[PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

By taking GENERIC_IOREMAP method, the generic ioremap_prot() and
iounmap() are visible and available to arch. This change will
simplify implementation by removing duplicated codes with generic
ioremap_prot() and iounmap(), and has the equivalent functioality.

For hexagon, the current ioremap() and iounmap() are the same as
generic version. After taking GENERIC_IOREMAP way, the old ioremap()
and iounmap() can be completely removed.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@quicinc.com>
Cc: linux-hexagon@vger.kernel.org
---
 arch/hexagon/Kconfig          |  1 +
 arch/hexagon/include/asm/io.h |  9 +++++--
 arch/hexagon/mm/ioremap.c     | 44 -----------------------------------
 3 files changed, 8 insertions(+), 46 deletions(-)
 delete mode 100644 arch/hexagon/mm/ioremap.c

diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 54eadf265178..17afffde1a7f 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -25,6 +25,7 @@ config HEXAGON
 	select NEED_SG_DMA_LENGTH
 	select NO_IOPORT_MAP
 	select GENERIC_IOMAP
+	select GENERIC_IOREMAP
 	select GENERIC_SMP_IDLE_THREAD
 	select STACKTRACE_SUPPORT
 	select GENERIC_CLOCKEVENTS_BROADCAST
diff --git a/arch/hexagon/include/asm/io.h b/arch/hexagon/include/asm/io.h
index 46a099de85b7..dcd9cbbf5934 100644
--- a/arch/hexagon/include/asm/io.h
+++ b/arch/hexagon/include/asm/io.h
@@ -170,8 +170,13 @@ static inline void writel(u32 data, volatile void __iomem *addr)
 #define writew_relaxed __raw_writew
 #define writel_relaxed __raw_writel
 
-void __iomem *ioremap(unsigned long phys_addr, unsigned long size);
-#define ioremap_uc(X, Y) ioremap((X), (Y))
+/*
+ * I/O memory mapping functions.
+ */
+#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
+		       (__HEXAGON_C_DEV << 6))
+
+#define ioremap_uc(addr, size) ioremap((addr), (size))
 
 
 #define __raw_writel writel
diff --git a/arch/hexagon/mm/ioremap.c b/arch/hexagon/mm/ioremap.c
deleted file mode 100644
index 255c5b1ee1a7..000000000000
--- a/arch/hexagon/mm/ioremap.c
+++ /dev/null
@@ -1,44 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * I/O remap functions for Hexagon
- *
- * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
- */
-
-#include <linux/io.h>
-#include <linux/vmalloc.h>
-#include <linux/mm.h>
-
-void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
-{
-	unsigned long last_addr, addr;
-	unsigned long offset = phys_addr & ~PAGE_MASK;
-	struct vm_struct *area;
-
-	pgprot_t prot = __pgprot(_PAGE_PRESENT|_PAGE_READ|_PAGE_WRITE
-					|(__HEXAGON_C_DEV << 6));
-
-	last_addr = phys_addr + size - 1;
-
-	/*  Wrapping not allowed  */
-	if (!size || (last_addr < phys_addr))
-		return NULL;
-
-	/*  Rounds up to next page size, including whole-page offset */
-	size = PAGE_ALIGN(offset + size);
-
-	area = get_vm_area(size, VM_IOREMAP);
-	addr = (unsigned long)area->addr;
-
-	if (ioremap_page_range(addr, addr+size, phys_addr, prot)) {
-		vunmap((void *)addr);
-		return NULL;
-	}
-
-	return (void __iomem *) (offset + addr);
-}
-
-void iounmap(const volatile void __iomem *addr)
-{
-	vunmap((void *) ((unsigned long) addr & PAGE_MASK));
-}
-- 
2.34.1

Re: [PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Arnd Bergmann]

On Thu, Feb 16, 2023, at 13:34, Baoquan He wrote:
> diff --git a/arch/hexagon/include/asm/io.h 
> b/arch/hexagon/include/asm/io.h
> index 46a099de85b7..dcd9cbbf5934 100644
> --- a/arch/hexagon/include/asm/io.h
> +++ b/arch/hexagon/include/asm/io.h
> @@ -170,8 +170,13 @@ static inline void writel(u32 data, volatile void 
> __iomem *addr)
>  #define writew_relaxed __raw_writew
>  #define writel_relaxed __raw_writel
> 
> -void __iomem *ioremap(unsigned long phys_addr, unsigned long size);
> -#define ioremap_uc(X, Y) ioremap((X), (Y))
> +/*
> + * I/O memory mapping functions.
> + */
> +#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
> +		       (__HEXAGON_C_DEV << 6))
> +
> +#define ioremap_uc(addr, size) ioremap((addr), (size))

I think we probably want to kill off ioremap_uc() here, and use
the generic version that just returns NULL.

