Merge pull request #1848 from antonio-nino-diaz-arm/an/docs

Minor changes to documentation and comments
diff --git a/docs/cpu-specific-build-macros.rst b/docs/cpu-specific-build-macros.rst
index 315457a..1f23b5b 100644
--- a/docs/cpu-specific-build-macros.rst
+++ b/docs/cpu-specific-build-macros.rst
@@ -132,6 +132,30 @@
 -  ``ERRATA_A72_859971``: This applies errata 859971 workaround to Cortex-A72
    CPU. This needs to be enabled only for revision <= r0p3 of the CPU.
 
+For Cortex-A73, the following errata build flags are defined :
+
+-  ``ERRATA_A73_855423``: This applies errata 855423 workaround to Cortex-A73
+   CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
+
+For Cortex-A75, the following errata build flags are defined :
+
+-  ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75
+   CPU. This needs to be enabled only for revision r0p0 of the CPU.
+
+-  ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75
+    CPU. This needs to be enabled only for revision r0p0 of the CPU.
+
+For Cortex-A76, the following errata build flags are defined :
+
+-  ``ERRATA_A76_1073348``: This applies errata 1073348 workaround to Cortex-A76
+   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
+
+-  ``ERRATA_A76_1130799``: This applies errata 1130799 workaround to Cortex-A76
+   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
+
+-  ``ERRATA_A76_1220197``: This applies errata 1220197 workaround to Cortex-A76
+   CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
+
 DSU Errata Workarounds
 ----------------------
 
diff --git a/include/arch/aarch64/arch.h b/include/arch/aarch64/arch.h
index b9d1f9f..1032d9a 100644
--- a/include/arch/aarch64/arch.h
+++ b/include/arch/aarch64/arch.h
@@ -251,6 +251,7 @@
 #define SCTLR_NTWE_BIT		(ULL(1) << 18)
 #define SCTLR_WXN_BIT		(ULL(1) << 19)
 #define SCTLR_UWXN_BIT		(ULL(1) << 20)
+#define SCTLR_IESB_BIT		(ULL(1) << 21)
 #define SCTLR_E0E_BIT		(ULL(1) << 24)
 #define SCTLR_EE_BIT		(ULL(1) << 25)
 #define SCTLR_UCI_BIT		(ULL(1) << 26)
diff --git a/include/lib/cpus/aarch64/cortex_a73.h b/include/lib/cpus/aarch64/cortex_a73.h
index 3b40180..61b2b73 100644
--- a/include/lib/cpus/aarch64/cortex_a73.h
+++ b/include/lib/cpus/aarch64/cortex_a73.h
@@ -31,4 +31,6 @@
 
 #define CORTEX_A73_IMP_DEF_REG1_DISABLE_LOAD_PASS_STORE	(ULL(1) << 3)
 
+#define CORTEX_A73_IMP_DEF_REG2		S3_0_C15_C0_2
+
 #endif /* CORTEX_A73_H */
diff --git a/include/lib/cpus/aarch64/cortex_a76.h b/include/lib/cpus/aarch64/cortex_a76.h
index 5779d7b..c2af8ca 100644
--- a/include/lib/cpus/aarch64/cortex_a76.h
+++ b/include/lib/cpus/aarch64/cortex_a76.h
@@ -18,9 +18,15 @@
 #define CORTEX_A76_CPUPWRCTLR_EL1	S3_0_C15_C2_7
 #define CORTEX_A76_CPUECTLR_EL1		S3_0_C15_C1_4
 
+#define CORTEX_A76_CPUECTLR_EL1_WS_THR_L2	(ULL(3) << 24)
+
 /*******************************************************************************
  * CPU Auxiliary Control register specific definitions.
  ******************************************************************************/
+#define CORTEX_A76_CPUACTLR_EL1		S3_0_C15_C1_0
+
+#define CORTEX_A76_CPUACTLR_EL1_DISABLE_STATIC_PREDICTION	(ULL(1) << 6)
+
 #define CORTEX_A76_CPUACTLR2_EL1	S3_0_C15_C1_1
 
