[dpdk-dev] [PATCH v2] pci: support both PIO and MMIO BAR for legacy virtio on x86

谢华伟(此时此刻) huawei.xhw at alibaba-inc.com
Wed Sep 30 16:59:48 CEST 2020


 From c13f981e287254cd0877cc7b98ee2dd7b80c3b69 Mon Sep 17 00:00:00 2001
From: "huawei.xhw" <huawei.xhw at alibaba-inc.com>
Date: Wed, 30 Sep 2020 22:37:03 +0800
Subject: [PATCH v2] pci:  support both PIO and MMIO BAR for legacy virtio on
  x86

Legacy virtio-pci only supports PIO BAR resource. As we need to create 
lots of
virtio devices and PIO resource on x86 is very limited, we expose MMIO BAR.

Kernel supports both PIO  and MMIO BAR for legacy virtio-pci device. We 
handles
different type of BAR in the similar way.

In previous implementation, with igb_uio we get PIO address from igb_uio
sysfs entry; with uio_pci_generic, we get PIO address from
/proc/ioports.
For PIO/MMIO RW, there is different path for different drivers and arch.
For VFIO, PIO/MMIO RW is through syscall, which has big performance
issue.
On X86, it assumes only PIO is supported.

All of the above is too much twisted.
This patch unifies the way to get both PIO and MMIO address for 
different driver
and arch, all from standard resource attr under pci sysfs.

We distinguish PIO and MMIO by their address like how kernel does. It is 
ugly but works.

Signed-off-by: huawei.xhw <huawei.xhw at alibaba-inc.com>
---
  drivers/bus/pci/linux/pci.c     |  89 +--------------------
  drivers/bus/pci/linux/pci_uio.c | 166 
+++++++++++++++++++++++++++-------------
  2 files changed, 118 insertions(+), 137 deletions(-)

diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
index bf27594..885e54e 100644
--- a/drivers/bus/pci/linux/pci.c
+++ b/drivers/bus/pci/linux/pci.c
@@ -687,71 +687,6 @@ 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)
@@ -762,18 +697,12 @@ int rte_pci_write_config(const struct 
rte_pci_device *device,
  #ifdef VFIO_PRESENT
      case RTE_PCI_KDRV_VFIO:
          if (pci_vfio_is_enabled())
-            ret = pci_vfio_ioport_map(dev, bar, p);
+            ret = pci_uio_ioport_map(dev, bar, p);
          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;
@@ -792,12 +721,10 @@ int rte_pci_write_config(const struct 
rte_pci_device *device,
      switch (p->dev->kdrv) {
  #ifdef VFIO_PRESENT
      case RTE_PCI_KDRV_VFIO:
-        pci_vfio_ioport_read(p, data, len, offset);
+        pci_uio_ioport_read(p, data, len, offset);
          break;
  #endif
      case RTE_PCI_KDRV_IGB_UIO:
-        pci_uio_ioport_read(p, data, len, offset);
-        break;
      case RTE_PCI_KDRV_UIO_GENERIC:
          pci_uio_ioport_read(p, data, len, offset);
          break;
@@ -813,12 +740,10 @@ int rte_pci_write_config(const struct 
rte_pci_device *device,
      switch (p->dev->kdrv) {
  #ifdef VFIO_PRESENT
      case RTE_PCI_KDRV_VFIO:
-        pci_vfio_ioport_write(p, data, len, offset);
+        pci_uio_ioport_write(p, data, len, offset);
          break;
  #endif
      case RTE_PCI_KDRV_IGB_UIO:
-        pci_uio_ioport_write(p, data, len, offset);
-        break;
      case RTE_PCI_KDRV_UIO_GENERIC:
          pci_uio_ioport_write(p, data, len, offset);
          break;
@@ -836,18 +761,12 @@ int rte_pci_write_config(const struct 
rte_pci_device *device,
  #ifdef VFIO_PRESENT
      case RTE_PCI_KDRV_VFIO:
          if (pci_vfio_is_enabled())
-            ret = pci_vfio_ioport_unmap(p);
+            ret = pci_uio_ioport_unmap(p);
          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 f3305a2..cf49e8f 100644
--- a/drivers/bus/pci/linux/pci_uio.c
+++ b/drivers/bus/pci/linux/pci_uio.c
@@ -373,52 +373,83 @@
  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];
+    char buf[BUFSIZ];
+    uint64_t phys_addr, end_addr, flags;
      int uio_num;
-    unsigned long start;
+    unsigned long base;
+    bool iobar;
+    int i;

-    if (rte_eal_iopl_init() != 0) {
-        RTE_LOG(ERR, EAL, "%s(): insufficient ioport permissions for 
PCI device %s\n",
-            __func__, dev->name);
+    /* 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, "Cannot open sysfs resource: %s\n",
+            strerror(errno));
          return -1;
      }

-    uio_num = pci_get_uio_dev(dev, dirname, sizeof(dirname), 0);
-    if (uio_num < 0)
-        return -1;
+    for (i = 0; i < bar + 1; i++) {
+        if (fgets(buf, sizeof(buf), f) == NULL) {
+            RTE_LOG(ERR, EAL, "Cannot read sysfs resource\n");
+            goto error;
+        }
+    }
+    if (pci_parse_one_sysfs_resource(buf, sizeof(buf), &phys_addr,
+        &end_addr, &flags) < 0)
+        goto error;

