PCI/DPC: Expose dpc_process_error(), dpc_reset_link() for use by EDR (aea47413) · Commits · 戴 / test

If firmware controls DPC, it is generally responsible for managing the DPC capability and events, and the OS should not access the DPC capability. However, if firmware controls DPC and both the OS and the platform support Error Disconnect Recover (EDR) notifications, the OS EDR notify handler is responsible for recovery, and the notify handler may read/write the DPC capability until it clears the DPC Trigger Status bit. See [1], sec 4.5.1, table 4-6. Expose some DPC error handling functions so they can be used by the EDR notify handler. [1] Downstream Port Containment Related Enhancements ECN, Jan 28, 2019, affecting PCI Firmware Specification, Rev. 3.2 https://members.pcisig.com/wg/PCI-SIG/document/12888 Link: https://lore.kernel.org/r/e9000bb15b3a4293e81d98bb29ead7c84a6393c9.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by:

Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by:

Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pci.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -449,6 +449,8 @@ void aer_print_error(struct pci_dev dev, struct aer_err_info info);
		void pci_save_dpc_state(struct pci_dev *dev);
		void pci_restore_dpc_state(struct pci_dev *dev);
		void pci_dpc_init(struct pci_dev *pdev);
		void dpc_process_error(struct pci_dev *pdev);
		pci_ers_result_t dpc_reset_link(struct pci_dev *pdev);
		#else
		static inline void pci_save_dpc_state(struct pci_dev *dev) {}
		static inline void pci_restore_dpc_state(struct pci_dev *dev) {}

drivers/pci/pcie/dpc.c

+9 −3

Original line number	Diff line number	Diff line
		@@ -89,7 +89,7 @@ static int dpc_wait_rp_inactive(struct pci_dev *pdev)
		return 0;
		}

		static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
		pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
		{
		u16 cap;

		@@ -193,9 +193,8 @@ static int dpc_get_aer_uncorrect_severity(struct pci_dev *dev,
		return 1;
		}

		static irqreturn_t dpc_handler(int irq, void *context)
		void dpc_process_error(struct pci_dev *pdev)
		{
		struct pci_dev *pdev = context;
		u16 cap = pdev->dpc_cap, status, source, reason, ext_reason;
		struct aer_err_info info;

		@@ -225,6 +224,13 @@ static irqreturn_t dpc_handler(int irq, void *context)
		pci_cleanup_aer_uncorrect_error_status(pdev);
		pci_aer_clear_fatal_status(pdev);
		}
		}

		static irqreturn_t dpc_handler(int irq, void *context)
		{
		struct pci_dev *pdev = context;

		dpc_process_error(pdev);

		/* We configure DPC so it only triggers on ERR_FATAL */
		pcie_do_recovery(pdev, pci_channel_io_frozen, dpc_reset_link);

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