 #define CORTEX_A76_CPUACTLR2_EL1_DISABLE_LOAD_PASS_STORE	(ULL(1) << 16)
diff --git a/lib/cpus/aarch64/cortex_a73.S b/lib/cpus/aarch64/cortex_a73.S
index 772b0be..6cfa4b5 100644
--- a/lib/cpus/aarch64/cortex_a73.S
+++ b/lib/cpus/aarch64/cortex_a73.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -35,7 +35,47 @@
 	ret
 endfunc cortex_a73_disable_smp
 
+	/* ---------------------------------------------------
+	 * Errata Workaround for Cortex A73 Errata #855423.
+	 * This applies only to revision <= r0p1 of Cortex A73.
+	 * Inputs:
+	 * x0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: x0-x17
+	 * ---------------------------------------------------
+	 */
+func errata_a73_855423_wa
+	/*
+	 * Compare x0 against revision r0p1
+	 */
+	mov	x17, x30
+	bl	check_errata_855423
+	cbz	x0, 1f
+	mrs	x1, CORTEX_A73_IMP_DEF_REG2
+	orr	x1, x1, #(1 << 7)
+	msr	CORTEX_A73_IMP_DEF_REG2, x1
+	isb
+1:
+	ret	x17
+endfunc errata_a73_855423_wa
+
+func check_errata_855423
+	mov	x1, #0x01
+	b	cpu_rev_var_ls
+endfunc check_errata_855423
+
+	/* -------------------------------------------------
+	 * The CPU Ops reset function for Cortex-A73.
+	 * -------------------------------------------------
+	 */
+
 func cortex_a73_reset_func
+	mov	x19, x30
+	bl	cpu_get_rev_var
+
+#if ERRATA_A73_855423
+	bl	errata_a73_855423_wa
+#endif
+
 #if IMAGE_BL31 && WORKAROUND_CVE_2017_5715
 	cpu_check_csv2	x0, 1f
 	adr	x0, wa_cve_2017_5715_bpiall_vbar
@@ -60,7 +100,7 @@
 	orr	x0, x0, #CORTEX_A73_CPUECTLR_SMP_BIT
 	msr	CORTEX_A73_CPUECTLR_EL1, x0
 	isb
-	ret
+	ret	x19
 endfunc cortex_a73_reset_func
 
 func cortex_a73_core_pwr_dwn
@@ -160,6 +200,7 @@
 	 * Report all errata. The revision-variant information is passed to
 	 * checking functions of each errata.
 	 */
+	report_errata ERRATA_A73_855423, cortex_a73, 855423
 	report_errata WORKAROUND_CVE_2017_5715, cortex_a73, cve_2017_5715
 	report_errata WORKAROUND_CVE_2018_3639, cortex_a73, cve_2018_3639
 
diff --git a/lib/cpus/aarch64/cortex_a75.S b/lib/cpus/aarch64/cortex_a75.S
index e121b7d..2040188 100644
--- a/lib/cpus/aarch64/cortex_a75.S
+++ b/lib/cpus/aarch64/cortex_a75.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -10,8 +10,81 @@
 #include <cpuamu.h>
 #include <cpu_macros.S>
 
