Subject: Re: [PATCH v4 1/1] vringh: IOMEM support

From: kernel test robot <[email-masked]>
Date: Fri, 2 Jun 2023 17:56:12 +0800

Hi Shunsuke,

kernel test robot noticed the following build warnings:

[auto build test WARNING on mst-vhost/linux-next]
[also build test WARNING on linus/master horms-ipvs/master v6.4-rc4 next-20230602]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Shunsuke-Mie/vringh-IOMEM-support/20230602-135351
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
patch link:    https://lore.kernel.org/r/20230602055211.309960-2-mie%40igel.co.jp
patch subject: [PATCH v4 1/1] vringh: IOMEM support
config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20230602/[email-masked]/config)
compiler: alpha-linux-gcc (GCC) 12.3.0
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/de2a1f5220c32e953400f225aba6bd294a8d41b8
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Shunsuke-Mie/vringh-IOMEM-support/20230602-135351
        git checkout de2a1f5220c32e953400f225aba6bd294a8d41b8
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=alpha olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=alpha SHELL=/bin/bash drivers/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email-masked]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email-masked]/

All warnings (new ones prefixed by >>):

>> drivers/vhost/vringh.c:1661:5: warning: no previous prototype for 'vringh_init_iomem' [-Wmissing-prototypes]
    1661 | int vringh_init_iomem(struct vringh *vrh, u64 features, unsigned int num,
         |     ^~~~~~~~~~~~~~~~~
>> drivers/vhost/vringh.c:1683:5: warning: no previous prototype for 'vringh_getdesc_iomem' [-Wmissing-prototypes]
    1683 | int vringh_getdesc_iomem(struct vringh *vrh, struct vringh_kiov *riov,
         |     ^~~~~~~~~~~~~~~~~~~~
>> drivers/vhost/vringh.c:1714:9: warning: no previous prototype for 'vringh_iov_pull_iomem' [-Wmissing-prototypes]
    1714 | ssize_t vringh_iov_pull_iomem(struct vringh *vrh, struct vringh_kiov *riov,
         |         ^~~~~~~~~~~~~~~~~~~~~
>> drivers/vhost/vringh.c:1729:9: warning: no previous prototype for 'vringh_iov_push_iomem' [-Wmissing-prototypes]
    1729 | ssize_t vringh_iov_push_iomem(struct vringh *vrh, struct vringh_kiov *wiov,
         |         ^~~~~~~~~~~~~~~~~~~~~
>> drivers/vhost/vringh.c:1744:6: warning: no previous prototype for 'vringh_abandon_iomem' [-Wmissing-prototypes]
    1744 | void vringh_abandon_iomem(struct vringh *vrh, unsigned int num)
         |      ^~~~~~~~~~~~~~~~~~~~
>> drivers/vhost/vringh.c:1759:5: warning: no previous prototype for 'vringh_complete_iomem' [-Wmissing-prototypes]
    1759 | int vringh_complete_iomem(struct vringh *vrh, u16 head, u32 len)
         |     ^~~~~~~~~~~~~~~~~~~~~
>> drivers/vhost/vringh.c:1777:6: warning: no previous prototype for 'vringh_notify_enable_iomem' [-Wmissing-prototypes]
    1777 | bool vringh_notify_enable_iomem(struct vringh *vrh)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/vhost/vringh.c:1790:6: warning: no previous prototype for 'vringh_notify_disable_iomem' [-Wmissing-prototypes]
    1790 | void vringh_notify_disable_iomem(struct vringh *vrh)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/vhost/vringh.c:1802:5: warning: no previous prototype for 'vringh_need_notify_iomem' [-Wmissing-prototypes]
    1802 | int vringh_need_notify_iomem(struct vringh *vrh)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~

