xtensa: mmu: Flush cache when altering pages

When the target has a cache way size (cache size / cache wasy) bigger
than the page size we have cache aliasing, since the number of bits
required by the cache index is bigger than the number of bits in the page
offset.

To avoid this problem we flush the whole cache on context switch or when
the current page table is changed.

Signed-off-by: Flavio Ceolin <[email protected]>

arch/xtensa/core/xtensa_mmu.c

@@ -244,8 +244,7 @@ static inline uint32_t *alloc_l2_table(void)
 static ALWAYS_INLINE void switch_page_tables(uint32_t *ptables, bool dtlb_inv, bool cache_inv)
 {
 	if (cache_inv) {
-		sys_cache_data_invd_range((void *)ptables, XTENSA_L1_PAGE_TABLE_SIZE);
-		sys_cache_data_invd_range((void *)l2_page_tables, sizeof(l2_page_tables));
+		sys_cache_data_flush_and_invd_all();
 	}
 
 	/* Invalidate data TLB to L1 page table */
@@ -683,6 +682,7 @@ void arch_mem_map(void *virt, uintptr_t phys, size_t size, uint32_t flags)
 	z_xtensa_mmu_tlb_ipi();
 #endif
 
+	sys_cache_data_flush_and_invd_all();
 	k_spin_unlock(&xtensa_mmu_lock, key);
 }
 
@@ -819,6 +819,7 @@ void arch_mem_unmap(void *addr, size_t size)
 	z_xtensa_mmu_tlb_ipi();
 #endif
 
+	sys_cache_data_flush_and_invd_all();
 	k_spin_unlock(&xtensa_mmu_lock, key);
 }
 
@@ -872,7 +873,7 @@ void z_xtensa_mmu_tlb_shootdown(void)
 			 * indicated by the current thread are different
 			 * than the current mapped page table.
 			 */
-			switch_page_tables((uint32_t *)thread_ptables, false, false);
+			switch_page_tables((uint32_t *)thread_ptables, true, true);
 		}
 
 	}
@@ -1053,6 +1054,7 @@ static inline int update_region(uint32_t *ptables, uintptr_t start,
 	}
 #endif
 
+	sys_cache_data_flush_and_invd_all();
 	k_spin_unlock(&xtensa_mmu_lock, key);
 
 	return ret;