diff options
author | Bjorn Helgaas <bhelgaas@google.com> | 2020-04-02 14:26:35 -0500 |
---|---|---|
committer | Bjorn Helgaas <bhelgaas@google.com> | 2020-04-02 14:26:35 -0500 |
commit | 3038685357ee10ad52796c8eb3a764a81ce59cef (patch) | |
tree | 14614db7c83fe718185a70eb998b1fd92abde05b /drivers | |
parent | eb81b249ba059443916d6cc0cfa3e1987aa938d9 (diff) | |
parent | 8edf5332c39340b9583cf9cba659eb7ec71f75b5 (diff) | |
download | linux-3038685357ee10ad52796c8eb3a764a81ce59cef.tar.bz2 |
Merge branch 'pci/hotplug'
- Disable in-band presence detection when possible (Alexandru Gagniuc)
- Poll for presence detect if in-band presence detection is disabled
(Alexandru Gagniuc)
- Add DMI table of systems that don't support in-band presence detection
(Stuart Hayes)
- Fix indefinite pciehp wait caused by race in handling sysfs requests
(Lukas Wunner)
- Fix pciehp MSI interrupt race that caused us to miss interrupts (Stuart
Hayes)
* pci/hotplug:
PCI: pciehp: Fix MSI interrupt race
PCI: pciehp: Fix indefinite wait on sysfs requests
PCI: pciehp: Add DMI table for in-band presence detection disabled
PCI: pciehp: Wait for PDS if in-band presence is disabled
PCI: pciehp: Disable in-band presence detect when possible
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/pci/hotplug/pciehp.h | 1 | ||||
-rw-r--r-- | drivers/pci/hotplug/pciehp_hpc.c | 93 |
2 files changed, 79 insertions, 15 deletions
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index aa61d4c219d7..ae44f46d1bf3 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -84,6 +84,7 @@ struct controller { struct pcie_device *pcie; u32 slot_cap; /* capabilities and quirks */ + unsigned int inband_presence_disabled:1; u16 slot_ctrl; /* control register access */ struct mutex ctrl_lock; diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 8a2cb1764386..53433b37e181 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -14,6 +14,7 @@ #define dev_fmt(fmt) "pciehp: " fmt +#include <linux/dmi.h> #include <linux/kernel.h> #include <linux/types.h> #include <linux/jiffies.h> @@ -26,6 +27,24 @@ #include "../pci.h" #include "pciehp.h" +static const struct dmi_system_id inband_presence_disabled_dmi_table[] = { + /* + * Match all Dell systems, as some Dell systems have inband + * presence disabled on NVMe slots (but don't support the bit to + * report it). Setting inband presence disabled should have no + * negative effect, except on broken hotplug slots that never + * assert presence detect--and those will still work, they will + * just have a bit of extra delay before being probed. + */ + { + .ident = "Dell System", + .matches = { + DMI_MATCH(DMI_OEM_STRING, "Dell System"), + }, + }, + {} +}; + static inline struct pci_dev *ctrl_dev(struct controller *ctrl) { return ctrl->pcie->port; @@ -252,6 +271,22 @@ static bool pci_bus_check_dev(struct pci_bus *bus, int devfn) return found; } +static void pcie_wait_for_presence(struct pci_dev *pdev) +{ + int timeout = 1250; + u16 slot_status; + + do { + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + if (slot_status & PCI_EXP_SLTSTA_PDS) + return; + msleep(10); + timeout -= 10; + } while (timeout > 0); + + pci_info(pdev, "Timeout waiting for Presence Detect\n"); +} + int pciehp_check_link_status(struct controller *ctrl) { struct pci_dev *pdev = ctrl_dev(ctrl); @@ -261,6 +296,9 @@ int pciehp_check_link_status(struct controller *ctrl) if (!pcie_wait_for_link(pdev, true)) return -1; + if (ctrl->inband_presence_disabled) + pcie_wait_for_presence(pdev); + found = pci_bus_check_dev(ctrl->pcie->port->subordinate, PCI_DEVFN(0, 0)); @@ -527,7 +565,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id) struct controller *ctrl = (struct controller *)dev_id; struct pci_dev *pdev = ctrl_dev(ctrl); struct device *parent = pdev->dev.parent; - u16 status, events; + u16 status, events = 0; /* * Interrupts only occur in D3hot or shallower and only if enabled @@ -552,6 +590,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id) } } +read_status: pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status); if (status == (u16) ~0) { ctrl_info(ctrl, "%s: no response from