2022-10-12 10:16:19

by Christophe Leroy

[permalink] [raw]
Subject: [RFC PATCH 3/8] mm/ioremap: Define generic_ioremap_prot() and generic_iounmap()

Define a generic version of ioremap_prot() and iounmap() that
architectures can call after they have performed the necessary
alteration to parameters and/or necessary verifications.

Signed-off-by: Christophe Leroy <[email protected]>
---
include/asm-generic/io.h | 4 ++++
mm/ioremap.c | 26 ++++++++++++++++++++------
2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index a68f8fbf423b..43eb4f62e954 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1073,9 +1073,13 @@ static inline bool iounmap_allowed(void *addr)
}
#endif

+void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
+ pgprot_t prot);
+
void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
unsigned long prot);
void iounmap(volatile void __iomem *addr);
+void generic_iounmap(volatile void __iomem *addr);

static inline void __iomem *ioremap(phys_addr_t addr, size_t size)
{
diff --git a/mm/ioremap.c b/mm/ioremap.c
index 8652426282cc..9f34a8f90b58 100644
--- a/mm/ioremap.c
+++ b/mm/ioremap.c
@@ -11,8 +11,8 @@
#include <linux/io.h>
#include <linux/export.h>

-void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
- unsigned long prot)
+void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
+ pgprot_t prot)
{
unsigned long offset, vaddr;
phys_addr_t last_addr;
@@ -28,7 +28,7 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
phys_addr -= offset;
size = PAGE_ALIGN(size + offset);

- if (!ioremap_allowed(phys_addr, size, prot))
+ if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
return NULL;

area = get_vm_area_caller(size, VM_IOREMAP,
@@ -38,17 +38,24 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
vaddr = (unsigned long)area->addr;
area->phys_addr = phys_addr;

- if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
- __pgprot(prot))) {
+ if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
free_vm_area(area);
return NULL;
}

return (void __iomem *)(vaddr + offset);
}
+
+#ifndef ioremap_prot
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+ unsigned long prot)
+{
+ return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
+}
EXPORT_SYMBOL(ioremap_prot);
+#endif

-void iounmap(volatile void __iomem *addr)
+void generic_iounmap(volatile void __iomem *addr)
{
void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);

@@ -58,4 +65,11 @@ void iounmap(volatile void __iomem *addr)
if (is_vmalloc_addr(vaddr))
vunmap(vaddr);
}
+
+#ifndef iounmap
+void iounmap(volatile void __iomem *addr)
+{
+ generic_iounmap(addr);
+}
EXPORT_SYMBOL(iounmap);
+#endif
--
2.37.1


2022-10-16 08:31:10

by Alexander Gordeev

[permalink] [raw]
Subject: Re: [RFC PATCH 3/8] mm/ioremap: Define generic_ioremap_prot() and generic_iounmap()

On Wed, Oct 12, 2022 at 12:09:39PM +0200, Christophe Leroy wrote:
> Define a generic version of ioremap_prot() and iounmap() that
> architectures can call after they have performed the necessary
> alteration to parameters and/or necessary verifications.
>
> Signed-off-by: Christophe Leroy <[email protected]>

[...]

> diff --git a/mm/ioremap.c b/mm/ioremap.c
> index 8652426282cc..9f34a8f90b58 100644
> --- a/mm/ioremap.c
> +++ b/mm/ioremap.c
> @@ -11,8 +11,8 @@
> #include <linux/io.h>
> #include <linux/export.h>
>
> -void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
> - unsigned long prot)
> +void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
> + pgprot_t prot)
> {
> unsigned long offset, vaddr;
> phys_addr_t last_addr;
> @@ -28,7 +28,7 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
> phys_addr -= offset;
> size = PAGE_ALIGN(size + offset);
>
> - if (!ioremap_allowed(phys_addr, size, prot))
> + if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
> return NULL;

It seems to me ioremap_allowed() is not needed anymore.
Whatever is checked here would move to architecture-
specific implementation.

