Merge "fix(cpus): workaround for Cortex-X3 erratum 2615812" into integration

4 files changed, 55 insertions, 4 deletions

diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 55e265c9a..d48f284fb 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -601,6 +601,10 @@ For Cortex-X3, the following errata build flags are defined :
   Cortex-X3 CPU. This needs to be enabled only for revisions r0p0 and r1p0
   of the CPU, it is fixed in r1p1.
 
+- ``ERRATA_X3_2615812``: This applies errata 2615812 workaround to Cortex-X3
+  CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
+  CPU, it is still open.
+
 For Cortex-A510, the following errata build flags are defined :
 
 -  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to
diff --git a/include/lib/cpus/aarch64/cortex_x3.h b/include/lib/cpus/aarch64/cortex_x3.h
index 076a87b35..ceafe6647 100644
--- a/include/lib/cpus/aarch64/cortex_x3.h
+++ b/include/lib/cpus/aarch64/cortex_x3.h
@@ -10,7 +10,7 @@
 #define CORTEX_X3_MIDR				U(0x410FD4E0)
 
 /* Cortex-X3 loop count for CVE-2022-23960 mitigation */
-#define CORTEX_X3_BHB_LOOP_COUNT			U(132)
+#define CORTEX_X3_BHB_LOOP_COUNT		U(132)
 
 /*******************************************************************************
  * CPU Extended Control register specific definitions
@@ -20,8 +20,10 @@
 /*******************************************************************************
  * CPU Power Control register specific definitions
  ******************************************************************************/
-#define CORTEX_X3_CPUPWRCTLR_EL1			S3_0_C15_C2_7
-#define CORTEX_X3_CPUPWRCTLR_EL1_CORE_PWRDN_BIT	U(1)
+#define CORTEX_X3_CPUPWRCTLR_EL1				S3_0_C15_C2_7
+#define CORTEX_X3_CPUPWRCTLR_EL1_CORE_PWRDN_BIT			U(1)
+#define CORTEX_X3_CPUPWRCTLR_EL1_WFI_RET_CTRL_BITS_SHIFT	U(4)
+#define CORTEX_X3_CPUPWRCTLR_EL1_WFE_RET_CTRL_BITS_SHIFT	U(7)
 
 /*******************************************************************************
  * CPU Auxiliary Control register 2 specific definitions.
diff --git a/lib/cpus/aarch64/cortex_x3.S b/lib/cpus/aarch64/cortex_x3.S
index bf1b6ec4a..f104b487f 100644
--- a/lib/cpus/aarch64/cortex_x3.S
+++ b/lib/cpus/aarch64/cortex_x3.S
@@ -59,6 +59,7 @@ func check_errata_cve_2022_23960
 endfunc check_errata_cve_2022_23960
 
 func cortex_x3_reset_func
+	mov	x19, x30
 	/* Disable speculative loads */
 	msr	SSBS, xzr
 
@@ -71,8 +72,14 @@ func cortex_x3_reset_func
 	msr	vbar_el3, x0
 #endif /* IMAGE_BL31 && WORKAROUND_CVE_2022_23960 */
 
+	bl	cpu_get_rev_var
+
+#if ERRATA_X3_2615812
+	bl	errata_cortex_x3_2615812_wa
+#endif /* ERRATA_X3_2615812 */
+
 	isb
-	ret
+	ret	x19
 endfunc cortex_x3_reset_func
 
 /* ----------------------------------------------------------------------
@@ -103,6 +110,35 @@ func check_errata_2313909
 	b	cpu_rev_var_ls
 endfunc check_errata_2313909
 
+/* ----------------------------------------------------------------------
+ * Errata Workaround for Cortex-X3 Erratum 2615812 on power-on.
+ * This applies to revision r0p0, r1p0, r1p1 of Cortex-X3. Open.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x1, x17
+ * ----------------------------------------------------------------------
+ */
+func errata_cortex_x3_2615812_wa
+	/* Check revision. */
+	mov	x17, x30
+	bl	check_errata_2615812
+	cbz	x0, 1f
+
+	/* Disable retention control for WFI and WFE. */
+	mrs	x0, CORTEX_X3_CPUPWRCTLR_EL1
+	bfi	x0, xzr, #CORTEX_X3_CPUPWRCTLR_EL1_WFI_RET_CTRL_BITS_SHIFT, #3
+	bfi	x0, xzr, #CORTEX_X3_CPUPWRCTLR_EL1_WFE_RET_CTRL_BITS_SHIFT, #3
+	msr	CORTEX_X3_CPUPWRCTLR_EL1, x0
+1:
+	ret	x17
+endfunc errata_cortex_x3_2615812_wa
+
+func check_errata_2615812
+	/* Applies to r1p1 and below. */
+	mov	x1, #0x11
+	b	cpu_rev_var_ls
+endfunc check_errata_2615812
+
 #if REPORT_ERRATA
 	/*
 	 * Errata printing function for Cortex-X3. Must follow AAPCS.
@@ -118,6 +154,7 @@ func cortex_x3_errata_report
 	 * checking functions of each errata.
 	 */
 	report_errata ERRATA_X3_2313909, cortex_x3, 2313909
+	report_errata ERRATA_X3_2615812, cortex_x3, 2615812
 	report_errata WORKAROUND_CVE_2022_23960, cortex_x3, cve_2022_23960
 
 	ldp	x8, x30, [sp], #16
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index f19c16e49..8ef794b45 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -659,6 +659,10 @@ ERRATA_X2_2371105	?=0
 # to revisions r0p0 and r1p0 of the Cortex-X3 cpu, it is fixed in r1p1.
 ERRATA_X3_2313909	?=0
 
+# Flag to apply erratum 2615812 workaround on powerdown. This erratum applies
+# to revisions r0p0, r1p0, r1p1 of the Cortex-X3 cpu, it is still open.
+ERRATA_X3_2615812	?=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
@@ -1288,6 +1292,10 @@ $(eval $(call add_define,ERRATA_X2_2371105))
 $(eval $(call assert_boolean,ERRATA_X3_2313909))
 $(eval $(call add_define,ERRATA_X3_2313909))
 
+# Process ERRATA_X3_2615812 flag
+$(eval $(call assert_boolean,ERRATA_X3_2615812))
+$(eval $(call add_define,ERRATA_X3_2615812))
+
 # Process ERRATA_A510_1922240 flag
 $(eval $(call assert_boolean,ERRATA_A510_1922240))
 $(eval $(call add_define,ERRATA_A510_1922240))