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

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Jun 02, 2023 at 05:56:12PM +0800, kernel test robot wrote:
> 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/20230602/202306021725.3otSfXPF-lkp@intel.com/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 <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202306021725.3otSfXPF-lkp@intel.com/
> 
> 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


You probably should put the relevant code within ifdef.

>   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	
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki