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From: Laurence Rochfort <laurence.rochfort@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Springer <rspringer@google.com>,
	Todd Poynor <toddpoynor@google.com>,
	Ben Chan <benchan@chromium.org>,
	devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
	laurence.rochfort@gmail.com
Subject: Re: [PATCH] staging: gasket: Fix sparse "incorrect type in assignment" warnings.
Date: Wed, 10 Oct 2018 15:03:05 +0100	[thread overview]
Message-ID: <20181010140305.GA20899@minipc.home> (raw)
In-Reply-To: <20181009131303.GC25423@kroah.com>

[-- Attachment #1: Type: text/plain, Size: 2602 bytes --]

On Tue, Oct 09, 2018 at 03:13:03PM +0200, Greg Kroah-Hartman wrote:
> On Thu, Oct 04, 2018 at 06:52:25PM +0100, Laurence Rochfort wrote:
> > Silence the below sparse warnings by casting betwen u8 __iomem *, and
> > void *.
> > 
> > warning: incorrect type in assignment (different address spaces)
> >    expected unsigned char [noderef] [usertype] <asn:2>*virt_base
> >    got void *[assigned] mem
> > warning: incorrect type in argument 3 (different address spaces)
> >    expected void *cpu_addr
> >    got unsigned char [noderef] [usertype] <asn:2>*virt_base
> > 
> > Signed-off-by: Laurence Rochfort <laurence.rochfort@gmail.com>
> > ---
> >  drivers/staging/gasket/gasket_page_table.c | 10 +++++-----
> >  1 file changed, 5 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
> > index d4c5f8a..7f5e5b3 100644
> > --- a/drivers/staging/gasket/gasket_page_table.c
> > +++ b/drivers/staging/gasket/gasket_page_table.c
> > @@ -1278,7 +1278,7 @@ int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
> >  				 dma_addr_t *dma_address, u64 index)
> >  {
> >  	dma_addr_t handle;
> > -	void *mem;
> > +	u8 __iomem *mem;
> >  	int j;
> >  	unsigned int num_pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
> >  	const struct gasket_driver_desc *driver_desc =
> > @@ -1290,7 +1290,7 @@ int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
> >  	if (num_pages == 0)
> >  		return -EINVAL;
> >  
> > -	mem = dma_alloc_coherent(gasket_get_device(gasket_dev),
> > +	mem = (u8 __iomem *)dma_alloc_coherent(gasket_get_device(gasket_dev),
> >  				 num_pages * PAGE_SIZE, &handle, 0);
> >  	if (!mem)
> >  		goto nomem;
> > @@ -1325,7 +1325,7 @@ int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
> >  nomem:
> >  	if (mem) {
> >  		dma_free_coherent(gasket_get_device(gasket_dev),
> > -				  num_pages * PAGE_SIZE, mem, handle);
> > +				  num_pages * PAGE_SIZE, (void __force *)mem, handle);
> >  	}
> >  
> >  	if (gasket_dev->page_table[index]->coherent_pages) {
> > @@ -1353,7 +1353,7 @@ int gasket_free_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
> >  	if (gasket_dev->coherent_buffer.length_bytes) {
> >  		dma_free_coherent(gasket_get_device(gasket_dev),
> >  				  gasket_dev->coherent_buffer.length_bytes,
> > -				  gasket_dev->coherent_buffer.virt_base,
> > +				  (void __force *)gasket_dev->coherent_buffer.virt_base,
> 
> We should not have to "force" anything here.  Something feels wrong in
> the definition of these variable types...

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From bde80ff6bdab740d838210aa3e664c8901b2142a Mon Sep 17 00:00:00 2001
From: Laurence Rochfort <laurence.rochfort@gmail.com>
Date: Thu, 4 Oct 2018 18:42:26 +0100
Subject: [PATCH v2] staging: gasket: Fix sparse "incorrect type in assignment"
 warnings.

Correct the coherent buffer data type and memory space cookie.

sparse errors were being generated when passing virt_base to
dma_alloc_coherent().

warning: incorrect type in assignment (different address spaces)
   expected unsigned char [noderef] [usertype] <asn:2>*virt_base
   got void *[assigned] mem
warning: incorrect type in argument 3 (different address spaces)
   expected void *cpu_addr
   got unsigned char [noderef] [usertype] <asn:2>*virt_base

Signed-off-by: Laurence Rochfort <laurence.rochfort@gmail.com>
---
Changes in v2:
- Correct data type rather than forcing type coersion, as per gkh

 drivers/staging/gasket/gasket_core.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/gasket/gasket_core.h b/drivers/staging/gasket/gasket_core.h
index 275fd0b..9d09678 100644
--- a/drivers/staging/gasket/gasket_core.h
+++ b/drivers/staging/gasket/gasket_core.h
@@ -231,7 +231,7 @@ struct gasket_coherent_buffer_desc {
 /* Coherent buffer structure. */
 struct gasket_coherent_buffer {
 	/* Virtual base address. */
-	u8 __iomem *virt_base;
+	void *virt_base;
 
 	/* Physical base address. */
 	ulong phys_base;
-- 
2.9.5


  reply	other threads:[~2018-10-10 13:53 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-04 17:52 [PATCH] staging: gasket: Fix sparse "incorrect type in assignment" warnings Laurence Rochfort
2018-10-09 13:13 ` Greg Kroah-Hartman
2018-10-10 14:03   ` Laurence Rochfort [this message]
2018-10-10 14:25     ` Greg Kroah-Hartman
2018-10-10 21:24       ` [PATCH v3] " Laurence Rochfort
2018-10-15 18:42         ` Todd Poynor

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