sdk: added fpga_pci_get_address to allow direct access mmap'ed regions

sdk/userspace/fpga_libs/fpga_pci/fpga_pci.c

@@ -398,3 +398,16 @@ int fpga_pci_write_burst(pci_bar_handle_t handle, uint64_t offset, uint32_t* dat
 err:
 	return FPGA_ERR_FAIL;
 }
+
+int
+fpga_pci_get_address(pci_bar_handle_t handle, uint64_t offset, size_t len,
+	void **ptr)
+{
+	fail_on(!ptr, err, "ptr is NULL");
+
+	*ptr = fpga_pci_bar_get_mem_at_offset(handle, offset, len);
+	fail_on(!*ptr, err, "fpga_plat_get_mem_at_offset failed");
+	return 0;
+err:
+	return FPGA_ERR_FAIL;
+}

sdk/userspace/include/fpga_pci.h

@@ -189,3 +189,17 @@ int fpga_pci_get_resource_map(int slot_id, int pf_id,
  * @returns 0 on success, non-zero on error
  */
 int fpga_pci_rescan_slot_app_pfs(int slot_id);
+
+/**
+ * Get a bounds checked pointer to memory in the mapped region for this handle.
+ *
+ * @param[in]   handle    handle provided by fpga_pci_attach
+ * @param[in]   offset    offset into the mmap'ed region
+ * @param[in]   dword_len the length of data to write in burst, in 4-byte DWORDs
+ *                        (used for bounds checking)
+ * @param[out]  ptr       pointer to memory
+ *
+ * @return 0 on success, non-zero on error (bounds errors in particular)
+ */
+int fpga_pci_get_address(pci_bar_handle_t handle, uint64_t offset,
+	uint64_t dword_len, void **ptr);