@@ -83,32 +83,6 @@ static inline void pciehp_free_irq(struct controller *ctrl)
free_irq(ctrl->pcie->irq, ctrl);
}
-static int pcie_poll_cmd(struct controller *ctrl, int timeout)
-{
- struct pci_dev *pdev = ctrl_dev(ctrl);
- u16 slot_status;
-
- do {
- pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
- if (PCI_POSSIBLE_ERROR(slot_status)) {
- ctrl_info(ctrl, "%s: no response from device\n",
- __func__);
- return 0;
- }
-
- if (slot_status & PCI_EXP_SLTSTA_CC) {
- pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
- PCI_EXP_SLTSTA_CC);
- ctrl->cmd_busy = 0;
- smp_mb();
- return 1;
- }
- msleep(10);
- timeout -= 10;
- } while (timeout >= 0);
- return 0; /* timeout */
-}
-
static void pcie_wait_cmd(struct controller *ctrl)
{
unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
@@ -138,10 +112,16 @@ static void pcie_wait_cmd(struct controller *ctrl)
timeout = cmd_timeout - now;
if (ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE &&
- ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE)
+ ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE) {
rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
- else
- rc = pcie_poll_cmd(ctrl, jiffies_to_msecs(timeout));
+ } else {
+ rc = pcie_poll_sltctl_cmd(ctrl_dev(ctrl), jiffies_to_msecs(timeout));
+ if (!rc) {
+ ctrl->cmd_busy = 0;
+ smp_mb();
+ rc = 1;
+ }
+ }
if (!rc)
ctrl_info(ctrl, "Timeout on hotplug command %#06x (issued %u msec ago)\n",
@@ -759,12 +759,17 @@ static inline void pcie_ecrc_get_policy(char *str) { }
#ifdef CONFIG_PCIEPORTBUS
void pcie_reset_lbms_count(struct pci_dev *port);
int pcie_lbms_count(struct pci_dev *port, unsigned long *val);
+int pcie_poll_sltctl_cmd(struct pci_dev *dev, int timeout_ms);
#else
static inline void pcie_reset_lbms_count(struct pci_dev *port) {}
static inline int pcie_lbms_count(struct pci_dev *port, unsigned long *val)
{
return -EOPNOTSUPP;
}
+static inline int pcie_poll_sltctl_cmd(struct pci_dev *dev, int timeout_ms)
+{
+ return 0;
+}
#endif
struct pci_dev_reset_methods {
@@ -18,6 +18,7 @@
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/aer.h>
+#include <linux/iopoll.h>
#include "../pci.h"
#include "portdrv.h"
@@ -205,6 +206,30 @@ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
return 0;
}
+/* Return 0 on command completed on time, otherwise return -ETIMEOUT */
+int pcie_poll_sltctl_cmd(struct pci_dev *dev, int timeout_ms)
+{
+ u16 slot_status = 0;
+ u32 slot_cap;
+ int ret = 0;
+ int __maybe_unused ret1;
+
+ /* Don't wait if the command complete event is not well supported */
+ pcie_capability_read_dword(dev, PCI_EXP_SLTCAP, &slot_cap);
+ if (!(slot_cap & PCI_EXP_SLTCAP_HPC) || slot_cap & PCI_EXP_SLTCAP_NCCS)
+ return ret;
+
+ ret = read_poll_timeout(pcie_capability_read_word, ret1,
+ (slot_status & PCI_EXP_SLTSTA_CC), 10000,
+ timeout_ms * 1000, true, dev, PCI_EXP_SLTSTA,
+ &slot_status);
+ if (!ret)
+ pcie_capability_write_word(dev, PCI_EXP_SLTSTA,
+ PCI_EXP_SLTSTA_CC);
+
+ return ret;
+}
+
/**
* get_port_device_capability - discover capabilities of a PCI Express port
* @dev: PCI Express port to examine
According to PCIe spec, after sending a hotplug command, software should wait some time for the command completion. Currently the waiting logic is implemented in pciehp driver, as the same logic will be reused by PCIe port driver, move it to port driver, which complies with the logic of CONFIG_HOTPLUG_PCI_PCIE depending on CONFIG_PCIEPORTBUS. Also convert the loop wait logic to helper read_poll_timeout() as suggested by Sathyanarayanan Kuppuswamy. Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com> --- drivers/pci/hotplug/pciehp_hpc.c | 38 ++++++++------------------------ drivers/pci/pci.h | 5 +++++ drivers/pci/pcie/portdrv.c | 25 +++++++++++++++++++++ 3 files changed, 39 insertions(+), 29 deletions(-)