From 3134233097791ae64002a51c2c8c9bf2ab200ea0 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 11 Apr 2017 17:33:12 +0100 Subject: PCI: Do not disregard parent resources starting at 0x0 Commit f44116ae8818 ("PCI: Remove pci_find_parent_resource() use for allocation") updated the logic that iterates over all bus resources and compares them to a given resource, in order to decide whether one is the parent of the latter. This change inadvertently causes pci_find_parent_resource() to disregard resources starting at address 0x0, resulting in an error such as the one below on ARM systems whose I/O window starts at 0x0. pci_bus 0000:00: root bus resource [mem 0x10000000-0x3efeffff window] pci_bus 0000:00: root bus resource [io 0x0000-0xffff window] pci_bus 0000:00: root bus resource [mem 0x8000000000-0xffffffffff window] pci_bus 0000:00: root bus resource [bus 00-0f] pci 0000:00:01.0: PCI bridge to [bus 01] pci 0000:00:02.0: PCI bridge to [bus 02] pci 0000:00:03.0: PCI bridge to [bus 03] pci 0000:00:03.0: can't claim BAR 13 [io 0x0000-0x0fff]: no compatible bridge window pci 0000:03:01.0: can't claim BAR 0 [io 0x0000-0x001f]: no compatible bridge window While this never happens on x86, it is perfectly legal in general for a PCI MMIO or IO window to start at address 0x0, and it was supported in the code before commit f44116ae8818. Drop the test for res->start != 0; resource_contains() already checks whether [start, end) completely covers the resource, and so it should be redundant. Signed-off-by: Ard Biesheuvel Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b01bd5b..d5575f6 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -455,7 +455,7 @@ struct resource *pci_find_parent_resource(const struct pci_dev *dev, pci_bus_for_each_resource(bus, r, i) { if (!r) continue; - if (res->start && resource_contains(r, res)) { + if (resource_contains(r, res)) { /* * If the window is prefetchable but the BAR is -- cgit v1.1 From 4ebeb1ec56d4c54a56b6f43c2603d9a4688c83ba Mon Sep 17 00:00:00 2001 From: CQ Tang Date: Tue, 30 May 2017 09:25:49 -0700 Subject: PCI: Restore PRI and PASID state after Function-Level Reset After a Function-Level Reset, PCI states need to be restored. Save PASID features and PRI reqs cached. [bhelgaas: search for capability only if PRI/PASID were enabled] Signed-off-by: CQ Tang Signed-off-by: Ashok Raj Signed-off-by: Bjorn Helgaas Cc: Joerg Roedel Cc: Jean-Phillipe Brucker Cc: David Woodhouse --- drivers/pci/pci.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b01bd5b..3b38e98 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -1173,6 +1174,8 @@ void pci_restore_state(struct pci_dev *dev) /* PCI Express register must be restored first */ pci_restore_pcie_state(dev); + pci_restore_pasid_state(dev); + pci_restore_pri_state(dev); pci_restore_ats_state(dev); pci_restore_vc_state(dev); -- cgit v1.1 From b014e96d1abbd67404bbe2018937b46466299e9e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 1 Jun 2017 13:10:37 +0200 Subject: PCI: Protect pci_error_handlers->reset_notify() usage with device_lock() Every method in struct device_driver or structures derived from it like struct pci_driver MUST provide exclusion vs the driver's ->remove() method, usually by using device_lock(). Protect use of pci_error_handlers->reset_notify() by holding the device lock while calling it. Note: - pci_dev_lock() calls device_lock() in addition to blocking user-space config accesses. - pci_err_handlers->reset_notify() is used inside pci_dev_save_and_disable() and pci_dev_restore(). We could hold the device lock directly in pci_reset_notify(), but we expand the region since we have several calls following each other. Without this, ->reset_notify() may race with ->remove() calls, which can be easily triggered in NVMe. [bhelgaas: changelog, add pci_reset_notify() comment] [bhelgaas: fold in fix from