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-rw-r--r--drivers/pci/pci.c35
-rw-r--r--drivers/pci/pci.h2
-rw-r--r--drivers/pci/probe.c5
-rw-r--r--include/linux/pci_regs.h13
4 files changed, 55 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 4859669f0ab5..557218222826 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1546,6 +1546,41 @@ void pci_enable_ari(struct pci_dev *dev)
}
/**
+ * pci_enable_acs - enable ACS if hardware support it
+ * @dev: the PCI device
+ */
+void pci_enable_acs(struct pci_dev *dev)
+{
+ int pos;
+ u16 cap;
+ u16 ctrl;
+
+ if (!dev->is_pcie)
+ return;
+
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
+ if (!pos)
+ return;
+
+ pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
+ pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
+
+ /* Source Validation */
+ ctrl |= (cap & PCI_ACS_SV);
+
+ /* P2P Request Redirect */
+ ctrl |= (cap & PCI_ACS_RR);
+
+ /* P2P Completion Redirect */
+ ctrl |= (cap & PCI_ACS_CR);
+
+ /* Upstream Forwarding */
+ ctrl |= (cap & PCI_ACS_UF);
+
+ pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
+}
+
+/**
* pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
* @dev: the PCI device
* @pin: the INTx pin (1=INTA, 2=INTB, 3=INTD, 4=INTD)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index d92d1954a2fb..33ed8e0aba1e 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -311,4 +311,6 @@ static inline int pci_resource_alignment(struct pci_dev *dev,
return resource_alignment(res);
}
+extern void pci_enable_acs(struct pci_dev *dev);
+
#endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2adb47574d86..aac5b156a5c5 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/cpumask.h>
#include <linux/pci-aspm.h>
+#include <linux/iommu.h>
#include "pci.h"
#define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
@@ -1004,6 +1005,10 @@ static void pci_init_capabilities(struct pci_dev *dev)
/* Single Root I/O Virtualization */
pci_iov_init(dev);
+
+ /* Enable ACS P2P upstream forwarding */
+ if (iommu_found())
+ pci_enable_acs(dev);
}
void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index dd0bed4f1cf0..d798770f08cd 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -502,6 +502,7 @@
#define PCI_EXT_CAP_ID_VC 2
#define PCI_EXT_CAP_ID_DSN 3
#define PCI_EXT_CAP_ID_PWR 4
+#define PCI_EXT_CAP_ID_ACS 13
#define PCI_EXT_CAP_ID_ARI 14
#define PCI_EXT_CAP_ID_ATS 15
#define PCI_EXT_CAP_ID_SRIOV 16
@@ -662,4 +663,16 @@
#define PCI_SRIOV_VFM_MO 0x2 /* Active.MigrateOut */
#define PCI_SRIOV_VFM_AV 0x3 /* Active.Available */
+/* Access Control Service */
+#define PCI_ACS_CAP 0x04 /* ACS Capability Register */
+#define PCI_ACS_SV 0x01 /* Source Validation */
+#define PCI_ACS_TB 0x02 /* Translation Blocking */
+#define PCI_ACS_RR 0x04 /* P2P Request Redirect */
+#define PCI_ACS_CR 0x08 /* P2P Completion Redirect */
+#define PCI_ACS_UF 0x10 /* Upstream Forwarding */
+#define PCI_ACS_EC 0x20 /* P2P Egress Control */
+#define PCI_ACS_DT 0x40 /* Direct Translated P2P */
+#define PCI_ACS_CTRL 0x06 /* ACS Control Register */
+#define PCI_ACS_EGRESS_CTL_V 0x08 /* ACS Egress Control Vector */
+
#endif /* LINUX_PCI_REGS_H */