drm/radeon: Use direct mapping for fast fb access on RS780/RS880 (v2)

v2: fix trailing whitespace

Signed-off-by: Samuel Li <samuel.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 0f30d0df1e07..0e5341695922 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1046,6 +1046,24 @@ int r600_mc_wait_for_idle(struct radeon_device *rdev)
         return -1;
 }
 
+uint32_t rs780_mc_rreg(struct radeon_device *rdev, uint32_t reg)
+{
+        uint32_t r;
+
+        WREG32(R_0028F8_MC_INDEX, S_0028F8_MC_IND_ADDR(reg));
+        r = RREG32(R_0028FC_MC_DATA);
+        WREG32(R_0028F8_MC_INDEX, ~C_0028F8_MC_IND_ADDR);
+        return r;
+}
+
+void rs780_mc_wreg(struct radeon_device *rdev, uint32_t reg, uint32_t v)
+{
+        WREG32(R_0028F8_MC_INDEX, S_0028F8_MC_IND_ADDR(reg) |
+                S_0028F8_MC_IND_WR_EN(1));
+        WREG32(R_0028FC_MC_DATA, v);
+        WREG32(R_0028F8_MC_INDEX, 0x7F);
+}
+
 static void r600_mc_program(struct radeon_device *rdev)
 {
         struct rv515_mc_save save;
@@ -1181,6 +1199,8 @@ static int r600_mc_init(struct radeon_device *rdev)
 {
         u32 tmp;
         int chansize, numchan;
+        uint32_t h_addr, l_addr;
+        unsigned long long k8_addr;
 
         /* Get VRAM informations */
         rdev->mc.vram_is_ddr = true;
@@ -1221,7 +1241,30 @@ static int r600_mc_init(struct radeon_device *rdev)
         if (rdev->flags & RADEON_IS_IGP) {
                 rs690_pm_info(rdev);
                 rdev->mc.igp_sideport_enabled = radeon_atombios_sideport_present(rdev);
+
+                if (rdev->family == CHIP_RS780 || rdev->family == CHIP_RS880) {
+                        /* Use K8 direct mapping for fast fb access. */
+                        rdev->fastfb_working = false;
+                        h_addr = G_000012_K8_ADDR_EXT(RREG32_MC(R_000012_MC_MISC_UMA_CNTL));
+                        l_addr = RREG32_MC(R_000011_K8_FB_LOCATION);
+                        k8_addr = ((unsigned long long)h_addr) << 32 | l_addr;
+#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE)
+                        if (k8_addr + rdev->mc.visible_vram_size < 0x100000000ULL)
+#endif
+                        {
+                                /* FastFB shall be used with UMA memory. Here it is simply disabled when sideport
+                                * memory is present.
+                                */
+                                if (rdev->mc.igp_sideport_enabled == false && radeon_fastfb == 1) {
+                                        DRM_INFO("Direct mapping: aper base at 0x%llx, replaced by direct mapping base 0x%llx.\n",
+                                                (unsigned long long)rdev->mc.aper_base, k8_addr);
+                                        rdev->mc.aper_base = (resource_size_t)k8_addr;
+                                        rdev->fastfb_working = true;
+                                }
+                        }
+                }
         }
+
         radeon_update_bandwidth_info(rdev);
         return 0;
 }