1 files changed, 398 insertions, 0 deletions

diff --git a/drivers/bus/vmbus/linux/vmbus_uio.c b/drivers/bus/vmbus/linux/vmbus_uio.c
new file mode 100644
index 00000000..856c6d66
--- /dev/null
+++ b/drivers/bus/vmbus/linux/vmbus_uio.c
@@ -0,0 +1,398 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2018, Microsoft Corporation.
+ * All Rights Reserved.
+ */
+
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <inttypes.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+
+#include <rte_log.h>
+#include <rte_bus.h>
+#include <rte_memory.h>
+#include <rte_eal_memconfig.h>
+#include <rte_common.h>
+#include <rte_malloc.h>
+#include <rte_bus_vmbus.h>
+#include <rte_string_fns.h>
+
+#include "private.h"
+
+/** Pathname of VMBUS devices directory. */
+#define SYSFS_VMBUS_DEVICES "/sys/bus/vmbus/devices"
+
+static void *vmbus_map_addr;
+
+/* Control interrupts */
+void vmbus_uio_irq_control(struct rte_vmbus_device *dev, int32_t onoff)
+{
+	if (write(dev->intr_handle.fd, &onoff, sizeof(onoff)) < 0) {
+		VMBUS_LOG(ERR, "cannot write to %d:%s",
+			dev->intr_handle.fd, strerror(errno));
+	}
+}
+
+int vmbus_uio_irq_read(struct rte_vmbus_device *dev)
+{
+	int32_t count;
+	int cc;
+
+	cc = read(dev->intr_handle.fd, &count, sizeof(count));
+	if (cc < (int)sizeof(count)) {
+		if (cc < 0) {
+			VMBUS_LOG(ERR, "IRQ read failed %s",
+				  strerror(errno));
+			return -errno;
+		}
+		VMBUS_LOG(ERR, "can't read IRQ count");
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+void
+vmbus_uio_free_resource(struct rte_vmbus_device *dev,
+		struct mapped_vmbus_resource *uio_res)
+{
+	rte_free(uio_res);
+
+	if (dev->intr_handle.uio_cfg_fd >= 0) {
+		close(dev->intr_handle.uio_cfg_fd);
+		dev->intr_handle.uio_cfg_fd = -1;
+	}
+
+	if (dev->intr_handle.fd >= 0) {
+		close(dev->intr_handle.fd);
+		dev->intr_handle.fd = -1;
+		dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
+	}
+}
+
+int
+vmbus_uio_alloc_resource(struct rte_vmbus_device *dev,
+			 struct mapped_vmbus_resource **uio_res)
+{
+	char devname[PATH_MAX]; /* contains the /dev/uioX */
+
+	/* save fd if in primary process */
+	snprintf(devname, sizeof(devname), "/dev/uio%u", dev->uio_num);
+	dev->intr_handle.fd = open(devname, O_RDWR);
+	if (dev->intr_handle.fd < 0) {
+		VMBUS_LOG(ERR, "Cannot open %s: %s",
+			devname, strerror(errno));
+		goto error;
+	}
+	dev->intr_handle.type = RTE_INTR_HANDLE_UIO_INTX;
+
+	/* allocate the mapping details for secondary processes*/
+	*uio_res = rte_zmalloc("UIO_RES", sizeof(**uio_res), 0);
+	if (*uio_res == NULL) {
+		VMBUS_LOG(ERR, "cannot store uio mmap details");
+		goto error;
+	}
+
+	strlcpy((*uio_res)->path, devname, PATH_MAX);
+	rte_uuid_copy((*uio_res)->id, dev->device_id);
+
+	return 0;
+
+error:
+	vmbus_uio_free_resource(dev, *uio_res);
+	return -1;
+}
+
+static int
+find_max_end_va(const struct rte_memseg_list *msl, void *arg)
+{
+	size_t sz = msl->memseg_arr.len * msl->page_sz;
+	void *end_va = RTE_PTR_ADD(msl->base_va, sz);
+	void **max_va = arg;
+
+	if (*max_va < end_va)
+		*max_va = end_va;
+	return 0;
+}
+
+/*
+ * TODO: this should be part of memseg api.
+ *       code is duplicated from PCI.