I see that there are only two callers of {devm_,}ioremap_uc() left in the
tree, so maybe we can even take that final step and remove it from
the interface. Maybe we can revisit [1] as part of this series.

     Arnd

[1] https://lore.kernel.org/all/20191111192258.2234502-1-arnd@arndb.de/

Re: [PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/16/23 at 01:53pm, Arnd Bergmann wrote:
> On Thu, Feb 16, 2023, at 13:34, Baoquan He wrote:
> > diff --git a/arch/hexagon/include/asm/io.h 
> > b/arch/hexagon/include/asm/io.h
> > index 46a099de85b7..dcd9cbbf5934 100644
> > --- a/arch/hexagon/include/asm/io.h
> > +++ b/arch/hexagon/include/asm/io.h
> > @@ -170,8 +170,13 @@ static inline void writel(u32 data, volatile void 
> > __iomem *addr)
> >  #define writew_relaxed __raw_writew
> >  #define writel_relaxed __raw_writel
> > 
> > -void __iomem *ioremap(unsigned long phys_addr, unsigned long size);
> > -#define ioremap_uc(X, Y) ioremap((X), (Y))
> > +/*
> > + * I/O memory mapping functions.
> > + */
> > +#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
> > +		       (__HEXAGON_C_DEV << 6))
> > +

Thanks for reviewing.

> > +#define ioremap_uc(addr, size) ioremap((addr), (size))
> 
> I think we probably want to kill off ioremap_uc() here, and use
> the generic version that just returns NULL.


-#define ioremap_uc(X, Y) ioremap((X), (Y))
+#define ioremap_uc(addr, size) ioremap((addr), (size))

Here, in fact the ioremap_uc() definition is not related. I just
improve the old definition passingly. And similar for other
ioremap_uc() adaptation.

> 
> I see that there are only two callers of {devm_,}ioremap_uc() left in the
> tree, so maybe we can even take that final step and remove it from
> the interface. Maybe we can revisit [1] as part of this series.

I see now. Christoph Hellwig ever mentioned in v2 reviewing, I
didn't get why. Thanks for the details. 
https://lore.kernel.org/all/YwHX98KBEnZw9t6e@infradead.org/T/#u

I am not sure if it's OK to do the change in this patchset, maybe
another patch?

Thanks
Baoquan

Re: [PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Arnd Bergmann]

On Thu, Feb 16, 2023, at 15:47, Baoquan He wrote:
> On 02/16/23 at 01:53pm, Arnd Bergmann wrote:
>> On Thu, Feb 16, 2023, at 13:34, Baoquan He wrote:
>> I see that there are only two callers of {devm_,}ioremap_uc() left in the
>> tree, so maybe we can even take that final step and remove it from
>> the interface. Maybe we can revisit [1] as part of this series.
>
> I see now. Christoph Hellwig ever mentioned in v2 reviewing, I
> didn't get why. Thanks for the details. 
> https://lore.kernel.org/all/YwHX98KBEnZw9t6e@infradead.org/T/#u
>
> I am not sure if it's OK to do the change in this patchset, maybe
> another patch?

Yes, a separate patch would be ideal. If you do the same change in
more than one architecture (other than ia64 and x86), you can combine
those into one patch.

    Arnd

Re: [PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/16/23 at 03:51pm, Arnd Bergmann wrote:
> On Thu, Feb 16, 2023, at 15:47, Baoquan He wrote:
> > On 02/16/23 at 01:53pm, Arnd Bergmann wrote:
> >> On Thu, Feb 16, 2023, at 13:34, Baoquan He wrote:
> >> I see that there are only two callers of {devm_,}ioremap_uc() left in the
> >> tree, so maybe we can even take that final step and remove it from
> >> the interface. Maybe we can revisit [1] as part of this series.
> >
> > I see now. Christoph Hellwig ever mentioned in v2 reviewing, I
> > didn't get why. Thanks for the details. 
> > https://lore.kernel.org/all/YwHX98KBEnZw9t6e@infradead.org/T/#u
> >
> > I am not sure if it's OK to do the change in this patchset, maybe
> > another patch?
> 
> Yes, a separate patch would be ideal. If you do the same change in
> more than one architecture (other than ia64 and x86), you can combine
> those into one patch.

I am making a patch to achieve this. There's trouble in mips since it
hasn't had <asm-generic/io.h> in <asm/io.h>, and adding that will cuase
build error. I will post the patch for reviewing.