[dpdk-dev] [PATCH 6/6] virtio: arm/arm64: memory mapped IO support in pmd driver

[Santosh Shukla <sshukla@mvista.com>]

This patch set add memory-mapped-IO support for arm/arm64 archs in virtio-pmd
driver. Patch creates ioport-mem device name /dev/igb_ioport. virtio_ethdev_init
function to open that device file for once, mappes 4K page_size memory such that
all entry in cat /proc/ioport {all PCI_IOBAR entry} mapped for once. For that
two ancessor api;s
- virtio_map_ioport : Maps all cat /proc/ioport pci iobars.
- virtio_set_ioport_addr : manages the each pci_iobar slot as an offset.

Tested for thunderX/arm64 platform, by creating maximum guest kernel supported
virtio-net-pci device i.e.. 31 max, then attaching all 32 interface to uio,
Verified with tespmd io_fwd application.

Signed-off-by: Santosh Shukla <sshukla@mvista.com>
Signed-off-by: Rizwan Ansari <ransari@mvista.com>
---
 drivers/net/virtio/virtio_ethdev.c        |  138 ++++++++++++++++++++++++++++-
 lib/librte_eal/linuxapp/igb_uio/igb_uio.c |   80 ++++++++++++++++-
 2 files changed, 214 insertions(+), 4 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 74c00ee..93b8784 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -63,6 +63,30 @@
 #include "virtqueue.h"
 #include "virtio_rxtx.h"
 
+#ifdef RTE_EXEC_ENV_LINUXAPP
+/* start address of first pci_iobar slot (user-space virtual-addres) */
+void *ioport_map;
+#if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64)
+
+#include <sys/mman.h>
+#define DEV_NAME		"/dev/igb_ioport"
+
+/* Keeping pci_ioport_size = 4k.
+ * So maximum mmaped pci_iobar supported =
+ * (ioport_size/pci_dev->mem_resource[0].len)
+ *
+ * note: kernel could allow maximum 32 virtio-net-pci interface, that mean
+ * maximum 32 PCI_IOBAR(s) where each PCI_IOBAR_LEN=0x20, so virtio_map_ioport()
+ * func by theory gonna support 4k/0x20 ==> 128 PCI_IOBAR(s), more than
+ * max-virtio-net-pci interface.
+ */
+#define PAGE_SIZE		4096
+#define PCI_IOPORT_SIZE		PAGE_SIZE
+#define PCI_IOPORT_MAX		128 /* 4k / 0x20 */
+
+int ioport_map_cnt;
+#endif /* ARM, ARM64 */
+#endif /* RTE_EXEC_ENV_LINUXAPP */
 
 static int eth_virtio_dev_init(struct rte_eth_dev *eth_dev);
 static int eth_virtio_dev_uninit(struct rte_eth_dev *eth_dev);
@@ -497,6 +521,18 @@ virtio_dev_close(struct rte_eth_dev *dev)
 	hw->started = 0;
 	virtio_dev_free_mbufs(dev);
 	virtio_free_queues(dev);
+
+#ifdef RTE_EXEC_ENV_LINUXAPP
+#if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64)
+
+	/* unmap ioport memory */
+	ioport_map_cnt--;
+	if (!ioport_map_cnt)
+		munmap(ioport_map, PCI_IOPORT_SIZE);
+
+	PMD_INIT_LOG(DEBUG, "unmapping ioport_mem %d\n", ioport_map_cnt);
+#endif
+#endif
 }
 
 static void
@@ -1172,7 +1208,6 @@ static int virtio_resource_init_by_ioports(struct rte_pci_device *pci_dev)
 
 			sscanf(ptr, "%04hx-%04hx", &start, &end);
 			size = end - start + 1;
-
 			break;
 		}
 	}
@@ -1256,6 +1291,81 @@ rx_func_get(struct rte_eth_dev *eth_dev)
 		eth_dev->rx_pkt_burst = &virtio_recv_pkts;
 }
 
