[dpdk-stable] [PATCH 20.11 1/2] bus/pci: use PCI standard sysfs entry to get PIO address

["谢华伟(此时此刻）" <huawei.xhw@alibaba-inc.com>]

Currently virtio PMD assumes legacy device uses PIO bar.
There are three ways to get PIO(PortIO) address for virtio legacy device.
    1) under igb_uio, get PIO address from uio/uio# sysfs attribute, for
instance: /sys/bus/pci/devices/0000:00:09.0/uio/uio0/portio/port0/start
    2) under uio_pci_generic
        for X86, get PIO address from /proc/ioport.
        for other ARCH, get PIO address from standard PCI sysfs attribute,
for instance: /sys/bus/pci/devices/0000:00:09.0/resource

Actually, "port0/start" in igb_uio and "resource" point to exactly the
same thing, i.e, pci_dev->resource[0] in kernel source code.

This patch refactors these messy things, and uses standard PCI sysfs
attribute "resource".

Signed-off-by: huawei xie <huawei.xhw@alibaba-inc.com>
---
 drivers/bus/pci/linux/pci.c     | 77 -----------------------------------------
 drivers/bus/pci/linux/pci_uio.c | 64 ++++++++++++++++++++++++----------
 2 files changed, 46 insertions(+), 95 deletions(-)

diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
index 2e1808b..0f38abf 100644
--- a/drivers/bus/pci/linux/pci.c
+++ b/drivers/bus/pci/linux/pci.c
@@ -677,71 +677,6 @@ int rte_pci_write_config(const struct rte_pci_device *device,
 	}
 }
 
-#if defined(RTE_ARCH_X86)
-static int
-pci_ioport_map(struct rte_pci_device *dev, int bar __rte_unused,
-		struct rte_pci_ioport *p)
-{
-	uint16_t start, end;
-	FILE *fp;
-	char *line = NULL;
-	char pci_id[16];
-	int found = 0;
-	size_t linesz;
-
-	if (rte_eal_iopl_init() != 0) {
-		RTE_LOG(ERR, EAL, "%s(): insufficient ioport permissions for PCI device %s\n",
-			__func__, dev->name);
-		return -1;
-	}
-
-	snprintf(pci_id, sizeof(pci_id), PCI_PRI_FMT,
-		 dev->addr.domain, dev->addr.bus,
-		 dev->addr.devid, dev->addr.function);
-
-	fp = fopen("/proc/ioports", "r");
-	if (fp == NULL) {
-		RTE_LOG(ERR, EAL, "%s(): can't open ioports\n", __func__);
-		return -1;
-	}
-
-	while (getdelim(&line, &linesz, '\n', fp) > 0) {
-		char *ptr = line;
-		char *left;
-		int n;
-
-		n = strcspn(ptr, ":");
-		ptr[n] = 0;
-		left = &ptr[n + 1];
-
-		while (*left && isspace(*left))
-			left++;
-
-		if (!strncmp(left, pci_id, strlen(pci_id))) {
-			found = 1;
-
-			while (*ptr && isspace(*ptr))
-				ptr++;
-
-			sscanf(ptr, "%04hx-%04hx", &start, &end);
-
-			break;
-		}
-	}
-
-	free(line);
-	fclose(fp);
-
-	if (!found)
-		return -1;
-
-	p->base = start;
-	RTE_LOG(DEBUG, EAL, "PCI Port IO found start=0x%x\n", start);
-
-	return 0;
-}
-#endif
-
 int
 rte_pci_ioport_map(struct rte_pci_device *dev, int bar,
 		struct rte_pci_ioport *p)
@@ -756,14 +691,8 @@ int rte_pci_write_config(const struct rte_pci_device *device,
 		break;
 #endif
 	case RTE_PCI_KDRV_IGB_UIO:
-		ret = pci_uio_ioport_map(dev, bar, p);
-		break;
 	case RTE_PCI_KDRV_UIO_GENERIC:
-#if defined(RTE_ARCH_X86)
-		ret = pci_ioport_map(dev, bar, p);
-#else
 		ret = pci_uio_ioport_map(dev, bar, p);
-#endif
 		break;
 	default:
 		break;
@@ -830,14 +759,8 @@ int rte_pci_write_config(const struct rte_pci_device *device,
 		break;
 #endif
 	case RTE_PCI_KDRV_IGB_UIO:
-		ret = pci_uio_ioport_unmap(p);
-		break;
 	case RTE_PCI_KDRV_UIO_GENERIC:
-#if defined(RTE_ARCH_X86)
-		ret = 0;
-#else
 		ret = pci_uio_ioport_unmap(p);
-#endif
 		break;
 	default:
 		break;
diff --git a/drivers/bus/pci/linux/pci_uio.c b/drivers/bus/pci/linux/pci_uio.c
index 624b2e2..aa03da7 100644
--- a/drivers/bus/pci/linux/pci_uio.c
+++ b/drivers/bus/pci/linux/pci_uio.c
@@ -373,10 +373,13 @@
 pci_uio_ioport_map(struct rte_pci_device *dev, int bar,
 		   struct rte_pci_ioport *p)
 {
+	FILE *f = NULL;
 	char dirname[PATH_MAX];
 	char filename[PATH_MAX];
-	int uio_num;
-	unsigned long start;
+	char buf[BUFSIZ];
+	uint64_t phys_addr, end_addr, flags;
+	unsigned long base;
+	int i;
 
