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charset="UTF-8" X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: E0F3EC000A X-Rspam-User: X-Stat-Signature: jr7gdkb9d66z14fxckitwxrrdfdgttek X-HE-Tag: 1791908748-631964 X-HE-Meta: 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 trFPDGuW 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Adopt the ARI Forwarding Enable bit on preserved bridges and update pci_dev->ari_enabled accordingly during a Live Update. This ensures that the preserved devices on the bridge's secondary bus can be identified with the same expanded 8-bit function number after a Live Update. pci_liveupdate_adopt_ari() updates the bridge's ari_enabled the same way, and from the same context, as pci_configure_ari() already does when it enables or disables ARI Forwarding on the bridge. Reviewed-by: Bjorn Helgaas Reviewed-by: Pranjal Shrivastava Signed-off-by: David Matlack --- drivers/pci/liveupdate.c | 35 +++++++++++++++++++++++++++++++++++ drivers/pci/liveupdate.h | 6 ++++++ drivers/pci/pci.c | 8 +++++++- 3 files changed, 48 insertions(+), 1 deletion(-) diff --git a/drivers/pci/liveupdate.c b/drivers/pci/liveupdate.c index 1d2324d339da..e640794cc8e6 100644 --- a/drivers/pci/liveupdate.c +++ b/drivers/pci/liveupdate.c @@ -189,6 +189,10 @@ * way after Live Update and ensures that IOMMU groups do not change. Note * that a device will use its adopted ACS controls for the lifetime of its * struct pci_dev (i.e. even after pci_liveupdate_finish()). + * + * * The PCI core adopts ARI Forwarding Enable on all bridges with downstream + * preserved devices to ensure that all preserved devices on the bridge's + * secondary bus are addressable after the Live Update. */ #define pr_fmt(fmt) "PCI: liveupdate: " fmt @@ -922,6 +926,37 @@ int pci_liveupdate_adopt_acs(struct pci_dev *dev) return 0; } +/** + * pci_liveupdate_adopt_ari() - Adopt ARI configuration + * @dev: The PCI device to adopt ARI configuration for + * + * For devices preserved across a Live Update, read the ARI state from + * hardware and adopt it. This ensures the device continues to use the ARI + * configuration established by the previous kernel. + * + * Return: 0 on success, or -EINVAL if the device was not preserved. + */ +int pci_liveupdate_adopt_ari(struct pci_dev *dev) +{ + u16 val; + + guard(rwsem_read)(&pci_liveupdate.rwsem); + + /* + * Unlike ACS, only adopt ARI while the bridge is incoming-preserved. + * Once all devices below the bridge have finished, recomputing ARI + * Forwarding Enable yields the same result for the same device, and + * must be allowed to change if a different device is hot-plugged. + */ + if (!dev->liveupdate.incoming) + return -EINVAL; + + pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &val); + + dev->ari_enabled = !!(val & PCI_EXP_DEVCTL2_ARI); + return 0; +} + /** * pci_liveupdate_is_incoming() - Check if a device is incoming-preserved * @dev: The PCI device to check diff --git a/drivers/pci/liveupdate.h b/drivers/pci/liveupdate.h index d4721ffcecb2..90b2754ecc0c 100644 --- a/drivers/pci/liveupdate.h +++ b/drivers/pci/liveupdate.h @@ -16,6 +16,7 @@ void pci_liveupdate_cleanup_device(struct pci_dev *dev); bool pci_liveupdate_preserve_bus_numbers(void); bool pci_liveupdate_refuse_bus_numbers(struct pci_bus *bus, struct pci_dev *dev); int pci_liveupdate_adopt_acs(struct pci_dev *dev); +int pci_liveupdate_adopt_ari(struct pci_dev *dev); #else static inline void pci_liveupdate_setup_device(struct pci_dev *dev) { @@ -40,6 +41,11 @@ static inline int pci_liveupdate_adopt_acs(struct pci_dev *dev) { return -EINVAL; } + +static inline int pci_liveupdate_adopt_ari(struct pci_dev *dev) +{ + return -EINVAL; +} #endif #endif /* DRIVERS_PCI_LIVEUPDATE_H */ diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 650d7f92f93a..e5b960ca26e6 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3705,7 +3705,7 @@ void pci_configure_ari(struct pci_dev *dev) u32 cap; struct pci_dev *bridge; - if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn) + if (!pci_is_pcie(dev) || dev->devfn) return; bridge = dev->bus->self; @@ -3716,6 +3716,12 @@ void pci_configure_ari(struct pci_dev *dev) if (!(cap & PCI_EXP_DEVCAP2_ARI)) return; + if (!pci_liveupdate_adopt_ari(bridge)) + return; + + if (pcie_ari_disabled) + return; + if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) { pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_ARI); -- 2.56.0.385.gd3acb90ef8-goog