+	/* --------------------------------------------------
+	 * Errata Workaround for Cortex A75 Errata #764081.
+	 * This applies only to revision r0p0 of Cortex A75.
+	 * Inputs:
+	 * x0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: x0-x17
+	 * --------------------------------------------------
+	 */
+func errata_a75_764081_wa
+	/*
+	 * Compare x0 against revision r0p0
+	 */
+	mov	x17, x30
+	bl	check_errata_764081
+	cbz	x0, 1f
+	mrs	x1, sctlr_el3
+	orr	x1, x1 ,#SCTLR_IESB_BIT
+	msr	sctlr_el3, x1
+	isb
+1:
+	ret	x17
+endfunc errata_a75_764081_wa
+
+func check_errata_764081
+	mov	x1, #0x00
+	b	cpu_rev_var_ls
+endfunc check_errata_764081
+
+	/* --------------------------------------------------
+	 * Errata Workaround for Cortex A75 Errata #790748.
+	 * This applies only to revision r0p0 of Cortex A75.
+	 * Inputs:
+	 * x0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: x0-x17
+	 * --------------------------------------------------
+	 */
+func errata_a75_790748_wa
+	/*
+	 * Compare x0 against revision r0p0
+	 */
+	mov	x17, x30
+	bl	check_errata_790748
+	cbz	x0, 1f
+	mrs	x1, CORTEX_A75_CPUACTLR_EL1
+	orr	x1, x1 ,#(1 << 13)
+	msr	CORTEX_A75_CPUACTLR_EL1, x1
+	isb
+1:
+	ret	x17
+endfunc errata_a75_790748_wa
+
+func check_errata_790748
+	mov	x1, #0x00
+	b	cpu_rev_var_ls
+endfunc check_errata_790748
+
+	/* -------------------------------------------------
+	 * The CPU Ops reset function for Cortex-A75.
+	 * -------------------------------------------------
+	 */
 func cortex_a75_reset_func
 	mov	x19, x30
+	bl	cpu_get_rev_var
+	mov	x18, x0
+
+#if ERRATA_A75_764081
+	mov	x0, x18
+	bl	errata_a75_764081_wa
+#endif
+
+#if ERRATA_A75_790748
+	mov	x0, x18
+	bl	errata_a75_790748_wa
+#endif
+
 #if IMAGE_BL31 && WORKAROUND_CVE_2017_5715
 	cpu_check_csv2	x0, 1f
 	adr	x0, wa_cve_2017_5715_bpiall_vbar
@@ -109,6 +182,8 @@
 	 * Report all errata. The revision-variant information is passed to
 	 * checking functions of each errata.
 	 */
+	report_errata ERRATA_A75_764081, cortex_a75, 764081
+	report_errata ERRATA_A75_790748, cortex_a75, 790748
 	report_errata WORKAROUND_CVE_2017_5715, cortex_a75, cve_2017_5715
 	report_errata WORKAROUND_CVE_2018_3639, cortex_a75, cve_2018_3639
 	report_errata ERRATA_DSU_936184, cortex_a75, dsu_936184
diff --git a/lib/cpus/aarch64/cortex_a76.S b/lib/cpus/aarch64/cortex_a76.S
index 27db74e..ac51343 100644
--- a/lib/cpus/aarch64/cortex_a76.S
+++ b/lib/cpus/aarch64/cortex_a76.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -189,6 +189,90 @@
 	b	serror_aarch32
 end_vector_entry cortex_a76_serror_aarch32
 
