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path: root/drivers/pci/hotplug/pciehp_hpc.c
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Diffstat (limited to 'drivers/pci/hotplug/pciehp_hpc.c')
-rw-r--r--drivers/pci/hotplug/pciehp_hpc.c93
1 files changed, 78 insertions, 15 deletions
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)" : "");