drm/radeon: implement pci config reset for evergreen/cayman (v2)

pci config reset is a low level reset that resets
the entire chip from the bus interface.  It can
be more reliable if soft reset fails.

v2: put behind module parameter

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

3 files changed, 59 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 21d975007037..4116d0279596 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -146,6 +146,7 @@ extern u32 si_get_csb_size(struct radeon_device *rdev);
 extern void si_get_csb_buffer(struct radeon_device *rdev, volatile u32 *buffer);
 extern u32 cik_get_csb_size(struct radeon_device *rdev);
 extern void cik_get_csb_buffer(struct radeon_device *rdev, volatile u32 *buffer);
+extern void rv770_set_clk_bypass_mode(struct radeon_device *rdev);
 
 static const u32 evergreen_golden_registers[] =
 {
@@ -3867,6 +3868,48 @@ static void evergreen_gpu_soft_reset(struct radeon_device *rdev, u32 reset_mask)
         evergreen_print_gpu_status_regs(rdev);
 }
 
+void evergreen_gpu_pci_config_reset(struct radeon_device *rdev)
+{
+        struct evergreen_mc_save save;
+        u32 tmp, i;
+
+        dev_info(rdev->dev, "GPU pci config reset\n");
+
+        /* disable dpm? */
+
+        /* Disable CP parsing/prefetching */
+        WREG32(CP_ME_CNTL, CP_ME_HALT | CP_PFP_HALT);
+        udelay(50);
+        /* Disable DMA */
+        tmp = RREG32(DMA_RB_CNTL);
+        tmp &= ~DMA_RB_ENABLE;
+        WREG32(DMA_RB_CNTL, tmp);
+        /* XXX other engines? */
+
+        /* halt the rlc */
+        r600_rlc_stop(rdev);
+
+        udelay(50);
+
+        /* set mclk/sclk to bypass */
+        rv770_set_clk_bypass_mode(rdev);
+        /* disable BM */
+        pci_clear_master(rdev->pdev);
+        /* disable mem access */
+        evergreen_mc_stop(rdev, &save);
+        if (evergreen_mc_wait_for_idle(rdev)) {
+                dev_warn(rdev->dev, "Wait for MC idle timed out !\n");
+        }
+        /* reset */
+        radeon_pci_config_reset(rdev);
+        /* wait for asic to come out of reset */
+        for (i = 0; i < rdev->usec_timeout; i++) {
+                if (RREG32(CONFIG_MEMSIZE) != 0xffffffff)
+                        break;
+                udelay(1);
+        }
+}
+
 int evergreen_asic_reset(struct radeon_device *rdev)
 {
         u32 reset_mask;
@@ -3876,10 +3919,17 @@ int evergreen_asic_reset(struct radeon_device *rdev)
         if (reset_mask)
                 r600_set_bios_scratch_engine_hung(rdev, true);
 
+        /* try soft reset */
         evergreen_gpu_soft_reset(rdev, reset_mask);
 
         reset_mask = evergreen_gpu_check_soft_reset(rdev);
 
+        /* try pci config reset */
+        if (reset_mask && radeon_hard_reset)
+                evergreen_gpu_pci_config_reset(rdev);
+
+        reset_mask = evergreen_gpu_check_soft_reset(rdev);
+
         if (!reset_mask)
                 r600_set_bios_scratch_engine_hung(rdev, false);
 
diff --git a/drivers/gpu/drm/radeon/evergreend.h b/drivers/gpu/drm/radeon/evergreend.h
index 17f990798992..f9c7963b3ee6 100644
--- a/drivers/gpu/drm/radeon/evergreend.h
+++ b/drivers/gpu/drm/radeon/evergreend.h
@@ -82,12 +82,16 @@
 #define CG_SPLL_FUNC_CNTL_2                             0x604
 #define         SCLK_MUX_SEL(x)                         ((x) << 0)
 #define         SCLK_MUX_SEL_MASK                       (0x1ff << 0)
+#define         SCLK_MUX_UPDATE                         (1 << 26)
 #define CG_SPLL_FUNC_CNTL_3                             0x608
 #define         SPLL_FB_DIV(x)                          ((x) << 0)
 #define         SPLL_FB_DIV_MASK                        (0x3ffffff << 0)
 #define         SPLL_DITHEN                             (1 << 28)
+#define CG_SPLL_STATUS                                  0x60c
+#define         SPLL_CHG_STATUS                         (1 << 1)
 
 #define MPLL_CNTL_MODE                                  0x61c
+#       define MPLL_MCLK_SEL                            (1 << 11)
 #       define SS_SSEN                                  (1 << 24)
 #       define SS_DSMODE_EN                             (1 << 25)
 
diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index 05a900945613..9f11a55962b5 100644
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -174,6 +174,7 @@ extern void evergreen_pcie_gen2_enable(struct radeon_device *rdev);
 extern void evergreen_program_aspm(struct radeon_device *rdev);
 extern void sumo_rlc_fini(struct radeon_device *rdev);
 extern int sumo_rlc_init(struct radeon_device *rdev);
+extern void evergreen_gpu_pci_config_reset(struct radeon_device *rdev);
 
 /* Firmware Names */
 MODULE_FIRMWARE("radeon/BARTS_pfp.bin");
@@ -1878,8 +1879,10 @@ int cayman_asic_reset(struct radeon_device *rdev)
 
         reset_mask = cayman_gpu_check_soft_reset(rdev);
 
-        if (!reset_mask)
-                r600_set_bios_scratch_engine_hung(rdev, false);
+        if (reset_mask)
+                evergreen_gpu_pci_config_reset(rdev);
+
+        r600_set_bios_scratch_engine_hung(rdev, false);
 
         return 0;
 }