[PATCH V2 12/16] drm/radeon: Make radeon card usable for Loongson.

[Huacai Chen]

1, Use 32-bit DMA as a workaround (Loongson has a hardware bug that it
   doesn't support DMA address above 4GB).
2, Read vga bios offered by system firmware.
3, Handle io prot correctly for MIPS.
4, Don't use swiotlb on Loongson machines (when use swiotlb, GPU reset
   occurs at resume from suspend).

Signed-off-by: Huacai Chen <chenhc at lemote.com>
Signed-off-by: Hongliang Tao <taohl at lemote.com>
Signed-off-by: Hua Yan <yanh at lemote.com>
Cc: dri-devel at lists.freedesktop.org
---
 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