Print erratum application report for CVE-2017-5715

Even though the workaround for CVE-2017-5715 is not a CPU erratum, the
code is piggybacking on the errata framework to print whether the
workaround was applied, missing or not needed.

Change-Id: I821197a4b8560c73fd894cd7cd9ecf9503c72fa3
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

lib/cpus/aarch64/cortex_a57.S

 /*
- * Copyright (c) 2014-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -328,6 +328,15 @@ func check_errata_859972
 	b	cpu_rev_var_ls
 endfunc check_errata_859972
 
+func check_errata_cve_2017_5715
+#if WORKAROUND_CVE_2017_5715
+	mov	x0, #ERRATA_APPLIES
+#else
+	mov	x0, #ERRATA_MISSING
+#endif
+	ret
+endfunc check_errata_cve_2017_5715
+
 	/* -------------------------------------------------
 	 * The CPU Ops reset function for Cortex-A57.
 	 * Shall clobber: x0-x19
@@ -518,7 +527,7 @@ func cortex_a57_errata_report
 	report_errata ERRATA_A57_829520, cortex_a57, 829520
 	report_errata ERRATA_A57_833471, cortex_a57, 833471
 	report_errata ERRATA_A57_859972, cortex_a57, 859972
-
+	report_errata WORKAROUND_CVE_2017_5715, cortex_a57, cve_2017_5715
 
 	ldp	x8, x30, [sp], #16
 	ret

lib/cpus/aarch64/cortex_a72.S

 /*
- * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -97,6 +97,15 @@ func check_errata_859971
 	b	cpu_rev_var_ls
 endfunc check_errata_859971
 
+func check_errata_cve_2017_5715
+#if WORKAROUND_CVE_2017_5715
+	mov	x0, #ERRATA_APPLIES
+#else
+	mov	x0, #ERRATA_MISSING
+#endif
+	ret
+endfunc check_errata_cve_2017_5715
+
 	/* -------------------------------------------------
 	 * The CPU Ops reset function for Cortex-A72.
 	 * -------------------------------------------------
@@ -249,6 +258,7 @@ func cortex_a72_errata_report
 	 * checking functions of each errata.
 	 */
 	report_errata ERRATA_A72_859971, cortex_a72, 859971
+	report_errata WORKAROUND_CVE_2017_5715, cortex_a72, cve_2017_5715
 
 	ldp	x8, x30, [sp], #16
 	ret

lib/cpus/aarch64/cortex_a73.S

 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -114,6 +114,36 @@ func cortex_a73_cluster_pwr_dwn
 	b	cortex_a73_disable_smp
 endfunc cortex_a73_cluster_pwr_dwn
 
+func check_errata_cve_2017_5715
+#if WORKAROUND_CVE_2017_5715
+	mov	x0, #ERRATA_APPLIES
+#else
+	mov	x0, #ERRATA_MISSING
+#endif
+	ret
+endfunc check_errata_cve_2017_5715
+
+#if REPORT_ERRATA
+/*
+ * Errata printing function for Cortex A75. Must follow AAPCS.
+ */
+func cortex_a73_errata_report
+	stp	x8, x30, [sp, #-16]!
+
+	bl	cpu_get_rev_var
+	mov	x8, x0
+
+	/*
+	 * Report all errata. The revision-variant information is passed to
+	 * checking functions of each errata.
+	 */
+	report_errata WORKAROUND_CVE_2017_5715, cortex_a73, cve_2017_5715
+
+	ldp	x8, x30, [sp], #16
+	ret
+endfunc cortex_a73_errata_report
+#endif
+
 	/* ---------------------------------------------
 	 * This function provides cortex_a73 specific
 	 * register information for crash reporting.

lib/cpus/aarch64/cortex_a75.S

 /*
- * 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
  */
@@ -151,6 +151,27 @@ func cortex_a75_reset_func
 	ret
 endfunc cortex_a75_reset_func
 
+func check_errata_cve_2017_5715
+	mrs	x0, id_aa64pfr0_el1
+	ubfx	x0, x0, #ID_AA64PFR0_CSV2_SHIFT, #ID_AA64PFR0_CSV2_LENGTH
+	/*
+	 * If the field equals to 1 then branch targets trained in one
+	 * context cannot affect speculative execution in a different context.
+	 */
+	cmp	x0, #1
+	beq	1f
+
+#if WORKAROUND_CVE_2017_5715
+	mov	x0, #ERRATA_APPLIES
+#else
+	mov	x0, #ERRATA_MISSING
+#endif
+	ret
+1:
+	mov	x0, #ERRATA_NOT_APPLIES
+	ret
+endfunc check_errata_cve_2017_5715
+
 	/* ---------------------------------------------
 	 * HW will do the cache maintenance while powering down
 	 * ---------------------------------------------
@@ -167,6 +188,27 @@ func cortex_a75_core_pwr_dwn
 	ret
 endfunc cortex_a75_core_pwr_dwn
 
+#if REPORT_ERRATA
+/*
+ * Errata printing function for Cortex A75. Must follow AAPCS.
+ */
+func cortex_a75_errata_report
+	stp	x8, x30, [sp, #-16]!
+
+	bl	cpu_get_rev_var
+	mov	x8, x0
+
+	/*
+	 * Report all errata. The revision-variant information is passed to
+	 * checking functions of each errata.
+	 */
+	report_errata WORKAROUND_CVE_2017_5715, cortex_a75, cve_2017_5715
+
+	ldp	x8, x30, [sp], #16
+	ret
+endfunc cortex_a75_errata_report
+#endif
+
 	/* ---------------------------------------------
 	 * This function provides cortex_a75 specific
 	 * register information for crash reporting.