ipath_file_ops.c

来自「linux 内核源代码」· C语言 代码 · 共 2,267 行 · 第 1/5 页

	struct ipath_devdata *dd;

	dd = pd->port_dd;

	/* variable access in ipath_poll_hdrqfull() needs this */
	rmb();
	pollflag = ipath_poll_hdrqfull(pd);

	if (pd->port_urgent != pd->port_urgent_poll) {
		pollflag |= POLLIN | POLLRDNORM;
		pd->port_urgent_poll = pd->port_urgent;
	}

	if (!pollflag) {
		/* this saves a spin_lock/unlock in interrupt handler... */
		set_bit(IPATH_PORT_WAITING_URG, &pd->port_flag);
		/* flush waiting flag so don't miss an event... */
		wmb();
		poll_wait(fp, &pd->port_wait, pt);
	}

	return pollflag;
}

static unsigned int ipath_poll_next(struct ipath_portdata *pd,
				    struct file *fp,
				    struct poll_table_struct *pt)
{
	u32 head;
	u32 tail;
	unsigned pollflag = 0;
	struct ipath_devdata *dd;

	dd = pd->port_dd;

	/* variable access in ipath_poll_hdrqfull() needs this */
	rmb();
	pollflag = ipath_poll_hdrqfull(pd);

	head = ipath_read_ureg32(dd, ur_rcvhdrhead, pd->port_port);
	tail = *(volatile u64 *)pd->port_rcvhdrtail_kvaddr;

	if (head != tail)
		pollflag |= POLLIN | POLLRDNORM;
	else {
		/* this saves a spin_lock/unlock in interrupt handler */
		set_bit(IPATH_PORT_WAITING_RCV, &pd->port_flag);
		/* flush waiting flag so we don't miss an event */
		wmb();

		set_bit(pd->port_port + INFINIPATH_R_INTRAVAIL_SHIFT,
			&dd->ipath_rcvctrl);

		ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
				 dd->ipath_rcvctrl);

		if (dd->ipath_rhdrhead_intr_off) /* arm rcv interrupt */
			ipath_write_ureg(dd, ur_rcvhdrhead,
					 dd->ipath_rhdrhead_intr_off | head,
					 pd->port_port);

		poll_wait(fp, &pd->port_wait, pt);
	}

	return pollflag;
}

static unsigned int ipath_poll(struct file *fp,
			       struct poll_table_struct *pt)
{
	struct ipath_portdata *pd;
	unsigned pollflag;

	pd = port_fp(fp);
	if (!pd)
		pollflag = 0;
	else if (pd->poll_type & IPATH_POLL_TYPE_URGENT)
		pollflag = ipath_poll_urgent(pd, fp, pt);
	else
		pollflag = ipath_poll_next(pd, fp, pt);

	return pollflag;
}

static int ipath_supports_subports(int user_swmajor, int user_swminor)
{
	/* no subport implementation prior to software version 1.3 */
	return (user_swmajor > 1) || (user_swminor >= 3);
}

static int ipath_compatible_subports(int user_swmajor, int user_swminor)
{
	/* this code is written long-hand for clarity */
	if (IPATH_USER_SWMAJOR != user_swmajor) {
		/* no promise of compatibility if major mismatch */
		return 0;
	}
	if (IPATH_USER_SWMAJOR == 1) {
		switch (IPATH_USER_SWMINOR) {
		case 0:
		case 1:
		case 2:
			/* no subport implementation so cannot be compatible */
			return 0;
		case 3:
			/* 3 is only compatible with itself */
			return user_swminor == 3;
		default:
			/* >= 4 are compatible (or are expected to be) */
			return user_swminor >= 4;
		}
	}
	/* make no promises yet for future major versions */
	return 0;
}

static int init_subports(struct ipath_devdata *dd,
			 struct ipath_portdata *pd,
			 const struct ipath_user_info *uinfo)
{
	int ret = 0;
	unsigned num_subports;
	size_t size;

