Report errata workaround status to console

The errata reporting policy is as follows:

  - If an errata workaround is enabled:

    - If it applies (i.e. the CPU is affected by the errata), an INFO
      message is printed, confirming that the errata workaround has been
      applied.

    - If it does not apply, a VERBOSE message is printed, confirming
      that the errata workaround has been skipped.

  - If an errata workaround is not enabled, but would have applied had
    it been, a WARN message is printed, alerting that errata workaround
    is missing.

The CPU errata messages are printed by both BL1 (primary CPU only) and
runtime firmware on debug builds, once for each CPU/errata combination.

Relevant output from Juno r1 console when ARM Trusted Firmware is built
with PLAT=juno LOG_LEVEL=50 DEBUG=1:

  VERBOSE: BL1: cortex_a57: errata workaround for 806969 was not applied
  VERBOSE: BL1: cortex_a57: errata workaround for 813420 was not applied
  INFO:    BL1: cortex_a57: errata workaround for disable_ldnp_overread was applied
  WARNING: BL1: cortex_a57: errata workaround for 826974 was missing!
  WARNING: BL1: cortex_a57: errata workaround for 826977 was missing!
  WARNING: BL1: cortex_a57: errata workaround for 828024 was missing!
  WARNING: BL1: cortex_a57: errata workaround for 829520 was missing!
  WARNING: BL1: cortex_a57: errata workaround for 833471 was missing!
  ...
  VERBOSE: BL31: cortex_a57: errata workaround for 806969 was not applied
  VERBOSE: BL31: cortex_a57: errata workaround for 813420 was not applied
  INFO:    BL31: cortex_a57: errata workaround for disable_ldnp_overread was applied
  WARNING: BL31: cortex_a57: errata workaround for 826974 was missing!
  WARNING: BL31: cortex_a57: errata workaround for 826977 was missing!
  WARNING: BL31: cortex_a57: errata workaround for 828024 was missing!
  WARNING: BL31: cortex_a57: errata workaround for 829520 was missing!
  WARNING: BL31: cortex_a57: errata workaround for 833471 was missing!
  ...
  VERBOSE: BL31: cortex_a53: errata workaround for 826319 was not applied
  INFO:    BL31: cortex_a53: errata workaround for disable_non_temporal_hint was applied

Also update documentation.

Change-Id: Iccf059d3348adb876ca121cdf5207bdbbacf2aba
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

4 files changed, 262 insertions, 3 deletions

diff --git a/include/lib/aarch64/arch.h b/include/lib/aarch64/arch.h
index 989667a7..3f718248 100644
--- a/include/lib/aarch64/arch.h
+++ b/include/lib/aarch64/arch.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2017, 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:
@@ -39,8 +39,10 @@
 #define MIDR_IMPL_SHIFT		0x18
 #define MIDR_VAR_SHIFT		20
 #define MIDR_VAR_BITS		4
+#define MIDR_VAR_MASK		0xf
 #define MIDR_REV_SHIFT		0
 #define MIDR_REV_BITS		4
+#define MIDR_REV_MASK		0xf
 #define MIDR_PN_MASK		0xfff
 #define MIDR_PN_SHIFT		0x4
 
diff --git a/include/lib/cpus/aarch32/cpu_macros.S b/include/lib/cpus/aarch32/cpu_macros.S
index 64df2366..bf16e180 100644
--- a/include/lib/cpus/aarch32/cpu_macros.S
+++ b/include/lib/cpus/aarch32/cpu_macros.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2017, 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:
@@ -31,6 +31,7 @@
 #define __CPU_MACROS_S__
 
 #include <arch.h>
+#include <errata_report.h>
 
 #define CPU_IMPL_PN_MASK	(MIDR_IMPL_MASK << MIDR_IMPL_SHIFT) | \
 				(MIDR_PN_MASK << MIDR_PN_SHIFT)
@@ -44,6 +45,16 @@
 /* Word size for 32-bit CPUs */
 #define CPU_WORD_SIZE			4
 
