From 25216afc9db53d85dc648aba8fb7f6d31f2c8731 Mon Sep 17 00:00:00 2001 From: Philipp Stanner Date: Thu, 13 Jun 2024 13:50:23 +0200 Subject: [PATCH] PCI: Add managed pcim_intx() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit pci_intx() is a "hybrid" function, i.e., it is managed if pcim_enable_device() has been called, but unmanaged otherwise. Add pcim_intx(), which is always managed, and implement pci_intx() using it. Remove the now-unused struct pci_devres.orig_intx and .restore_intx and find_pci_dr(). Link: https://lore.kernel.org/r/20240613115032.29098-11-pstanner@redhat.com Signed-off-by: Philipp Stanner [kwilczynski: squashed in https://lore.kernel.org/r/426645d40776198e0fcc942f4a6cac4433c7a9aa.camel@redhat.com to fix problem reported and tested by Ashish Kalra : https://lore.kernel.org/r/20240708214656.4721-1-Ashish.Kalra@amd.com https://lore.kernel.org/r/8c4634e9-4f02-4c54-9c89-d75e2f4bf026@amd.com/] Signed-off-by: Krzysztof Wilczyński [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas --- drivers/pci/devres.c | 84 ++++++++++++++++++++++++++++++++++++-------- drivers/pci/pci.c | 19 +++++----- drivers/pci/pci.h | 13 +++---- 3 files changed, 85 insertions(+), 31 deletions(-) diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c index d3c29ec30ad735..f7b7184384124c 100644 --- a/drivers/pci/devres.c +++ b/drivers/pci/devres.c @@ -43,6 +43,11 @@ struct pcim_iomap_devres { void __iomem *table[PCI_STD_NUM_BARS]; }; +/* Used to restore the old INTx state on driver detach. */ +struct pcim_intx_devres { + int orig_intx; +}; + enum pcim_addr_devres_type { /* Default initializer. */ PCIM_ADDR_DEVRES_TYPE_INVALID, @@ -406,27 +411,78 @@ static inline bool mask_contains_bar(int mask, int bar) return mask & BIT(bar); } -static void pcim_release(struct device *gendev, void *res) +/* + * 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) { - struct pci_dev *dev = to_pci_dev(gendev); - struct pci_devres *this = res; + u16 pci_command, new; - if (this->restore_intx) - pci_intx(dev, this->orig_intx); + pci_read_config_word(pdev, PCI_COMMAND, &pci_command); - if (pci_is_enabled(dev) && !dev->pinned) - pci_disable_device(dev); + 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); } -/* - * TODO: After the last four callers in pci.c are ported, find_pci_dr() - * needs to be made static again. +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); +} + +static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev) +{ + struct pcim_intx_devres *res; + + res = devres_find(dev, pcim_intx_restore, NULL, NULL); + if (res) + return res; + + res = devres_alloc(pcim_intx_restore, sizeof(*res), GFP_KERNEL); + if (res) + devres_add(dev, res); + + return res; +} + +/** + * pcim_intx - managed pci_intx() + * @pdev: the PCI device to operate on + * @enable: boolean: whether to enable or disable PCI INTx + * + * Returns: 0 on success, -ENOMEM on error. + * + * Enable/disable PCI INTx for device @pdev. + * Restore the original state on driver detach. */ -struct pci_devres *find_pci_dr(struct pci_dev *pdev) +int pcim_intx(struct pci_dev *pdev, int enable) { - if (pci_is_managed(pdev)) - return devres_find(&pdev->dev, pcim_release, NULL, NULL); - return NULL; + struct pcim_intx_devres *res; + + res = get_or_create_intx_devres(&pdev->dev); + if (!res) + return -ENOMEM; + + res->orig_intx = !enable; + __pcim_intx(pdev, enable); + + return 0; +} + +static void pcim_release(struct device *gendev, void *res) +{ + struct pci_dev *dev = to_pci_dev(gendev); + + if (pci_is_enabled(dev) && !dev->pinned) + pci_disable_device(dev); } static struct pci_devres *get_pci_dr(struct pci_dev *pdev) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index a0fad5990f03cf..807f8be043cd43 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4442,12 +4442,18 @@ void pci_disable_parity(struct pci_dev *dev) * NOTE: * This is a "hybrid" function: It's normally unmanaged, but becomes managed * when pcim_enable_device() has been called in advance. This hybrid feature is - * DEPRECATED! + * DEPRECATED! If you want managed cleanup, use pcim_intx() instead. */ void pci_intx(struct pci_dev *pdev, int enable) { u16 pci_command, new; + /* Preserve the "hybrid" behavior for backwards compatibility */ + if (pci_is_managed(pdev)) { + WARN_ON_ONCE(pcim_intx(pdev, enable) != 0); + return; + } + pci_read_config_word(pdev, PCI_COMMAND, &pci_command); if (enable) @@ -4455,17 +4461,8 @@ void pci_intx(struct pci_dev *pdev, int enable) else new = pci_command | PCI_COMMAND_INTX_DISABLE; - if (new != pci_command) { - struct pci_devres *dr; - + if (new != pci_command) pci_write_config_word(pdev, PCI_COMMAND, new); - - dr = find_pci_dr(pdev); - if (dr && !dr->restore_intx) { - dr->restore_intx = 1; - dr->orig_intx = !enable; - } - } } EXPORT_SYMBOL_GPL(pci_intx); diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 9a12f6774431fe..21cb4417635081 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -816,16 +816,17 @@ static inline pci_power_t mid_pci_get_power_state(struct pci_dev *pdev) * there's no need to track it separately. pci_devres is initialized * when a device is enabled using managed PCI device enable interface. * - * TODO: Struct pci_devres and find_pci_dr() only need to be here because - * they're used in pci.c. Port or move these functions to devres.c and - * then remove them from here. + * TODO: Struct pci_devres only needs to be here because they're used in pci.c. + * Port or move these functions to devres.c and then remove them from here. */ struct pci_devres { - unsigned int orig_intx:1; - unsigned int restore_intx:1; + /* + * TODO: + * This struct is now surplus. Remove it by refactoring pci/devres.c + */ }; -struct pci_devres *find_pci_dr(struct pci_dev *pdev); +int pcim_intx(struct pci_dev *dev, int enable); int pcim_request_region(struct pci_dev *pdev, int bar, const char *name); int pcim_request_region_exclusive(struct pci_dev *pdev, int bar,