	/*
	 * If the user is requesting zero subports,
	 * skip the subport allocation.
	 */
	if (uinfo->spu_subport_cnt <= 0)
		goto bail;

	/* Self-consistency check for ipath_compatible_subports() */
	if (ipath_supports_subports(IPATH_USER_SWMAJOR, IPATH_USER_SWMINOR) &&
	    !ipath_compatible_subports(IPATH_USER_SWMAJOR,
				       IPATH_USER_SWMINOR)) {
		dev_info(&dd->pcidev->dev,
			 "Inconsistent ipath_compatible_subports()\n");
		goto bail;
	}

	/* Check for subport compatibility */
	if (!ipath_compatible_subports(uinfo->spu_userversion >> 16,
				       uinfo->spu_userversion & 0xffff)) {
		dev_info(&dd->pcidev->dev,
			 "Mismatched user version (%d.%d) and driver "
			 "version (%d.%d) while port sharing. Ensure "
                         "that driver and library are from the same "
                         "release.\n",
			 (int) (uinfo->spu_userversion >> 16),
                         (int) (uinfo->spu_userversion & 0xffff),
			 IPATH_USER_SWMAJOR,
	                 IPATH_USER_SWMINOR);
		goto bail;
	}
	if (uinfo->spu_subport_cnt > INFINIPATH_MAX_SUBPORT) {
		ret = -EINVAL;
		goto bail;
	}

	num_subports = uinfo->spu_subport_cnt;
	pd->subport_uregbase = vmalloc(PAGE_SIZE * num_subports);
	if (!pd->subport_uregbase) {
		ret = -ENOMEM;
		goto bail;
	}
	/* Note: pd->port_rcvhdrq_size isn't initialized yet. */
	size = ALIGN(dd->ipath_rcvhdrcnt * dd->ipath_rcvhdrentsize *
		     sizeof(u32), PAGE_SIZE) * num_subports;
	pd->subport_rcvhdr_base = vmalloc(size);
	if (!pd->subport_rcvhdr_base) {
		ret = -ENOMEM;
		goto bail_ureg;
	}

	pd->subport_rcvegrbuf = vmalloc(pd->port_rcvegrbuf_chunks *
					pd->port_rcvegrbuf_size *
					num_subports);
	if (!pd->subport_rcvegrbuf) {
		ret = -ENOMEM;
		goto bail_rhdr;
	}

	pd->port_subport_cnt = uinfo->spu_subport_cnt;
	pd->port_subport_id = uinfo->spu_subport_id;
	pd->active_slaves = 1;
	set_bit(IPATH_PORT_MASTER_UNINIT, &pd->port_flag);
	memset(pd->subport_uregbase, 0, PAGE_SIZE * num_subports);
	memset(pd->subport_rcvhdr_base, 0, size);
	memset(pd->subport_rcvegrbuf, 0, pd->port_rcvegrbuf_chunks *
				         pd->port_rcvegrbuf_size *
				         num_subports);
	goto bail;

bail_rhdr:
	vfree(pd->subport_rcvhdr_base);
bail_ureg:
	vfree(pd->subport_uregbase);
	pd->subport_uregbase = NULL;
bail:
	return ret;
}

static int try_alloc_port(struct ipath_devdata *dd, int port,
			  struct file *fp,
			  const struct ipath_user_info *uinfo)
{
	struct ipath_portdata *pd;
	int ret;

	if (!(pd = dd->ipath_pd[port])) {
		void *ptmp;

		pd = kzalloc(sizeof(struct ipath_portdata), GFP_KERNEL);

