lkml.org 
[lkml]   [2022]   [Sep]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 2/3] PCI/PTM: Implement pci_enable_ptm() for Root Ports, Switch Upstream Ports
Date
From: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/pcie/ptm.c | 34 +++++++++++++++++++++++++++-------
1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
index b6a417247ce3..ad283818f37b 100644
--- a/drivers/pci/pcie/ptm.c
+++ b/drivers/pci/pcie/ptm.c
@@ -167,11 +167,11 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
if (!pos)
return -EINVAL;

- pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
- if (!(cap & PCI_PTM_CAP_REQ))
- return -EINVAL;
-
/*
+ * Root Ports and Switch Upstream Ports have been configured
+ * by pci_ptm_init(), so preserve their PCI_PTM_CTRL_ROOT and
+ * granularity.
+ *
* For a PCIe Endpoint, PTM is only useful if the endpoint can
* issue PTM requests to upstream devices that have PTM enabled.
*
@@ -179,19 +179,39 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
* 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) {
+ if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
+ pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+ if (pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) {
+ ups = pci_upstream_bridge(dev);
+ if (!ups || !ups->ptm_enabled)
+ return -EINVAL;
+ }
+
+ pci_read_config_dword(dev, pos + PCI_PTM_CTRL, &ctrl);
+ ctrl |= PCI_PTM_CTRL_ENABLE;
+ } else if (pci_pcie_type(dev) == PCI_EXP_TYPE_ENDPOINT) {
+ pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+ if (!(cap & PCI_PTM_CAP_REQ))
+ return -EINVAL;
+
ups = pci_upstream_bridge(dev);
if (!ups || !ups->ptm_enabled)
return -EINVAL;

dev->ptm_granularity = ups->ptm_granularity;
+ ctrl = PCI_PTM_CTRL_ENABLE;
+ ctrl |= dev->ptm_granularity << 8;
} else if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
+ pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap);
+ if (!(cap & PCI_PTM_CAP_REQ))
+ return -EINVAL;
+
dev->ptm_granularity = 0;
+ ctrl = PCI_PTM_CTRL_ENABLE;
+ ctrl |= dev->ptm_granularity << 8;
} 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;

--
2.25.1
\
 
 \ /
  Last update: 2022-09-03 01:38    [W:0.178 / U:0.824 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site