-    /* 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;
+    if (flags & IORESOURCE_IO) {
+        iobar = 1;
+        base = (unsigned long)phys_addr;
+        RTE_LOG(INFO, EAL, "%s(): PIO BAR %08lx detected\n", __func__, 
base);
+    } else if (flags & IORESOURCE_MEM) {
+        iobar = 0;
+        base = (unsigned long)dev->mem_resource[bar].addr;
+        RTE_LOG(INFO, EAL, "%s(): MMIO BAR %08lx detected\n", __func__, 
base);
+    } else {
+        RTE_LOG(ERR, EAL, "%s(): unknown BAR type\n", __func__);
+        goto error;
+    }
+
+    if (iobar && rte_eal_iopl_init() != 0) {
+        RTE_LOG(ERR, EAL, "%s(): insufficient ioport permissions for 
PCI device %s\n",
+            __func__, dev->name);
+        goto error;
      }
-    /* ensure we don't get anything funny here, read/write will cast to
-     * uin16_t */
-    if (start > UINT16_MAX)
-        return -1;

      /* FIXME only for primary process ? */
-    if (dev->intr_handle.type == RTE_INTR_HANDLE_UNKNOWN) {
+    if (dev->intr_handle.type == RTE_INTR_HANDLE_UNKNOWN &&
+        dev->kdrv == RTE_KDRV_UIO_GENERIC) {
+        uio_num = pci_get_uio_dev(dev, dirname, sizeof(dirname), 0);
+        if (uio_num < 0)
+            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 IO port 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
@@ -489,6 +520,61 @@
  }
  #endif

+#define PIO_MAX 0x10000
+static inline uint8_t ioread8(void *addr)
+{
+    uint8_t val;
+
+    val = (uint64_t)(uintptr_t)addr >= PIO_MAX ?
+        *(volatile uint8_t *)addr :
+        inb((unsigned long)addr);
+
+    return val;
+}
+
+static inline uint16_t ioread16(void *addr)
+{
+    uint16_t val;
+
+    val = (uint64_t)(uintptr_t)addr >= PIO_MAX ?
+        *(volatile uint16_t *)addr :
+        inw((unsigned long)addr);
+
+    return val;
+}
+
+static inline uint32_t ioread32(void *addr)
+{
+    uint32_t val;
+
+    val = (uint64_t)(uintptr_t)addr >= PIO_MAX ?
+        *(volatile uint32_t *)addr :
+    inl((unsigned long)addr);
+
+    return val;
+}
+
+static inline void iowrite8(uint8_t val, void *addr)
+{
+    (uint64_t)(uintptr_t)addr >= PIO_MAX ?
+        *(volatile uint8_t *)addr = val :
+        outb(val, (unsigned long)addr);
+}
+
+static inline void iowrite16(uint16_t val, void *addr)
+{
+    (uint64_t)(uintptr_t)addr >= PIO_MAX ?
+        *(volatile uint16_t *)addr = val :
+        outw(val, (unsigned long)addr);
+}
+
+static inline void iowrite32(uint32_t val, void *addr)
+{
+    (uint64_t)(uintptr_t)addr >= PIO_MAX ?
+        *(volatile uint32_t *)addr = val :
+        outl(val, (unsigned long)addr);
+}
+
  void
  pci_uio_ioport_read(struct rte_pci_ioport *p,
              void *data, size_t len, off_t offset)
@@ -500,25 +586,13 @@
      for (d = data; len > 0; d += size, reg += size, len -= size) {
          if (len >= 4) {
              size = 4;
-#if defined(RTE_ARCH_X86)
-            *(uint32_t *)d = inl(reg);
-#else
-            *(uint32_t *)d = *(volatile uint32_t *)reg;
-#endif
+            *(uint32_t *)d = ioread32((void *)reg);
          } else if (len >= 2) {
              size = 2;
-#if defined(RTE_ARCH_X86)
-            *(uint16_t *)d = inw(reg);
-#else
-            *(uint16_t *)d = *(volatile uint16_t *)reg;
-#endif
+            *(uint16_t *)d = ioread16((void *)reg);
          } else {
              size = 1;
-#if defined(RTE_ARCH_X86)
-            *d = inb(reg);
-#else
-            *d = *(volatile uint8_t *)reg;
-#endif
+            *d = ioread8((void *)reg);
          }
      }
  }
@@ -534,25 +608,13 @@
      for (s = data; len > 0; s += size, reg += size, len -= size) {
          if (len >= 4) {
              size = 4;
-#if defined(RTE_ARCH_X86)
-            outl_p(*(const uint32_t *)s, reg);
-#else
-            *(volatile uint32_t *)reg = *(const uint32_t *)s;
-#endif
+            iowrite32(*(const uint32_t *)s, (void *)reg);
          } else if (len >= 2) {
              size = 2;
-#if defined(RTE_ARCH_X86)
-            outw_p(*(const uint16_t *)s, reg);
-#else
-            *(volatile uint16_t *)reg = *(const uint16_t *)s;
-#endif
+            iowrite16(*(const uint16_t *)s, (void *)reg);
          } else {
              size = 1;
-#if defined(RTE_ARCH_X86)
-            outb_p(*s, reg);
-#else
-            *(volatile uint8_t *)reg = *s;
-#endif
+            iowrite8(*s, (void *)reg);
          }
      }
  }
-- 
1.8.3.1


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