		/*
		 * Allocate memory for use in ipath_tid_update() just once
		 * at open, not per call.  Reduces cost of expected send
		 * setup.
		 */
		ptmp = kmalloc(dd->ipath_rcvtidcnt * sizeof(u16) +
			       dd->ipath_rcvtidcnt * sizeof(struct page **),
			       GFP_KERNEL);
		if (!pd || !ptmp) {
			ipath_dev_err(dd, "Unable to allocate portdata "
				      "memory, failing open\n");
			ret = -ENOMEM;
			kfree(pd);
			kfree(ptmp);
			goto bail;
		}
		dd->ipath_pd[port] = pd;
		dd->ipath_pd[port]->port_port = port;
		dd->ipath_pd[port]->port_dd = dd;
		dd->ipath_pd[port]->port_tid_pg_list = ptmp;
		init_waitqueue_head(&dd->ipath_pd[port]->port_wait);
	}
	if (!pd->port_cnt) {
		pd->userversion = uinfo->spu_userversion;
		init_user_egr_sizes(pd);
		if ((ret = init_subports(dd, pd, uinfo)) != 0)
			goto bail;
		ipath_cdbg(PROC, "%s[%u] opened unit:port %u:%u\n",
			   current->comm, current->pid, dd->ipath_unit,
			   port);
		pd->port_cnt = 1;
		port_fp(fp) = pd;
		pd->port_pid = current->pid;
		strncpy(pd->port_comm, current->comm, sizeof(pd->port_comm));
		ipath_stats.sps_ports++;
		ret = 0;
	} else
		ret = -EBUSY;

bail:
	return ret;
}

static inline int usable(struct ipath_devdata *dd)
{
	return dd &&
		(dd->ipath_flags & IPATH_PRESENT) &&
		dd->ipath_kregbase &&
		dd->ipath_lid &&
		!(dd->ipath_flags & (IPATH_LINKDOWN | IPATH_DISABLED
				     | IPATH_LINKUNK));
}

static int find_free_port(int unit, struct file *fp,
			  const struct ipath_user_info *uinfo)
{
	struct ipath_devdata *dd = ipath_lookup(unit);
	int ret, i;

	if (!dd) {
		ret = -ENODEV;
		goto bail;
	}

	if (!usable(dd)) {
		ret = -ENETDOWN;
		goto bail;
	}

	for (i = 1; i < dd->ipath_cfgports; i++) {
		ret = try_alloc_port(dd, i, fp, uinfo);
		if (ret != -EBUSY)
			goto bail;
	}
	ret = -EBUSY;

bail:
	return ret;
}

static int find_best_unit(struct file *fp,
			  const struct ipath_user_info *uinfo)
{
	int ret = 0, i, prefunit = -1, devmax;
	int maxofallports, npresent, nup;
	int ndev;

	devmax = ipath_count_units(&npresent, &nup, &maxofallports);

	/*
	 * This code is present to allow a knowledgeable person to
	 * specify the layout of processes to processors before opening
	 * this driver, and then we'll assign the process to the "closest"
	 * InfiniPath chip to that processor (we assume reasonable connectivity,
	 * for now).  This code assumes that if affinity has been set
	 * before this point, that at most one cpu is set; for now this
	 * is reasonable.  I check for both cpus_empty() and cpus_full(),
	 * in case some kernel variant sets none of the bits when no
	 * affinity is set.  2.6.11 and 12 kernels have all present
	 * cpus set.  Some day we'll have to fix it up further to handle
	 * a cpu subset.  This algorithm fails for two HT chips connected
	 * in tunnel fashion.  Eventually this needs real topology
	 * information.  There may be some issues with dual core numbering
	 * as well.  This needs more work prior to release.
	 */
	if (!cpus_empty(current->cpus_allowed) &&
	    !cpus_full(current->cpus_allowed)) {
		int ncpus = num_online_cpus(), curcpu = -1, nset = 0;
		for (i = 0; i < ncpus; i++)
			if (cpu_isset(i, current->cpus_allowed)) {
				ipath_cdbg(PROC, "%s[%u] affinity set for "
					   "cpu %d/%d\n", current->comm,
					   current->pid, i, ncpus);
				curcpu = i;
				nset++;
			}
		if (curcpu != -1 && nset != ncpus) {
			if (npresent) {
				prefunit = curcpu / (ncpus / npresent);
				ipath_cdbg(PROC,"%s[%u] %d chips, %d cpus, "
					  "%d cpus/chip, select unit %d\n",
					  current->comm, current->pid,
					  npresent, ncpus, ncpus / npresent,
					  prefunit);
			}
		}
	}

