riscv: Introduce set_kernel_memory helper

This helper should be used for setting permissions to the kernel
mapping as it takes pointers as arguments and then avoids explicit cast
to unsigned long needed for the set_memory_* API.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
index 086f757e8ba3cc690517c29d38ef5624b881211a..135f726c4c1d9db6961da979b003ac1ed84b6dc9 100644 (file)
--- a/arch/riscv/include/asm/set_memory.h
+++ b/arch/riscv/include/asm/set_memory.h
@@ -17,6 +17,16 @@ int set_memory_x(unsigned long addr, int numpages);
 int set_memory_nx(unsigned long addr, int numpages);
 int set_memory_rw_nx(unsigned long addr, int numpages);
 void protect_kernel_text_data(void);
+static __always_inline int set_kernel_memory(char *startp, char *endp,
+                                            int (*set_memory)(unsigned long start,
+                                                              int num_pages))
+{
+       unsigned long start = (unsigned long)startp;
+       unsigned long end = (unsigned long)endp;
+       int num_pages = PAGE_ALIGN(end - start) >> PAGE_SHIFT;
+
+       return set_memory(start, num_pages);
+}
 #else
 static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; }
 static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; }
@@ -24,6 +34,12 @@ static inline int set_memory_x(unsigned long addr, int numpages) { return 0; }
 static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }
 static inline void protect_kernel_text_data(void) {}
 static inline int set_memory_rw_nx(unsigned long addr, int numpages) { return 0; }
+static inline int set_kernel_memory(char *startp, char *endp,
+                                   int (*set_memory)(unsigned long start,
+                                                     int num_pages))
+{
+       return 0;
+}
 #endif
 
 #if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)