+/*
+ * Whether errata status needs reporting. Errata status is printed in debug
+ * builds for both BL1 and BL32 images.
+ */
+#if (defined(IMAGE_BL1) || defined(IMAGE_BL32)) && DEBUG
+# define REPORT_ERRATA	1
+#else
+# define REPORT_ERRATA	0
+#endif
+
 	/*
 	 * Define the offsets to the fields in cpu_ops structure.
 	 */
@@ -59,6 +70,22 @@ CPU_RESET_FUNC: /* cpu_ops reset_func */
 CPU_PWR_DWN_OPS: /* cpu_ops power down functions */
 	.space  (4 * CPU_MAX_PWR_DWN_OPS)
 #endif
+
+/*
+ * Fields required to print errata status. Only in BL32 that the printing
+ * require mutual exclusion and printed flag.
+ */
+#if REPORT_ERRATA
+CPU_ERRATA_FUNC: /* CPU errata status printing function */
+	.space  4
+#ifdef IMAGE_BL32
+CPU_ERRATA_LOCK:
+	.space	4
+CPU_ERRATA_PRINTED:
+	.space	4
+#endif
+#endif
+
 CPU_OPS_SIZE = .
 
 	/*
@@ -137,6 +164,79 @@ CPU_OPS_SIZE = .
 	  .endif
 	.endif
 #endif
+
+#if REPORT_ERRATA
+	.ifndef \_name\()_cpu_str
+	  /*
+	   * Place errata reported flag, and the spinlock to arbitrate access to
+	   * it in the data section.
+	   */
+	  .pushsection .data
+	  define_asm_spinlock \_name\()_errata_lock
+	  \_name\()_errata_reported:
+	  .word	0
+	  .popsection
+
+	  /* Place CPU string in rodata */
+	  .pushsection .rodata
+	  \_name\()_cpu_str:
+	  .asciz "\_name"
+	  .popsection
+	.endif
+
+	/*
+	 * Weakly-bound, optional errata status printing function for CPUs of
+	 * this class.
+	 */
+	.weak \_name\()_errata_report
+	.word \_name\()_errata_report
+
+#ifdef IMAGE_BL32
+	/* Pointers to errata lock and reported flag */
+	.word \_name\()_errata_lock
+	.word \_name\()_errata_reported
+#endif
+#endif
+	.endm
+
+#if REPORT_ERRATA
+	/*
+	 * Print status of a CPU errata
+	 *
+	 * _chosen:
+	 *	Identifier indicating whether or not a CPU errata has been
+	 *	compiled in.
+	 * _cpu:
+	 *	Name of the CPU
+	 * _id:
+	 *	Errata identifier
+	 * _rev_var:
+	 *	Register containing the combined value CPU revision and variant
+	 *	- typically the return value of cpu_get_rev_var
+	 */
+	.macro report_errata _chosen, _cpu, _id, _rev_var=r4
+	/* Stash a string with errata ID */
+	.pushsection .rodata
+	\_cpu\()_errata_\_id\()_str:
+	.asciz	"\_id"
+	.popsection
+
+	/* Check whether errata applies */
+	mov	r0, \_rev_var
+	bl	check_errata_\_id
+
+	.ifeq \_chosen
+	/*
+	 * Errata workaround has not been compiled in. If the errata would have
+	 * applied had it been compiled in, print its status as missing.
+	 */
+	cmp	r0, #0
+	movne	r0, #ERRATA_MISSING
+	.endif
+	ldr	r1, =\_cpu\()_cpu_str
+	ldr	r2, =\_cpu\()_errata_\_id\()_str
+	bl	errata_print_msg
 	.endm
+#endif
 
 #endif /* __CPU_MACROS_S__ */
diff --git a/include/lib/cpus/aarch64/cpu_macros.S b/include/lib/cpus/aarch64/cpu_macros.S
index 5012877e..e3b4afdc 100644
--- a/include/lib/cpus/aarch64/cpu_macros.S
+++ b/include/lib/cpus/aarch64/cpu_macros.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2017, 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:
@@ -31,6 +31,7 @@
 #define __CPU_MACROS_S__
 
 #include <arch.h>
+#include <errata_report.h>
 
 #define CPU_IMPL_PN_MASK	(MIDR_IMPL_MASK << MIDR_IMPL_SHIFT) | \
 				(MIDR_PN_MASK << MIDR_PN_SHIFT)
@@ -44,6 +45,16 @@
 /* Word size for 64-bit CPUs */
 #define CPU_WORD_SIZE			8
 
