treewide: Add a function to change page permissions

For armv8 we are adding proper page permissions for the relocated U-Boot
binary. Add a weak function that can be used across architectures to change
the page permissions

Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on AML-S905X-CC
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

4 files changed, 43 insertions, 0 deletions

diff --git a/arch/arm/cpu/arm926ejs/cache.c b/arch/arm/cpu/arm926ejs/cache.c
index 5b87a3af91b..71b8ad0f71d 100644
--- a/arch/arm/cpu/arm926ejs/cache.c
+++ b/arch/arm/cpu/arm926ejs/cache.c
@@ -5,6 +5,7 @@
  */
 #include <cpu_func.h>
 #include <asm/cache.h>
+#include <linux/errno.h>
 #include <linux/types.h>
 
 #if !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
@@ -88,3 +89,8 @@ void enable_caches(void)
 	dcache_enable();
 #endif
 }
+
+int __weak pgprot_set_attrs(phys_addr_t addr, size_t size, enum pgprot_attrs perm)
+{
+	return -ENOSYS;
+}
diff --git a/arch/arm/cpu/armv7/cache_v7.c b/arch/arm/cpu/armv7/cache_v7.c
index d11420d2fdd..371dc92cd46 100644
--- a/arch/arm/cpu/armv7/cache_v7.c
+++ b/arch/arm/cpu/armv7/cache_v7.c
@@ -6,6 +6,7 @@
  */
 #include <cpu_func.h>
 #include <asm/cache.h>
+#include <linux/errno.h>
 #include <linux/types.h>
 #include <asm/armv7.h>
 #include <asm/utils.h>
@@ -209,3 +210,8 @@ __weak void v7_outer_cache_flush_all(void) {}
 __weak void v7_outer_cache_inval_all(void) {}
 __weak void v7_outer_cache_flush_range(u32 start, u32 end) {}
 __weak void v7_outer_cache_inval_range(u32 start, u32 end) {}
+
+int __weak pgprot_set_attrs(phys_addr_t addr, size_t size, enum pgprot_attrs perm)
+{
+	return -ENOSYS;
+}
diff --git a/arch/arm/cpu/armv7m/cache.c b/arch/arm/cpu/armv7m/cache.c
index b6d08b7aad7..8e7db734055 100644
--- a/arch/arm/cpu/armv7m/cache.c
+++ b/arch/arm/cpu/armv7m/cache.c
@@ -11,6 +11,7 @@
 #include <asm/cache.h>
 #include <asm/io.h>
 #include <linux/bitops.h>
+#include <linux/errno.h>
 
 /* Cache maintenance operation registers */
 
@@ -370,3 +371,8 @@ void enable_caches(void)
 	dcache_enable();
 #endif
 }
+
+int __weak pgprot_set_attrs(phys_addr_t addr, size_t size, enum pgprot_attrs perm)
+{
+	return -ENOSYS;
+}
diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
index c9948e99e2e..12ae9bd0603 100644
--- a/arch/arm/cpu/armv8/cache_v8.c
+++ b/arch/arm/cpu/armv8/cache_v8.c
@@ -14,6 +14,7 @@
 #include <asm/global_data.h>
 #include <asm/system.h>
 #include <asm/armv8/mmu.h>
+#include <linux/errno.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -1032,6 +1033,30 @@ void mmu_change_region_attr(phys_addr_t addr, size_t siz, u64 attrs)
 	mmu_change_region_attr_nobreak(addr, siz, attrs);
 }
 
+int pgprot_set_attrs(phys_addr_t addr, size_t size, enum pgprot_attrs perm)
+{
+	u64 attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) | PTE_BLOCK_INNER_SHARE | PTE_TYPE_VALID;
+
+	switch (perm) {
+	case MMU_ATTR_RO:
+		attrs |= PTE_BLOCK_PXN | PTE_BLOCK_UXN | PTE_BLOCK_RO;
+		break;
+	case MMU_ATTR_RX:
+		attrs |= PTE_BLOCK_RO;
+		break;
+	case MMU_ATTR_RW:
+		attrs |= PTE_BLOCK_PXN | PTE_BLOCK_UXN;
+		break;
+	default:
+		log_err("Unknown attribute %d\n", perm);
+		return -EINVAL;
+	}
+
+	mmu_change_region_attr_nobreak(addr, size, attrs);
+
+	return 0;
+}
+
 #else	/* !CONFIG_IS_ENABLED(SYS_DCACHE_OFF) */
 
 /*