drm/radeon/kms: add support for gen2 pcie link speeds

Supported on rv6xx/r7xx/evergreen.  Cards come up in gen1 mode.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/rv770.c b/drivers/gpu/drm/radeon/rv770.c
index 645aa1f..3a264aa 100644
--- a/drivers/gpu/drm/radeon/rv770.c
+++ b/drivers/gpu/drm/radeon/rv770.c
@@ -41,6 +41,7 @@
 
 static void rv770_gpu_init(struct radeon_device *rdev);
 void rv770_fini(struct radeon_device *rdev);
+static void rv770_pcie_gen2_enable(struct radeon_device *rdev);
 
 u32 rv770_page_flip(struct radeon_device *rdev, int crtc_id, u64 crtc_base)
 {
@@ -1124,6 +1125,9 @@ static int rv770_startup(struct radeon_device *rdev)
 {
 	int r;
 
+	/* enable pcie gen2 link */
+	rv770_pcie_gen2_enable(rdev);
+
 	if (!rdev->me_fw || !rdev->pfp_fw || !rdev->rlc_fw) {
 		r = r600_init_microcode(rdev);
 		if (r) {
@@ -1362,3 +1366,75 @@ void rv770_fini(struct radeon_device *rdev)
 	rdev->bios = NULL;
 	radeon_dummy_page_fini(rdev);
 }
+
+static void rv770_pcie_gen2_enable(struct radeon_device *rdev)
+{
+	u32 link_width_cntl, lanes, speed_cntl, tmp;
+	u16 link_cntl2;
+
+	if (rdev->flags & RADEON_IS_IGP)
+		return;
+
+	if (!(rdev->flags & RADEON_IS_PCIE))
+		return;
+
+	/* x2 cards have a special sequence */
+	if (ASIC_IS_X2(rdev))
+		return;
+
+	/* advertise upconfig capability */
+	link_width_cntl = RREG32_PCIE_P(PCIE_LC_LINK_WIDTH_CNTL);
+	link_width_cntl &= ~LC_UPCONFIGURE_DIS;
+	WREG32_PCIE_P(PCIE_LC_LINK_WIDTH_CNTL, link_width_cntl);
+	link_width_cntl = RREG32_PCIE_P(PCIE_LC_LINK_WIDTH_CNTL);
+	if (link_width_cntl & LC_RENEGOTIATION_SUPPORT) {
+		lanes = (link_width_cntl & LC_LINK_WIDTH_RD_MASK) >> LC_LINK_WIDTH_RD_SHIFT;
+		link_width_cntl &= ~(LC_LINK_WIDTH_MASK |
+				     LC_RECONFIG_ARC_MISSING_ESCAPE);
+		link_width_cntl |= lanes | LC_RECONFIG_NOW |
+			LC_RENEGOTIATE_EN | LC_UPCONFIGURE_SUPPORT;
+		WREG32_PCIE_P(PCIE_LC_LINK_WIDTH_CNTL, link_width_cntl);
+	} else {
+		link_width_cntl |= LC_UPCONFIGURE_DIS;
+		WREG32_PCIE_P(PCIE_LC_LINK_WIDTH_CNTL, link_width_cntl);
+	}
+
+	speed_cntl = RREG32_PCIE_P(PCIE_LC_SPEED_CNTL);
+	if ((speed_cntl & LC_OTHER_SIDE_EVER_SENT_GEN2) &&
+	    (speed_cntl & LC_OTHER_SIDE_SUPPORTS_GEN2)) {
+
+		tmp = RREG32(0x541c);
+		WREG32(0x541c, tmp | 0x8);
+		WREG32(MM_CFGREGS_CNTL, MM_WR_TO_CFG_EN);
+		link_cntl2 = RREG16(0x4088);
+		link_cntl2 &= ~TARGET_LINK_SPEED_MASK;
+		link_cntl2 |= 0x2;
+		WREG16(0x4088, link_cntl2);
+		WREG32(MM_CFGREGS_CNTL, 0);
+
+		speed_cntl = RREG32_PCIE_P(PCIE_LC_SPEED_CNTL);
+		speed_cntl &= ~LC_TARGET_LINK_SPEED_OVERRIDE_EN;
+		WREG32_PCIE_P(PCIE_LC_SPEED_CNTL, speed_cntl);
+
+		speed_cntl = RREG32_PCIE_P(PCIE_LC_SPEED_CNTL);
+		speed_cntl |= LC_CLR_FAILED_SPD_CHANGE_CNT;
+		WREG32_PCIE_P(PCIE_LC_SPEED_CNTL, speed_cntl);
+
+		speed_cntl = RREG32_PCIE_P(PCIE_LC_SPEED_CNTL);
+		speed_cntl &= ~LC_CLR_FAILED_SPD_CHANGE_CNT;
+		WREG32_PCIE_P(PCIE_LC_SPEED_CNTL, speed_cntl);
+
+		speed_cntl = RREG32_PCIE_P(PCIE_LC_SPEED_CNTL);
+		speed_cntl |= LC_GEN2_EN_STRAP;
+		WREG32_PCIE_P(PCIE_LC_SPEED_CNTL, speed_cntl);
+
+	} else {
+		link_width_cntl = RREG32_PCIE_P(PCIE_LC_LINK_WIDTH_CNTL);
+		/* XXX: only disable it if gen1 bridge vendor == 0x111d or 0x1106 */
+		if (1)
+			link_width_cntl |= LC_UPCONFIGURE_DIS;
+		else
+			link_width_cntl &= ~LC_UPCONFIGURE_DIS;
+		WREG32_PCIE_P(PCIE_LC_LINK_WIDTH_CNTL, link_width_cntl);
+	}
+}