From d7d55536c6cd1f80295b6d7483ad0587b148bde4 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Wed, 11 Jan 2017 11:50:06 +1100 Subject: drivers/pci/hotplug: Handle presence detection change properly The surprise hotplug is driven by interrupt in PowerNV PCI hotplug driver. In the interrupt handler, pnv_php_interrupt(), we bail when pnv_pci_get_presence_state() returns zero wrongly. It causes the presence change event is always ignored incorrectly. This fixes the issue by bailing on error (non-zero value) returned from pnv_pci_get_presence_state(). Fixes: 360aebd85a4 ("drivers/pci/hotplug: Support surprise hotplug in powernv driver") Cc: stable@vger.kernel.org #v4.9+ Reported-by: Hank Chang Signed-off-by: Gavin Shan Tested-by: Willie Liauw Signed-off-by: Michael Ellerman --- drivers/pci/hotplug/pnv_php.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/pci/hotplug/pnv_php.c') diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 56efaf72d08e..306728cb5785 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -707,8 +707,12 @@ static irqreturn_t pnv_php_interrupt(int irq, void *data) added = !!(lsts & PCI_EXP_LNKSTA_DLLLA); } else if (sts & PCI_EXP_SLTSTA_PDC) { ret = pnv_pci_get_presence_state(php_slot->id, &presence); - if (!ret) + if (ret) { + dev_warn(&pdev->dev, "PCI slot [%s] error %d getting presence (0x%04x), to retry the operation.\n", + php_slot->name, ret, sts); return IRQ_HANDLED; + } + added = !!(presence == OPAL_PCI_SLOT_PRESENT); } else { return IRQ_NONE; -- cgit From d0c424971f70501ec0a0364117b9934db039c9cc Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Wed, 11 Jan 2017 11:50:07 +1100 Subject: drivers/pci/hotplug: Fix initial state for empty slot In PowerNV PCI hotplug driver, the initial PCI slot's state is set to PNV_PHP_STATE_POPULATED if no PCI devices are connected to the slot. The PCI devices that are hot added to the slot won't be probed and populated because of the check in pnv_php_enable(): /* Check if the slot has been configured */ if (php_slot->state != PNV_PHP_STATE_REGISTERED) return 0; This fixes the issue by leaving the slot in PNV_PHP_STATE_REGISTERED state initially if nothing is connected to the slot. Fixes: 360aebd85a4 ("drivers/pci/hotplug: Support surprise hotplug in powernv driver") Cc: stable@vger.kernel.org #v4.9+ Reported-by: Hank Chang Signed-off-by: Gavin Shan Tested-by: Willie Liauw Signed-off-by: Michael Ellerman --- drivers/pci/hotplug/pnv_php.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'drivers/pci/hotplug/pnv_php.c') diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 306728cb5785..41304b313512 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -430,9 +430,21 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan) if (ret) return ret; - /* Proceed if there have nothing behind the slot */ - if (presence == OPAL_PCI_SLOT_EMPTY) + /* + * Proceed if there have nothing behind the slot. However, + * we should leave the slot in registered state at the + * beginning. Otherwise, the PCI devices inserted afterwards + * won't be probed and populated. + */ + if (presence == OPAL_PCI_SLOT_EMPTY) { + if (!php_slot->power_state_check) { + php_slot->power_state_check = true; + + return 0; + } + goto scan; + } /* * If the power supply to the slot is off, we can't detect -- cgit From 454593e54cac126a0f49d4b65f90a5e518c51404 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Wed, 11 Jan 2017 11:50:08 +1100 Subject: drivers/pci/hotplug: Mask PDC interrupt if required We're supporting surprise hotplug on PCI slots behind root port or PCIe switch downstream ports, which don't claim the capability in hardware register (offset: PCIe cap + PCI_EXP_SLTCAP). PEX8718 is one of the examples. For those PCI slots, the PDC (Presence Detection Change) event isn't reliable and the underly (skiboot) firmware has best judgement. This masks the PDC event when skiboot requests by "ibm,slot-broken-pdc" property in PCI slot's device-tree node. Reported-by: Hank Chang Signed-off-by: Gavin Shan Tested-by: Willie Liauw Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/pnv-pci.h | 2 ++ drivers/pci/hotplug/pnv_php.c | 27 ++++++++++++++++++++++----- 2 files changed, 24 insertions(+), 5 deletions(-) (limited to 'drivers/pci/hotplug/pnv_php.c') diff --git a/arch/powerpc/include/asm/pnv-pci.h b/arch/powerpc/include/asm/pnv-pci.h index 696438f09aea..de9681034353 100644 --- a/arch/powerpc/include/asm/pnv-pci.h +++ b/arch/powerpc/include/asm/pnv-pci.h @@ -57,6 +57,8 @@ struct pnv_php_slot { uint64_t id; char *name; int slot_no; + unsigned int flags; +#define PNV_PHP_FLAG_BROKEN_PDC 0x1 struct kref kref; #define PNV_PHP_STATE_INITIALIZED 0 #define PNV_PHP_STATE_REGISTERED 1 diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 41304b313512..63cd9f354b79 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -717,7 +717,8 @@ static irqreturn_t pnv_php_interrupt(int irq, void *data) if (sts & PCI_EXP_SLTSTA_DLLSC) { pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lsts); added = !!