Dan Carpenter : http://lkml.kernel.org/r/20170701135323.x5vaj4e2wcs2mcro@mwanda] Link: http://lkml.kernel.org/r/20170601111039.8913-2-hch@lst.de Reported-by: Rakesh Pandit Tested-by: Rakesh Pandit Signed-off-by: Christoph Hellwig Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 3b38e98..f4587f6 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4143,6 +4143,12 @@ static void pci_reset_notify(struct pci_dev *dev, bool prepare) { const struct pci_error_handlers *err_handler = dev->driver ? dev->driver->err_handler : NULL; + + /* + * dev->driver->err_handler->reset_notify() is protected against + * races with ->remove() by the device lock, which must be held by + * the caller. + */ if (err_handler && err_handler->reset_notify) err_handler->reset_notify(dev, prepare); } @@ -4278,11 +4284,13 @@ int pci_reset_function(struct pci_dev *dev) if (rc) return rc; + pci_dev_lock(dev); pci_dev_save_and_disable(dev); - rc = pci_dev_reset(dev, 0); + rc = __pci_dev_reset(dev, 0); pci_dev_restore(dev); + pci_dev_unlock(dev); return rc; } @@ -4302,16 +4310,14 @@ int pci_try_reset_function(struct pci_dev *dev) if (rc) return rc; - pci_dev_save_and_disable(dev); + if (!pci_dev_trylock(dev)) + return -EAGAIN; - if (pci_dev_trylock(dev)) { - rc = __pci_dev_reset(dev, 0); - pci_dev_unlock(dev); - } else - rc = -EAGAIN; + pci_dev_save_and_disable(dev); + rc = __pci_dev_reset(dev, 0); + pci_dev_unlock(dev); pci_dev_restore(dev); - return rc; } EXPORT_SYMBOL_GPL(pci_try_reset_function); @@ -4461,7 +4467,9 @@ static void pci_bus_save_and_disable(struct pci_bus *bus) struct pci_dev *dev; list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_lock(dev); pci_dev_save_and_disable(dev); + pci_dev_unlock(dev); if (dev->subordinate) pci_bus_save_and_disable(dev->subordinate); } @@ -4476,7 +4484,9 @@ static void pci_bus_restore(struct pci_bus *bus) struct pci_dev *dev; list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_lock(dev); pci_dev_restore(dev); + pci_dev_unlock(dev); if (dev->subordinate) pci_bus_restore(dev->subordinate); } -- cgit v1.1 From 99b3c58f7ba7fae801e501b45c5fcf6e08d9247f Mon Sep 17 00:00:00 2001 From: Piotr Gregor Date: Fri, 26 May 2017 22:02:25 +0100 Subject: PCI: Test INTx masking during enumeration, not at run-time The test for INTx masking via PCI_COMMAND_INTX_DISABLE performed in pci_intx_mask_supported() should be done before the device can be used. This is to avoid writing PCI_COMMAND while the driver owns the device, in case that has any effect on MSI/MSI-X interrupts. Move the content of pci_intx_mask_supported() to pci_intx_mask_broken() and call it from pci_setup_device(). The test result can be queried at any time later using the same pci_intx_mask_supported() interface as before (though with changed implementation), so callers (uio, vfio) should be unaffected. Signed-off-by: Piotr Gregor [bhelgaas: changelog, remove quirk check, remove locking, move dev->broken_intx_masking assignment to caller] Signed-off-by: Bjorn Helgaas Reviewed-by: Alex Williamson Acked-by: Michael S. Tsirkin --- drivers/pci/pci.c | 42 +----------------------------------------- 1 file changed, 1 insertion(+), 41 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b01bd5b..7c4e1aa 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3708,46 +3708,6 @@ void pci_intx(struct pci_dev *pdev, int enable) } EXPORT_SYMBOL_GPL(pci_intx); -/** - * pci_intx_mask_supported - probe for INTx masking support - * @dev: the PCI device to operate on - * - * Check if the device dev support INTx masking via the config space - * command word. - */ -bool pci_intx_mask_supported(struct pci_dev *dev) -{ - bool mask_supported = false; - u16 orig, new; - - if (dev->broken_intx_masking) - return false; - - pci_cfg_access_lock(dev); - - pci_read_config_word(dev, PCI_COMMAND, &orig); - pci_write_config_word(dev, PCI_COMMAND, - orig ^ PCI_COMMAND_INTX_DISABLE); - pci_read_config_word(dev, PCI_COMMAND, &new); - - /* - * There's no way to protect against hardware bugs or detect them - * reliably, but as long as we know what the value should be, let's - * go ahead and check it. - */ - if ((new ^ orig) & ~PCI_COMMAND_INTX_DISABLE) { - dev_err(&dev->dev, "Command register changed from 0x%x to 0x%x: driver or hardware bug?