	/*
	 * user ports start at 1, kernel port is 0
	 * For now, we do round-robin access across all chips
	 */

	if (prefunit != -1)
		devmax = prefunit + 1;
recheck:
	for (i = 1; i < maxofallports; i++) {
		for (ndev = prefunit != -1 ? prefunit : 0; ndev < devmax;
		     ndev++) {
			struct ipath_devdata *dd = ipath_lookup(ndev);

			if (!usable(dd))
				continue; /* can't use this unit */
			if (i >= dd->ipath_cfgports)
				/*
				 * Maxed out on users of this unit. Try
				 * next.
				 */
				continue;
			ret = try_alloc_port(dd, i, fp, uinfo);
			if (!ret)
				goto done;
		}
	}

	if (npresent) {
		if (nup == 0) {
			ret = -ENETDOWN;
			ipath_dbg("No ports available (none initialized "
				  "and ready)\n");
		} else {
			if (prefunit > 0) {
				/* if started above 0, retry from 0 */
				ipath_cdbg(PROC,
					   "%s[%u] no ports on prefunit "
					   "%d, clear and re-check\n",
					   current->comm, current->pid,
					   prefunit);
				devmax = ipath_count_units(NULL, NULL,
							   NULL);
				prefunit = -1;
				goto recheck;
			}
			ret = -EBUSY;
			ipath_dbg("No ports available\n");
		}
	} else {
		ret = -ENXIO;
		ipath_dbg("No boards found\n");
	}

done:
	return ret;
}

static int find_shared_port(struct file *fp,
			    const struct ipath_user_info *uinfo)
{
	int devmax, ndev, i;
	int ret = 0;

	devmax = ipath_count_units(NULL, NULL, NULL);

	for (ndev = 0; ndev < devmax; ndev++) {
		struct ipath_devdata *dd = ipath_lookup(ndev);

		if (!dd)
			continue;
		for (i = 1; i < dd->ipath_cfgports; i++) {
			struct ipath_portdata *pd = dd->ipath_pd[i];

			/* Skip ports which are not yet open */
			if (!pd || !pd->port_cnt)
				continue;
			/* Skip port if it doesn't match the requested one */
			if (pd->port_subport_id != uinfo->spu_subport_id)
				continue;
			/* Verify the sharing process matches the master */
			if (pd->port_subport_cnt != uinfo->spu_subport_cnt ||
			    pd->userversion != uinfo->spu_userversion ||
			    pd->port_cnt >= pd->port_subport_cnt) {
				ret = -EINVAL;
				goto done;
			}
			port_fp(fp) = pd;
			subport_fp(fp) = pd->port_cnt++;
			tidcursor_fp(fp) = 0;
			pd->active_slaves |= 1 << subport_fp(fp);
			ipath_cdbg(PROC,
				   "%s[%u] %u sharing %s[%u] unit:port %u:%u\n",
				   current->comm, current->pid,
				   subport_fp(fp),
				   pd->port_comm, pd->port_pid,
				   dd->ipath_unit, pd->port_port);
			ret = 1;
			goto done;
		}
	}

done:
	return ret;
}

static int ipath_open(struct inode *in, struct file *fp)
{
	/* The real work is performed later in ipath_assign_port() */
	fp->private_data = kzalloc(sizeof(struct ipath_filedata), GFP_KERNEL);
	return fp->private_data ? 0 : -ENOMEM;
}