device\n", __func__); @@ -564,24 +603,37 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id) * Slot Status contains plain status bits as well as event * notification bits; right now we only want the event bits. */ - events = status & (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | - PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC | - PCI_EXP_SLTSTA_DLLSC); + status &= PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | + PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC | + PCI_EXP_SLTSTA_DLLSC; /* * If we've already reported a power fault, don't report it again * until we've done something to handle it. */ if (ctrl->power_fault_detected) - events &= ~PCI_EXP_SLTSTA_PFD; + status &= ~PCI_EXP_SLTSTA_PFD; + events |= status; if (!events) { if (parent) pm_runtime_put(parent); return IRQ_NONE; } - pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events); + if (status) { + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events); + + /* + * In MSI mode, all event bits must be zero before the port + * will send a new interrupt (PCIe Base Spec r5.0 sec 6.7.3.4). + * So re-read the Slot Status register in case a bit was set + * between read and write. + */ + if (pci_dev_msi_enabled(pdev) && !pciehp_poll_mode) + goto read_status; + } + ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events); if (parent) pm_runtime_put(parent); @@ -625,17 +677,15 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id) if (atomic_fetch_and(~RERUN_ISR, &ctrl->pending_events) & RERUN_ISR) { ret = pciehp_isr(irq, dev_id); enable_irq(irq); - if (ret != IRQ_WAKE_THREAD) { - pci_config_pm_runtime_put(pdev); - return ret; - } + if (ret != IRQ_WAKE_THREAD) + goto out; } synchronize_hardirq(irq); events = atomic_xchg(&ctrl->pending_events, 0); if (!events) { - pci_config_pm_runtime_put(pdev); - return IRQ_NONE; + ret = IRQ_NONE; + goto out; } /* Check Attention Button Pressed */ @@ -664,10 +714,12 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id) pciehp_handle_presence_or_link_change(ctrl, events); up_read(&ctrl->reset_lock); + ret = IRQ_HANDLED; +out: pci_config_pm_runtime_put(pdev); ctrl->ist_running = false; wake_up(&ctrl->requester); - return IRQ_HANDLED; + return ret; } static int pciehp_poll(void *data) @@ -848,7 +900,7 @@ static inline void dbg_ctrl(struct controller *ctrl) struct controller *pcie_init(struct pcie_device *dev) { struct controller *ctrl; - u32 slot_cap, link_cap; + u32 slot_cap, slot_cap2, link_cap; u8 poweron; struct pci_dev *pdev = dev->port; struct pci_bus *subordinate = pdev->subordinate; @@ -883,6 +935,16 @@ struct controller *pcie_init(struct pcie_device *dev) ctrl->state = list_empty(&subordinate->devices) ? OFF_STATE : ON_STATE; up_read(&pci_bus_sem); + pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP2, &slot_cap2); + if (slot_cap2 & PCI_EXP_SLTCAP2_IBPD) { + pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_IBPD_DISABLE, + PCI_EXP_SLTCTL_IBPD_DISABLE); + ctrl->inband_presence_disabled = 1; + } + + if (dmi_first_match(inband_presence_disabled_dmi_table)) + ctrl->inband_presence_disabled = 1; + /* Check if Data Link Layer Link Active Reporting is implemented */ pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap); @@ -892,7 +954,7 @@ struct controller *pcie_init(struct pcie_device *dev) PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC); - ctrl_info(ctrl, "Slot #%d AttnBtn%c PwrCtrl%c MRL%c AttnInd%c PwrInd%c HotPlug%c Surprise%c Interlock%c NoCompl%c LLActRep%c%s\n", + ctrl_info(ctrl, "Slot #%d AttnBtn%c PwrCtrl%c MRL%c AttnInd%c PwrInd%c HotPlug%c Surprise%c Interlock%c NoCompl%c IbPresDis%c LLActRep%c%s\n", (slot_cap & PCI_EXP_SLTCAP_PSN) >> 19, FLAG(slot_cap, PCI_EXP_SLTCAP_ABP), FLAG(slot_cap, PCI_EXP_SLTCAP_PCP), @@ -903,6 +965,7 @@ struct controller *pcie_init(struct pcie_device *dev) FLAG(slot_cap, PCI_EXP_SLTCAP_HPS), FLAG(slot_cap, PCI_EXP_SLTCAP_EIP), FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS), + FLAG(slot_cap2, PCI_EXP_SLTCAP2_IBPD), FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC), pdev->broken_cmd_compl ? " (with Cmd Compl erratum)" : ""); |