\n", - orig, new); - } else if ((new ^ orig) & PCI_COMMAND_INTX_DISABLE) { - mask_supported = true; - pci_write_config_word(dev, PCI_COMMAND, orig); - } - - pci_cfg_access_unlock(dev); - return mask_supported; -} -EXPORT_SYMBOL_GPL(pci_intx_mask_supported); - static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask) { struct pci_bus *bus = dev->bus; @@ -3798,7 +3758,7 @@ done: * @dev: the PCI device to operate on * * Check if the device dev has its INTx line asserted, mask it and - * return true in that case. False is returned if not interrupt was + * return true in that case. False is returned if no interrupt was * pending. */ bool pci_check_and_mask_intx(struct pci_dev *dev) -- cgit v1.1 From 666ff6f83e1db6ed847abf44eb5e3402d82b9350 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 23 Jun 2017 14:58:11 +0200 Subject: PCI/PM: Avoid using device_may_wakeup() for runtime PM pci_target_state() calls device_may_wakeup() which checks whether or not the device may wake up the system from sleep states, but pci_target_state() is used for runtime PM too. Since runtime PM is expected to always enable remote wakeup if possible, modify pci_target_state() to take additional argument indicating whether or not it should look for a state from which the device can signal wakeup and pass either the return value of device_can_wakeup(), or "false" (if the device itself is not wakeup-capable) to it from the code related to runtime PM. While at it, fix the comment in pci_dev_run_wake() which is not about sleep states. Signed-off-by: Rafael J. Wysocki Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/pci.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 563901c..05c2a13 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1960,12 +1960,13 @@ EXPORT_SYMBOL(pci_wake_from_d3); /** * pci_target_state - find an appropriate low power state for a given PCI dev * @dev: PCI device + * @wakeup: Whether or not wakeup functionality will be enabled for the device. * * Use underlying platform code to find a supported low power state for @dev. * If the platform can't manage @dev, return the deepest state from which it * can generate wake events, based on any available PME info. */ -static pci_power_t pci_target_state(struct pci_dev *dev) +static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup) { pci_power_t target_state = PCI_D3hot; @@ -2002,7 +2003,7 @@ static pci_power_t pci_target_state(struct pci_dev *dev) if (dev->current_state == PCI_D3cold) target_state = PCI_D3cold; - if (device_may_wakeup(&dev->dev)) { + if (wakeup) { /* * Find the deepest state from which the device can generate * wake-up events, make it the target state and enable device @@ -2028,13 +2029,14 @@ static pci_power_t pci_target_state(struct pci_dev *dev) */ int pci_prepare_to_sleep(struct pci_dev *dev) { - pci_power_t target_state = pci_target_state(dev); + bool wakeup = device_may_wakeup(&dev->dev); + pci_power_t target_state = pci_target_state(dev, wakeup); int error; if (target_state == PCI_POWER_ERROR) return -EIO; - pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev)); + pci_enable_wake(dev, target_state, wakeup); error = pci_set_power_state(dev, target_state); @@ -2067,9 +2069,10 @@ EXPORT_SYMBOL(pci_back_from_sleep); */ int pci_finish_runtime_suspend(struct pci_dev *dev) { - pci_power_t target_state = pci_target_state(dev); + pci_power_t target_state; int error; + target_state = pci_target_state(dev, device_can_wakeup(&dev->dev)); if (target_state == PCI_POWER_ERROR) return -EIO; @@ -2105,8 +2108,8 @@ bool pci_dev_run_wake(struct pci_dev *dev) if (!dev->pme_support) return false; - /* PME-capable in principle, but not from the intended sleep state */ - if (!pci_pme_capable(dev, pci_target_state(dev))) + /* PME-capable in principle, but not from the target power state */ + if (!pci_pme_capable(dev, pci_target_state(dev, false))) return false; while (bus->parent) { @@ -2141,9 +2144,10 @@ EXPORT_SYMBOL_GPL(pci_dev_run_wake); bool pci_dev_keep_suspended(struct pci_dev *pci_dev) { struct device *dev = &pci_dev->dev; + bool wakeup = device_may_wakeup(dev); if (!pm_runtime_suspended(dev) - || pci_target_state(pci_dev) != pci_dev->current_state + || pci_target_state(pci_dev, wakeup) != pci_dev->current_state || platform_pci_need_resume(pci_dev) || (pci_dev->dev_flags & PCI_DEV_FLAGS_NEEDS_RESUME)) return false; @@ -2161,7 +2165,7 @@ bool pci_dev_keep_suspended(struct pci_dev *pci_dev) spin_lock_irq(&dev->power.lock); if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold && - !device_may_wakeup(dev)) + !wakeup) __pci_pme_active(pci_dev, false); spin_unlock_irq(&dev->power.lock); -- cgit v1.1 From 775755ed3c65fb2d31f9268162495d76eaa2c281 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 1 Jun 2017 13:10:38 +0200 Subject: PCI: Split ->reset_notify() method into ->reset_prepare() and ->reset_done() The pci_error_handlers->reset_notify() method had a flag to indicate whether to prepare for or clean up after a reset. The prepare and done cases have no shared functionality whatsoever, so split them into separate methods. [bhelgaas: changelog, update locking comments] Link: http://lkml.kernel.org/r/20170601111039.8913-3-hch@lst.de Signed-off-by: Christoph Hellwig Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f4587f6..56407eb 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4130,32 +4130,18 @@ static void pci_dev_unlock(struct pci_dev *dev) pci_cfg_access_unlock(dev); } -/** - * pci_reset_notify - notify device driver of reset - * @dev: device to be notified of reset - * @prepare: 'true' if device is about to be reset; 'false' if reset attempt - * completed - * - * Must be called prior to device access being disabled and after device - * access is restored. - */ -static void pci_reset_notify(struct pci_dev *dev, bool prepare) +static void pci_dev_save_and_disable(struct pci_dev *dev) { const struct pci_error_handlers *err_handler = dev->driver ? dev->driver->err_handler : NULL; /* - * dev->driver->err_handler->reset_notify() is protected against + * dev->driver->err_handler->reset_prepare() is protected against * races with ->remove() by the device lock, which must be held by * the caller. */ - if (err_handler && err_handler->reset_notify) - err_handler->reset_notify(dev, prepare); -} - -static void pci_dev_save_and_disable(struct pci_dev *dev) -{ - pci_reset_notify(dev, true); + if (err_handler && err_handler->reset_prepare) + err_handler->reset_prepare(dev); /* * Wake-up device prior to save. PM registers default to D0 after @@ -4177,8 +4163,18 @@ static void pci_dev_save_and_disable(struct pci_dev *dev) static void pci_dev_restore(struct pci_dev *dev) { + const struct pci_error_handlers *err_handler = + dev->driver ? dev->driver->err_handler : NULL; + pci_restore_state(dev); - pci_reset_notify(dev, false); + + /* + * dev->driver->err_handler->reset_done() is protected against + * races with ->remove() by the device lock, which must be held by + * the caller. + */ + if (err_handler && err_handler->reset_done) + err_handler->reset_done(dev); } static int pci_dev_reset(struct pci_dev *dev, int probe) -- cgit v1.1 From 52354b9d1f46aae7386db7bb8ec8484b5488087f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 1 Jun 2017 13:10:39 +0200 Subject: PCI: Remove __pci_dev_reset() and pci_dev_reset() Implement