> area = get_vm_area_caller(size, VM_IOREMAP,
> @@ -38,17 +38,24 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
> vaddr = (unsigned long)area->addr;
> area->phys_addr = phys_addr;
>
> - if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
> - __pgprot(prot))) {
> + if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
> free_vm_area(area);
> return NULL;
> }
>
> return (void __iomem *)(vaddr + offset);
> }
> +
> +#ifndef ioremap_prot

I guess, this is also needed:

#define ioremap_prot ioremap_prot

> +void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
> + unsigned long prot)
> +{
> + return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
> +}
> EXPORT_SYMBOL(ioremap_prot);
> +#endif
>
> -void iounmap(volatile void __iomem *addr)
> +void generic_iounmap(volatile void __iomem *addr)
> {
> void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
>
> @@ -58,4 +65,11 @@ void iounmap(volatile void __iomem *addr)
> if (is_vmalloc_addr(vaddr))
> vunmap(vaddr);
> }
> +
> +#ifndef iounmap

Same here.

> +void iounmap(volatile void __iomem *addr)
> +{
> + generic_iounmap(addr);
> +}
> EXPORT_SYMBOL(iounmap);
> +#endif

2022-10-16 17:00:23

by Christophe Leroy

[permalink] [raw]
Subject: Re: [RFC PATCH 3/8] mm/ioremap: Define generic_ioremap_prot() and generic_iounmap()



Le 16/10/2022 à 10:14, Alexander Gordeev a écrit :
> On Wed, Oct 12, 2022 at 12:09:39PM +0200, Christophe Leroy wrote:
>> Define a generic version of ioremap_prot() and iounmap() that
>> architectures can call after they have performed the necessary
>> alteration to parameters and/or necessary verifications.
>>
>> Signed-off-by: Christophe Leroy <[email protected]>
>
> [...]
>
>> diff --git a/mm/ioremap.c b/mm/ioremap.c
>> index 8652426282cc..9f34a8f90b58 100644
>> --- a/mm/ioremap.c
>> +++ b/mm/ioremap.c
>> @@ -11,8 +11,8 @@
>> #include <linux/io.h>
>> #include <linux/export.h>
>>
>> -void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
>> - unsigned long prot)
>> +void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
>> + pgprot_t prot)
>> {
>> unsigned long offset, vaddr;
>> phys_addr_t last_addr;
>> @@ -28,7 +28,7 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
>> phys_addr -= offset;
>> size = PAGE_ALIGN(size + offset);
>>
>> - if (!ioremap_allowed(phys_addr, size, prot))
>> + if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
>> return NULL;
>
> It seems to me ioremap_allowed() is not needed anymore.
> Whatever is checked here would move to architecture-
> specific implementation.

Yes can probably be removed as a follow-up. I didn't want to change
existing implementations at the first place, and see what it looks like
once all architectures have been looked at.

>
>> area = get_vm_area_caller(size, VM_IOREMAP,
>> @@ -38,17 +38,24 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
>> vaddr = (unsigned long)area->addr;
>> area->phys_addr = phys_addr;
>>
>> - if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
>> - __pgprot(prot))) {
>> + if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
>> free_vm_area(area);
>> return NULL;
>> }
>>
>> return (void __iomem *)(vaddr + offset);
>> }
>> +
>> +#ifndef ioremap_prot
>
> I guess, this is also needed:
>
> #define ioremap_prot ioremap_prot

Why would it need that ? We are in ioremap.c, any define done here is
exclusively seen here in this C file. It's not like a header file.

>
>> +void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
>> + unsigned long prot)
>> +{
>> + return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
>> +}
>> EXPORT_SYMBOL(ioremap_prot);
>> +#endif
>>
>> -void iounmap(volatile void __iomem *addr)
>> +void generic_iounmap(volatile void __iomem *addr)
>> {
>> void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
>>
>> @@ -58,4 +65,11 @@ void iounmap(volatile void __iomem *addr)
>> if (is_vmalloc_addr(vaddr))
>> vunmap(vaddr);
>> }
>> +
>> +#ifndef iounmap
>
> Same here.

Same, I don't see what it would add.

>
>> +void iounmap(volatile void __iomem *addr)
>> +{
>> + generic_iounmap(addr);
>> +}
>> EXPORT_SYMBOL(iounmap);
>> +#endif