void pci_ptm_init(struct pci_dev *dev)
{
int pos;
u32 cap, ctrl;
u8 local_clock;
struct pci_dev *ups;
if (!pci_is_pcie(dev))
return;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);
if (!pos)
return;
/*
* Enable PTM only on interior devices (root ports, switch ports,
* etc.) on the assumption that it causes no link traffic until an
* endpoint enables it.
*/
if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT ||
pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END))
return;
pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
local_clock = (cap & PCI_PTM_GRANULARITY_MASK) >> 8;
/*
* There's no point in enabling PTM unless it's enabled in the
* upstream device or this device can be a PTM Root itself. Per
* the spec recommendation (PCIe r3.1, sec 7.32.3), select the
* furthest upstream Time Source as the PTM Root.
*/
ups = pci_upstream_bridge(dev);
if (ups && ups->ptm_enabled) {
ctrl = PCI_PTM_CTRL_ENABLE;
if (ups->ptm_granularity == 0)
dev->ptm_granularity = 0;
else if (ups->ptm_granularity > local_clock)
dev->ptm_granularity = ups->ptm_granularity;
} else {
if (cap & PCI_PTM_CAP_ROOT) {
ctrl = PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT;
dev->ptm_root = 1;
dev->ptm_granularity = local_clock;
} else
return;
}
ctrl |= dev->ptm_granularity << 8;
pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl);
dev->ptm_enabled = 1;
pci_ptm_info(dev);
}
/**
* amdgpu_atpx_detect - detect whether we have PX
*
* Check if we have a PX system (all asics).
* Returns true if we have a PX system, false if not.
*/
static bool amdgpu_atpx_detect(void)
{
char acpi_method_name[255] = { 0 };
struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
struct pci_dev *pdev = NULL;
bool has_atpx = false;
int vga_count = 0;
bool d3_supported = false;
struct pci_dev *parent_pdev;
while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
vga_count++;
has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true);
parent_pdev = pci_upstream_bridge(pdev);
d3_supported |= parent_pdev && parent_pdev->bridge_d3;
amdgpu_atpx_get_quirks(pdev);
}
while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) {
vga_count++;
has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true);
parent_pdev = pci_upstream_bridge(pdev);
d3_supported |= parent_pdev && parent_pdev->bridge_d3;
amdgpu_atpx_get_quirks(pdev);
}
if (has_atpx && vga_count == 2) {
acpi_get_name(amdgpu_atpx_priv.atpx.handle, ACPI_FULL_PATHNAME, &buffer);
pr_info("vga_switcheroo: detected switching method %s handle\n",
acpi_method_name);
amdgpu_atpx_priv.atpx_detected = true;
amdgpu_atpx_priv.bridge_pm_usable = d3_supported;
amdgpu_atpx_init();
return true;
}
return false;
}
/**
* radeon_atpx_detect - detect whether we have PX
*
* Check if we have a PX system (all asics).
* Returns true if we have a PX system, false if not.
*/
static bool radeon_atpx_detect(void)
{
char acpi_method_name[255] = { 0 };
struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
struct pci_dev *pdev = NULL;
bool has_atpx = false;
int vga_count = 0;
bool d3_supported = false;
struct pci_dev *parent_pdev;
while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
vga_count++;
has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
parent_pdev = pci_upstream_bridge(pdev);
d3_supported |= parent_pdev && parent_pdev->bridge_d3;
}
/* some newer PX laptops mark the dGPU as a non-VGA display device */
while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) {
vga_count++;
has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
parent_pdev = pci_upstream_bridge(pdev);
d3_supported |= parent_pdev && parent_pdev->bridge_d3;
}
if (has_atpx && vga_count == 2) {
acpi_get_name(radeon_atpx_priv.atpx.handle, ACPI_FULL_PATHNAME, &buffer);
printk(KERN_INFO "vga_switcheroo: detected switching method %s handle\n",
acpi_method_name);
radeon_atpx_priv.atpx_detected = true;
radeon_atpx_priv.bridge_pm_usable = d3_supported;
radeon_atpx_init();
return true;
}
return false;
}
int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
{
int pos;
u32 cap, ctrl;
struct pci_dev *ups;
if (!pci_is_pcie(dev))
return -EINVAL;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);
if (!pos)
return -EINVAL;
pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
if (!(cap & PCI_PTM_CAP_REQ))
return -EINVAL;
/*
* For a PCIe Endpoint, PTM is only useful if the endpoint can
* issue PTM requests to upstream devices that have PTM enabled.
*
* For Root Complex Integrated Endpoints, there is no upstream
* device, so there must be some implementation-specific way to
* associate the endpoint with a time source.
*/
if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
ups = pci_upstream_bridge(dev);
if (!ups || !ups->ptm_enabled)
return -EINVAL;
dev->ptm_granularity = ups->ptm_granularity;
} else if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
dev->ptm_granularity = 0;
} else
return -EINVAL;
ctrl = PCI_PTM_CTRL_ENABLE;
ctrl |= dev->ptm_granularity << 8;
pci_write_config_dword(dev, pos + PCI_PTM_CTRL, ctrl);
dev->ptm_enabled = 1;
pci_ptm_info(dev);
if (granularity)
*granularity = dev->ptm_granularity;
return 0;
}
