Cortex-A55: workarounds for errata 1221012

The workaround is added to the Cortex-A55 cpu specific file. The
workaround is disabled by default and have to be explicitly enabled by
the platform integrator.

Change-Id: I3e6fd10df6444122a8ee7d08058946ff1cc912f8
Signed-off-by: Ambroise Vincent <[email protected]>

diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index e49c73e7b90a4a1cbf3bfd79e1d1d7608f1c22db..07983a901866ac5c74958b8d8d15fe2496e988c5 100644 (file)
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -143,6 +143,9 @@ For Cortex-A55, the following errata build flags are defined :
 -  ``ERRATA_A55_903758``: This applies errata 903758 workaround to Cortex-A55
    CPU. This needs to be enabled only for revision <= r0p1 of the CPU.
 
+-  ``ERRATA_A55_1221012``: This applies errata 1221012 workaround to Cortex-A55
+   CPU. This needs to be enabled only for revision <= r1p0 of the CPU.
+
 For Cortex-A57, the following errata build flags are defined :
 
 -  ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57

diff --git a/include/lib/cpus/aarch64/cortex_a55.h b/include/lib/cpus/aarch64/cortex_a55.h
index feac1d2f0832edf24187354e00f7b849af24560c..60ed957df2ca75840495e5592e0073ae1ebba75a 100644 (file)
--- a/include/lib/cpus/aarch64/cortex_a55.h
+++ b/include/lib/cpus/aarch64/cortex_a55.h
@@ -39,4 +39,10 @@
 /* Definitions of register field mask in CORTEX_A55_CPUPWRCTLR_EL1 */
 #define CORTEX_A55_CORE_PWRDN_EN_MASK  U(0x1)
 
+/* Instruction patching registers */
+#define CPUPSELR_EL3   S3_6_C15_C8_0
+#define CPUPCR_EL3     S3_6_C15_C8_1
+#define CPUPOR_EL3     S3_6_C15_C8_2
+#define CPUPMR_EL3     S3_6_C15_C8_3
+
 #endif /* CORTEX_A55_H */

diff --git a/lib/cpus/aarch64/cortex_a55.S b/lib/cpus/aarch64/cortex_a55.S
index 0ef373a0a80f4306207c6545e73589b473f2c446..8e138244b83fa575d2164481153db372be95fe89 100644 (file)
--- a/lib/cpus/aarch64/cortex_a55.S
+++ b/lib/cpus/aarch64/cortex_a55.S
@@ -175,6 +175,53 @@ func check_errata_903758
        b       cpu_rev_var_ls
 endfunc check_errata_903758
 
+       /* -----------------------------------------------------
+        * Errata Workaround for Cortex A55 Errata #1221012.
+        * This applies only to revisions <= r1p0 of Cortex A55.
+        * Inputs:
+        * x0: variant[4:7] and revision[0:3] of current cpu.
+        * Shall clobber: x0-x17
+        * -----------------------------------------------------
+        */
+func errata_a55_1221012_wa
+       /*
+        * Compare x0 against revision r1p0
+        */
+       mov     x17, x30
+       bl      check_errata_1221012
+       cbz     x0, 1f
+       mov     x0, #0x0020
+       movk    x0, #0x0850, lsl #16
+       msr     CPUPOR_EL3, x0
+       mov     x0, #0x0000
+       movk    x0, #0x1FF0, lsl #16
+       movk    x0, #0x2, lsl #32
+       msr     CPUPMR_EL3, x0
+       mov     x0, #0x03fd
+       movk    x0, #0x0110, lsl #16
+       msr     CPUPCR_EL3, x0
+       mov     x0, #0x1
+       msr     CPUPSELR_EL3, x0
+       mov     x0, #0x0040
+       movk    x0, #0x08D0, lsl #16
+       msr     CPUPOR_EL3, x0
+       mov     x0, #0x0040
+       movk    x0, #0x1FF0, lsl #16
+       movk    x0, #0x2, lsl #32
+       msr     CPUPMR_EL3, x0
+       mov     x0, #0x03fd
+       movk    x0, #0x0110, lsl #16
+       msr     CPUPCR_EL3, x0
+       isb
+1:
+       ret     x17
+endfunc errata_a55_1221012_wa
+
+func check_errata_1221012
+       mov     x1, #0x10
+       b       cpu_rev_var_ls
+endfunc check_errata_1221012
+
 func cortex_a55_reset_func
        mov     x19, x30
 
@@ -214,6 +261,11 @@ func cortex_a55_reset_func
        bl      errata_a55_903758_wa
 #endif
 
+#if ERRATA_A55_1221012
+       mov     x0, x18
+       bl      errata_a55_1221012_wa
+#endif
+
        ret     x19
 endfunc cortex_a55_reset_func
 
@@ -253,6 +305,7 @@ func cortex_a55_errata_report
        report_errata ERRATA_A55_798797, cortex_a55, 798797
        report_errata ERRATA_A55_846532, cortex_a55, 846532
        report_errata ERRATA_A55_903758, cortex_a55, 903758
+       report_errata ERRATA_A55_1221012, cortex_a55, 1221012
 
        ldp     x8, x30, [sp], #16
        ret

diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index e45d79d99ae0ff2bc153d1100679ac3a0786d1ec..599e11ed5a135085c64d5e5bfc24e0282b340406 100644 (file)
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -134,6 +134,10 @@ ERRATA_A55_846532  ?=0
 # only to revision <= r0p1 of the Cortex A55 cpu.
 ERRATA_A55_903758      ?=0
 
+# Flag to apply erratum 1221012 workaround during reset. This erratum applies
+# only to revision <= r1p0 of the Cortex A55 cpu.
+ERRATA_A55_1221012     ?=0
+
 # Flag to apply erratum 806969 workaround during reset. This erratum applies
 # only to revision r0p0 of the Cortex A57 cpu.
 ERRATA_A57_806969      ?=0
@@ -319,6 +323,10 @@ $(eval $(call add_define,ERRATA_A55_846532))
 $(eval $(call assert_boolean,ERRATA_A55_903758))
 $(eval $(call add_define,ERRATA_A55_903758))
 
+# Process ERRATA_A55_1221012 flag
+$(eval $(call assert_boolean,ERRATA_A55_1221012))
+$(eval $(call add_define,ERRATA_A55_1221012))
+
 # Process ERRATA_A57_806969 flag
 $(eval $(call assert_boolean,ERRATA_A57_806969))
 $(eval $(call add_define,ERRATA_A57_806969))