[dpdk-dev] [PATCH v4 06/14] eal: pci: vfio: add rd/wr func for pci bar space

[Santosh Shukla]

Introducing below api for pci bar space rd/wr. Currently used for
pci iobar rd/wr.

Api's are:
- rte_eal_pci_read_bar
- rte_eal_pci_write_bar

virtio when used for vfio-mode then virtio driver will use these api
to do rd/wr operation on ioport pci bar.

Signed-off-by: Santosh Shukla <sshukla at mvista.com>
---
v3->v4:
- Using RTE_SET_USED(_var_) for unused variable for !VFIO_PRESENT case.
  As per v3 review comment from Bruce. 

lib/librte_eal/common/include/rte_pci.h    |   38 ++++++++++++++++++++++++++++
 lib/librte_eal/linuxapp/eal/eal_pci.c      |   37 +++++++++++++++++++++++++++
 lib/librte_eal/linuxapp/eal/eal_pci_init.h |    6 +++++
 lib/librte_eal/linuxapp/eal/eal_pci_vfio.c |   28 ++++++++++++++++++++
 4 files changed, 109 insertions(+)

diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
index 334c12e..53437cc 100644
--- a/lib/librte_eal/common/include/rte_pci.h
+++ b/lib/librte_eal/common/include/rte_pci.h
@@ -471,6 +471,44 @@ int rte_eal_pci_read_config(const struct rte_pci_device *device,
 			    void *buf, size_t len, off_t offset);
 
 /**
+ * Read PCI bar 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 bar space
+ * @param bar_idx
+ *   The pci bar index (valid range is 0..5)
+ */
+int rte_eal_pci_read_bar(const struct rte_pci_device *device,
+			 void *buf, size_t len, off_t offset, int bar_idx);
+
+/**
+ * Write PCI bar 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
+ * @param bar_idx
+ *   The pci bar index (valid range is 0..5)
+*/
+int rte_eal_pci_write_bar(const struct rte_pci_device *device,
+			  const void *buf, size_t len, off_t offset,
+			  int bar_idx);
+
+
+/**
  * Write PCI config space.
  *
  * @param device
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
index bc5b5be..8c1a49d 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
@@ -621,6 +621,43 @@ int rte_eal_pci_write_config(const struct rte_pci_device *device,
 	}
 }
 
+int rte_eal_pci_read_bar(const struct rte_pci_device *device,
+			 void *buf, size_t len, off_t offset,
+			 int bar_idx)
+
+{
+#ifdef VFIO_PRESENT
+	const struct rte_intr_handle *intr_handle = &device->intr_handle;
+	return pci_vfio_read_bar(intr_handle, buf, len, offset, bar_idx);
+#else
+	/* UIO's not applicable */
+	RTE_SET_USED(device);
+	RTE_SET_USED(buf);
+	RTE_SET_USED(len);
+	RTE_SET_USED(offset);
+	RTE_SET_USED(bar_idx);
+	return 0;
+#endif
+}
+
+int rte_eal_pci_write_bar(const struct rte_pci_device *device,
+			  const void *buf, size_t len, off_t offset,
+			  int bar_idx)
+{
+#ifdef VFIO_PRESENT
+	const struct rte_intr_handle *intr_handle = &device->intr_handle;
+	return pci_vfio_write_bar(intr_handle, buf, len, offset, bar_idx);
+#else
+	/* UIO's not applicable */
+	RTE_SET_USED(device);
+	RTE_SET_USED(buf);
+	RTE_SET_USED(len);
+	RTE_SET_USED(offset);
+	RTE_SET_USED(bar_idx);
+	return 0;
+#endif
+}
+
 /* 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 a17c708..3bc592b 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_init.h
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_init.h
@@ -68,6 +68,12 @@ int pci_vfio_read_config(const struct rte_intr_handle *intr_handle,
 int pci_vfio_write_config(const struct rte_intr_handle *intr_handle,
 			  const void *buf, size_t len, off_t offs);
 
+int pci_vfio_read_bar(const struct rte_intr_handle *intr_handle,
+		      void *buf, size_t len, off_t offs, int bar_idx);
+
+int pci_vfio_write_bar(const struct rte_intr_handle *intr_handle,
+		       const void *buf, size_t len, off_t offs, int bar_idx);
+
 /* 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_vfio.c b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
index abde779..df407ef 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
@@ -93,6 +93,34 @@ pci_vfio_write_config(const struct rte_intr_handle *intr_handle,
 	       VFIO_GET_REGION_ADDR(VFIO_PCI_CONFIG_REGION_INDEX) + offs);
 }
 
+int
+pci_vfio_read_bar(const struct rte_intr_handle *intr_handle,
+		  void *buf, size_t len, off_t offs, int bar_idx)
+{
+	if (bar_idx < VFIO_PCI_BAR0_REGION_INDEX
+	   || bar_idx > VFIO_PCI_BAR5_REGION_INDEX) {
+		RTE_LOG(ERR, EAL, "invalid bar_idx!\n");
+		return -1;
+	}
+
+	return pread64(intr_handle->vfio_dev_fd, buf, len,
+		       VFIO_GET_REGION_ADDR(bar_idx) + offs);
+}
+
+int
+pci_vfio_write_bar(const struct rte_intr_handle *intr_handle,
+		   const void *buf, size_t len, off_t offs, int bar_idx)
+{
+	if (bar_idx < VFIO_PCI_BAR0_REGION_INDEX
+	   || bar_idx > VFIO_PCI_BAR5_REGION_INDEX) {
+		RTE_LOG(ERR, EAL, "invalid bar_idx!\n");
+		return -1;
+	}
+
+	return pwrite64(intr_handle->vfio_dev_fd, buf, len,
+			VFIO_GET_REGION_ADDR(bar_idx) + 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,
-- 
1.7.9.5