[Nouveau] [PATCH v4 6/9] pci: implement PCIe speed change for kepler+

[Karol Herbst]

v2: rename functions
v3: remove pcie2 accessors

Signed-off-by: Karol Herbst <nouveau at karolherbst.de>
---
 drm/nouveau/nvkm/subdev/pci/gk104.c | 186 ++++++++++++++++++++++++++++++++++++
 1 file changed, 186 insertions(+)

diff --git a/drm/nouveau/nvkm/subdev/pci/gk104.c b/drm/nouveau/nvkm/subdev/pci/gk104.c
index 47c4736..e88817c 100644
--- a/drm/nouveau/nvkm/subdev/pci/gk104.c
+++ b/drm/nouveau/nvkm/subdev/pci/gk104.c
@@ -23,6 +23,187 @@
  */
 #include "priv.h"
 
+static int
+gk104_pcie_version_supported(struct nvkm_pci *pci)
+{
+	return (nvkm_rd32(pci->subdev.device, 0x8c1c0) & 0x4) == 0x4 ? 2 : 1;
+}
+
+static void
+gk104_pcie_set_cap_speed(struct nvkm_pci *pci, enum nvkm_pcie_speed speed)
+{
+	struct nvkm_device *device = pci->subdev.device;
+
+	switch (speed) {
+	case NVKM_PCIE_SPEED_2_5:
+		gf100_pcie_set_cap_speed(pci, false);
+		nvkm_mask(device, 0x8c1c0, 0x30000, 0x10000);
+		break;
+	case NVKM_PCIE_SPEED_5_0:
+		gf100_pcie_set_cap_speed(pci, true);
+		nvkm_mask(device, 0x8c1c0, 0x30000, 0x20000);
+		break;
+	case NVKM_PCIE_SPEED_8_0:
+		gf100_pcie_set_cap_speed(pci, true);
+		nvkm_mask(device, 0x8c1c0, 0x30000, 0x30000);
+		break;
+	}
+}
+
+static enum nvkm_pcie_speed
+gk104_pcie_cap_speed(struct nvkm_pci *pci)
+{
+	int speed = gf100_pcie_cap_speed(pci);
+	if (speed < 0)
+		return speed;
+
+	if (speed == 0)
+		return NVKM_PCIE_SPEED_2_5;
+
+	if (speed >= 1) {
+		int speed2 = nvkm_rd32(pci->subdev.device, 0x8c1c0) & 0x30000;
+		switch (speed2) {
+		case 0x00000:
+		case 0x10000:
+			return NVKM_PCIE_SPEED_2_5;
+		case 0x20000:
+			return NVKM_PCIE_SPEED_5_0;
+		case 0x30000:
+			return NVKM_PCIE_SPEED_8_0;
+		}
+	}
+	return -EINVAL;
+}
+
+static void
+gk104_pcie_set_lnkctl_speed(struct nvkm_pci *pci, enum nvkm_pcie_speed speed)
+{
+	u8 reg_v = 0;
+	switch (speed) {
+	case NVKM_PCIE_SPEED_2_5:
+		reg_v = 1;
+		break;
+	case NVKM_PCIE_SPEED_5_0:
+		reg_v = 2;
+		break;
+	case NVKM_PCIE_SPEED_8_0:
+		reg_v = 3;
+		break;
+	}
+	nvkm_pci_mask(pci, 0xa8, 0x3, reg_v);
+}
+
+static enum nvkm_pcie_speed
+gk104_pcie_lnkctl_speed(struct nvkm_pci *pci)
+{
+	u8 reg_v = nvkm_pci_rd32(pci, 0xa8) & 0x3;
+	switch (reg_v) {
+	case 0:
+	case 1:
+		return NVKM_PCIE_SPEED_2_5;
+	case 2:
+		return NVKM_PCIE_SPEED_5_0;
+	case 3:
+		return NVKM_PCIE_SPEED_8_0;
+	}
+	return -1;
+}
+
+static enum nvkm_pcie_speed
+gk104_pcie_max_speed(struct nvkm_pci *pci)
+{
+	u32 max_speed = nvkm_rd32(pci->subdev.device, 0x8c1c0) & 0x300000;
+	switch (max_speed) {
+	case 0x000000:
+		return NVKM_PCIE_SPEED_8_0;
+	case 0x100000:
+		return NVKM_PCIE_SPEED_5_0;
