diff mbox series

[v2,1/4] iov_iter: Provide copy_iomem_to|from_iter()

Message ID 20241112200454.2211-2-michal.wajdeczko@intel.com (mailing list archive)
State New
Headers show
Series Add iomem helpers for use from debugfs | expand

Commit Message

Michal Wajdeczko Nov. 12, 2024, 8:04 p.m. UTC
Define simple copy helpers that work on I/O memory. This will
allow reuse of existing framework functions in new use cases.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
---
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
---
v2: use iterate_and_advance to treat user_iter separately (Matthew)
---
 include/linux/uio.h |  3 +++
 lib/iov_iter.c      | 66 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+)

Comments

kernel test robot Nov. 14, 2024, 1:29 a.m. UTC | #1
Hi Michal,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-xe/drm-xe-next]
[also build test WARNING on brauner-vfs/vfs.all akpm-mm/mm-nonmm-unstable linus/master v6.12-rc7 next-20241113]
[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/Michal-Wajdeczko/iov_iter-Provide-copy_iomem_to-from_iter/20241113-080831
base:   https://gitlab.freedesktop.org/drm/xe/kernel.git drm-xe-next
patch link:    https://lore.kernel.org/r/20241112200454.2211-2-michal.wajdeczko%40intel.com
patch subject: [PATCH v2 1/4] iov_iter: Provide copy_iomem_to|from_iter()
config: x86_64-randconfig-123-20241113 (https://download.01.org/0day-ci/archive/20241114/202411140935.iEbIWcpc-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241114/202411140935.iEbIWcpc-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411140935.iEbIWcpc-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> lib/iov_iter.c:373:47: sparse: sparse: cast removes address space '__iomem' of expression
   lib/iov_iter.c:386:47: sparse: sparse: cast removes address space '__iomem' of expression
>> lib/iov_iter.c:349:33: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected void const volatile [noderef] __iomem * @@     got void * @@
   lib/iov_iter.c:349:33: sparse:     expected void const volatile [noderef] __iomem *
   lib/iov_iter.c:349:33: sparse:     got void *
   lib/iov_iter.c:330:37: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected void const volatile [noderef] __iomem * @@     got void * @@
   lib/iov_iter.c:330:37: sparse:     expected void const volatile [noderef] __iomem *
   lib/iov_iter.c:330:37: sparse:     got void *
>> lib/iov_iter.c:362:21: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void volatile [noderef] __iomem * @@     got void *to @@
   lib/iov_iter.c:362:21: sparse:     expected void volatile [noderef] __iomem *
   lib/iov_iter.c:362:21: sparse:     got void *to
>> lib/iov_iter.c:338:24: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void volatile [noderef] __iomem * @@     got void * @@
   lib/iov_iter.c:338:24: sparse:     expected void volatile [noderef] __iomem *
   lib/iov_iter.c:338:24: sparse:     got void *

vim +/__iomem +373 lib/iov_iter.c

   333	
   334	static __always_inline
   335	size_t memcpy_iomem_from_iter(void *iter_from, size_t progress, size_t len,
   336				      void *to, void *priv2)
   337	{
 > 338		memcpy_toio(to + progress, iter_from, len);
   339		return 0;
   340	}
   341	
   342	static __always_inline
   343	size_t copy_iomem_to_user_iter(void __user *iter_to, size_t progress,
   344				       size_t len, void *from, void *priv2)
   345	{
   346		unsigned char buf[SMP_CACHE_BYTES];
   347		size_t chunk = min(len, sizeof(buf));
   348	
 > 349		memcpy_fromio(buf, from + progress, chunk);
   350		chunk -= copy_to_user_iter(iter_to, progress, chunk, buf, priv2);
   351		return len - chunk;
   352	}
   353	
   354	static __always_inline
   355	size_t copy_iomem_from_user_iter(void __user *iter_from, size_t progress,
   356					 size_t len, void *to, void *priv2)
   357	{
   358		unsigned char buf[SMP_CACHE_BYTES];
   359		size_t chunk = min(len, sizeof(buf));
   360	
   361		chunk -= copy_from_user_iter(iter_from, progress, chunk, buf, priv2);
 > 362		memcpy_toio(to, buf, chunk);
   363		return len - chunk;
   364	}
   365	
   366	size_t copy_iomem_to_iter(const void __iomem *from, size_t bytes, struct iov_iter *i)
   367	{
   368		if (WARN_ON_ONCE(i->data_source))
   369			return 0;
   370		if (user_backed_iter(i))
   371			might_fault();
   372	
 > 373		return iterate_and_advance(i, bytes, (void *)from,
   374					   copy_iomem_to_user_iter,
   375					   memcpy_iomem_to_iter);
   376	}
   377	EXPORT_SYMBOL(copy_iomem_to_iter);
   378
diff mbox series

