[v6,03/19] openrisc: mm: remove unneeded early ioremap code

Message ID 20230609075528.9390-4-bhe@redhat.com
State New
Headers
Series mm: ioremap: Convert architectures to take GENERIC_IOREMAP way |

Commit Message

Baoquan He June 9, 2023, 7:55 a.m. UTC
  Under arch/openrisc, there isn't any place where ioremap() is called.
It means that there isn't early ioremap handling needed in openrisc,
So the early ioremap handling code in ioremap() of
arch/openrisc/mm/ioremap.c is unnecessary and can be removed.

And also remove the special handling in iounmap() since no page
is got from fixmap pool along with early ioremap code removing
in ioremap().

Link: https://lore.kernel.org/linux-mm/YwxfxKrTUtAuejKQ@oscomms1/
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: openrisc@lists.librecores.org
---
v5->v6:
  Remove the special handling in iounmap() because no page is got from
  fixmap pool along with early ioremap code removing in ioremap() - Mike.

 arch/openrisc/mm/ioremap.c | 43 +++++---------------------------------
 1 file changed, 5 insertions(+), 38 deletions(-)
  

Comments

Christoph Hellwig June 10, 2023, 6:24 a.m. UTC | #1
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
  
Mike Rapoport June 11, 2023, 5:44 a.m. UTC | #2
On Fri, Jun 09, 2023 at 03:55:12PM +0800, Baoquan He wrote:
> Under arch/openrisc, there isn't any place where ioremap() is called.
> It means that there isn't early ioremap handling needed in openrisc,
> So the early ioremap handling code in ioremap() of
> arch/openrisc/mm/ioremap.c is unnecessary and can be removed.
> 
> And also remove the special handling in iounmap() since no page
> is got from fixmap pool along with early ioremap code removing
> in ioremap().
> 
> Link: https://lore.kernel.org/linux-mm/YwxfxKrTUtAuejKQ@oscomms1/
> Signed-off-by: Baoquan He <bhe@redhat.com>
> Acked-by: Stafford Horne <shorne@gmail.com>
> Cc: Jonas Bonn <jonas@southpole.se>
> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
> Cc: Stafford Horne <shorne@gmail.com>
> Cc: openrisc@lists.librecores.org

Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
> v5->v6:
>   Remove the special handling in iounmap() because no page is got from
>   fixmap pool along with early ioremap code removing in ioremap() - Mike.
> 
>  arch/openrisc/mm/ioremap.c | 43 +++++---------------------------------
>  1 file changed, 5 insertions(+), 38 deletions(-)
> 
> diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c
> index 8ec0dafecf25..cdbcc7e73684 100644
> --- a/arch/openrisc/mm/ioremap.c
> +++ b/arch/openrisc/mm/ioremap.c
> @@ -22,8 +22,6 @@
>  
>  extern int mem_init_done;
>  
> -static unsigned int fixmaps_used __initdata;
> -
>  /*
>   * Remap an arbitrary physical address space into the kernel virtual
>   * address space. Needed when the kernel wants to access high addresses
> @@ -52,24 +50,14 @@ void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
>  	p = addr & PAGE_MASK;
>  	size = PAGE_ALIGN(last_addr + 1) - p;
>  
> -	if (likely(mem_init_done)) {
> -		area = get_vm_area(size, VM_IOREMAP);
> -		if (!area)
> -			return NULL;
> -		v = (unsigned long)area->addr;
> -	} else {
> -		if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS)
> -			return NULL;
> -		v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used);
> -		fixmaps_used += (size >> PAGE_SHIFT);
> -	}
> +	area = get_vm_area(size, VM_IOREMAP);
> +	if (!area)
> +		return NULL;
> +	v = (unsigned long)area->addr;
>  
>  	if (ioremap_page_range(v, v + size, p,
>  			__pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) {
> -		if (likely(mem_init_done))
> -			vfree(area->addr);
> -		else
> -			fixmaps_used -= (size >> PAGE_SHIFT);
> +		vfree(area->addr);
>  		return NULL;
>  	}
>  
> @@ -79,27 +67,6 @@ EXPORT_SYMBOL(ioremap);
>  
>  void iounmap(volatile void __iomem *addr)
>  {
> -	/* If the page is from the fixmap pool then we just clear out
> -	 * the fixmap mapping.
> -	 */
> -	if (unlikely((unsigned long)addr > FIXADDR_START)) {
> -		/* This is a bit broken... we don't really know
> -		 * how big the area is so it's difficult to know
> -		 * how many fixed pages to invalidate...
> -		 * just flush tlb and hope for the best...
> -		 * consider this a FIXME
> -		 *
> -		 * Really we should be clearing out one or more page
> -		 * table entries for these virtual addresses so that
> -		 * future references cause a page fault... for now, we
> -		 * rely on two things:
> -		 *   i)  this code never gets called on known boards
> -		 *   ii) invalid accesses to the freed areas aren't made
> -		 */
> -		flush_tlb_all();
> -		return;
> -	}
> -
>  	return vfree((void *)(PAGE_MASK & (unsigned long)addr));
>  }
>  EXPORT_SYMBOL(iounmap);
> -- 
> 2.34.1
>
  

Patch

diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c
index 8ec0dafecf25..cdbcc7e73684 100644
--- a/arch/openrisc/mm/ioremap.c
+++ b/arch/openrisc/mm/ioremap.c
@@ -22,8 +22,6 @@ 
 
 extern int mem_init_done;
 
-static unsigned int fixmaps_used __initdata;
-
 /*
  * Remap an arbitrary physical address space into the kernel virtual
  * address space. Needed when the kernel wants to access high addresses
@@ -52,24 +50,14 @@  void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
 	p = addr & PAGE_MASK;
 	size = PAGE_ALIGN(last_addr + 1) - p;
 
-	if (likely(mem_init_done)) {
-		area = get_vm_area(size, VM_IOREMAP);
-		if (!area)
-			return NULL;
-		v = (unsigned long)area->addr;
-	} else {
-		if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS)
-			return NULL;
-		v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used);
-		fixmaps_used += (size >> PAGE_SHIFT);
-	}
+	area = get_vm_area(size, VM_IOREMAP);
+	if (!area)
+		return NULL;
+	v = (unsigned long)area->addr;
 
 	if (ioremap_page_range(v, v + size, p,
 			__pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) {
-		if (likely(mem_init_done))
-			vfree(area->addr);
-		else
-			fixmaps_used -= (size >> PAGE_SHIFT);
+		vfree(area->addr);
 		return NULL;
 	}
 
@@ -79,27 +67,6 @@  EXPORT_SYMBOL(ioremap);
 
 void iounmap(volatile void __iomem *addr)
 {
-	/* If the page is from the fixmap pool then we just clear out
-	 * the fixmap mapping.
-	 */
-	if (unlikely((unsigned long)addr > FIXADDR_START)) {
-		/* This is a bit broken... we don't really know
-		 * how big the area is so it's difficult to know
-		 * how many fixed pages to invalidate...
-		 * just flush tlb and hope for the best...
-		 * consider this a FIXME
-		 *
-		 * Really we should be clearing out one or more page
-		 * table entries for these virtual addresses so that
-		 * future references cause a page fault... for now, we
-		 * rely on two things:
-		 *   i)  this code never gets called on known boards
-		 *   ii) invalid accesses to the freed areas aren't made
-		 */
-		flush_tlb_all();
-		return;
-	}
-
 	return vfree((void *)(PAGE_MASK & (unsigned long)addr));
 }
 EXPORT_SYMBOL(iounmap);