On 2018-08-16 02:56, Jon Derrick wrote:
Some users may want to disable downstream port containment (DPC), so
give them this option
Signed-off-by: Jon Derrick <jonathan.derrick@xxxxxxxxx>
---
drivers/pci/pci.c | 2 ++
drivers/pci/pci.h | 6 ++++++
drivers/pci/pcie/dpc.c | 48
++++++++++++++++++++++++++++++++++++++----------
include/linux/pci.h | 6 ++++++
4 files changed, 52 insertions(+), 10 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 80da484..4e629c2 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6062,6 +6062,8 @@ static int __init pci_setup(char *str)
pcie_ats_disabled = true;
} else if (!strcmp(str, "noaer")) {
pci_no_aer();
+ } else if (!strcmp(str, "nodpc")) {
+ pci_no_dpc();
} else if (!strcmp(str, "earlydump")) {
pci_early_dump = true;
} else if (!strncmp(str, "realloc=", 8)) {
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 6e0d152..f73f29e 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -536,4 +536,10 @@ static inline void
pci_aer_clear_fatal_status(struct pci_dev *dev) { }
static inline void pci_aer_clear_device_status(struct pci_dev *dev) {
}
#endif
+#ifdef CONFIG_PCIE_DPC
+void pci_no_dpc(void);
+#else
+static inline void pci_no_dpc(void) { }
+#endif
+
#endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index f03279f..068fca0 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -44,6 +44,18 @@ struct dpc_dev {
"Memory Request Completion Timeout", /* Bit Position 18 */
};
+static int pcie_dpc_disable;
+
+void pci_no_dpc(void)
+{
+ pcie_dpc_disable = 1;
+}
+
+bool pci_dpc_available(void)
+{
+ return !pcie_dpc_disable && pci_aer_available() && pci_msi_enabled();
1) why do you check pci_aer_available() ?
2) and pci_aer_available() already internally checks pci_msi_enabled();
+}
+
static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
{
unsigned long timeout = jiffies + HZ;
@@ -209,6 +221,17 @@ static irqreturn_t dpc_irq(int irq, void *context)
return IRQ_HANDLED;
}
+static void dpc_disable(struct pci_dev *pdev)
+{
+ u16 cap_pos, ctl;
+
+ cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
+ pci_read_config_word(pdev, cap_pos + PCI_EXP_DPC_CTL, &ctl);
+ ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_EN_NONFATAL |
+ PCI_EXP_DPC_CTL_INT_EN);
+ pci_write_config_word(pdev, cap_pos + PCI_EXP_DPC_CTL, ctl);
+}
+
#define FLAG(x, y) (((x) & (y)) ? '+' : '-')
static int dpc_probe(struct pcie_device *dev)
{
@@ -221,9 +244,16 @@ static int dpc_probe(struct pcie_device *dev)
if (pcie_aer_get_firmware_first(pdev))
return -ENOTSUPP;
+ if (!pci_dpc_available()) {
+ status = -ENOTSUPP;
+ goto disable_dpc;
+ }
+
dpc = devm_kzalloc(device, sizeof(*dpc), GFP_KERNEL);
- if (!dpc)
- return -ENOMEM;
+ if (!dpc) {
+ status = -ENOMEM;
+ goto disable_dpc;
+ }
dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
dpc->dev = dev;
@@ -235,7 +265,7 @@ static int dpc_probe(struct pcie_device *dev)
if (status) {
dev_warn(device, "request IRQ%d failed: %d\n", dev->irq,
status);
- return status;
+ goto disable_dpc;
}
pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap);
@@ -260,17 +290,15 @@ static int dpc_probe(struct pcie_device *dev)
FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), dpc->rp_log_size,
FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE));
return status;
+
+disable_dpc:
+ dpc_disable(pdev);
+ return status;
}
static void dpc_remove(struct pcie_device *dev)
{
- struct dpc_dev *dpc = get_service_data(dev);
- struct pci_dev *pdev = dev->port;
- u16 ctl;
-
- pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
- ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN);
- pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
+ dpc_disable(dev->port);
}
static struct pcie_port_service_driver dpcdriver = {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 5454e6b..559b792 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1473,6 +1473,12 @@ static inline int pci_irqd_intx_xlate(struct
irq_domain *d,
static inline bool pci_aer_available(void) { return false; }
#endif
+#ifdef CONFIG_PCIE_DPC
+bool pci_dpc_available(void);
+#else
+static inline bool pci_dpc_available(void) { return false; }
+#endif
+
#ifdef CONFIG_PCIE_ECRC
void pcie_set_ecrc_checking(struct pci_dev *dev);
void pcie_ecrc_get_policy(char *str);