+/*
+ * Whether errata status needs reporting. Errata status is printed in debug
+ * builds for both BL1 and BL31 images.
+ */
+#if (defined(IMAGE_BL1) || defined(IMAGE_BL31)) && DEBUG
+# define REPORT_ERRATA	1
+#else
+# define REPORT_ERRATA	0
+#endif
+
 	/*
 	 * Define the offsets to the fields in cpu_ops structure.
 	 */
@@ -59,6 +70,22 @@ CPU_RESET_FUNC: /* cpu_ops reset_func */
 CPU_PWR_DWN_OPS: /* cpu_ops power down functions */
 	.space  (8 * CPU_MAX_PWR_DWN_OPS)
 #endif
+
+/*
+ * Fields required to print errata status. Only in BL31 that the printing
+ * require mutual exclusion and printed flag.
+ */
+#if REPORT_ERRATA
+CPU_ERRATA_FUNC:
+	.space	8
+#ifdef IMAGE_BL31
+CPU_ERRATA_LOCK:
+	.space	8
+CPU_ERRATA_PRINTED:
+	.space	8
+#endif
+#endif
+
 #if defined(IMAGE_BL31) && CRASH_REPORTING
 CPU_REG_DUMP: /* cpu specific register dump for crash reporting */
 	.space  8
@@ -141,9 +168,84 @@ CPU_OPS_SIZE = .
 	  .endif
 	.endif
 #endif
+
+#if REPORT_ERRATA
+	.ifndef \_name\()_cpu_str
+	  /*
+	   * Place errata reported flag, and the spinlock to arbitrate access to
+	   * it in the data section.
+	   */
+	  .pushsection .data
+	  define_asm_spinlock \_name\()_errata_lock
+	  \_name\()_errata_reported:
+	  .word	0
+	  .popsection
+
+	  /* Place CPU string in rodata */
+	  .pushsection .rodata
+	  \_name\()_cpu_str:
+	  .asciz "\_name"
+	  .popsection
+	.endif
+
+	/*
+	 * Weakly-bound, optional errata status printing function for CPUs of
+	 * this class.
+	 */
+	.weak \_name\()_errata_report
+	.quad \_name\()_errata_report
+
+#ifdef IMAGE_BL31
+	/* Pointers to errata lock and reported flag */
+	.quad \_name\()_errata_lock
+	.quad \_name\()_errata_reported
+#endif
+#endif
+
 #if defined(IMAGE_BL31) && CRASH_REPORTING
 	.quad \_name\()_cpu_reg_dump
 #endif
 	.endm
 
+#if REPORT_ERRATA
+	/*
+	 * Print status of a CPU errata
+	 *
+	 * _chosen:
+	 *	Identifier indicating whether or not a CPU errata has been
+	 *	compiled in.
+	 * _cpu:
+	 *	Name of the CPU
+	 * _id:
+	 *	Errata identifier
+	 * _rev_var:
+	 *	Register containing the combined value CPU revision and variant
+	 *	- typically the return value of cpu_get_rev_var
+	 */
+	.macro report_errata _chosen, _cpu, _id, _rev_var=x8
+	/* Stash a string with errata ID */
+	.pushsection .rodata
+	\_cpu\()_errata_\_id\()_str:
+	.asciz	"\_id"
+	.popsection
+
+	/* Check whether errata applies */
+	mov	x0, \_rev_var
+	bl	check_errata_\_id
+
+	.ifeq \_chosen
+	/*
+	 * Errata workaround has not been compiled in. If the errata would have
+	 * applied had it been compiled in, print its status as missing.
+	 */
+	cbz	x0, 900f
+	mov	x0, #ERRATA_MISSING
+	.endif
+900:
+	adr	x1, \_cpu\()_cpu_str
+	adr	x2, \_cpu\()_errata_\_id\()_str
+	bl	errata_print_msg
+	.endm
+#endif
+
 #endif /* __CPU_MACROS_S__ */
diff --git a/include/lib/cpus/errata_report.h b/include/lib/cpus/errata_report.h
new file mode 100644
index 00000000..6c6a844d
--- /dev/null
+++ b/include/lib/cpus/errata_report.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2017, 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.
+ */
+
+#ifndef __ERRATA_H__
+#define __ERRATA_H__
+
+#ifndef __ASSEMBLY__
+
+#include <arch.h>
+#include <arch_helpers.h>
+#include <spinlock.h>
+#include <utils.h>
+
+#if DEBUG
+void print_errata_status(void);
+#else
+static inline void print_errata_status(void) {}
+#endif
+
+#endif /* __ASSEMBLY__ */
+
+/* Errata status */
+#define ERRATA_NOT_APPLIES	0
+#define ERRATA_APPLIES		1
+#define ERRATA_MISSING		2
+
+#endif /* __ERRATA_H__ */
+