powerpc/mpc85xx: work around erratum A-006593

Erratum A-006593 is "Atomic store may report failure but still allow
the store data to be visible".

The workaround is: "Set CoreNet Platform Cache register CPCHDBCR0 bit
21 to 1'b1.  This may have a small impact on synthetic write bandwidth
benchmarks but should have a negligible impact on real code."

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>

arch/powerpc/cpu/mpc85xx/cmd_errata.c

@@ -257,6 +257,9 @@ static int do_errata(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 #endif
 #ifdef CONFIG_SYS_FSL_ERRATUM_USB14
 	puts("Work-around for Erratum USB14 enabled\n");
+#endif
+#ifdef CONFIG_SYS_FSL_ERRATUM_A006593
+	puts("Work-around for Erratum A006593 enabled\n");
 #endif
 	return 0;
 }

arch/powerpc/cpu/mpc85xx/cpu_init.c

@@ -172,6 +172,9 @@ static void enable_cpc(void)
 #ifdef CONFIG_SYS_FSL_ERRATUM_CPC_A003
 		setbits_be32(&cpc->cpchdbcr0, CPC_HDBCR0_DATA_ECC_SCRUB_DIS);
 #endif
+#ifdef CONFIG_SYS_FSL_ERRATUM_A006593
+		setbits_be32(&cpc->cpchdbcr0, 1 << (31 - 21));
+#endif
 
 		out_be32(&cpc->cpccsr0, CPC_CSR0_CE | CPC_CSR0_PE);
 		/* Read back to sync write */

arch/powerpc/include/asm/config_mpc85xx.h

@@ -555,6 +555,7 @@
 #define CONFIG_SYS_FSL_ERRATUM_A004468
 #define CONFIG_SYS_FSL_ERRATUM_A_004934
 #define CONFIG_SYS_FSL_ERRATUM_A005871
+#define CONFIG_SYS_FSL_ERRATUM_A006593
 #define CONFIG_SYS_CCSRBAR_DEFAULT	0xfe000000
 #define CONFIG_SYS_FSL_PCI_VER_3_X
 
@@ -576,6 +577,7 @@
 #define CONFIG_SYS_FSL_USB1_PHY_ENABLE
 #define CONFIG_SYS_FSL_ERRATUM_A_004934
 #define CONFIG_SYS_FSL_ERRATUM_A005871
+#define CONFIG_SYS_FSL_ERRATUM_A006593
 #define CONFIG_SYS_CCSRBAR_DEFAULT	0xfe000000
 
 #ifdef CONFIG_PPC_B4860