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authorKefeng Wang <wangkefeng.wang@huawei.com>2022-06-07 15:50:25 +0300
committerWill Deacon <will@kernel.org>2022-06-27 14:22:31 +0300
commit18e780b4e6ab89a3a10f46d151971863562c1c91 (patch)
treeaf78abe8a479005ef769c60ac3d772d4a6afc014 /include/asm-generic
parenta14fff1c0379d0422c5ca0084b0ab86ed7bedf3e (diff)
downloadlinux-18e780b4e6ab89a3a10f46d151971863562c1c91.tar.xz
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 'include/asm-generic')
-rw-r--r--include/asm-generic/io.h26
1 files changed, 26 insertions, 0 deletions
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);