+ */
+static void *
+vmbus_find_max_end_va(void)
+{
+	void *va = NULL;
+
+	rte_memseg_list_walk(find_max_end_va, &va);
+	return va;
+}
+
+int
+vmbus_uio_map_resource_by_index(struct rte_vmbus_device *dev, int idx,
+				struct mapped_vmbus_resource *uio_res,
+				int flags)
+{
+	size_t size = dev->resource[idx].len;
+	struct vmbus_map *maps = uio_res->maps;
+	void *mapaddr;
+	off_t offset;
+	int fd;
+
+	/* devname for mmap  */
+	fd = open(uio_res->path, O_RDWR);
+	if (fd < 0) {
+		VMBUS_LOG(ERR, "Cannot open %s: %s",
+			  uio_res->path, strerror(errno));
+		return -1;
+	}
+
+	/* try mapping somewhere close to the end of hugepages */
+	if (vmbus_map_addr == NULL)
+		vmbus_map_addr = vmbus_find_max_end_va();
+
+	/* offset is special in uio it indicates which resource */
+	offset = idx * PAGE_SIZE;
+
+	mapaddr = vmbus_map_resource(vmbus_map_addr, fd, offset, size, flags);
+	close(fd);
+
+	if (mapaddr == MAP_FAILED)
+		return -1;
+
+	dev->resource[idx].addr = mapaddr;
+	vmbus_map_addr = RTE_PTR_ADD(mapaddr, size);
+
+	/* Record result of sucessful mapping for use by secondary */
+	maps[idx].addr = mapaddr;
+	maps[idx].size = size;
+
+	return 0;
+}
+
+static int vmbus_uio_map_primary(struct vmbus_channel *chan,
+				 void **ring_buf, uint32_t *ring_size)
+{
+	struct mapped_vmbus_resource *uio_res;
+
+	uio_res = vmbus_uio_find_resource(chan->device);
+	if (!uio_res) {
+		VMBUS_LOG(ERR, "can not find resources!");
+		return -ENOMEM;
+	}
+
+	if (uio_res->nb_maps < VMBUS_MAX_RESOURCE) {
+		VMBUS_LOG(ERR, "VMBUS: only %u resources found!",
+			  uio_res->nb_maps);
+		return -EINVAL;
+	}
+
+	*ring_size = uio_res->maps[HV_TXRX_RING_MAP].size / 2;
+	*ring_buf  = uio_res->maps[HV_TXRX_RING_MAP].addr;
+	return 0;
+}
+
+static int vmbus_uio_map_subchan(const struct rte_vmbus_device *dev,
+				 const struct vmbus_channel *chan,
+				 void **ring_buf, uint32_t *ring_size)
+{
+	char ring_path[PATH_MAX];
+	size_t file_size;
+	struct stat sb;
+	int fd;
+
+	snprintf(ring_path, sizeof(ring_path),
+		 "%s/%s/channels/%u/ring",
+		 SYSFS_VMBUS_DEVICES, dev->device.name,
+		 chan->relid);
+
+	fd = open(ring_path, O_RDWR);
+	if (fd < 0) {
+		VMBUS_LOG(ERR, "Cannot open %s: %s",
+			  ring_path, strerror(errno));
+		return -errno;
+	}
+
+	if (fstat(fd, &sb) < 0) {
+		VMBUS_LOG(ERR, "Cannot state %s: %s",
+			  ring_path, strerror(errno));
+		close(fd);
+		return -errno;
+	}
+	file_size = sb.st_size;
+
+	if (file_size == 0 || (file_size & (PAGE_SIZE - 1))) {
+		VMBUS_LOG(ERR, "incorrect size %s: %zu",
+			  ring_path, file_size);
+
+		close(fd);
+		return -EINVAL;
+	}
+
+	*ring_size = file_size / 2;
+	*ring_buf = vmbus_map_resource(vmbus_map_addr, fd,
+				       0, sb.st_size, 0);
+	close(fd);
+
+	if (ring_buf == MAP_FAILED)
+		return -EIO;
+
+	vmbus_map_addr = RTE_PTR_ADD(ring_buf, file_size);
+	return 0;
+}
+
+int vmbus_uio_map_rings(struct vmbus_channel *chan)
+{
+	const struct rte_vmbus_device *dev = chan->device;
+	uint32_t ring_size;
+	void *ring_buf;
+	int ret;
+
+	/* Primary channel */
+	if (chan->subchannel_id == 0)
+		ret = vmbus_uio_map_primary(chan, &ring_buf, &ring_size);
+	else
+		ret = vmbus_uio_map_subchan(dev, chan, &ring_buf, &ring_size);
+
+	if (ret)
+		return ret;
