arm64: mmu_change_region_attr() add an option not to break PTEs

The ARM ARM (Rev L.a) on section 8.17.1 describes the cases where
break-before-make is required when changing live page tables.
Since we can use a function to tweak block and page permissions,
where BBM is not required split the existing mmu_change_region_attr()
into two functions and create one that doesn't require BBM. Subsequent
patches will use the new function to map the U-Boot binary with proper
page permissions.
While at it add function descriptions in their header files.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 091082281c7..849b3d0efb7 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -303,8 +303,26 @@ void flush_l3_cache(void);
  * @emerg: Also map the region in the emergency table
  */
 void mmu_map_region(phys_addr_t start, u64 size, bool emerg);
+
+/**
+ * mmu_change_region_attr() - change a mapped region attributes
+ *
+ * @start: Start address of the region
+ * @size:  Size of the region
+ * @aatrs: New attributes
+ */
 void mmu_change_region_attr(phys_addr_t start, size_t size, u64 attrs);
 
+/**
+ * mmu_change_region_attr_nobreak() - change a mapped region attributes without doing
+ *                                    break-before-make
+ *
+ * @start: Start address of the region
+ * @size:  Size of the region
+ * @aatrs: New attributes
+ */
+void mmu_change_region_attr_nobreak(phys_addr_t addr, size_t size, u64 attrs);
+
 /*
  * smc_call() - issue a secure monitor call
  *