bus/pci: configure PCI bus master

Add the API to set 'Bus Master Enable' bit to be enabled or disabled in
the PCI command register.

Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Acked-by: Ray Kinsella <mdr@ashroe.eu>

diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
index ee7f966..35d7d09 100644 (file)
--- a/drivers/bus/pci/pci_common.c
+++ b/drivers/bus/pci/pci_common.c
@@ -746,6 +746,34 @@ rte_pci_find_ext_capability(struct rte_pci_device *dev, uint32_t cap)
        return 0;
 }
 
+int
+rte_pci_set_bus_master(struct rte_pci_device *dev, bool enable)
+{
+       uint16_t old_cmd, cmd;
+
+       if (rte_pci_read_config(dev, &old_cmd, sizeof(old_cmd),
+                               RTE_PCI_COMMAND) < 0) {
+               RTE_LOG(ERR, EAL, "error in reading PCI command register\n");
+               return -1;
+       }
+
+       if (enable)
+               cmd = old_cmd | RTE_PCI_COMMAND_MASTER;
+       else
+               cmd = old_cmd & ~RTE_PCI_COMMAND_MASTER;
+
+       if (cmd == old_cmd)
+               return 0;
+
+       if (rte_pci_write_config(dev, &cmd, sizeof(cmd),
+                                RTE_PCI_COMMAND) < 0) {
+               RTE_LOG(ERR, EAL, "error in writing PCI command register\n");
+               return -1;
+       }
+
+       return 0;
+}
+
 struct rte_pci_bus rte_pci_bus = {
        .bus = {
                .scan = rte_pci_scan,

diff --git a/drivers/bus/pci/rte_bus_pci.h b/drivers/bus/pci/rte_bus_pci.h
index 64886b4..976c33c 100644 (file)
--- a/drivers/bus/pci/rte_bus_pci.h
+++ b/drivers/bus/pci/rte_bus_pci.h
@@ -249,6 +249,20 @@ void rte_pci_dump(FILE *f);
 __rte_experimental
 off_t rte_pci_find_ext_capability(struct rte_pci_device *dev, uint32_t cap);
 
+/**
+ * Enables/Disables Bus Master for device's PCI command register.
+ *
+ *  @param dev
+ *    A pointer to rte_pci_device structure.
+ *  @param enable
+ *    Enable or disable Bus Master.
+ *
+ *  @return
+ *  0 on success, -1 on error in PCI config space read/write.
+ */
+__rte_experimental
+int rte_pci_set_bus_master(struct rte_pci_device *dev, bool enable);
+
 /**
  * Register a PCI driver.
  *

diff --git a/drivers/bus/pci/version.map b/drivers/bus/pci/version.map
index f33ed0a..00fac88 100644 (file)
--- a/drivers/bus/pci/version.map
+++ b/drivers/bus/pci/version.map
@@ -21,4 +21,7 @@ EXPERIMENTAL {
        global:
 
        rte_pci_find_ext_capability;
+
+       # added in 21.08
+       rte_pci_set_bus_master;
 };

diff --git a/lib/pci/rte_pci.h b/lib/pci/rte_pci.h
index a8f8e40..1f33d68 100644 (file)
--- a/lib/pci/rte_pci.h
+++ b/lib/pci/rte_pci.h
@@ -32,6 +32,10 @@ extern "C" {
 
 #define RTE_PCI_VENDOR_ID      0x00    /* 16 bits */
 #define RTE_PCI_DEVICE_ID      0x02    /* 16 bits */
+#define RTE_PCI_COMMAND                0x04    /* 16 bits */
+
+/* PCI Command Register */
+#define RTE_PCI_COMMAND_MASTER 0x4     /* Bus Master Enable */
 
 /* PCI Express capability registers */
 #define RTE_PCI_EXP_DEVCTL     8       /* Device Control */