+#ifdef RTE_EXEC_ENV_LINUXAPP
+#if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64)
+
+static int
+virtio_map_ioport(void **resource_addr)
+{
+	int fd;
+	int ret = 0;
+
+	fd = open(DEV_NAME, O_RDWR);
+	if (fd < 0) {
+		PMD_INIT_LOG(ERR, "device file %s open error: %d\n",
+			     DEV_NAME, fd);
+		ret = -1;
+		goto out;
+	}
+
+	ioport_map = mmap(NULL, PCI_IOPORT_SIZE,
+			PROT_EXEC | PROT_WRITE | PROT_READ, MAP_SHARED, fd, 0);
+
+	if (ioport_map == MAP_FAILED) {
+		PMD_INIT_LOG(ERR, "mmap: failed to map bar Address=%p\n",
+				*resource_addr);
+		ret = -ENOMEM;
+		goto out1;
+	}
+
+	PMD_INIT_LOG(INFO, "First pci_iobar mapped at %p\n", ioport_map);
+
+out1:
+	close(fd);
+out:
+	return ret;
+}
+
+static int
+virtio_set_ioport_addr(void **resource_addr, unsigned long offset)
+{
+	int ret = 0;
+
+	if (ioport_map_cnt >= PCI_IOPORT_MAX) {
+		ret = -1;
+		PMD_INIT_LOG(ERR,
+			     "ioport_map_cnt(%d) greater than"
+			     "PCI_IOPORT_MAX(%d)\n",
+			     ioport_map_cnt, PCI_IOPORT_MAX);
+		goto out;
+	}
+	*resource_addr = (void *)((char *)ioport_map + (ioport_map_cnt)*offset);
+	ioport_map_cnt++;
+
+	PMD_INIT_LOG(DEBUG, "pci.resource_addr %p ioport_map_cnt %d\n",
+			*resource_addr, ioport_map_cnt);
+out:
+	return ret;
+}
+#else /* !ARM, !ARM64 */
+static int
+virtio_map_ioport(void *resource_addr)
+{
+	(void)resource_addr;
+	return 0;
+}
+
+static int
+virtio_set_ioport_addr(void *resource_addr, unsigned long offset)
+{
+	(void)resource_addr;
+	(void)offset;
+	return 0;
+}
+
+#endif /* ARM, ARM64 */
+#endif /* RTE_EXEC_ENV_LINUXAPP */
+
 /*
  * This function is based on probe() function in virtio_pci.c
  * It returns 0 on success.
@@ -1294,8 +1404,31 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
 	if (virtio_resource_init(pci_dev) < 0)
 		return -1;
 
+#ifdef	RTE_EXEC_ENV_LINUXAPP
+	int ret = 0;
+
+	/* Map the all IOBAR entry from /proc/ioport to 4k page_size only once.
+	 * Later virtio_set_ioport_addr() func will update correct bar_addr
+	 * eachk ioport (i.e..pci_dev->mem_resource[0].addr)
+	 */
+	if (!ioport_map) {
+		ret = virtio_map_ioport(&pci_dev->mem_resource[0].addr);
+		if (ret < 0)
+			return -1;
+	}
+
+	ret = virtio_set_ioport_addr(&pci_dev->mem_resource[0].addr,
+					pci_dev->mem_resource[0].len);
+	if (ret < 0)
+		return -1;
+
+	PMD_INIT_LOG(INFO, "ioport_map %p resource_addr %p resource_len :%ld\n",
+			ioport_map, pci_dev->mem_resource[0].addr,
+			(unsigned long)pci_dev->mem_resource[0].len);
+
+#endif
 	hw->use_msix = virtio_has_msix(&pci_dev->addr);
-	hw->io_base = (uint32_t)(uintptr_t)pci_dev->mem_resource[0].addr;
+	hw->io_base = (unsigned long)(uintptr_t)pci_dev->mem_resource[0].addr;
 
 	/* Reset the device although not necessary at startup */
 	vtpci_reset(hw);
@@ -1430,7 +1563,6 @@ eth_virtio_dev_uninit(struct rte_eth_dev *eth_dev)
 		rte_intr_callback_unregister(&pci_dev->intr_handle,
 						virtio_interrupt_handler,
 						eth_dev);
-
 	PMD_INIT_LOG(DEBUG, "dev_uninit completed");
 
 	return 0;
diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
index f5617d2..b154a44 100644
--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
@@ -324,6 +324,61 @@ igbuio_dom0_pci_mmap(struct uio_info *info, struct vm_area_struct *vma)
 }
 #endif
 
