Merge "fix(errata): workaround for Cortex-X2 erratum 2147715" into integration

docs/design/cpu-specific-build-macros.rst

@@ -490,6 +490,10 @@ For Cortex-X2, the following errata build flags are defined :
    Cortex-X2 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
    r2p0 of the CPU, it is fixed in r2p1.
 
+-  ``ERRATA_X2_2147715``: This applies errata 2147715 workaround to
+   Cortex-X2 CPU. This needs to be enabled only for revision r2p0 of the CPU,
+   it is fixed in r2p1.
+
 For Cortex-A510, the following errata build flags are defined :
 
 -  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to

include/lib/cpus/aarch64/cortex_x2.h

@@ -33,6 +33,12 @@
 #define CORTEX_X2_CPUPWRCTLR_EL1				S3_0_C15_C2_7
 #define CORTEX_X2_CPUPWRCTLR_EL1_CORE_PWRDN_BIT			U(1)
 
+/*******************************************************************************
+ * CPU Auxiliary Control Register definitions
+ ******************************************************************************/
+#define CORTEX_X2_CPUACTLR_EL1					S3_0_C15_C1_0
+#define CORTEX_X2_CPUACTLR_EL1_BIT_22				(ULL(1) << 22)
+
 /*******************************************************************************
  * CPU Auxiliary Control Register 5 definitions
  ******************************************************************************/

lib/cpus/aarch64/cortex_x2.S

@@ -237,6 +237,36 @@ func check_errata_cve_2022_23960
 	ret
 endfunc check_errata_cve_2022_23960
 
+	/* ---------------------------------------------------------
+	 * Errata Workaround for Cortex-X2 Errata 2147715.
+	 * This applies only to revisions r2p0 and is fixed in r2p1.
+	 * Inputs:
+	 * x0: variant[4:7] and revision[0:3] of current cpu.
+	 * Shall clobber: x0, x1, x17
+	 * ---------------------------------------------------------
+	 */
+func errata_x2_2147715_wa
+	/* Compare x0 against revision r2p0 */
+	mov     x17, x30
+	bl      check_errata_2147715
+	cbz     x0, 1f
+
+	/* Apply the workaround by setting bit 22 in CPUACTLR_EL1. */
+	mrs     x1, CORTEX_X2_CPUACTLR_EL1
+	orr     x1, x1, CORTEX_X2_CPUACTLR_EL1_BIT_22
+	msr     CORTEX_X2_CPUACTLR_EL1, x1
+
+1:
+	ret     x17
+endfunc errata_x2_2147715_wa
+
+func check_errata_2147715
+	/* Applies to r2p0 */
+	mov	x1, #0x20
+	mov	x2, #0x20
+	b	cpu_rev_var_range
+endfunc check_errata_2147715
+
 	/* ----------------------------------------------------
 	 * HW will do the cache maintenance while powering down
 	 * ----------------------------------------------------
@@ -268,10 +298,11 @@ func cortex_x2_errata_report
 	 * checking functions of each errata.
 	 */
 	report_errata ERRATA_X2_2002765, cortex_x2, 2002765
-	report_errata ERRATA_X2_2058056, cortex_x2, 2058056
-	report_errata ERRATA_X2_2083908, cortex_x2, 2083908
 	report_errata ERRATA_X2_2017096, cortex_x2, 2017096
+	report_errata ERRATA_X2_2058056, cortex_x2, 2058056
 	report_errata ERRATA_X2_2081180, cortex_x2, 2081180
+	report_errata ERRATA_X2_2083908, cortex_x2, 2083908
+	report_errata ERRATA_X2_2147715, cortex_x2, 2147715
 	report_errata ERRATA_X2_2216384, cortex_x2, 2216384
 	report_errata WORKAROUND_CVE_2022_23960, cortex_x2, cve_2022_23960
 
@@ -321,6 +352,11 @@ func cortex_x2_reset_func
 	bl	errata_x2_2216384_wa
 #endif
 
+#if ERRATA_X2_2147715
+	mov	x0, x18
+	bl	errata_x2_2147715_wa
+#endif
+
 #if IMAGE_BL31 && WORKAROUND_CVE_2022_23960
 	/*
 	 * The Cortex-X2 generic vectors are overridden to apply errata

lib/cpus/cpu-ops.mk

@@ -547,6 +547,10 @@ ERRATA_X2_2081180	?=0
 # r2p1.
 ERRATA_X2_2216384	?=0
 
+# Flag to apply erratum 2147715 workaround during reset. This erratum applies
+# only to revision r2p0 of the Cortex-X2 cpu, it is fixed in r2p1.
+ERRATA_X2_2147715	?=0
+
 # Flag to apply erratum 1922240 workaround during reset. This erratum applies
 # to revision r0p0 of the Cortex-A510 cpu and is fixed in r0p1.
 ERRATA_A510_1922240	?=0
@@ -1046,6 +1050,10 @@ $(eval $(call add_define,ERRATA_X2_2081180))
 $(eval $(call assert_boolean,ERRATA_X2_2216384))
 $(eval $(call add_define,ERRATA_X2_2216384))
 
+# Process ERRATA_X2_2147715 flag
+$(eval $(call assert_boolean,ERRATA_X2_2147715))
+$(eval $(call add_define,ERRATA_X2_2147715))
+
 # Process ERRATA_A510_1922240 flag
 $(eval $(call assert_boolean,ERRATA_A510_1922240))
 $(eval $(call add_define,ERRATA_A510_1922240))