| Message ID | 20220607125027.44946-5-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: Cleanup ioremap() and support ioremap_prot() | expand |
On 06/07/22 at 08:50pm, Kefeng Wang wrote: > Add special hook for architecture to verify addr, size or prot > when ioremap() or iounmap(), which will make the generic ioremap > more useful. > > ioremap_allowed() return a bool, > - true means continue to remap > - false means skip remap and return directly > iounmap_allowed() return a bool, > - true means continue to vunmap > - false code means skip vunmap and return directly > > Meanwhile, only vunmap the address when it is in vmalloc area > as the generic ioremap only returns vmalloc addresses. LGTM, Reviewed-by: Baoquan He <bhe@redhat.com> > > Acked-by: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > include/asm-generic/io.h | 26 ++++++++++++++++++++++++++ > mm/ioremap.c | 11 ++++++++++- > 2 files changed, 36 insertions(+), 1 deletion(-) > > diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h > index b76379628a02..db5b890eaff7 100644 > --- a/include/asm-generic/io.h > +++ b/include/asm-generic/io.h > @@ -964,6 +964,32 @@ static inline void iounmap(volatile void __iomem *addr) > #elif defined(CONFIG_GENERIC_IOREMAP) > #include <linux/pgtable.h> > > +/* > + * Arch code can implement the following two hooks when using GENERIC_IOREMAP > + * ioremap_allowed() return a bool, > + * - true means continue to remap > + * - false means skip remap and return directly > + * iounmap_allowed() return a bool, > + * - true means continue to vunmap > + * - false means skip vunmap and return directly > + */ > +#ifndef ioremap_allowed > +#define ioremap_allowed ioremap_allowed > +static inline bool ioremap_allowed(phys_addr_t phys_addr, size_t size, > + unsigned long prot) > +{ > + return true; > +} > +#endif > + > +#ifndef iounmap_allowed > +#define iounmap_allowed iounmap_allowed > +static inline bool iounmap_allowed(void *addr) > +{ > + return true; > +} > +#endif > + > void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size, > unsigned long prot); > void iounmap(volatile void __iomem *addr); > diff --git a/mm/ioremap.c b/mm/ioremap.c > index e1d008e8f87f..8652426282cc 100644 > --- a/mm/ioremap.c > +++ b/mm/ioremap.c > @@ -28,6 +28,9 @@ 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)) > + return NULL; > + > area = get_vm_area_caller(size, VM_IOREMAP, > __builtin_return_address(0)); > if (!area) > @@ -47,6 +50,12 @@ EXPORT_SYMBOL(ioremap_prot); > > void iounmap(volatile void __iomem *addr) > { > - vunmap((void *)((unsigned long)addr & PAGE_MASK)); > + void *vaddr = (void *)((unsigned long)addr & PAGE_MASK); > + > + if (!iounmap_allowed(vaddr)) > + return; > + > + if (is_vmalloc_addr(vaddr)) > + vunmap(vaddr); > } > EXPORT_SYMBOL(iounmap); > -- > 2.35.3 > >
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index b76379628a02..db5b890eaff7 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -964,6 +964,32 @@ static inline void iounmap(volatile void __iomem *addr) #elif defined(CONFIG_GENERIC_IOREMAP) #include <linux/pgtable.h> +/* + * Arch code can implement the following two hooks when using GENERIC_IOREMAP + * ioremap_allowed() return a bool, + * - true means continue to remap + * - false means skip remap and return directly + * iounmap_allowed() return a bool, + * - true means continue to vunmap + * - false means skip vunmap and return directly + */ +#ifndef ioremap_allowed +#define ioremap_allowed ioremap_allowed +static inline bool ioremap_allowed(phys_addr_t phys_addr, size_t size, + unsigned long prot) +{ + return true; +} +#endif + +#ifndef iounmap_allowed +#define iounmap_allowed iounmap_allowed +static inline bool iounmap_allowed(void *addr) +{ + return true; +} +#endif + void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size, unsigned long prot); void iounmap(volatile void __iomem *addr); diff --git a/mm/ioremap.c b/mm/ioremap.c index e1d008e8f87f..8652426282cc 100644 --- a/mm/ioremap.c +++ b/mm/ioremap.c @@ -28,6 +28,9 @@ 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)) + return NULL; + area = get_vm_area_caller(size, VM_IOREMAP, __builtin_return_address(0)); if (!area) @@ -47,6 +50,12 @@ EXPORT_SYMBOL(ioremap_prot); void iounmap(volatile void __iomem *addr) { - vunmap((void *)((unsigned long)addr & PAGE_MASK)); + void *vaddr = (void *)((unsigned long)addr & PAGE_MASK); + + if (!iounmap_allowed(vaddr)) + return; + + if (is_vmalloc_addr(vaddr)) + vunmap(vaddr); } EXPORT_SYMBOL(iounmap);
Add special hook for architecture to verify addr, size or prot when ioremap() or iounmap(), which will make the generic ioremap more useful. ioremap_allowed() return a bool, - true means continue to remap - false means skip remap and return directly iounmap_allowed() return a bool, - true means continue to vunmap - false code means skip vunmap and return directly Meanwhile, only vunmap the address when it is in vmalloc area as the generic ioremap only returns vmalloc addresses. Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- include/asm-generic/io.h | 26 ++++++++++++++++++++++++++ mm/ioremap.c | 11 ++++++++++- 2 files changed, 36 insertions(+), 1 deletion(-)