+	case 0x200000:
+		return NVKM_PCIE_SPEED_2_5;
+	}
+	return NVKM_PCIE_SPEED_2_5;
+}
+
+static void
+gk104_pcie_set_link_speed(struct nvkm_pci *pci, enum nvkm_pcie_speed speed)
+{
+	struct nvkm_device *device = pci->subdev.device;
+	u32 mask_value;
+
+	switch (speed) {
+	default:
+	case NVKM_PCIE_SPEED_2_5:
+		mask_value = 0x80000;
+		break;
+	case NVKM_PCIE_SPEED_5_0:
+		mask_value = 0x40000;
+		break;
+	case NVKM_PCIE_SPEED_8_0:
+		mask_value = 0x00000;
+		break;
+	}
+	nvkm_mask(device, 0x8c040, 0xc0000, mask_value);
+	nvkm_mask(device, 0x8c040, 0x1, 0x1);
+}
+
+static int
+gk104_pcie_init(struct nvkm_pci * pci)
+{
+	if (!pci_is_pcie(pci->pdev))
+		return -ENODEV;
+
+	if (gf100_pcie_version(pci) > 1) {
+		enum nvkm_pcie_speed
+			lnkctl_speed = gk104_pcie_lnkctl_speed(pci),
+			max_speed = gk104_pcie_max_speed(pci),
+			cap_speed = gk104_pcie_cap_speed(pci);
+
+		if (cap_speed != max_speed) {
+			nvkm_debug(&pci->subdev, "adjusting cap speed to max speed\n");
+			gk104_pcie_set_cap_speed(pci, max_speed);
+			cap_speed = gk104_pcie_cap_speed(pci);
+			if (cap_speed != max_speed)
+				nvkm_error(&pci->subdev, "couldn't adjust cap speed\n");
+		}
+
+		if (lnkctl_speed != max_speed) {
+			nvkm_debug(&pci->subdev,
+				"adjusting link control speed to max speed\n");
+			gk104_pcie_set_lnkctl_speed(pci, max_speed);
+			lnkctl_speed = gk104_pcie_lnkctl_speed(pci);
+			if (lnkctl_speed != max_speed)
+				nvkm_error(&pci->subdev,
+					"couldn't adjust link control speed\n");
+		}
+	}
+	return 0;
+}
+
+static int
+gk104_pcie_set_link(struct nvkm_pci *pci, enum nvkm_pcie_speed req_speed,
+	u8 req_width)
+{
+	enum nvkm_pcie_speed
+		lnk_ctl_speed = gk104_pcie_lnkctl_speed(pci),
+		lnk_cap_speed = gk104_pcie_cap_speed(pci);
+
+	if (req_speed > lnk_cap_speed) {
+		req_speed = lnk_cap_speed;
+		nvkm_warn(&pci->subdev, "dropping requested PCIe speed due to low"
+				" cap speed\n");
+	}
+
+	if (req_speed > lnk_ctl_speed) {
+		req_speed = lnk_ctl_speed;
+		nvkm_warn(&pci->subdev, "dropping requested PCIe speed due to low"
+				" control speed\n");
+	}
+
+	gk104_pcie_set_link_speed(pci, req_speed);
+	return 0;
+}
+
+
 static const struct nvkm_pci_func
 gk104_pci_func = {
 	.rd32 = nv40_pci_rd32,
@@ -30,10 +211,15 @@ gk104_pci_func = {
 	.wr32 = nv40_pci_wr32,
 	.msi_rearm = nv40_pci_msi_rearm,
 
+	.pcie.init = gk104_pcie_init,
+	.pcie.set_link = gk104_pcie_set_link,
+
+	.pcie.max_speed = gk104_pcie_max_speed,
 	.pcie.cur_speed = g84_pcie_cur_speed,
 
 	.pcie.set_version = gf100_pcie_set_version,
 	.pcie.version = gf100_pcie_version,
+	.pcie.version_supported = gk104_pcie_version_supported,
 };
 
 int
-- 
2.6.4