[PATCH v5 1/4] eal: provide functions to access PCI config

[Stephen Hemminger <stephen@networkplumber.org>]

Some drivers need ability to access PCI config (for example for power
management). This adds an abstraction to do this for both Linux
and BSD.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 lib/librte_eal/bsdapp/eal/eal_pci.c             | 83 +++++++++++++++++++++++++
 lib/librte_eal/bsdapp/eal/rte_eal_version.map   |  3 +-
 lib/librte_eal/common/include/rte_pci.h         | 32 ++++++++++
 lib/librte_eal/linuxapp/eal/eal_pci.c           | 50 +++++++++++++++
 lib/librte_eal/linuxapp/eal/eal_pci_init.h      | 11 ++++
 lib/librte_eal/linuxapp/eal/eal_pci_uio.c       | 14 +++++
 lib/librte_eal/linuxapp/eal/eal_pci_vfio.c      | 16 +++++
 lib/librte_eal/linuxapp/eal/rte_eal_version.map |  3 +-
 8 files changed, 210 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c
index ed31222..61ae429 100644
--- a/lib/librte_eal/bsdapp/eal/eal_pci.c
+++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
@@ -397,6 +397,89 @@ error:
 	return -1;
 }
 
+/* Read PCI config space. */
+int rte_eal_pci_read_config(const struct rte_pci_device *dev,
+			    void *buf, size_t len, off_t offset)
+{
+	int fd = -1;
+	struct pci_io pi = {
+		.pi_sel = {
+			.pc_domain = dev->addr.domain,
+			.pc_bus = dev->addr.bus,
+			.pc_dev = dev->addr.devid,
+			.pc_func = dev->addr.function,
+		},
+		.pi_reg = offset,
+		.pi_width = len,
+	};
+
+	if (len == 3 || len > sizeof(pi.pi_data)) {
+		RTE_LOG(ERR, EAL, "%s(): invalid pci read length\n", __func__);
+		goto error;
+	}
+
+	fd = open("/dev/pci", O_RDONLY);
+	if (fd < 0) {
+		RTE_LOG(ERR, EAL, "%s(): error opening /dev/pci\n", __func__);
+		goto error;
+	}
+
+	if (ioctl(fd, PCIOCREAD, &pi) < 0)
+		goto error;
+	close(fd);
+
+	memcpy(buf, &pi.pi_data, len);
+	return 0;
+
+ error:
+	if (fd >= 0)
+		close(fd);
+	return -1;
+}
+
+/* Write PCI config space. */
+int rte_eal_pci_write_config(const struct rte_pci_device *dev,
+			     const void *buf, size_t len, off_t offset)
+{
+	int fd = -1;
+
+	struct pci_io pi = {
+		.pi_sel = {
+			.pc_domain = dev->addr.domain,
+			.pc_bus = dev->addr.bus,
+			.pc_dev = dev->addr.devid,
+			.pc_func = dev->addr.function,
+		},
+		.pi_reg = offset,
+		.pi_data = *(u_int32_t *)buf,
+		.pi_width = len,
+	};
+
+	if (len == 3 || len > sizeof(pi.pi_data)) {
+		RTE_LOG(ERR, EAL, "%s(): invalid pci read length\n", __func__);
+		goto error;
+	}
+
+	memcpy(pi.pi_data, buf, len);
+
+	fd = open("/dev/pci", O_RDONLY);
+	if (fd < 0) {
+		RTE_LOG(ERR, EAL, "%s(): error opening /dev/pci\n", __func__);
+		goto error;
+	}
+
+	if (ioctl(fd, PCIOCWRITE, &pi) < 0)
+		goto error;
+
+	close(fd);
+	return 0;
+
+ error:
+	if (fd >= 0)
+		close(fd);
+	return -1;
+}
+
 /* Init the PCI EAL subsystem */
 int
 rte_eal_pci_init(void)
diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
index b2d4441..47323ae 100644
--- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
@@ -117,5 +117,6 @@ DPDK_2.1 {
 
 	rte_eal_pci_detach;
 	rte_memzone_free;
-
+	rte_eal_pci_read_config;
+	rte_eal_pci_write_config;
 } DPDK_2.0;
diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
index e3ca3fc..34cafa6 100644
--- a/lib/librte_eal/common/include/rte_pci.h
+++ b/lib/librte_eal/common/include/rte_pci.h
@@ -455,6 +455,38 @@ void rte_eal_pci_register(struct rte_pci_driver *driver);
  */
 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 len
+ *   The length of the data buffer.
+ * @param offset
+ *   The offset into PCI config space
+ */
+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 len
+ *   The length of the data buffer.
+ * @param offset
+ *   The offset into PCI config space
+ */
+int rte_eal_pci_write_config(const struct rte_pci_device *device,
+			     const void *buf, size_t len, off_t offset);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
index 9a28ede..6e45aac 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
@@ -572,6 +572,56 @@ pci_config_space_set(struct rte_pci_device *dev)
 }
 #endif
 