vim +/vringh_init_iomem +1661 drivers/vhost/vringh.c

  1647	
  1648	/**
  1649	 * vringh_init_iomem - initialize a vringh for a vring on io-memory.
  1650	 * @vrh: the vringh to initialize.
  1651	 * @features: the feature bits for this ring.
  1652	 * @num: the number of elements.
  1653	 * @weak_barriers: true if we only need memory barriers, not I/O.
  1654	 * @desc: the userspace descriptor pointer.
  1655	 * @avail: the userspace avail pointer.
  1656	 * @used: the userspace used pointer.
  1657	 *
  1658	 * Returns an error if num is invalid: you should check pointers
  1659	 * yourself!
  1660	 */
> 1661	int vringh_init_iomem(struct vringh *vrh, u64 features, unsigned int num,
  1662			      bool weak_barriers, struct vring_desc *desc,
  1663			      struct vring_avail *avail, struct vring_used *used)
  1664	{
  1665		return vringh_init_kern(vrh, features, num, weak_barriers, desc, avail,
  1666					used);
  1667	}
  1668	EXPORT_SYMBOL(vringh_init_iomem);
  1669	
  1670	/**
  1671	 * vringh_getdesc_iomem - get next available descriptor from vring on io-memory.
  1672	 * @vrh: the vring on io-memory.
  1673	 * @riov: where to put the readable descriptors (or NULL)
  1674	 * @wiov: where to put the writable descriptors (or NULL)
  1675	 * @head: head index we received, for passing to vringh_complete_iomem().
  1676	 * @gfp: flags for allocating larger riov/wiov.
  1677	 *
  1678	 * Returns 0 if there was no descriptor, 1 if there was, or -errno.
  1679	 *
  1680	 * There some notes, and those are same with vringh_getdesc_kern(). Please see
  1681	 * it.
  1682	 */
> 1683	int vringh_getdesc_iomem(struct vringh *vrh, struct vringh_kiov *riov,
  1684				 struct vringh_kiov *wiov, u16 *head, gfp_t gfp)
  1685	{
  1686		int err;
  1687	
  1688		err = __vringh_get_head(vrh, getu16_iomem, &vrh->last_avail_idx);
  1689		if (err < 0)
  1690			return err;
  1691	
  1692		/* Empty... */
  1693		if (err == vrh->vring.num)
  1694			return 0;
  1695	
  1696		*head = err;
  1697		err = __vringh_iov(vrh, *head, riov, wiov, no_range_check, NULL, gfp,
  1698				   copydesc_iomem);
  1699		if (err)
  1700			return err;
  1701	
  1702		return 1;
  1703	}
  1704	EXPORT_SYMBOL(vringh_getdesc_iomem);
  1705	
  1706	/**
  1707	 * vringh_iov_pull_iomem - copy bytes from vring_iov.
  1708	 * @riov: the riov as passed to vringh_getdesc_iomem() (updated as we consume)
  1709	 * @dst: the place to copy.
  1710	 * @len: the maximum length to copy.
  1711	 *
  1712	 * Returns the bytes copied <= len or a negative errno.
  1713	 */
> 1714	ssize_t vringh_iov_pull_iomem(struct vringh *vrh, struct vringh_kiov *riov,
  1715				      void *dst, size_t len)
  1716	{
  1717		return vringh_iov_xfer(vrh, riov, dst, len, xfer_from_iomem);
  1718	}
  1719	EXPORT_SYMBOL(vringh_iov_pull_iomem);
  1720	
  1721	/**
  1722	 * vringh_iov_push_iomem - copy bytes into vring_iov.
  1723	 * @wiov: the wiov as passed to vringh_getdesc_iomem() (updated as we consume)
  1724	 * @src: the place to copy from.
  1725	 * @len: the maximum length to copy.
  1726	 *
  1727	 * Returns the bytes copied <= len or a negative errno.
  1728	 */
> 1729	ssize_t vringh_iov_push_iomem(struct vringh *vrh, struct vringh_kiov *wiov,
  1730				      const void *src, size_t len)
  1731	{
  1732		return vringh_iov_xfer(vrh, wiov, (void *)src, len, xfer_to_iomem);
  1733	}
  1734	EXPORT_SYMBOL(vringh_iov_push_iomem);
  1735	
  1736	/**
  1737	 * vringh_abandon_iomem - we've decided not to handle the descriptor(s).
  1738	 * @vrh: the vring.
  1739	 * @num: the number of descriptors to put back (ie. num
  1740	 *	 vringh_getdesc_iomem() to undo).
  1741	 *
  1742	 * The next vringh_get_kern() will return the old descriptor(s) again.
  1743	 */
> 1744	void vringh_abandon_iomem(struct vringh *vrh, unsigned int num)
  1745	{
  1746		vringh_abandon_kern(vrh, num);
  1747	}
  1748	EXPORT_SYMBOL(vringh_abandon_iomem);
  1749	
  1750	/**
  1751	 * vringh_complete_iomem - we've finished with descriptor, publish it.
  1752	 * @vrh: the vring.
  1753	 * @head: the head as filled in by vringh_getdesc_iomem().
  1754	 * @len: the length of data we have written.
  1755	 *
  1756	 * You should check vringh_need_notify_iomem() after one or more calls
  1757	 * to this function.
  1758	 */
> 1759	int vringh_complete_iomem(struct vringh *vrh, u16 head, u32 len)
  1760	{
  1761		struct vring_used_elem used;
  1762	
  1763		used.id = cpu_to_vringh32(vrh, head);
  1764		used.len = cpu_to_vringh32(vrh, len);
  1765	
  1766		return __vringh_complete(vrh, &used, 1, putu16_iomem, putused_iomem);
  1767	}
  1768	EXPORT_SYMBOL(vringh_complete_iomem);
  1769	
  1770	/**
  1771	 * vringh_notify_enable_iomem - we want to know if something changes.
  1772	 * @vrh: the vring.
  1773	 *
  1774	 * This always enables notifications, but returns false if there are
  1775	 * now more buffers available in the vring.
  1776	 */
> 1777	bool vringh_notify_enable_iomem(struct vringh *vrh)
  1778	{
  1779		return __vringh_notify_enable(vrh, getu16_iomem, putu16_iomem);
  1780	}
  1781	EXPORT_SYMBOL(vringh_notify_enable_iomem);
  1782	
  1783	/**
  1784	 * vringh_notify_disable_iomem - don't tell us if something changes.
  1785	 * @vrh: the vring.
  1786	 *
  1787	 * This is our normal running state: we disable and then only enable when
  1788	 * we're going to sleep.
  1789	 */
> 1790	void vringh_notify_disable_iomem(struct vringh *vrh)
  1791	{
  1792		__vringh_notify_disable(vrh, putu16_iomem);
  1793	}
  1794	EXPORT_SYMBOL(vringh_notify_disable_iomem);
  1795	
  1796	/**
  1797	 * vringh_need_notify_iomem - must we tell the other side about used buffers?
  1798	 * @vrh: the vring we've called vringh_complete_iomem() on.
  1799	 *
  1800	 * Returns -errno or 0 if we don't need to tell the other side, 1 if we do.
  1801	 */
> 1802	int vringh_need_notify_iomem(struct vringh *vrh)
  1803	{
  1804		return __vringh_need_notify(vrh, getu16_iomem);
  1805	}
  1806	EXPORT_SYMBOL(vringh_need_notify_iomem);
  1807	

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