+	/* --------------------------------------------------
+	 * Errata Workaround for Cortex A76 Errata #1073348.
+	 * This applies only to revision <= r1p0 of Cortex A76.
+	 * Inputs:
+	 * x0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: x0-x17
+	 * --------------------------------------------------
+	 */
+func errata_a76_1073348_wa
+	/*
+	 * Compare x0 against revision r1p0
+	 */
+	mov	x17, x30
+	bl	check_errata_1073348
+	cbz	x0, 1f
+	mrs	x1, CORTEX_A76_CPUACTLR_EL1
+	orr	x1, x1 ,#CORTEX_A76_CPUACTLR_EL1_DISABLE_STATIC_PREDICTION
+	msr	CORTEX_A76_CPUACTLR_EL1, x1
+	isb
+1:
+	ret	x17
+	endfunc errata_a76_1073348_wa
+
+func check_errata_1073348
+	mov	x1, #0x10
+	b	cpu_rev_var_ls
+endfunc check_errata_1073348
+
+	/* --------------------------------------------------
+	 * Errata Workaround for Cortex A76 Errata #1130799.
+	 * This applies only to revision <= r2p0 of Cortex A76.
+	 * Inputs:
+	 * x0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: x0-x17
+	 * --------------------------------------------------
+	 */
+func errata_a76_1130799_wa
+	/*
+	 * Compare x0 against revision r2p0
+	 */
+	mov	x17, x30
+	bl	check_errata_1130799
+	cbz	x0, 1f
+	mrs	x1, CORTEX_A76_CPUACTLR2_EL1
+	orr	x1, x1 ,#(1 << 59)
+	msr	CORTEX_A76_CPUACTLR2_EL1, x1
+	isb
+1:
+	ret	x17
+endfunc errata_a76_1130799_wa
+
+func check_errata_1130799
+	mov	x1, #0x20
+	b	cpu_rev_var_ls
+endfunc check_errata_1130799
+
+	/* --------------------------------------------------
+	 * Errata Workaround for Cortex A76 Errata #1220197.
+	 * This applies only to revision <= r2p0 of Cortex A76.
+	 * Inputs:
+	 * x0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: x0-x17
+	 * --------------------------------------------------
+	 */
+func errata_a76_1220197_wa
+/*
+ * Compare x0 against revision r2p0
+ */
+	mov	x17, x30
+	bl	check_errata_1220197
+	cbz	x0, 1f
+	mrs	x1, CORTEX_A76_CPUECTLR_EL1
+	orr	x1, x1, #CORTEX_A76_CPUECTLR_EL1_WS_THR_L2
+	msr	CORTEX_A76_CPUECTLR_EL1, x1
+	isb
+1:
+	ret	x17
+endfunc errata_a76_1220197_wa
+
+func check_errata_1220197
+	mov	x1, #0x20
+	b	cpu_rev_var_ls
+endfunc check_errata_1220197
+
 func check_errata_cve_2018_3639
 #if WORKAROUND_CVE_2018_3639
 	mov	x0, #ERRATA_APPLIES
@@ -206,8 +290,30 @@
 	ret
 endfunc cortex_a76_disable_wa_cve_2018_3639
 
+	/* -------------------------------------------------
+	 * The CPU Ops reset function for Cortex-A76.
+	 * Shall clobber: x0-x19
+	 * -------------------------------------------------
+	 */
 func cortex_a76_reset_func
 	mov	x19, x30
+	bl	cpu_get_rev_var
+	mov	x18, x0
+
+#if ERRATA_A76_1073348
+	mov	x0, x18
+	bl	errata_a76_1073348_wa
+#endif
+
+#if ERRATA_A76_1130799
+	mov	x0, x18
+	bl	errata_a76_1130799_wa
+#endif
+
+#if ERRATA_A76_1220197
+	mov	x0, x18
+	bl	errata_a76_1220197_wa
+#endif
 
 #if WORKAROUND_CVE_2018_3639
 	/* If the PE implements SSBS, we don't need the dynamic workaround */
@@ -271,6 +377,9 @@
 	 * Report all errata. The revision-variant information is passed to
 	 * checking functions of each errata.
 	 */
+	report_errata ERRATA_A76_1073348, cortex_a76, 1073348
+	report_errata ERRATA_A76_1130799, cortex_a76, 1130799
+	report_errata ERRATA_A76_1220197, cortex_a76, 1220197
 	report_errata WORKAROUND_CVE_2018_3639, cortex_a76, cve_2018_3639
 	report_errata ERRATA_DSU_936184, cortex_a76, dsu_936184
 
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 7824df2..02208f0 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -119,6 +119,30 @@
 # only to revision <= r0p3 of the Cortex A72 cpu.
 ERRATA_A72_859971	?=0
 