 	if (rte_eal_iopl_init() != 0) {
 		RTE_LOG(ERR, EAL, "%s(): insufficient ioport permissions for PCI device %s\n",
@@ -384,41 +387,66 @@
 		return -1;
 	}
 
-	uio_num = pci_get_uio_dev(dev, dirname, sizeof(dirname), 0);
-	if (uio_num < 0)
+	/* open and read addresses of the corresponding resource in sysfs */
+	snprintf(filename, sizeof(filename), "%s/" PCI_PRI_FMT "/resource",
+		rte_pci_get_sysfs_path(), dev->addr.domain, dev->addr.bus,
+		dev->addr.devid, dev->addr.function);
+	f = fopen(filename, "r");
+	if (f == NULL) {
+		RTE_LOG(ERR, EAL, "%s(): Cannot open sysfs resource: %s\n",
+			__func__, strerror(errno));
 		return -1;
+	}
 
-	/* get portio start */
-	snprintf(filename, sizeof(filename),
-		 "%s/portio/port%d/start", dirname, bar);
-	if (eal_parse_sysfs_value(filename, &start) < 0) {
-		RTE_LOG(ERR, EAL, "%s(): cannot parse portio start\n",
-			__func__);
-		return -1;
+	for (i = 0; i < bar + 1; i++) {
+		if (fgets(buf, sizeof(buf), f) == NULL) {
+			RTE_LOG(ERR, EAL, "%s(): Cannot read sysfs resource\n", __func__);
+			goto error;
+		}
 	}
-	/* ensure we don't get anything funny here, read/write will cast to
-	 * uin16_t */
-	if (start > UINT16_MAX)
-		return -1;
+	if (pci_parse_one_sysfs_resource(buf, sizeof(buf), &phys_addr,
+		&end_addr, &flags) < 0)
+		goto error;
+
+	if (!(flags & IORESOURCE_IO)) {
+		RTE_LOG(ERR, EAL, "%s(): bar resource other than IO is not supported\n", __func__);
+		goto error;
+	}
+	base = (unsigned long)phys_addr;
+	RTE_LOG(INFO, EAL, "%s(): PIO BAR %08lx detected\n", __func__, base);
+
+	if (base > UINT16_MAX)
+		goto error;
 
 	/* FIXME only for primary process ? */
 	if (dev->intr_handle.type == RTE_INTR_HANDLE_UNKNOWN) {
+		int uio_num = pci_get_uio_dev(dev, dirname, sizeof(dirname), 0);
+		if (uio_num < 0) {
+			RTE_LOG(ERR, EAL, "cannot open %s: %s\n",
+				dirname, strerror(errno));
+			goto error;
+		}
 
 		snprintf(filename, sizeof(filename), "/dev/uio%u", uio_num);
 		dev->intr_handle.fd = open(filename, O_RDWR);
 		if (dev->intr_handle.fd < 0) {
 			RTE_LOG(ERR, EAL, "Cannot open %s: %s\n",
 				filename, strerror(errno));
-			return -1;
+			goto error;
 		}
 		dev->intr_handle.type = RTE_INTR_HANDLE_UIO;
 	}
 
-	RTE_LOG(DEBUG, EAL, "PCI Port IO found start=0x%lx\n", start);
+	RTE_LOG(DEBUG, EAL, "PCI Port IO found start=0x%lx\n", base);
 
-	p->base = start;
+	p->base = base;
 	p->len = 0;
+	fclose(f);
 	return 0;
+error:
+	if (f)
+		fclose(f);
+	return -1;
 }
 #else
 int
-- 
1.8.3.1