(lsts & PCI_EXP_LNKSTA_DLLLA); - } else if (sts & PCI_EXP_SLTSTA_PDC) { + } else if (!(php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) && + (sts & PCI_EXP_SLTSTA_PDC)) { ret = pnv_pci_get_presence_state(php_slot->id, &presence); if (ret) { dev_warn(&pdev->dev, "PCI slot [%s] error %d getting presence (0x%04x), to retry the operation.\n", @@ -768,6 +769,7 @@ static irqreturn_t pnv_php_interrupt(int irq, void *data) static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq) { struct pci_dev *pdev = php_slot->pdev; + u32 broken_pdc = 0; u16 sts, ctrl; int ret; @@ -779,9 +781,18 @@ static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq) return; } + /* Check PDC (Presence Detection Change) is broken or not */ + ret = of_property_read_u32(php_slot->dn, "ibm,slot-broken-pdc", + &broken_pdc); + if (!ret && broken_pdc) + php_slot->flags |= PNV_PHP_FLAG_BROKEN_PDC; + /* Clear pending interrupts */ pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts); - sts |= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC); + if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) + sts |= PCI_EXP_SLTSTA_DLLSC; + else + sts |= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC); pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts); /* Request the interrupt */ @@ -795,9 +806,15 @@ static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq) /* Enable the interrupts */ pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl); - ctrl |= (PCI_EXP_SLTCTL_HPIE | - PCI_EXP_SLTCTL_PDCE | - PCI_EXP_SLTCTL_DLLSCE); + if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) { + ctrl &= ~PCI_EXP_SLTCTL_PDCE; + ctrl |= (PCI_EXP_SLTCTL_HPIE | + PCI_EXP_SLTCTL_DLLSCE); + } else { + ctrl |= (PCI_EXP_SLTCTL_HPIE | + PCI_EXP_SLTCTL_PDCE | + PCI_EXP_SLTCTL_DLLSCE); + } pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl); /* The interrupt is initialized successfully when @irq is valid */ -- cgit From 36c7c9da40c408a71e5e6bfe12e57dcf549a296d Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 16 Feb 2017 10:22:32 +1100 Subject: pci/hotplug/pnv-php: Remove WARN_ON() in pnv_php_put_slot() The WARN_ON() causes unnecessary backtrace when putting the parent slot, which is likely to be NULL. WARNING: CPU: 2 PID: 1071 at drivers/pci/hotplug/pnv_php.c:85 \ pnv_php_release+0xcc/0x150 [pnv_php] : Call Trace: [c0000003bc007c10] [d00000000ad613c4] pnv_php_release+0x144/0x150 [pnv_php] [c0000003bc007c40] [c0000000006641d8] pci_hp_deregister+0x238/0x330 [c0000003bc007cd0] [d00000000ad61440] pnv_php_unregister_one+0x70/0xa0 [pnv_php] [c0000003bc007d10] [d00000000ad614c0] pnv_php_unregister+0x50/0x80 [pnv_php] [c0000003bc007d40] [d00000000ad61e84] pnv_php_exit+0x50/0xcb4 [pnv_php] [c0000003bc007d70] [c00000000019499c] SyS_delete_module+0x1fc/0x2a0 [c0000003bc007e30] [c00000000000b184] system_call+0x38/0xe0 Cc: # v4.8+ Fixes: 66725152fb9f ("PCI/hotplug: PowerPC PowerNV PCI hotplug driver") Signed-off-by: Gavin Shan Reviewed-by: Andrew Donnellan Tested-by: Vaibhav Jain Signed-off-by: Michael Ellerman --- drivers/pci/hotplug/pnv_php.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/pci/hotplug/pnv_php.c') diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 63cd9f354b79..da1bbf3eda55 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -76,7 +76,7 @@ static void pnv_php_free_slot(struct kref *kref) static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot) { - if (WARN_ON(!php_slot)) + if (!php_slot) return; kref_put(&php_slot->kref, pnv_php_free_slot); -- cgit From 303529d6ef1293513c2c73c9ab86489eebb37d08 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 16 Feb 2017 10:22:33 +1100 Subject: pci/hotplug/pnv-php: Disable surprise hotplug capability on conflicts The root port or PCIe switch downstream port might have been associated with driver other than pnv-php. The MSI or MSIx might also have been enabled by that driver (e.g. pcieport_drv). Attempt to enable MSI incurs below backtrace: PowerPC PowerNV PCI Hotplug Driver version: 0.1 ------------[ cut here ]------------ WARNING: CPU: 19 PID: 1004 at drivers/pci/msi.c:1071 \ __pci_enable_msi_range+0x84/0x4e0 NIP [c000000000665c34] __pci_enable_msi_range+0x84/0x4e0 LR [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0 