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From: Mikulas Patocka <mpatocka@redhat.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	Vishal Verma <vishal.l.verma@intel.com>,
	Dave Jiang <dave.jiang@intel.com>,
	Ira Weiny <ira.weiny@intel.com>,
	Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
	Eric Sandeen <esandeen@redhat.com>,
	Dave Chinner <dchinner@redhat.com>,
	"Kani, Toshi" <toshi.kani@hpe.com>,
	"Norton, Scott J" <scott.norton@hpe.com>,
	"Tadakamadla,
	Rajesh (DCIG/CDI/HPS Perf)"  <rajesh.tadakamadla@hpe.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	linux-nvdimm <linux-nvdimm@lists.01.org>
Subject: [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache
Date: Wed, 16 Sep 2020 06:57:10 -0400 (EDT)	[thread overview]
Message-ID: <alpine.LRH.2.02.2009160649560.20720@file01.intranet.prod.int.rdu2.redhat.com> (raw)
In-Reply-To: <alpine.LRH.2.02.2009151332280.3851@file01.intranet.prod.int.rdu2.redhat.com>



On Tue, 15 Sep 2020, Mikulas Patocka wrote:

> 
> 
> On Tue, 15 Sep 2020, Mikulas Patocka wrote:
> 
> > > > - __copy_from_user_inatomic_nocache doesn't flush cache for leading and
> > > > trailing bytes.
> > > 
> > > You want copy_user_flushcache(). See how fs/dax.c arranges for
> > > dax_copy_from_iter() to route to pmem_copy_from_iter().
> > 
> > Is it something new for the kernel 5.10? I see only __copy_user_flushcache 
> > that is implemented just for x86 and arm64.
> > 
> > There is __copy_from_user_flushcache implemented for x86, arm64 and power. 
> > It is used in lib/iov_iter.c under
> > #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE - so should I use this?
> > 
> > Mikulas
> 
> ... and __copy_user_flushcache is not exported for modules. So, I am stuck 
> with __copy_from_user_inatomic_nocache.
> 
> Mikulas

I'm submitting this patch that adds the required exports (so that we could 
use __copy_from_user_flushcache on x86, arm64 and powerpc). Please, queue 
it for the next merge window.


From: Mikulas Patocka <mpatocka@redhat.com>

Export the symbols __copy_user_flushcache and __copy_from_user_flushcache,
so that modules can use this functionality.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 arch/arm64/lib/uaccess_flushcache.c |    1 +
 arch/powerpc/lib/pmem.c             |    1 +
 arch/x86/lib/usercopy_64.c          |    1 +
 3 files changed, 3 insertions(+)

Index: linux-2.6/arch/arm64/lib/uaccess_flushcache.c
===================================================================
--- linux-2.6.orig/arch/arm64/lib/uaccess_flushcache.c	2020-09-16 12:44:15.068038000 +0200
+++ linux-2.6/arch/arm64/lib/uaccess_flushcache.c	2020-09-16 12:44:15.068038000 +0200
@@ -38,3 +38,4 @@ unsigned long __copy_user_flushcache(voi
 	__clean_dcache_area_pop(to, n - rc);
 	return rc;
 }
+EXPORT_SYMBOL_GPL(__copy_user_flushcache);
Index: linux-2.6/arch/x86/lib/usercopy_64.c
===================================================================
--- linux-2.6.orig/arch/x86/lib/usercopy_64.c	2020-09-16 12:44:15.068038000 +0200
+++ linux-2.6/arch/x86/lib/usercopy_64.c	2020-09-16 12:44:15.068038000 +0200
@@ -134,6 +134,7 @@ long __copy_user_flushcache(void *dst, c
 
 	return rc;
 }
+EXPORT_SYMBOL_GPL(__copy_user_flushcache);
 
 void __memcpy_flushcache(void *_dst, const void *_src, size_t size)
 {
Index: linux-2.6/arch/powerpc/lib/pmem.c
===================================================================
--- linux-2.6.orig/arch/powerpc/lib/pmem.c	2020-09-16 12:44:15.068038000 +0200
+++ linux-2.6/arch/powerpc/lib/pmem.c	2020-09-16 12:44:15.068038000 +0200
@@ -75,6 +75,7 @@ long __copy_from_user_flushcache(void *d
 
 	return copied;
 }
+EXPORT_SYMBOL_GPL(__copy_from_user_flushcache);
 
 void memcpy_flushcache(void *dest, const void *src, size_t size)
 {


  reply	other threads:[~2020-09-16 19:14 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-15 12:34 [RFC] nvfs: a filesystem for persistent memory Mikulas Patocka
2020-09-15 13:00 ` Matthew Wilcox
2020-09-15 13:24   ` Mikulas Patocka
2020-09-22 10:04   ` Ritesh Harjani
2020-09-15 15:16 ` Dan Williams
2020-09-15 16:58   ` Mikulas Patocka
2020-09-15 17:38     ` Mikulas Patocka
2020-09-16 10:57       ` Mikulas Patocka [this message]
2020-09-16 16:21         ` [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache Dan Williams
2020-09-16 17:24           ` Mikulas Patocka
2020-09-16 17:40             ` Dan Williams
2020-09-16 18:06               ` Mikulas Patocka
2020-09-21 16:20                 ` NVFS XFS metadata (was: [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache) Mikulas Patocka
2020-09-22  5:03                   ` Dave Chinner
2020-09-22 16:46                     ` Mikulas Patocka
2020-09-22 17:25                       ` Matthew Wilcox
2020-09-24 15:00                         ` Mikulas Patocka
2020-09-28 15:22                           ` Mikulas Patocka
2020-09-23  2:45                       ` Dave Chinner
2020-09-23  9:20                         ` A bug in ext4 with big directories (was: NVFS XFS metadata) Mikulas Patocka
2020-09-23  9:44                           ` Jan Kara
2020-09-23 12:46                             ` Mikulas Patocka
2020-09-23 20:20                             ` Andreas Dilger
2020-09-23 17:19                         ` NVFS XFS metadata (was: [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache) Mikulas Patocka
2020-09-23  9:57                       ` Jan Kara
2020-09-23 13:11                         ` Mikulas Patocka
2020-09-23 15:04                           ` Matthew Wilcox
2020-09-22 12:28                   ` Matthew Wilcox
2020-09-22 12:39                     ` Mikulas Patocka
2020-09-16 18:56               ` [PATCH] pmem: fix __copy_user_flushcache Mikulas Patocka
2020-09-18  1:53                 ` Dan Williams
2020-09-18 12:25                   ` the "read" syscall sees partial effects of the "write" syscall Mikulas Patocka
2020-09-18 13:13                     ` Jan Kara
2020-09-18 18:02                       ` Linus Torvalds
2020-09-20 23:41                       ` Dave Chinner
2020-09-17  6:50               ` [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache Christoph Hellwig
2020-09-21 16:19   ` [RFC] nvfs: a filesystem for persistent memory Mikulas Patocka
2020-09-21 16:29     ` Dan Williams
2020-09-22 15:43     ` Ira Weiny

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