mm: introduce update memory flags api

There are cases when attributes of mapped virtual memory need
to be updated. E.g. in case there is loadable library/module
code loaded to the l2 memory then memory needs to be read-write.
After the code is loaded and is ready to be executed then
attributes of mapped memory should be updated to
read-only/executable without loosing memory contents.

Signed-off-by: Jaroslaw Stelter <Jaroslaw.Stelter@intel.com>

drivers/mm/mm_drv_common.c

@@ -434,3 +434,38 @@ out:
 
 __weak FUNC_ALIAS(sys_mm_drv_simple_move_array,
 		  sys_mm_drv_move_array, int);
+
+int sys_mm_drv_simple_update_region_flags(void *virt, size_t size, uint32_t flags)
+{
+	k_spinlock_key_t key;
+	int ret = 0;
+	size_t offset;
+
+	CHECKIF(!sys_mm_drv_is_virt_addr_aligned(virt) ||
+		!sys_mm_drv_is_size_aligned(size)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	key = k_spin_lock(&sys_mm_drv_common_lock);
+
+	for (offset = 0; offset < size; offset += CONFIG_MM_DRV_PAGE_SIZE) {
+		uint8_t *va = (uint8_t *)virt + offset;
+
+		int ret2 = sys_mm_drv_update_page_flags(va, flags);
+
+		if (ret2 != 0) {
+			__ASSERT(false, "cannot update flags %p\n", va);
+
+			ret = ret2;
+		}
+	}
+
+	k_spin_unlock(&sys_mm_drv_common_lock, key);
+
+out:
+	return ret;
+}
+
+__weak FUNC_ALIAS(sys_mm_drv_simple_update_region_flags,
+		  sys_mm_drv_update_region_flags, int);

drivers/mm/mm_drv_common.h

@@ -270,4 +270,27 @@ int sys_mm_drv_simple_move_array(void *virt_old, size_t size,
 				 void *virt_new,
 				 uintptr_t *phys_new, size_t phys_cnt);
 
+/**
+ * @brief Update memory region flags
+ *
+ * This changes the attributes of physical memory which is already
+ * mapped to a virtual address. This is useful when use case of
+ * specific memory region  changes.
+ * E.g. when the library/module code is copied to the memory then
+ * it needs to be read-write and after it has already
+ * been copied and library/module code is ready to be executed then
+ * attributes need to be changed to read-only/executable.
+ * Calling this API must not cause losing memory contents.
+ *
+ * @param virt Page-aligned virtual address to be updated
+ * @param size Page-aligned size of the mapped memory region in bytes
+ * @param flags Caching, access and control flags, see SYS_MM_MEM_* macros
+ *
+ * @retval 0 if successful
+ * @retval -EINVAL if invalid arguments are provided
+ * @retval -EFAULT if virtual addresses is not mapped
+ */
+
+int sys_mm_drv_simple_update_region_flags(void *virt, size_t size, uint32_t flags);
+
 #endif /* ZEPHYR_DRIVERS_SYSTEM_MM_DRV_COMMON_H_ */

drivers/mm/mm_drv_intel_adsp_tlb.c

@@ -261,6 +261,28 @@ int sys_mm_drv_page_flag_get(void *virt, uint32_t *flags)
 	return 0;
 }
 
+int sys_mm_drv_update_page_flags(void *virt, uint32_t flags)
+{
+	ARG_UNUSED(virt);
+	ARG_UNUSED(flags);
+
+	/*
+	 * There are no caching mode, or R/W, or eXecution (etc.) bits.
+	 * So just return 0.
+	 */
+
+	return 0;
+}
+
+int sys_mm_drv_update_region_flags(void *virt, size_t size,
+				   uint32_t flags)
+{
+	void *va = z_soc_cached_ptr(virt);
+
+	return sys_mm_drv_simple_update_region_flags(va, size, flags);
+}
+
+
 int sys_mm_drv_remap_region(void *virt_old, size_t size,
 			    void *virt_new)
 {