Call Trace: [c000000384d67600] [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0 [c000000384d676e0] [d00000000aa31b04] pnv_php_register+0x564/0x5a0 [pnv_php] [c000000384d677c0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php] [c000000384d678a0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php] [c000000384d67980] [d00000000aa31dfc] pnv_php_init+0x60/0x98 [pnv_php] [c000000384d679f0] [c00000000000cfdc] do_one_initcall+0x6c/0x1d0 [c000000384d67ab0] [c000000000b92354] do_init_module+0x94/0x254 [c000000384d67b40] [c00000000019719c] load_module+0x258c/0x2c60 [c000000384d67d30] [c000000000197bb0] SyS_finit_module+0xf0/0x170 [c000000384d67e30] [c00000000000b184] system_call+0x38/0xe0 This fixes the issue by skipping enabling the surprise hotplug capability if the MSI or MSIx on the PCI slot's upstream port has been enabled by other driver. Cc: # v4.9+ Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver") Signed-off-by: Gavin Shan Reviewed-by: Andrew Donnellan Tested-by: Vaibhav Jain Signed-off-by: Michael Ellerman --- drivers/pci/hotplug/pnv_php.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/pci/hotplug/pnv_php.c') diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index da1bbf3eda55..6d36b7630491 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -826,6 +826,14 @@ static void pnv_php_enable_irq(struct pnv_php_slot *php_slot) struct pci_dev *pdev = php_slot->pdev; int irq, ret; + /* + * The MSI/MSIx interrupt might have been occupied by other + * drivers. Don't populate the surprise hotplug capability + * in that case. + */ + if (pci_dev_msi_enabled(pdev)) + return; + ret = pci_enable_device(pdev); if (ret) { dev_warn(&pdev->dev, "Error %d enabling device\n", ret); -- cgit From 49f4b08e61547a5ccd2db551d994c4503efe5666 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 16 Feb 2017 10:22:34 +1100 Subject: pci/hotplug/pnv-php: Disable MSI and PCI device properly pnv_php_disable_irq() can be called in two paths: Bailing path in pnv_php_enable_irq() or releasing slot. The MSI (or MSIx) interrupts is disabled unconditionally in pnv_php_disable_irq(). It's wrong because that might be enabled by drivers other than pnv-php. This disables MSI (or MSIx) interrupts and the PCI device only if it was enabled by pnv-php. In the error path of pnv_php_enable_irq(), we rely on the newly added parameter @disable_device. In the path of releasing slot, @pnv_php->irq is checked. Cc: # v4.9+ Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver") Signed-off-by: Gavin Shan Reviewed-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/pci/hotplug/pnv_php.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) (limited to 'drivers/pci/hotplug/pnv_php.c') diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 6d36b7630491..335a55684cd8 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -35,9 +35,11 @@ static void pnv_php_register(struct device_node *dn); static void pnv_php_unregister_one(struct device_node *dn); static void pnv_php_unregister(struct device_node *dn); -static void pnv_php_disable_irq(struct pnv_php_slot *php_slot) +static void pnv_php_disable_irq(struct pnv_php_slot *php_slot, + bool disable_device) { struct pci_dev *pdev = php_slot->pdev; + int irq = php_slot->irq; u16 ctrl; if (php_slot->irq > 0) { @@ -56,10 +58,14 @@ static void pnv_php_disable_irq(struct pnv_php_slot *php_slot) php_slot->wq = NULL; } - if (pdev->msix_enabled) - pci_disable_msix(pdev); - else if (pdev->msi_enabled) - pci_disable_msi(pdev); + if (disable_device || irq > 0) { + if (pdev->msix_enabled) + pci_disable_msix(pdev); + else if (pdev->msi_enabled) + pci_disable_msi(pdev); + + pci_disable_device(pdev); + } } static void pnv_php_free_slot(struct kref *kref) @@ -68,7 +74,7 @@ static void pnv_php_free_slot(struct kref *kref) struct pnv_php_slot, kref); WARN_ON(!list_empty(&php_slot->children)); - pnv_php_disable_irq(php_slot); + pnv_php_disable_irq(php_slot, false); kfree(php_slot->name); kfree(php_slot); } @@ -777,7 +783,7 @@ static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq) php_slot->wq = alloc_workqueue("pciehp-%s", 0, 0, php_slot->name); if (!php_slot->wq) { dev_warn(&pdev->dev, "Cannot alloc workqueue\n"); - pnv_php_disable_irq(php_slot); + pnv_php_disable_irq(php_slot, true); return; } @@ -799,7 +805,7 @@ static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq) ret = request_irq(irq, pnv_php_interrupt, IRQF_SHARED, php_slot->name, php_slot); if (ret) { - pnv_php_disable_irq(php_slot); + pnv_php_disable_irq(php_slot, true); dev_warn(&pdev->dev, "Error %d enabling IRQ %d\n", ret, irq); return; } -- cgit