[PATCH 10/14] drm/radeon: Make radeon card usable for Loongson.

[Huacai Chen <chenhuacai@xxxxxxxxx>]

1, Use 32bit DMA as a workaround.
2, Read vga bios offered by system firmware.
3, Handle io prot correctly for MIPS.
4, Don't use swiotlb on Loongson machines.

Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
Signed-off-by: Hongliang Tao <taohl@xxxxxxxxxx>
Signed-off-by: Hua Yan <yanh@xxxxxxxxxx>
---
 drivers/gpu/drm/drm_vm.c               |    2 +-
 drivers/gpu/drm/radeon/radeon_bios.c   |   32 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/radeon/radeon_device.c |    5 +++++
 drivers/gpu/drm/radeon/radeon_ttm.c    |    6 +++---
 drivers/gpu/drm/ttm/ttm_bo_util.c      |    2 +-
 include/drm/drm_sarea.h                |    2 ++
 6 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
index 961ee08..3f06166 100644
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -62,7 +62,7 @@ static pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma)
 		tmp = pgprot_writecombine(tmp);
 	else
 		tmp = pgprot_noncached(tmp);
-#elif defined(__sparc__) || defined(__arm__)
+#elif defined(__sparc__) || defined(__arm__) || defined(__mips__)
 	tmp = pgprot_noncached(tmp);
 #endif
 	return tmp;
diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
index 501f488..2630e22 100644
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -29,6 +29,7 @@
 #include "radeon_reg.h"
 #include "radeon.h"
 #include "atom.h"
+#include <asm/bootinfo.h>
 
 #include <linux/vga_switcheroo.h>
 #include <linux/slab.h>
@@ -73,6 +74,32 @@ static bool igp_read_bios_from_vram(struct radeon_device *rdev)
 	return true;
 }
 
+#ifdef CONFIG_CPU_LOONGSON3
+extern u64 vgabios_addr;
+static bool loongson3_read_bios(struct radeon_device *rdev)
+{
+	u8 *bios;
+	resource_size_t size = 512 * 1024; /* ??? */
+
+	rdev->bios = NULL;
+
+	bios = (u8 *)vgabios_addr;
+	if (!bios) {
+		return false;
+	}
+
+	if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
+		return false;
+	}
+	rdev->bios = kmalloc(size, GFP_KERNEL);
+	if (rdev->bios == NULL) {
+		return false;
+	}
+	memcpy(rdev->bios, bios, size);
+	return true;
+}
+#endif
+
 static bool radeon_read_bios(struct radeon_device *rdev)
 {
 	uint8_t __iomem *bios;
@@ -490,6 +517,11 @@ bool radeon_get_bios(struct radeon_device *rdev)
 	if (r == false) {
 		r = radeon_read_disabled_bios(rdev);
 	}
+#ifdef CONFIG_CPU_LOONGSON3
+	if (r == false) {
+		r = loongson3_read_bios(rdev);
+	}
+#endif
 	if (r == false || rdev->bios == NULL) {
 		DRM_ERROR("Unable to locate a BIOS ROM\n");
 		rdev->bios = NULL;
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 066c98b..8aac7ab 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -777,6 +777,11 @@ int radeon_device_init(struct radeon_device *rdev,
 	    (rdev->family < CHIP_RS400))
 		rdev->need_dma32 = true;
 
+#ifdef CONFIG_CPU_LOONGSON3
+	/* Workaround: Loongson 3 doesn't support 40-bits DMA */
+	rdev->need_dma32 = true;
+#endif
+
 	dma_bits = rdev->need_dma32 ? 32 : 40;
 	r = pci_set_dma_mask(rdev->pdev, DMA_BIT_MASK(dma_bits));
 	if (r) {
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index c94a225..f49bdd1 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -630,7 +630,7 @@ static int radeon_ttm_tt_populate(struct ttm_tt *ttm)
 	}
 #endif
 
-#ifdef CONFIG_SWIOTLB
+#if defined(CONFIG_SWIOTLB) && !defined(CONFIG_CPU_LOONGSON3)
 	if (swiotlb_nr_tbl()) {
 		return ttm_dma_populate(&gtt->ttm, rdev->dev);
 	}
@@ -676,7 +676,7 @@ static void radeon_ttm_tt_unpopulate(struct ttm_tt *ttm)
 	}
 #endif
 
-#ifdef CONFIG_SWIOTLB
+#if defined(CONFIG_SWIOTLB) && !defined(CONFIG_CPU_LOONGSON3)
 	if (swiotlb_nr_tbl()) {
 		ttm_dma_unpopulate(&gtt->ttm, rdev->dev);
 		return;
@@ -906,7 +906,7 @@ static int radeon_ttm_debugfs_init(struct radeon_device *rdev)
 	radeon_mem_types_list[i].show = &ttm_page_alloc_debugfs;
 	radeon_mem_types_list[i].driver_features = 0;
 	radeon_mem_types_list[i++].data = NULL;
-#ifdef CONFIG_SWIOTLB
+#if defined(CONFIG_SWIOTLB) && !defined(CONFIG_CPU_LOONGSON3)
 	if (swiotlb_nr_tbl()) {
 		sprintf(radeon_mem_types_names[i], "ttm_dma_page_pool");
 		radeon_mem_types_list[i].name = radeon_mem_types_names[i];
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index f8187ea..0df71ea 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -472,7 +472,7 @@ pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp)
 	else
 		tmp = pgprot_noncached(tmp);
 #endif
-#if defined(__sparc__)
+#if defined(__sparc__) || defined(__mips__)
 	if (!(caching_flags & TTM_PL_FLAG_CACHED))
 		tmp = pgprot_noncached(tmp);
 #endif
diff --git a/include/drm/drm_sarea.h b/include/drm/drm_sarea.h
index ee5389d..1d1a858 100644
--- a/include/drm/drm_sarea.h
+++ b/include/drm/drm_sarea.h
@@ -37,6 +37,8 @@
 /* SAREA area needs to be at least a page */
 #if defined(__alpha__)
 #define SAREA_MAX                       0x2000U
+#elif defined(__mips__)
+#define SAREA_MAX                       0x4000U
 #elif defined(__ia64__)
 #define SAREA_MAX                       0x10000U	/* 64kB */
 #else
-- 
1.7.7.3