From: Jon Derrick <jonathan.derrick@intel.com>
To: <linux-pci@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>, <linux-doc@vger.kernel.org>,
Bjorn Helgaas <helgaas@kernel.org>,
Keith Busch <keith.busch@intel.com>,
Sinan Kaya <okaya@kernel.org>,
Oza Pawandeep <poza@codeaurora.org>,
Dongdong Liu <liudongdong3@huawei.com>,
Jon Derrick <jonathan.derrick@intel.com>
Subject: [PATCH 1/2] PCI/DPC: Add 'nodpc' parameter
Date: Wed, 15 Aug 2018 15:26:39 -0600 [thread overview]
Message-ID: <1534368400-2807-1-git-send-email-jonathan.derrick@intel.com> (raw)
Some users may want to disable downstream port containment (DPC), so
give them this option
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
---
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();
+}
+
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);
--
1.8.3.1
next reply other threads:[~2018-08-15 21:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-15 21:26 Jon Derrick [this message]
2018-08-15 21:26 ` [PATCH 2/2] Documentation: Document pci=nodpc Jon Derrick
2018-08-15 23:03 ` [PATCH 1/2] PCI/DPC: Add 'nodpc' parameter Keith Busch
2018-08-16 9:27 ` poza
2018-08-16 15:45 ` Derrick, Jonathan
2018-08-16 15:49 ` Matthew Wilcox
2018-08-16 15:50 ` Derrick, Jonathan
2018-08-16 20:31 ` Bjorn Helgaas
2018-08-16 20:50 ` Derrick, Jonathan
2018-08-16 21:19 ` Keith Busch
2018-08-16 21:28 ` Derrick, Jonathan
2018-08-17 14:25 ` Bjorn Helgaas
2018-08-17 14:45 ` Derrick, Jonathan
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