6.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Philipp Stanner <pstanner@xxxxxxxxxx> [ Upstream commit f546e8033d8f3e45d49622f04ca2fde650b80f6d ] pci_intx() is a hybrid function which sometimes performs devres operations, depending on whether pcim_enable_device() has been used to enable the pci_dev. This sometimes-managed nature of the function is problematic. Notably, it causes the function to allocate under some circumstances which makes it unusable from interrupt context. Export pcim_intx() (which is always managed) and rename __pcim_intx() (which is never managed) to pci_intx_unmanaged() and export it as well. Then all callers of pci_intx() can be ported to the version they need, depending whether they use pci_enable_device() or pcim_enable_device(). Link: https://lore.kernel.org/r/20241209130632.132074-3-pstanner@xxxxxxxxxx Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx> [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Reviewed-by: Damien Le Moal <dlemoal@xxxxxxxxxx> Stable-dep-of: d555ed45a5a1 ("PCI: Restore original INTX_DISABLE bit by pcim_intx()") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/pci/devres.c | 24 +++--------------------- drivers/pci/pci.c | 29 +++++++++++++++++++++++++++++ include/linux/pci.h | 2 ++ 3 files changed, 34 insertions(+), 21 deletions(-) diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c index 3b59a86a764b1..3594eea379931 100644 --- a/drivers/pci/devres.c +++ b/drivers/pci/devres.c @@ -411,31 +411,12 @@ static inline bool mask_contains_bar(int mask, int bar) return mask & BIT(bar); } -/* - * This is a copy of pci_intx() used to bypass the problem of recursive - * function calls due to the hybrid nature of pci_intx(). - */ -static void __pcim_intx(struct pci_dev *pdev, int enable) -{ - u16 pci_command, new; - - pci_read_config_word(pdev, PCI_COMMAND, &pci_command); - - if (enable) - new = pci_command & ~PCI_COMMAND_INTX_DISABLE; - else - new = pci_command | PCI_COMMAND_INTX_DISABLE; - - if (new != pci_command) - pci_write_config_word(pdev, PCI_COMMAND, new); -} - static void pcim_intx_restore(struct device *dev, void *data) { struct pci_dev *pdev = to_pci_dev(dev); struct pcim_intx_devres *res = data; - __pcim_intx(pdev, res->orig_intx); + pci_intx_unmanaged(pdev, res->orig_intx); } static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev) @@ -472,10 +453,11 @@ int pcim_intx(struct pci_dev *pdev, int enable) return -ENOMEM; res->orig_intx = !enable; - __pcim_intx(pdev, enable); + pci_intx_unmanaged(pdev, enable); return 0; } +EXPORT_SYMBOL_GPL(pcim_intx); static void pcim_disable_device(void *pdev_raw) { diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 661f98c6c63a3..d3c3425f7bc57 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4482,6 +4482,35 @@ void pci_disable_parity(struct pci_dev *dev) } } +/** + * pci_intx_unmanaged - enables/disables PCI INTx for device dev, + * unmanaged version + * @pdev: the PCI device to operate on + * @enable: boolean: whether to enable or disable PCI INTx + * + * Enables/disables PCI INTx for device @pdev + * + * This function behavios identically to pci_intx(), but is never managed with + * devres. + */ +void pci_intx_unmanaged(struct pci_dev *pdev, int enable) +{ + u16 pci_command, new; + + pci_read_config_word(pdev, PCI_COMMAND, &pci_command); + + if (enable) + new = pci_command & ~PCI_COMMAND_INTX_DISABLE; + else + new = pci_command | PCI_COMMAND_INTX_DISABLE; + + if (new == pci_command) + return; + + pci_write_config_word(pdev, PCI_COMMAND, new); +} +EXPORT_SYMBOL_GPL(pci_intx_unmanaged); + /** * pci_intx - enables/disables PCI INTx for device dev * @pdev: the PCI device to operate on diff --git a/include/linux/pci.h b/include/linux/pci.h index db9b47ce3eefd..b5eb8bda655dc 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1350,6 +1350,7 @@ int __must_check pcim_set_mwi(struct pci_dev *dev); int pci_try_set_mwi(struct pci_dev *dev); void pci_clear_mwi(struct pci_dev *dev); void pci_disable_parity(struct pci_dev *dev); +void pci_intx_unmanaged(struct pci_dev *pdev, int enable); void pci_intx(struct pci_dev *dev, int enable); bool pci_check_and_mask_intx(struct pci_dev *dev); bool pci_check_and_unmask_intx(struct pci_dev *dev); @@ -2297,6 +2298,7 @@ static inline void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev) { } #endif +int pcim_intx(struct pci_dev *pdev, int enabled); int pcim_request_all_regions(struct pci_dev *pdev, const char *name); void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen); void __iomem *pcim_iomap_region(struct pci_dev *pdev, int bar, -- 2.39.5