+
+	vmbus_br_setup(&chan->txbr, ring_buf, ring_size);
+	vmbus_br_setup(&chan->rxbr, (char *)ring_buf + ring_size, ring_size);
+	return 0;
+}
+
+static int vmbus_uio_sysfs_read(const char *dir, const char *name,
+				unsigned long *val, unsigned long max_range)
+{
+	char path[PATH_MAX];
+	FILE *f;
+	int ret;
+
+	snprintf(path, sizeof(path), "%s/%s", dir, name);
+	f = fopen(path, "r");
+	if (!f) {
+		VMBUS_LOG(ERR, "can't open %s:%s",
+			  path, strerror(errno));
+		return -errno;
+	}
+
+	if (fscanf(f, "%lu", val) != 1)
+		ret = -EIO;
+	else if (*val > max_range)
+		ret = -ERANGE;
+	else
+		ret = 0;
+	fclose(f);
+
+	return ret;
+}
+
+static bool vmbus_uio_ring_present(const struct rte_vmbus_device *dev,
+				   uint32_t relid)
+{
+	char ring_path[PATH_MAX];
+
+	/* Check if kernel has subchannel sysfs files */
+	snprintf(ring_path, sizeof(ring_path),
+		 "%s/%s/channels/%u/ring",
+		 SYSFS_VMBUS_DEVICES, dev->device.name, relid);
+
+	return access(ring_path, R_OK|W_OK) == 0;
+}
+
+bool vmbus_uio_subchannels_supported(const struct rte_vmbus_device *dev,
+				     const struct vmbus_channel *chan)
+{
+	return vmbus_uio_ring_present(dev, chan->relid);
+}
+
+static bool vmbus_isnew_subchannel(struct vmbus_channel *primary,
+				   unsigned long id)
+{
+	const struct vmbus_channel *c;
+
+	STAILQ_FOREACH(c, &primary->subchannel_list, next) {
+		if (c->relid == id)
+			return false;
+	}
+	return true;
+}
+
+int vmbus_uio_get_subchan(struct vmbus_channel *primary,
+			  struct vmbus_channel **subchan)
+{
+	const struct rte_vmbus_device *dev = primary->device;
+	char chan_path[PATH_MAX], subchan_path[PATH_MAX];
+	struct dirent *ent;
+	DIR *chan_dir;
+
+	snprintf(chan_path, sizeof(chan_path),
+		 "%s/%s/channels",
+		 SYSFS_VMBUS_DEVICES, dev->device.name);
+
+	chan_dir = opendir(chan_path);
+	if (!chan_dir) {
+		VMBUS_LOG(ERR, "cannot open %s: %s",
+			  chan_path, strerror(errno));
+		return -errno;
+	}
+
+	while ((ent = readdir(chan_dir))) {
+		unsigned long relid, subid, monid;
+		char *endp;
+		int err;
+
+		if (ent->d_name[0] == '.')
+			continue;
+
+		errno = 0;
+		relid = strtoul(ent->d_name, &endp, 0);
+		if (*endp || errno != 0 || relid > UINT16_MAX) {
+			VMBUS_LOG(NOTICE, "not a valid channel relid: %s",
+				  ent->d_name);
+			continue;
+		}
+
+		snprintf(subchan_path, sizeof(subchan_path), "%s/%lu",
+			 chan_path, relid);
+		err = vmbus_uio_sysfs_read(subchan_path, "subchannel_id",
+					   &subid, UINT16_MAX);
+		if (err) {
+			VMBUS_LOG(NOTICE, "invalid subchannel id %lu",
+				  subid);
+			closedir(chan_dir);
+			return err;
+		}
+
+		if (subid == 0)
+			continue;	/* skip primary channel */
+
+		if (!vmbus_isnew_subchannel(primary, relid))
+			continue;
+
+		if (!vmbus_uio_ring_present(dev, relid))
+			continue;	/* Ring may not be ready yet */
+
+		err = vmbus_uio_sysfs_read(subchan_path, "monitor_id",
+					   &monid, UINT8_MAX);
+		if (err) {
+			VMBUS_LOG(NOTICE, "invalid monitor id %lu",
+				  monid);
+			return err;
+		}
+
+		err = vmbus_chan_create(dev, relid, subid, monid, subchan);
+		if (err) {
+			VMBUS_LOG(NOTICE, "subchannel setup failed");
+			return err;
+		}
+		break;
+	}
+	closedir(chan_dir);
+
+	return (ent == NULL) ? -ENOENT : 0;
+}