powerpc/mpc85xx: Make NMG_CPU_A011 workaround conditional
This erratum applies to the following SoCs:
P4080 rev 1.0, 2.0, fixed in rev 3.0
P2041 rev 1.0, 1.1, fixed in rev 2.0
P3041 rev 1.0, 1.1, fixed in rev 2.0.
Workaround for erratum NMG_CPU_A011 is enabled by default. This workaround
may degrade performance. P4080 erratum CPU22 shares the same workaround.
So it is always enabled for P4080. For other SoCs, it can be disabled by
hwconfig with syntax:
fsl_cpu_a011:disable
Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/arch/powerpc/cpu/mpc85xx/cpu_init.c b/arch/powerpc/cpu/mpc85xx/cpu_init.c
index fc6c287..74863b4 100644
--- a/arch/powerpc/cpu/mpc85xx/cpu_init.c
+++ b/arch/powerpc/cpu/mpc85xx/cpu_init.c
@@ -38,6 +38,7 @@
#include <asm/fsl_law.h>
#include <asm/fsl_serdes.h>
#include <asm/fsl_srio.h>
+#include <hwconfig.h>
#include <linux/compiler.h>
#include "mp.h"
#ifdef CONFIG_SYS_QE_FMAN_FW_IN_NAND
@@ -47,6 +48,8 @@
#include "../../../../drivers/block/fsl_sata.h"
+#define HWCONFIG_BUFFER_SIZE 128
+
DECLARE_GLOBAL_DATA_PTR;
#ifdef CONFIG_QE
@@ -311,11 +314,41 @@
#if defined(CONFIG_SYS_P4080_ERRATUM_CPU22) || \
defined(CONFIG_SYS_FSL_ERRATUM_NMG_CPU_A011)
/*
+ * CPU22 and NMG_CPU_A011 share the same workaround.
* CPU22 applies to P4080 rev 1.0, 2.0, fixed in 3.0
* NMG_CPU_A011 applies to P4080 rev 1.0, 2.0, fixed in 3.0
- * also applies to P3041 rev 1.0, 1.1, P2041 rev 1.0, 1.1
+ * also applies to P3041 rev 1.0, 1.1, P2041 rev 1.0, 1.1, both
+ * fixed in 2.0. NMG_CPU_A011 is activated by default and can
+ * be disabled by hwconfig with syntax:
+ *
+ * fsl_cpu_a011:disable
*/
- if (SVR_SOC_VER(svr) != SVR_P4080 || SVR_MAJ(svr) < 3) {
+ extern int enable_cpu_a011_workaround;
+#ifdef CONFIG_SYS_P4080_ERRATUM_CPU22
+ enable_cpu_a011_workaround = (SVR_MAJ(svr) < 3);
+#else
+ char buffer[HWCONFIG_BUFFER_SIZE];
+ char *buf = NULL;
+ int n, res;
+
+ n = getenv_f("hwconfig", buffer, sizeof(buffer));
+ if (n > 0)
+ buf = buffer;
+
+ res = hwconfig_arg_cmp_f("fsl_cpu_a011", "disable", buf);
+ if (res > 0)
+ enable_cpu_a011_workaround = 0;
+ else {
+ if (n >= HWCONFIG_BUFFER_SIZE) {
+ printf("fsl_cpu_a011 was not found. hwconfig variable "
+ "may be too long\n");
+ }
+ enable_cpu_a011_workaround =
+ (SVR_SOC_VER(svr) == SVR_P4080 && SVR_MAJ(svr) < 3) ||
+ (SVR_SOC_VER(svr) != SVR_P4080 && SVR_MAJ(svr) < 2);
+ }
+#endif
+ if (enable_cpu_a011_workaround) {
flush_dcache();
mtspr(L1CSR2, (mfspr(L1CSR2) | L1CSR2_DCWS));
sync();