+# Flag to apply erratum 855423 workaround during reset. This erratum applies
+# only to revision <= r0p1 of the Cortex A73 cpu.
+ERRATA_A73_855423	?=0
+
+# Flag to apply erratum 764081 workaround during reset. This erratum applies
+# only to revision <= r0p0 of the Cortex A75 cpu.
+ERRATA_A75_764081	?=0
+
+# Flag to apply erratum 790748 workaround during reset. This erratum applies
+# only to revision <= r0p0 of the Cortex A75 cpu.
+ERRATA_A75_790748	?=0
+
+# Flag to apply erratum 1073348 workaround during reset. This erratum applies
+# only to revision <= r1p0 of the Cortex A76 cpu.
+ERRATA_A76_1073348	?=0
+
+# Flag to apply erratum 1130799 workaround during reset. This erratum applies
+# only to revision <= r2p0 of the Cortex A76 cpu.
+ERRATA_A76_1130799	?=0
+
+# Flag to apply erratum 1220197 workaround during reset. This erratum applies
+# only to revision <= r2p0 of the Cortex A76 cpu.
+ERRATA_A76_1220197	?=0
+
 # Flag to apply T32 CLREX workaround during reset. This erratum applies
 # only to r0p0 and r1p0 of the Neoverse N1 cpu.
 ERRATA_N1_1043202	?=1
@@ -188,6 +212,30 @@
 $(eval $(call assert_boolean,ERRATA_A72_859971))
 $(eval $(call add_define,ERRATA_A72_859971))
 
+# Process ERRATA_A73_855423 flag
+$(eval $(call assert_boolean,ERRATA_A73_855423))
+$(eval $(call add_define,ERRATA_A73_855423))
+
+# Process ERRATA_A75_764081 flag
+$(eval $(call assert_boolean,ERRATA_A75_764081))
+$(eval $(call add_define,ERRATA_A75_764081))
+
+# Process ERRATA_A75_790748 flag
+$(eval $(call assert_boolean,ERRATA_A75_790748))
+$(eval $(call add_define,ERRATA_A75_790748))
+
+# Process ERRATA_A76_1073348 flag
+$(eval $(call assert_boolean,ERRATA_A76_1073348))
+$(eval $(call add_define,ERRATA_A76_1073348))
+
+# Process ERRATA_A76_1130799 flag
+$(eval $(call assert_boolean,ERRATA_A76_1130799))
+$(eval $(call add_define,ERRATA_A76_1130799))
+
+# Process ERRATA_A76_1220197 flag
+$(eval $(call assert_boolean,ERRATA_A76_1220197))
+$(eval $(call add_define,ERRATA_A76_1220197))
+
 # Process ERRATA_N1_1043202 flag
 $(eval $(call assert_boolean,ERRATA_N1_1043202))
 $(eval $(call add_define,ERRATA_N1_1043202))
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c
index 83f6e48..89d7ed6 100644
--- a/lib/el3_runtime/aarch64/context_mgmt.c
+++ b/lib/el3_runtime/aarch64/context_mgmt.c
@@ -187,6 +187,14 @@
 					| SCTLR_NTWI_BIT | SCTLR_NTWE_BIT;
 	}
 
+#if ERRATA_A75_764081
+	/*
+	 * If workaround of errata 764081 for Cortex-A75 is used then set
+	 * SCTLR_EL1.IESB to enable Implicit Error Synchronization Barrier.
+	 */
+	sctlr_elx |= SCTLR_IESB_BIT;
+#endif
+
 	/*
 	 * Store the initialised SCTLR_EL1 value in the cpu_context - SCTLR_EL2
 	 * and other EL2 registers are set up by cm_prepare_ns_entry() as they
@@ -319,6 +327,14 @@
 							   CTX_SCTLR_EL1);
 			sctlr_elx &= SCTLR_EE_BIT;
 			sctlr_elx |= SCTLR_EL2_RES1;
+#if ERRATA_A75_764081
+			/*
+			 * If workaround of errata 764081 for Cortex-A75 is used
+			 * then set SCTLR_EL2.IESB to enable Implicit Error
+			 * Synchronization Barrier.
+			 */
+			sctlr_elx |= SCTLR_IESB_BIT;
+#endif
 			write_sctlr_el2(sctlr_elx);
 		} else if (el_implemented(2) != EL_IMPL_NONE) {
 			el2_unused = true;