+/* Read PCI config space. */
+int rte_eal_pci_read_config(const struct rte_pci_device *device,
+			    void *buf, size_t len, off_t offset)
+{
+	const struct rte_intr_handle *intr_handle = &device->intr_handle;
+
+	switch (intr_handle->type) {
+	case RTE_INTR_HANDLE_UIO:
+	case RTE_INTR_HANDLE_UIO_INTX:
+		return pci_uio_read_config(intr_handle, buf, len, offset);
+
+#ifdef VFIO_PRESENT
+	case RTE_INTR_HANDLE_VFIO_MSIX:
+	case RTE_INTR_HANDLE_VFIO_MSI:
+	case RTE_INTR_HANDLE_VFIO_LEGACY:
+		return pci_vfio_read_config(intr_handle, buf, len, offset);
+#endif
+	default:
+		RTE_LOG(ERR, EAL,
+			"Unknown handle type of fd %d\n",
+					intr_handle->fd);
+		return -1;
+	}
+}
+
+/* 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)
+{
+	const struct rte_intr_handle *intr_handle = &device->intr_handle;
+
+	switch (intr_handle->type) {
+	case RTE_INTR_HANDLE_UIO:
+	case RTE_INTR_HANDLE_UIO_INTX:
+		return pci_uio_write_config(intr_handle, buf, len, offset);
+
+#ifdef VFIO_PRESENT
+	case RTE_INTR_HANDLE_VFIO_MSIX:
+	case RTE_INTR_HANDLE_VFIO_MSI:
+	case RTE_INTR_HANDLE_VFIO_LEGACY:
+		return pci_vfio_write_config(intr_handle, buf, len, offset);
+#endif
+	default:
+		RTE_LOG(ERR, EAL,
+			"Unknown handle type of fd %d\n",
+					intr_handle->fd);
+		return -1;
+	}
+}
+
 /* Init the PCI EAL subsystem */
 int
 rte_eal_pci_init(void)
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_init.h b/lib/librte_eal/linuxapp/eal/eal_pci_init.h
index 7104b13..a17c708 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_init.h
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_init.h
@@ -49,6 +49,11 @@ void pci_uio_free_resource(struct rte_pci_device *dev,
 int pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
 		struct mapped_pci_resource *uio_res, int map_idx);
 
+int pci_uio_read_config(const struct rte_intr_handle *intr_handle,
+			void *buf, size_t len, off_t offs);
+int pci_uio_write_config(const struct rte_intr_handle *intr_handle,
+			 const void *buf, size_t len, off_t offs);
+
 #ifdef VFIO_PRESENT
 
 #define VFIO_MAX_GROUPS 64
@@ -57,6 +62,12 @@ int pci_vfio_enable(void);
 int pci_vfio_is_enabled(void);
 int pci_vfio_mp_sync_setup(void);
 
+/* access config space */
+int pci_vfio_read_config(const struct rte_intr_handle *intr_handle,
+			 void *buf, size_t len, off_t offs);
+int pci_vfio_write_config(const struct rte_intr_handle *intr_handle,
+			  const void *buf, size_t len, off_t offs);
+
 /* map VFIO resource prototype */
 int pci_vfio_map_resource(struct rte_pci_device *dev);
 int pci_vfio_get_group_fd(int iommu_group_fd);
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
index c35feb4..fca7987 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
@@ -53,6 +53,20 @@ void *pci_map_addr = NULL;
 
 #define OFF_MAX              ((uint64_t)(off_t)-1)
 
+int
+pci_uio_read_config(const struct rte_intr_handle *intr_handle,
+		    void *buf, size_t len, off_t offset)
+{
+	return pread(intr_handle->uio_cfg_fd, buf, len, offset);
+}
+
+int
+pci_uio_write_config(const struct rte_intr_handle *intr_handle,
+		     const void *buf, size_t len, off_t offset)
+{
+	return pwrite(intr_handle->uio_cfg_fd, buf, len, offset);
+}
+
 static int
 pci_uio_set_bus_master(int dev_fd)
 {
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
index cf5ac50..0e6c48a 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
@@ -77,6 +77,22 @@ EAL_REGISTER_TAILQ(rte_vfio_tailq)
 /* per-process VFIO config */
 static struct vfio_config vfio_cfg;
 
+int
+pci_vfio_read_config(const struct rte_intr_handle *intr_handle,
+		    void *buf, size_t len, off_t offs)
+{
+	return pread64(intr_handle->vfio_dev_fd, buf, len,
+	       VFIO_GET_REGION_ADDR(VFIO_PCI_CONFIG_REGION_INDEX) + offs);
+}
+
+int
+pci_vfio_write_config(const struct rte_intr_handle *intr_handle,
+		    const void *buf, size_t len, off_t offs)
+{
+	return pwrite64(intr_handle->vfio_dev_fd, buf, len,
+	       VFIO_GET_REGION_ADDR(VFIO_PCI_CONFIG_REGION_INDEX) + offs);
+}
+
 /* get PCI BAR number where MSI-X interrupts are */
 static int
 pci_vfio_get_msix_bar(int fd, int *msix_bar, uint32_t *msix_table_offset,
diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
index b2d4441..47323ae 100644
--- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
@@ -117,5 +117,6 @@ DPDK_2.1 {
 
 	rte_eal_pci_detach;
 	rte_memzone_free;
-
+	rte_eal_pci_read_config;
+	rte_eal_pci_write_config;
 } DPDK_2.0;
-- 
2.1.4