[U-Boot] [PATCH V2 7/9] ARM: OMAP3: Introduce OMAP3 Cortex-A8 revision specific errata

[Nishanth Menon]

430973: Stale prediction on replaced inter working branch causes
	Cortex-A8 to execute in the wrong ARM/Thumb state
Impacts: Everything lower than r2p1
Work around: Set IBE to 1

454179: Stale prediction may inhibit target address misprediction on
	next predicted taken branch
Impacts: Everything lower than r2p1
Work around:  Set IBE and disable branch size mispredict to 1

621766: Under a specific set of conditions, executing a sequence of
	NEON or vfp load instructions can cause processor deadlock
Impacts: Everything lower than r2p1
Work around: Set L1NEON to 1

Since the OMAP3 generation of processors have a wide variety of CPU
revisions, it is more logical to enforce an implementation using
revision checks.

Signed-off-by: Nishanth Menon <nm at ti.com>
---
 README                                      |    3 +++
 arch/arm/cpu/armv7/omap3/board.c            |    2 +-
 arch/arm/cpu/armv7/omap3/lowlevel_init.S    |   37 +++++++++++++++++++++++++++
 arch/arm/include/asm/arch-omap3/sys_proto.h |    1 +
 4 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/README b/README
index d76cdc68d406..f309e27bbd02 100644
--- a/README
+++ b/README
@@ -625,6 +625,9 @@ The following options need to be configured:
 		with CONFIG_ARM_ARCH_CP15_ERRATA define. These need to have an
 		SoC specific implementation of the erratum workaround to
 		function.
+		CONFIG_ARM_ERRATA_430973
+		CONFIG_ARM_ERRATA_454179
+		CONFIG_ARM_ERRATA_621766
 		CONFIG_ARM_ERRATA_798870
 
 - Driver Model
diff --git a/arch/arm/cpu/armv7/omap3/board.c b/arch/arm/cpu/armv7/omap3/board.c
index 51abc4b09e36..7ce30949a6c6 100644
--- a/arch/arm/cpu/armv7/omap3/board.c
+++ b/arch/arm/cpu/armv7/omap3/board.c
@@ -408,7 +408,7 @@ static void omap3_emu_romcode_call(u32 service_id, u32 *parameters)
 	do_omap3_emu_romcode_call(service_id, OMAP3_PUBLIC_SRAM_SCRATCH_AREA);
 }
 
-static void omap3_update_aux_cr_secure(u32 set_bits, u32 clear_bits)
+void omap3_update_aux_cr_secure(u32 set_bits, u32 clear_bits)
 {
 	u32 acr;
 
diff --git a/arch/arm/cpu/armv7/omap3/lowlevel_init.S b/arch/arm/cpu/armv7/omap3/lowlevel_init.S
index 84591b8b5bab..b8e6ebccd4e7 100644
--- a/arch/arm/cpu/armv7/omap3/lowlevel_init.S
+++ b/arch/arm/cpu/armv7/omap3/lowlevel_init.S
@@ -48,6 +48,43 @@ ENTRY(do_omap3_emu_romcode_call)
 	POP {r4-r12, pc}
 ENDPROC(do_omap3_emu_romcode_call)
 
+#ifdef CONFIG_ARM_ARCH_CP15_ERRATA
+	.globl  arch_cp15_errata_workaround
+/*
+ * R0 has MIDR
+ * R1 has CPU Variant (bits 20-23)
+ * R2 has CPU Revision (bits 0-3)
+ * R3 is compbined CPU variant << 4 + CPU revision
+ */
+ENTRY(arch_cp15_errata_workaround)
+	push    {r4-r12, lr}		@ save registers - ROM code may pollute
+
+	mov r0, #0			@ Nothing to set in ACR
+	mov r1, #0			@ Nothing to clear in ACR
+
+#ifdef CONFIG_ARM_ERRATA_454179
+	cmp r3, #0x21			@ Only on < r2p1
+	orrlt r0, r0, #(0x3 << 6)	@ Set DBSM(BIT7) and IBE(BIT6) bits
+#endif
+
+#ifdef CONFIG_ARM_ERRATA_430973
+	cmp r3, #0x21			@ Only on < r2p1
+	orrlt r0, r0, #(0x1 << 6)	@ Set IBE bit
+#endif
+
+#ifdef CONFIG_ARM_ERRATA_621766
+	cmp r3, #0x21			@ Only on < r2p1
+	orrlt r0, r0, #(0x1 << 5)	@ Set L1NEON bit
+#endif
+
+	add r2, r1, r0
+	teq r2, #0			@ See if nothing to set or clear
+	bne	omap3_update_aux_cr_secure	@update as per ROM code configuration needs
+
+	pop     {r4-r12, pc}		@restore the registers back.
+ENDPROC(arch_cp15_errata_workaround)
+#endif
+
 #if !defined(CONFIG_SYS_NAND_BOOT) && !defined(CONFIG_SYS_NAND_BOOT)
 /**************************************************************************
  * cpy_clk_code: relocates clock code into SRAM where its safer to execute
diff --git a/arch/arm/include/asm/arch-omap3/sys_proto.h b/arch/arm/include/asm/arch-omap3/sys_proto.h
index c06605d533d3..56126fe8e863 100644
--- a/arch/arm/include/asm/arch-omap3/sys_proto.h
+++ b/arch/arm/include/asm/arch-omap3/sys_proto.h
@@ -74,5 +74,6 @@ void dieid_num_r(void);
 void get_dieid(u32 *id);
 void do_omap3_emu_romcode_call(u32 service_id, u32 parameters);
 void omap_smc1(u32 service, u32 val);
+void omap3_update_aux_cr_secure(u32 set_bits, u32 clear_bits);
 u32 warm_reset(void);
 #endif
-- 
1.7.9.5