the reset probing / reset chain directly in __pci_probe_reset_function() and __pci_reset_function_locked() respectively. Link: http://lkml.kernel.org/r/20170601111039.8913-4-hch@lst.de Signed-off-by: Christoph Hellwig Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 108 ++++++++++++++++++++++++++---------------------------- 1 file changed, 52 insertions(+), 56 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 56407eb..7a75502 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4071,40 +4071,6 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) return pci_reset_hotplug_slot(dev->slot->hotplug, probe); } -static int __pci_dev_reset(struct pci_dev *dev, int probe) -{ - int rc; - - might_sleep(); - - rc = pci_dev_specific_reset(dev, probe); - if (rc != -ENOTTY) - goto done; - - if (pcie_has_flr(dev)) { - if (!probe) - pcie_flr(dev); - rc = 0; - goto done; - } - - rc = pci_af_flr(dev, probe); - if (rc != -ENOTTY) - goto done; - - rc = pci_pm_reset(dev, probe); - if (rc != -ENOTTY) - goto done; - - rc = pci_dev_reset_slot_function(dev, probe); - if (rc != -ENOTTY) - goto done; - - rc = pci_parent_bus_reset(dev, probe); -done: - return rc; -} - static void pci_dev_lock(struct pci_dev *dev) { pci_cfg_access_lock(dev); @@ -4177,21 +4143,6 @@ static void pci_dev_restore(struct pci_dev *dev) err_handler->reset_done(dev); } -static int pci_dev_reset(struct pci_dev *dev, int probe) -{ - int rc; - - if (!probe) - pci_dev_lock(dev); - - rc = __pci_dev_reset(dev, probe); - - if (!probe) - pci_dev_unlock(dev); - - return rc; -} - /** * __pci_reset_function - reset a PCI device function * @dev: PCI device to reset @@ -4211,7 +4162,13 @@ static int pci_dev_reset(struct pci_dev *dev, int probe) */ int __pci_reset_function(struct pci_dev *dev) { - return pci_dev_reset(dev, 0); + int ret; + + pci_dev_lock(dev); + ret = __pci_reset_function_locked(dev); + pci_dev_unlock(dev); + + return ret; } EXPORT_SYMBOL_GPL(__pci_reset_function); @@ -4236,7 +4193,27 @@ EXPORT_SYMBOL_GPL(__pci_reset_function); */ int __pci_reset_function_locked(struct pci_dev *dev) { - return __pci_dev_reset(dev, 0); + int rc; + + might_sleep(); + + rc = pci_dev_specific_reset(dev, 0); + if (rc != -ENOTTY) + return rc; + if (pcie_has_flr(dev)) { + pcie_flr(dev); + return 0; + } + rc = pci_af_flr(dev, 0); + if (rc != -ENOTTY) + return rc; + rc = pci_pm_reset(dev, 0); + if (rc != -ENOTTY) + return rc; + rc = pci_dev_reset_slot_function(dev, 0); + if (rc != -ENOTTY) + return rc; + return pci_parent_bus_reset(dev, 0); } EXPORT_SYMBOL_GPL(__pci_reset_function_locked); @@ -4253,7 +4230,26 @@ EXPORT_SYMBOL_GPL(__pci_reset_function_locked); */ int pci_probe_reset_function(struct pci_dev *dev) { - return pci_dev_reset(dev, 1); + int rc; + + might_sleep(); + + rc = pci_dev_specific_reset(dev, 1); + if (rc != -ENOTTY) + return rc; + if (pcie_has_flr(dev)) + return 0; + rc = pci_af_flr(dev, 1); + if (rc != -ENOTTY) + return rc; + rc = pci_pm_reset(dev, 1); + if (rc != -ENOTTY) + return rc; + rc = pci_dev_reset_slot_function(dev, 1); + if (rc != -ENOTTY) + return rc; + + return pci_parent_bus_reset(dev, 1); } /** @@ -4276,14 +4272,14 @@ int pci_reset_function(struct pci_dev *dev) { int rc; - rc = pci_dev_reset(dev, 1); + rc = pci_probe_reset_function(dev); if (rc) return rc; pci_dev_lock(dev); pci_dev_save_and_disable(dev); - rc = __pci_dev_reset(dev, 0); + rc = __pci_reset_function_locked(dev); pci_dev_restore(dev); pci_dev_unlock(dev); @@ -4302,7 +4298,7 @@ int pci_try_reset_function(struct pci_dev *dev) { int rc; - rc = pci_dev_reset(dev, 1); + rc = pci_probe_reset_function(dev); if (rc) return rc; @@ -4310,7 +4306,7 @@ int pci_try_reset_function(struct pci_dev *dev) return -EAGAIN; pci_dev_save_and_disable(dev); - rc = __pci_dev_reset(dev, 0); + rc = __pci_reset_function_locked(dev); pci_dev_unlock(dev); pci_dev_restore(dev); -- cgit v1.1