drm/radeon/kms: AGP systems need PCI bus mastering enabled

We might not hit this yet, but when if we do any sort of writeback
we really need to enable PCI bus mastering on these systems from
what I can see.

This enables PCI BM on all radeons that require it.
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/r100.c

@@ -94,6 +94,15 @@ int r100_pci_gart_init(struct radeon_device *rdev)
 	return radeon_gart_table_ram_alloc(rdev);
 }
 
+/* required on r1xx, r2xx, r300, r(v)350, r420/r481, rs400/rs480 */
+void r100_enable_bm(struct radeon_device *rdev)
+{
+	uint32_t tmp;
+	/* Enable bus mastering */
+	tmp = RREG32(RADEON_BUS_CNTL) & ~RADEON_BUS_MASTER_DIS;
+	WREG32(RADEON_BUS_CNTL, tmp);
+}
+
 int r100_pci_gart_enable(struct radeon_device *rdev)
 {
 	uint32_t tmp;
@@ -105,9 +114,6 @@ int r100_pci_gart_enable(struct radeon_device *rdev)
 	WREG32(RADEON_AIC_LO_ADDR, rdev->mc.gtt_location);
 	tmp = rdev->mc.gtt_location + rdev->mc.gtt_size - 1;
 	WREG32(RADEON_AIC_HI_ADDR, tmp);
-	/* Enable bus mastering */
-	tmp = RREG32(RADEON_BUS_CNTL) & ~RADEON_BUS_MASTER_DIS;
-	WREG32(RADEON_BUS_CNTL, tmp);
 	/* set PCI GART page-table base address */
 	WREG32(RADEON_AIC_PT_BASE, rdev->gart.table_addr);
 	tmp = RREG32(RADEON_AIC_CNTL) | RADEON_PCIGART_TRANSLATE_EN;
@@ -3108,6 +3114,7 @@ static int r100_startup(struct radeon_device *rdev)
 	r100_gpu_init(rdev);
 	/* Initialize GART (initialize after TTM so we can allocate
 	 * memory through TTM but finalize after TTM) */
+	r100_enable_bm(rdev);
 	if (rdev->flags & RADEON_IS_PCI) {
 		r = r100_pci_gart_enable(rdev);
 		if (r)

drivers/gpu/drm/radeon/r300.c

@@ -1193,6 +1193,12 @@ static int r300_startup(struct radeon_device *rdev)
 		if (r)
 			return r;
 	}
+
+	if (rdev->family == CHIP_R300 ||
+	    rdev->family == CHIP_R350 ||
+	    rdev->family == CHIP_RV350)
+		r100_enable_bm(rdev);
+
 	if (rdev->flags & RADEON_IS_PCI) {
 		r = r100_pci_gart_enable(rdev);
 		if (r)

drivers/gpu/drm/radeon/r420.c

@@ -335,6 +335,9 @@ int r420_init(struct radeon_device *rdev)
 	if (r) {
 		return r;
 	}
+	if (rdev->family == CHIP_R420)
+		r100_enable_bm(rdev);
+
 	if (rdev->flags & RADEON_IS_PCIE) {
 		r = rv370_pcie_gart_init(rdev);
 		if (r)

drivers/gpu/drm/radeon/radeon.h

@@ -1029,6 +1029,7 @@ extern int r100_cs_parse_packet0(struct radeon_cs_parser *p,
 extern int r100_cs_packet_parse(struct radeon_cs_parser *p,
 				struct radeon_cs_packet *pkt,
 				unsigned idx);
+extern void r100_enable_bm(struct radeon_device *rdev);
 
 /* rv200,rv250,rv280 */
 extern void r200_set_safe_registers(struct radeon_device *rdev);

drivers/gpu/drm/radeon/rs400.c

@@ -387,6 +387,7 @@ static int rs400_startup(struct radeon_device *rdev)
 	r300_clock_startup(rdev);
 	/* Initialize GPU configuration (# pipes, ...) */
 	rs400_gpu_init(rdev);
+	r100_enable_bm(rdev);
 	/* Initialize GART (initialize after TTM so we can allocate
 	 * memory through TTM but finalize after TTM) */
 	r = rs400_gart_enable(rdev);