Add support for selected Cortex-A57 errata workarounds

This patch adds workarounds for selected errata which affect the Cortex-A57 r0p0
part. Each workaround has a build time flag which should be used by the platform
port to enable or disable the corresponding workaround. The workarounds are
disabled by default. An assertion is raised if the platform enables a workaround
which does not match the CPU revision at runtime.

Change-Id: I9ae96b01c6ff733d04dc733bd4e67dbf77b29fb0

Makefile

@@ -138,6 +138,10 @@ msg_start:
 
 include plat/${PLAT}/platform.mk
 
+# By default all CPU errata workarounds are disabled. This can be
+# overridden by the platform.
+include lib/cpus/cpu-errata.mk
+
 ifdef BL1_SOURCES
 NEED_BL1 := yes
 include bl1/bl1.mk

include/lib/aarch64/arch.h

@@ -37,6 +37,8 @@
  ******************************************************************************/
 #define MIDR_IMPL_MASK		0xff
 #define MIDR_IMPL_SHIFT		0x18
+#define MIDR_VAR_SHIFT		20
+#define MIDR_REV_SHIFT		0
 #define MIDR_PN_MASK		0xfff
 #define MIDR_PN_SHIFT		0x4
 

include/lib/cpus/aarch64/cortex_a57.h

@@ -44,4 +44,12 @@
 #define CPUECTLR_L2_IPFTCH_DIST_MASK	(0x3 << 35)
 #define CPUECTLR_L2_DPFTCH_DIST_MASK	(0x3 << 32)
 
+/*******************************************************************************
+ * CPU Auxiliary Control register specific definitions.
+ ******************************************************************************/
+#define CPUACTLR_EL1			S3_1_C15_C2_0	/* Instruction def. */
+
+#define CPUACTLR_NO_ALLOC_WBWA         (1 << 49)
+#define CPUACTLR_DCC_AS_DCCI           (1 << 44)
+
 #endif /* __CORTEX_A57_H__ */

lib/cpus/aarch64/cortex_a57.S

@@ -29,6 +29,7 @@
  */
 #include <arch.h>
 #include <asm_macros.S>
+#include <assert_macros.S>
 #include <cortex_a57.h>
 #include <cpu_macros.S>
 #include <plat_macros.S>
@@ -81,6 +82,32 @@ func cortex_a57_disable_ext_debug
 	ret
 
 func cortex_a57_reset_func
+#if ERRATA_A57_806969 || ERRATA_A57_813420
+	/* ---------------------------------------------
+	 * Ensure that the following errata is only
+	 * applied on r0p0 parts.
+	 * ---------------------------------------------
+	 */
+#if ASM_ASSERTION
+	mrs	x0, midr_el1
+	ubfx	x1, x0, #MIDR_VAR_SHIFT, #4
+	ubfx	x2, x0, #MIDR_REV_SHIFT, #4
+	orr	x0, x1, x2
+	cmp	x0, #0
+	ASM_ASSERT(eq)
+#endif
+	mov	x1, xzr
+#if ERRATA_A57_806969
+	orr	x1, x1, #CPUACTLR_NO_ALLOC_WBWA
+#endif
+#if ERRATA_A57_813420
+	orr	x1, x1, #CPUACTLR_DCC_AS_DCCI
+#endif
+	mrs	x0, CPUACTLR_EL1
+	orr	x0, x0, x1
+	msr	CPUACTLR_EL1, x0
+#endif
+
 	/* ---------------------------------------------
 	 * As a bare minimum enable the SMP bit.
 	 * ---------------------------------------------

lib/cpus/cpu-errata.mk

@@ -0,0 +1,48 @@
+#
+# Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# Redistributions of source code must retain the above copyright notice, this
+# list of conditions and the following disclaimer.
+#
+# Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# Neither the name of ARM nor the names of its contributors may be used
+# to endorse or promote products derived from this software without specific
+# prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+
+# CPU Errata Build flags. These should be enabled by the
+# platform if the errata needs to be applied.
+
+# Flag to apply errata 806969 during reset. This errata applies only to
+# revision r0p0 of the Cortex A57 cpu.
+ERRATA_A57_806969	?=0
+
+# Flag to apply errata 813420 during reset. This errata applies only to
+# revision r0p0 of the Cortex A57 cpu.
+ERRATA_A57_813420	?=0
+
+# Process ERRATA_A57_806969 flag
+$(eval $(call assert_boolean,ERRATA_A57_806969))
+$(eval $(call add_define,ERRATA_A57_806969))
+
+# Process ERRATA_A57_813420 flag
+$(eval $(call assert_boolean,ERRATA_A57_813420))
+$(eval $(call add_define,ERRATA_A57_813420))