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authorBjorn Helgaas <bhelgaas@google.com>2022-09-09 15:25:00 -0500
committerBjorn Helgaas <bhelgaas@google.com>2022-09-12 15:29:37 -0500
commite8bdc5ea481638e0a4fd5639050d2b170417f493 (patch)
tree84ad8da885d4b5aad8def5c1c52f38811fedb77e /include
parent118b9dfdc18b68abf736a71330e3ad1f5af7e47e (diff)
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PCI/PTM: Add pci_suspend_ptm() and pci_resume_ptm()
We disable PTM during suspend because that allows some Root Ports to enter lower-power PM states, which means we also need to disable PTM for all downstream devices. Add pci_suspend_ptm() and pci_resume_ptm() for this purpose. pci_enable_ptm() and pci_disable_ptm() are for drivers to use to enable or disable PTM. They use dev->ptm_enabled to keep track of whether PTM should be enabled. pci_suspend_ptm() and pci_resume_ptm() are PCI core-internal functions to temporarily disable PTM during suspend and (depending on dev->ptm_enabled) re-enable PTM during resume. Enable/disable/suspend/resume all use internal __pci_enable_ptm() and __pci_disable_ptm() functions that only update the PTM Control register. Outline: pci_enable_ptm(struct pci_dev *dev) { __pci_enable_ptm(dev); dev->ptm_enabled = 1; pci_ptm_info(dev); } pci_disable_ptm(struct pci_dev *dev) { if (dev->ptm_enabled) { __pci_disable_ptm(dev); dev->ptm_enabled = 0; } } pci_suspend_ptm(struct pci_dev *dev) { if (dev->ptm_enabled) __pci_disable_ptm(dev); } pci_resume_ptm(struct pci_dev *dev) { if (dev->ptm_enabled) __pci_enable_ptm(dev); } Nothing currently calls pci_resume_ptm(); the suspend path saves the PTM state before disabling PTM, so the PTM state restore in the resume path implicitly re-enables it. A future change will use pci_resume_ptm() to fix some problems with this approach. Link: https://lore.kernel.org/r/20220909202505.314195-5-helgaas@kernel.org Tested-by: Rajvi Jingar <rajvi.jingar@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Diffstat (limited to 'include')
-rw-r--r--include/linux/pci.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 54be939023a3..cb5f796e3319 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1678,10 +1678,12 @@ bool pci_ats_disabled(void);
#ifdef CONFIG_PCIE_PTM
int pci_enable_ptm(struct pci_dev *dev, u8 *granularity);
+void pci_disable_ptm(struct pci_dev *dev);
bool pcie_ptm_enabled(struct pci_dev *dev);
#else
static inline int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
{ return -EINVAL; }
+static inline void pci_disable_ptm(struct pci_dev *dev) { }
static inline bool pcie_ptm_enabled(struct pci_dev *dev)
{ return false; }
#endif