_error;
+	}
+	if (*buf++ != 0x00000000) {
+		DRM_ERROR("Illegal header5 header data\n");
+		return state_error;
+	}
+	if (eat_words(&buf, buf_end, data)) 
+		return state_error;
+	if ((data & 3) && verify_video_tail(&buf, buf_end, 4 - (data & 3))) 
+		return state_error;
+	*buffer = buf;
+	return state_command;
+	       
+} 
+
+static __inline__ verifier_state_t
+via_parse_vheader5( drm_via_private_t *dev_priv, uint32_t const **buffer, const uint32_t *buf_end )
+{
+  uint32_t addr, count, i;
+	const uint32_t *buf = *buffer;
+	
+	addr = *buf++ & ~VIA_VIDEOMASK;
+	i = count = *buf;
+	buf += 3;
+	while(i--) {
+		VIA_WRITE(addr, *buf++);
+	}
+	if (count & 3) buf += 4 - (count & 3);
+	*buffer = buf;
+	return state_command;	       
+} 
+
+
+static __inline__ verifier_state_t
+via_check_vheader6( uint32_t const **buffer, const uint32_t *buf_end )
+{
+	uint32_t data;
+	const uint32_t *buf = *buffer;
+	uint32_t i;
+
+
+	if (buf_end - buf < 4) {
+		DRM_ERROR("Illegal termination of video header6 command\n");
+		return state_error;
+	}
+	buf++;
+	data = *buf++;
+	if (*buf++ != 0x00F60000) {
+		DRM_ERROR("Illegal header6 header data\n");
+		return state_error;
+	}
+	if (*buf++ != 0x00000000) {
+		DRM_ERROR("Illegal header6 header data\n");
+		return state_error;
+	}
+	if ((buf_end - buf) < (data << 1)) {
+		DRM_ERROR("Illegal termination of video header6 command\n");
+		return state_error;
+	}
+	for (i=0; i<data; ++i) {
+		if (verify_mmio_address(*buf++))
+			return state_error;
+		buf++;
+	}
+	data <<= 1;
+	if ((data & 3) && verify_video_tail(&buf, buf_end, 4 - (data & 3)))
+		return state_error;
+	*buffer = buf;
+	return state_command;
+} 
+
+static __inline__ verifier_state_t
+via_parse_vheader6( drm_via_private_t *dev_priv, uint32_t const **buffer, const uint32_t *buf_end )
+{
+
+  uint32_t addr, count, i;
+	const uint32_t *buf = *buffer;
+
+	i = count = *++buf;
+	buf += 3;
+	while(i--) {
+		addr = *buf++;
+		VIA_WRITE(addr, *buf++);
+	}
+	count <<= 1;
+	if (count & 3) buf += 4 - (count & 3);
+	*buffer = buf;
+	return state_command;
+} 
+
+
+
+int 
+via_verify_command_stream(const uint32_t * buf, unsigned int size, drm_device_t *dev,
+			  int agp)
+{
+
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	drm_via_state_t *hc_state = &dev_priv->hc_state;
+	drm_via_state_t saved_state = *hc_state;
+	uint32_t cmd;
+	const uint32_t *buf_end = buf + ( size >> 2 );
+	verifier_state_t state = state_command;
+	int pro_group_a = dev_priv->pro_group_a;
+	
+	hc_state->dev = dev;
+	hc_state->unfinished = no_sequence;
+	hc_state->map_cache = NULL;
+	hc_state->agp = agp;
+	hc_state->buf_start = buf;
+	dev_priv->num_fire_offsets = 0;
+
+	while (buf < buf_end) {
+
+		switch (state) {
+		case state_header2:
+		  state = via_check_header2( &buf, buf_end, hc_state );
+			break;
+		case state_header1:
+			state = via_check_header1( &buf, buf_end );
+			break;
+		case state_vheader5:
+			state = via_check_vheader5( &buf, buf_end );
+			break;
+		case state_vheader6:
+			state = via_check_vheader6( &buf, buf_end );
+			break;
+		case state_command:
+			if (HALCYON_HEADER2 == (cmd = *buf)) 
+				state = state_header2;
+			else if ((cmd & HALCYON_HEADER1MASK) == HALCYON_HEADER1) 
+				state = state_header1;
+			else if (pro_group_a && (cmd & VIA_VIDEOMASK) == VIA_VIDEO_HEADER5)
+				state = state_vheader5;
+			else if (pro_group_a && (cmd & VIA_VIDEOMASK) == VIA_VIDEO_HEADER6)
+				state = state_vheader6;
+			else {
+				DRM_ERROR("Invalid / Unimplemented DMA HEADER command. 0x%x\n",
+					  cmd);
+				state = state_error;
+			}
+			break;
+		case state_error:
+		default:
+			*hc_state = saved_state;
+			return DRM_ERR(EINVAL);			
+		}
+	}	
+	if (state == state_error) {
+		*hc_state = saved_state;
+		return DRM_ERR(EINVAL);
+	}
+	return 0;
+}
+
+int 
+via_parse_command_stream(drm_device_t *dev, const uint32_t * buf, unsigned int size)
+{
+
+	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
+	uint32_t cmd;
+	const uint32_t *buf_end = buf + ( size >> 2 );
+	verifier_state_t state = state_command;
+	int fire_count = 0;
+	
+	while (buf < buf_end) {
+
+		switch (state) {
+		case state_header2:
+		  state = via_parse_header2( dev_priv, &buf, buf_end, &fire_count );
+			break;
+		case state_header1:
+			state = via_parse_header1( dev_priv, &buf, buf_end );
+			break;
+		case state_vheader5:
+			state = via_parse_vheader5( dev_priv, &buf, buf_end );
+			break;
+		case state_vheader6:
+			state = via_parse_vheader6( dev_priv, &buf, buf_end );
+			break;
+		case state_command:
+			if (HALCYON_HEADER2 == (cmd = *buf)) 
+				state = state_header2;
+			else if ((cmd & HALCYON_HEADER1MASK) == HALCYON_HEADER1) 
+				state = state_header1;
+			else if ((cmd & VIA_VIDEOMASK) == VIA_VIDEO_HEADER5)
+				state = state_vheader5;
+			else if ((cmd & VIA_VIDEOMASK) == VIA_VIDEO_HEADER6)
+				state = state_vheader6;
+			else {
+				DRM_ERROR("Invalid / Unimplemented DMA HEADER command. 0x%x\n",
+					  cmd);
+				state = state_error;
+			}
+			break;
+		case state_error:
+		default:
+			return DRM_ERR(EINVAL);			
+		}
+	}	
+	if (state == state_error) {
+		return DRM_ERR(EINVAL);
+	}
+	return 0;
+}
+
+
+
+static void 
+setup_hazard_table(hz_init_t init_table[], hazard_t table[], int size)
+{
+	int i;
+
+	for(i=0; i<256; ++i) {
+		table[i] = forbidden_command;
+	}
+
+	for(i=0; i<size; ++i) {
+		table[init_table[i].code] = init_table[i].hz;
+	}
+}
+
+void 
+via_init_command_verifier( void )
+{
+	setup_hazard_table(init_table1, table1, sizeof(init_table1) / sizeof(hz_init_t));
+	setup_hazard_table(init_table2, table2, sizeof(init_table2) / sizeof(hz_init_t));
+	setup_hazard_table(init_table3, table3, sizeof(init_table3) / sizeof(hz_init_t));
+}