drivers/gpu/drm/nouveau/nvkm/subdev/pci/pcie.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/nouveau/nvkm/subdev/pci/pcie.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/nouveau/nvkm/subdev/pci/pcie.c
Extension
.c
Size
4340 bytes
Lines
165
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

#include "priv.h"

static char *nvkm_pcie_speeds[] = {
	"2.5GT/s",
	"5.0GT/s",
	"8.0GT/s",
};

static enum nvkm_pcie_speed
nvkm_pcie_speed(enum pci_bus_speed speed)
{
	switch (speed) {
	case PCIE_SPEED_2_5GT:
		return NVKM_PCIE_SPEED_2_5;
	case PCIE_SPEED_5_0GT:
		return NVKM_PCIE_SPEED_5_0;
	case PCIE_SPEED_8_0GT:
		return NVKM_PCIE_SPEED_8_0;
	default:
		/* XXX 0x16 is 8_0, assume 0x17 will be 16_0 for now */
		if (speed == 0x17)
			return NVKM_PCIE_SPEED_8_0;
		return -1;
	}
}

static int
nvkm_pcie_get_version(struct nvkm_pci *pci)
{
	if (!pci->func->pcie.version)
		return -ENOSYS;

	return pci->func->pcie.version(pci);
}

static int
nvkm_pcie_get_max_version(struct nvkm_pci *pci)
{
	if (!pci->func->pcie.version_supported)
		return -ENOSYS;

	return pci->func->pcie.version_supported(pci);
}

static int
nvkm_pcie_set_version(struct nvkm_pci *pci, int version)
{
	if (!pci->func->pcie.set_version)
		return -ENOSYS;

	nvkm_trace(&pci->subdev, "set to version %i\n", version);
	pci->func->pcie.set_version(pci, version);
	return nvkm_pcie_get_version(pci);
}

int
nvkm_pcie_oneinit(struct nvkm_pci *pci)
{
	if (pci->func->pcie.max_speed)
		nvkm_debug(&pci->subdev, "pcie max speed: %s\n",
			   nvkm_pcie_speeds[pci->func->pcie.max_speed(pci)]);
	return 0;
}

int
nvkm_pcie_init(struct nvkm_pci *pci)
{
	struct nvkm_subdev *subdev = &pci->subdev;
	int ret;

	/* raise pcie version first */
	ret = nvkm_pcie_get_version(pci);
	if (ret > 0) {
		int max_version = nvkm_pcie_get_max_version(pci);
		if (max_version > 0 && max_version > ret)
			ret = nvkm_pcie_set_version(pci, max_version);

		if (ret < max_version)
			nvkm_error(subdev, "couldn't raise version: %i\n", ret);
	}

	if (pci->func->pcie.init)
		pci->func->pcie.init(pci);

	if (pci->pcie.speed != -1)
		nvkm_pcie_set_link(pci, pci->pcie.speed, pci->pcie.width);

	return 0;
}

Annotation

Implementation Notes