[dpdk-dev,1/4] pci: allow access to PCI config space
Commit Message
Here is a revised version that works for both UIO and VFIO.
The config access is property of device not the I/O model.
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: [PATCH 1/4] pci: allow access to PCI config space
Some drivers need ability to access PCI config (for example for power
management). This adds an abstraction to do this; only implemented
on Linux, but should be possible on BSD.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
lib/librte_eal/common/include/rte_pci.h | 29 +++++++++++++++++++++++++++++
lib/librte_eal/linuxapp/eal/eal_pci.c | 15 +++++++++++++++
lib/librte_eal/linuxapp/eal/eal_pci_uio.c | 10 ++++++++++
3 files changed, 54 insertions(+)
===================================================================
@@ -152,6 +152,7 @@
uint16_t max_vfs; /**< sriov enable if not zero */
int numa_node; /**< NUMA node connection */
struct rte_devargs *devargs; /**< Device user arguments */
+ int config_fd; /**< PCI config access */
};
/** Any PCI device identifier (vendor, device, ...) */
@@ -304,6 +305,34 @@
*/
void rte_eal_pci_unregister(struct rte_pci_driver *driver);
+/**
+ * Read PCI config space.
+ *
+ * @param device
+ * A pointer to a rte_pci_device structure describing the device
+ * to use
+ * @param buf
+ * A data buffer where the bytes should be read into
+ * @param size
+ * The length of the data buffer.
+ */
+int rte_eal_pci_read_config(const struct rte_pci_device *device,
+ void *buf, size_t len, off_t offset);
+
+/**
+ * Write PCI config space.
+ *
+ * @param device
+ * A pointer to a rte_pci_device structure describing the device
+ * to use
+ * @param buf
+ * A data buffer containing the bytes should be written
+ * @param size
+ * The length of the data buffer.
+ */
+int rte_eal_pci_write_config(const struct rte_pci_device *device,
+ const void *buf, size_t len, off_t offset);
+
#ifdef __cplusplus
}
#endif
===================================================================
@@ -34,6 +34,7 @@
#include <string.h>
#include <dirent.h>
#include <sys/mman.h>
+#include <sys/fcntl.h>
#include <rte_log.h>
#include <rte_pci.h>
@@ -233,6 +234,7 @@
dev->addr.bus = bus;
dev->addr.devid = devid;
dev->addr.function = function;
+ dev->config_fd = -1;
/* get vendor id */
snprintf(filename, sizeof(filename), "%s/vendor", dirname);
@@ -498,6 +500,26 @@
#endif
static int
+pci_config_open(struct rte_pci_device *dev)
+{
+ struct rte_pci_addr *loc = &dev->addr;
+ char filename[PATH_MAX];
+
+ /* Open fd for access to PCI config */
+ snprintf(filename, sizeof(filename),
+ SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/config",
+ loc->domain, loc->bus, loc->devid, loc->function);
+ dev->config_fd = open(filename, O_RDWR);
+ if (dev->config_fd < 0) {
+ RTE_LOG(ERR, EAL, "%s(): cannot open %s: %s\n",
+ __func__, filename, strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+static int
pci_map_device(struct rte_pci_device *dev)
{
int ret, mapped = 0;
@@ -518,7 +540,8 @@
if (ret != 0)
return ret;
}
- return 0;
+
+ return pci_config_open(dev);
}
/*
@@ -595,6 +618,20 @@
return 1;
}
+/* Read PCI config space. */
+int rte_eal_pci_read_config(const struct rte_pci_device *device,
+ void *buf, size_t len, off_t offset)
+{
+ return pread(device->config_fd, buf, len, offset);
+}
+
+/* Write PCI config space. */
+int rte_eal_pci_write_config(const struct rte_pci_device *device,
+ const void *buf, size_t len, off_t offset)
+{
+ return pwrite(device->config_fd, buf, len, offset);
+}
+
/* Init the PCI EAL subsystem */
int
rte_eal_pci_init(void)