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authorKefeng Wang <wangkefeng.wang@huawei.com>2022-06-07 20:50:25 +0800
committerWill Deacon <will@kernel.org>2022-06-27 12:22:31 +0100
commit18e780b4e6ab89a3a10f46d151971863562c1c91 (patch)
treeaf78abe8a479005ef769c60ac3d772d4a6afc014 /mm/ioremap.c
parenta14fff1c0379d0422c5ca0084b0ab86ed7bedf3e (diff)
mm: ioremap: Add ioremap/iounmap_allowed()
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> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Baoquan He <bhe@redhat.com> Link: https://lore.kernel.org/r/20220607125027.44946-5-wangkefeng.wang@huawei.com Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'mm/ioremap.c')
-rw-r--r--mm/ioremap.c11
1 files changed, 10 insertions, 1 deletions
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);