Patch

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 853f9de5aa05..354a6b2d1e94 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -183,6 +183,9 @@  size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
 size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
 size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
 
+size_t copy_iomem_to_iter(const void __iomem *from, size_t bytes, struct iov_iter *i);
+size_t copy_iomem_from_iter(void __iomem *to, size_t bytes, struct iov_iter *i);
+
 static inline size_t copy_folio_to_iter(struct folio *folio, size_t offset,
 		size_t bytes, struct iov_iter *i)
 {
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 908e75a28d90..80feff9c8875 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -323,6 +323,72 @@  size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
 EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache);
 #endif
 
+static __always_inline
+size_t memcpy_iomem_to_iter(void *iter_to, size_t progress, size_t len,
+			    void *from, void *priv2)
+{
+	memcpy_fromio(iter_to, from + progress, len);
+	return 0;
+}
+
+static __always_inline
+size_t memcpy_iomem_from_iter(void *iter_from, size_t progress, size_t len,
+			      void *to, void *priv2)
+{
+	memcpy_toio(to + progress, iter_from, len);
+	return 0;
+}
+
+static __always_inline
+size_t copy_iomem_to_user_iter(void __user *iter_to, size_t progress,
+			       size_t len, void *from, void *priv2)
+{
+	unsigned char buf[SMP_CACHE_BYTES];
+	size_t chunk = min(len, sizeof(buf));
+
+	memcpy_fromio(buf, from + progress, chunk);
+	chunk -= copy_to_user_iter(iter_to, progress, chunk, buf, priv2);
+	return len - chunk;
+}
+
+static __always_inline
+size_t copy_iomem_from_user_iter(void __user *iter_from, size_t progress,
+				 size_t len, void *to, void *priv2)
+{
+	unsigned char buf[SMP_CACHE_BYTES];
+	size_t chunk = min(len, sizeof(buf));
+
+	chunk -= copy_from_user_iter(iter_from, progress, chunk, buf, priv2);
+	memcpy_toio(to, buf, chunk);
+	return len - chunk;
+}
+
+size_t copy_iomem_to_iter(const void __iomem *from, size_t bytes, struct iov_iter *i)
+{
+	if (WARN_ON_ONCE(i->data_source))
+		return 0;
+	if (user_backed_iter(i))
+		might_fault();
+
+	return iterate_and_advance(i, bytes, (void *)from,
+				   copy_iomem_to_user_iter,
+				   memcpy_iomem_to_iter);
+}
+EXPORT_SYMBOL(copy_iomem_to_iter);
+
+size_t copy_iomem_from_iter(void __iomem *to, size_t bytes, struct iov_iter *i)
+{
+	if (WARN_ON_ONCE(!i->data_source))
+		return 0;
+	if (user_backed_iter(i))
+		might_fault();
+
+	return iterate_and_advance(i, bytes, (void *)to,
+				   copy_iomem_from_user_iter,
+				   memcpy_iomem_from_iter);
+}
+EXPORT_SYMBOL(copy_iomem_from_iter);
+
 static inline bool page_copy_sane(struct page *page, size_t offset, size_t n)
 {
 	struct page *head;