xlat v2: Split MMU setup and enable
At present, the function provided by the translation library to enable
MMU constructs appropriate values for translation library, and programs
them to the right registers. The construction of initial values,
however, is only required once as both the primary and secondaries
program the same values.
Additionally, the MMU-enabling function is written in C, which means
there's an active stack at the time of enabling MMU. On some systems,
like Arm DynamIQ, having active stack while enabling MMU during warm
boot might lead to coherency problems.
This patch addresses both the above problems by:
- Splitting the MMU-enabling function into two: one that sets up
values to be programmed into the registers, and another one that
takes the pre-computed values and writes to the appropriate
registers. With this, the primary effectively calls both functions
to have the MMU enabled, but secondaries only need to call the
latter.
- Rewriting the function that enables MMU in assembly so that it
doesn't use stack.
This patch fixes a bunch of MISRA issues on the way.
Change-Id: I0faca97263a970ffe765f0e731a1417e43fbfc45
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/include/lib/xlat_tables/xlat_tables_v2_helpers.h b/include/lib/xlat_tables/xlat_tables_v2_helpers.h
index de1c2d4..e1ea2b6 100644
--- a/include/lib/xlat_tables/xlat_tables_v2_helpers.h
+++ b/include/lib/xlat_tables/xlat_tables_v2_helpers.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -16,6 +16,13 @@
#error "Do not include this header file directly. Include xlat_tables_v2.h instead."
#endif
+/* Offsets into mmu_cfg_params array. All parameters are 32 bits wide. */
+#define MMU_CFG_MAIR0 0
+#define MMU_CFG_TCR 1
+#define MMU_CFG_TTBR0_LO 2
+#define MMU_CFG_TTBR0_HI 3
+#define MMU_CFG_PARAM_MAX 4
+
#ifndef __ASSEMBLY__
#include <cassert.h>
@@ -24,6 +31,9 @@
#include <xlat_tables_arch.h>
#include <xlat_tables_defs.h>
+/* Parameters of register values required when enabling MMU */
+extern uint32_t mmu_cfg_params[MMU_CFG_PARAM_MAX];
+
/* Forward declaration */
struct mmap_region;
@@ -162,6 +172,8 @@
.initialized = 0, \
}
+#endif /*__ASSEMBLY__*/
+
#if AARCH64
/*
@@ -187,6 +199,4 @@
#endif /* AARCH64 */
-#endif /*__ASSEMBLY__*/
-
#endif /* __XLAT_TABLES_V2_HELPERS_H__ */