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>

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);
 

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)
 

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");
@@ -1878,7 +1879,9 @@ int cayman_asic_reset(struct radeon_device *rdev)
 
 	reset_mask = cayman_gpu_check_soft_reset(rdev);
 
-	if (!reset_mask)
+	if (reset_mask)
+		evergreen_gpu_pci_config_reset(rdev);
+
 	r600_set_bios_scratch_engine_hung(rdev, false);
 
 	return 0;