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Return -ENOTTY when device capabilities, function scope, cached HDM state, or required cache synchronization do not permit a safe reset. Signed-off-by: Srirangan Madhavan --- drivers/pci/cxl.c | 12 +++++++++--- drivers/pci/pci.c | 1 + include/linux/pci.h | 2 +- 3 files changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/pci/cxl.c b/drivers/pci/cxl.c index 4c6b712ed4fa..7a225e215ca5 100644 --- a/drivers/pci/cxl.c +++ b/drivers/pci/cxl.c @@ -642,7 +642,7 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe) rc = cxl_pci_device_dvsec(pdev, &dvsec, &cap); if (rc) - return rc; + return probe ? -ENOTTY : rc; if (!(cap & PCI_DVSEC_CXL_CACHE_CAPABLE) || !(cap & PCI_DVSEC_CXL_MEM_CAPABLE) || !(cap & PCI_DVSEC_CXL_RST_CAPABLE) || @@ -651,9 +651,9 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe) rc = pci_read_config_word(pdev, dvsec + PCI_DVSEC_CXL_CTRL, &ctrl); if (rc) - return pcibios_err_to_errno(rc); + return probe ? -ENOTTY : pcibios_err_to_errno(rc); if (PCI_POSSIBLE_ERROR(ctrl)) - return -ENODEV; + return probe ? -ENOTTY : -ENODEV; if (!(ctrl & PCI_DVSEC_CXL_CACHE_ENABLE) || !(ctrl & PCI_DVSEC_CXL_MEM_ENABLE)) return -ENOTTY; @@ -675,5 +675,11 @@ int cxl_reset_function(struct pci_dev *pdev, bool probe) if (!cpu_cache_has_invalidate_memregion()) return -ENOTTY; + /* Raw reset callers may not have saved the PCI state needed for restore. */ + if (!pdev->state_saved) { + pci_err(pdev, "CXL reset requires saved PCI state\n"); + return -EINVAL; + } + return cxl_reset_execute(pdev, dvsec, cap); } diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index fe611340f5ab..b58a6a613311 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5148,6 +5148,7 @@ const struct pci_reset_fn_method pci_reset_fn_methods[] = { { }, { pci_dev_specific_reset, .name = "device_specific" }, { pci_dev_acpi_reset, .name = "acpi" }, + { cxl_reset_function, .name = "cxl_reset" }, { pcie_reset_flr, .name = "flr" }, { pci_af_flr, .name = "af_flr" }, { pci_pm_reset, .name = "pm" }, diff --git a/include/linux/pci.h b/include/linux/pci.h index 7bb37fcb556d..743b57ff885a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -52,7 +52,7 @@ PCI_STATUS_PARITY) /* Number of reset methods used in pci_reset_fn_methods array in pci.c */ -#define PCI_NUM_RESET_METHODS 8 +#define PCI_NUM_RESET_METHODS 9 #define PCI_RESET_PROBE true #define PCI_RESET_DO_RESET false -- 2.43.0