bsps/arm: Add support for small pages MMU

The small page MMU support reduces the granularity for memory settings
through the MMU from 1MiB sections to 4KiB small pages.

Enable it by default on the realview_pbx_a9_qemu BSP.

1 files changed, 48 insertions, 9 deletions

diff --git a/bsps/arm/include/bsp/arm-cp15-start.h b/bsps/arm/include/bsp/arm-cp15-start.h
index a749f7dc98..220423fefe 100644
--- a/bsps/arm/include/bsp/arm-cp15-start.h
+++ b/bsps/arm/include/bsp/arm-cp15-start.h
@@ -9,7 +9,7 @@
 
 /*
  * Copyright (c) 2013 Hesham AL-Matary.
- * Copyright (c) 2009-2014 embedded brains GmbH.  All rights reserved.
+ * Copyright (c) 2009-2019 embedded brains GmbH.  All rights reserved.
  *
  *  embedded brains GmbH
  *  Dornierstr. 4
@@ -28,6 +28,7 @@
 #include <libcpu/arm-cp15.h>
 #include <bsp/start.h>
 #include <bsp/linker-symbols.h>
+#include <bspopts.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -106,16 +107,35 @@ arm_cp15_start_set_translation_table_entries(
   const arm_cp15_start_section_config *config
 )
 {
-  uint32_t i = ARM_MMU_SECT_GET_INDEX(config->begin);
-  uint32_t iend =
-    ARM_MMU_SECT_GET_INDEX(ARM_MMU_SECT_MVA_ALIGN_UP(config->end));
-  uint32_t index_mask = (1U << (32 - ARM_MMU_SECT_BASE_SHIFT)) - 1U;
-
   if (config->begin != config->end) {
+    uint32_t i;
+    uint32_t iend;
+    uint32_t index_mask;
+    uint32_t flags;
+#ifdef ARM_MMU_USE_SMALL_PAGES
+    uint32_t *pt;
+
+    pt = &ttb[ARM_MMU_TRANSLATION_TABLE_ENTRY_COUNT];
+    i = ARM_MMU_SMALL_PAGE_GET_INDEX(config->begin);
+    iend = ARM_MMU_SMALL_PAGE_GET_INDEX(ARM_MMU_SECT_MVA_ALIGN_UP(config->end));
+    index_mask = (1U << (32 - ARM_MMU_SMALL_PAGE_BASE_SHIFT)) - 1U;
+    flags = ARM_MMU_SECT_FLAGS_TO_SMALL_PAGE(config->flags);
+
+    while (i != iend) {
+      pt[i] = (i << ARM_MMU_SMALL_PAGE_BASE_SHIFT) | flags;
+      i = (i + 1U) & index_mask;
+    }
+#else
+    i = ARM_MMU_SECT_GET_INDEX(config->begin);
+    iend = ARM_MMU_SECT_GET_INDEX(ARM_MMU_SECT_MVA_ALIGN_UP(config->end));
+    index_mask = (1U << (32 - ARM_MMU_SECT_BASE_SHIFT)) - 1U;
+    flags = config->flags;
+
     while (i != iend) {
-      ttb [i] = (i << ARM_MMU_SECT_BASE_SHIFT) | config->flags;
+      ttb[i] = (i << ARM_MMU_SECT_BASE_SHIFT) | flags;
       i = (i + 1U) & index_mask;
     }
+#endif
   }
 }
 
@@ -127,16 +147,35 @@ arm_cp15_start_setup_translation_table(
   size_t config_count
 )
 {
-  uint32_t dac = ARM_CP15_DAC_DOMAIN(client_domain, ARM_CP15_DAC_CLIENT);
+#ifdef ARM_MMU_USE_SMALL_PAGES
+  uint32_t *pt;
+#endif
+  uint32_t dac;
   size_t i;
 
+  dac = ARM_CP15_DAC_DOMAIN(client_domain, ARM_CP15_DAC_CLIENT);
   arm_cp15_set_domain_access_control(dac);
   arm_cp15_set_translation_table_base(ttb);
 
   /* Initialize translation table with invalid entries */
+#ifdef ARM_MMU_USE_SMALL_PAGES
+  pt = &ttb[ARM_MMU_TRANSLATION_TABLE_ENTRY_COUNT];
+  for (i = 0; i < ARM_MMU_TRANSLATION_TABLE_ENTRY_COUNT; ++i) {
+    size_t j;
+
+    for (j = 0; j < ARM_MMU_SMALL_PAGE_TABLE_ENTRY_COUNT; ++j) {
+      pt[j] = 0;
+    }
+
+    ttb[i] = (uint32_t) pt | (client_domain << ARM_MMU_SECT_DOMAIN_SHIFT)
+      | ARM_MMU_PAGE_TABLE_DEFAULT;
+    pt += ARM_MMU_SMALL_PAGE_TABLE_ENTRY_COUNT;
+  }
+#else
   for (i = 0; i < ARM_MMU_TRANSLATION_TABLE_ENTRY_COUNT; ++i) {
-    ttb [i] = 0;
+    ttb[i] = 0;
   }
+#endif
 
   for (i = 0; i < config_count; ++i) {
     arm_cp15_start_set_translation_table_entries(ttb, &config_table [i]);