+#if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64)
+#ifdef CONFIG_HAS_IOPORT_MAP
+/*
+ * mmap driver to map x86-style PCI_IOBAR (i.e..cat /proc/ioport pci-bar-memory)
+ * from kernel-space virtual address to user-space virtual address. This module
+ * required for non-x86 archs example arm/arm64, as those archs donot do
+ * IO_MAP_IO types access, Infact supports memory-mapped-IO. That is because
+ * arm/arm64 doesn't support direct IO instruction, so the design approach is to
+ * map `cat /proc/ioport` PCI_IOBAR's kernel-space virtual-addr to user-space
+ * virtual-addr. Therefore the need for mmap-driver.
+ */
+#include <linux/fs.h>		/* file_operations */
+#include <linux/miscdevice.h>
+#include <linux/mm.h>		/* VM_IO */
+#include <linux/uaccess.h>
+#include <asm/page.h>
+#include <linux/sched.h>
+#include <linux/pid.h>
+
+void *__iomem mapped_io; /* ioport addr of `cat /proc/ioport` */
+
+static int igb_ioport_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct page *npage;
+	int ret = 0;
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	npage = vmalloc_to_page(mapped_io);
+	ret = remap_pfn_range(vma, vma->vm_start,
+				page_to_pfn(npage),
+				vma->vm_end - vma->vm_start,
+				vma->vm_page_prot);
+	if (ret) {
+		pr_info("Error: Failed to remap pfn=%lu error=%d\n",
+			page_to_pfn(npage), ret);
+	}
+	return 0;
+}
+
+static const struct file_operations igb_ioport_fops = {
+	.mmap		= igb_ioport_mmap,
+};
+
+static struct miscdevice igb_ioport_dev = {
+	.minor	= MISC_DYNAMIC_MINOR,
+	.name	= "igb_ioport",
+	.fops	= &igb_ioport_fops
+};
+#else /* !CONFIG_HAS_IOPORT_MAP */
+
+#error "CONFIG_HAS_IOPORT_MAP not supported for $RTE_ARCH"
+
+#endif /* CONFIG_HAS_IOPORT_MAP */
+#endif /* RTE_ARCH_ARM, RTE_ARCH_ARM64 */
+
 /* Remap pci resources described by bar #pci_bar in uio resource n. */
 static int
 igbuio_pci_setup_iomem(struct pci_dev *dev, struct uio_info *info,
@@ -365,11 +420,22 @@ igbuio_pci_setup_ioport(struct pci_dev *dev, struct uio_info *info,
 	if (addr == 0 || len == 0)
 		return -EINVAL;
 
+#if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64)
+	/*
+	 * TODO: KNI/procfs:: porttype entry need to be added for ARM/ARM64,
+	 * for below mmap driver;
+	 * */
+	mapped_io = ioport_map(addr, 0);
+	info->port[n].name = name;
+	info->port[n].start = (unsigned long)(uintptr_t)mapped_io;
+	info->port[n].size = len;
+	info->port[n].porttype = UIO_PORT_X86;
+#else
 	info->port[n].name = name;
 	info->port[n].start = addr;
 	info->port[n].size = len;
 	info->port[n].porttype = UIO_PORT_X86;
-
+#endif
 	return 0;
 }
 
@@ -615,6 +681,15 @@ igbuio_pci_init_module(void)
 {
 	int ret;
 
+#if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64)
+	ret = misc_register(&igb_ioport_dev);
+	if (ret < 0) {
+		pr_info("Error: failed to register ioport map driver (%d)\n",
+				ret);
+		return ret;
+	}
+#endif
+
 	ret = igbuio_config_intr_mode(intr_mode);
 	if (ret < 0)
 		return ret;
@@ -625,6 +700,9 @@ igbuio_pci_init_module(void)
 static void __exit
 igbuio_pci_exit_module(void)
 {
+#if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64)
+	misc_deregister(&igb_ioport_dev);
+#endif
 	pci_unregister_driver(&igbuio_pci_driver);
 }
 
-- 
1.7.9.5