On 01/13/2015 05:19 AM, Bhupesh Sharma wrote:
This patch adds basic constructs in the ARMv8 u-boot code to handle and apply Cortex-A57 specific erratas.
As and example, the framework showcases how erratas 826974 and 828024 can be handled and applied.
Later on this framework can be extended to include other erratas.
Signed-off-by: Bhupesh Sharma bhupesh.sharma@freescale.com
arch/arm/cpu/armv8/start.S | 47 ++++++++++++++++++++++++++++++++++++++++++ arch/arm/include/asm/macro.h | 20 ++++++++++++++++++ 2 files changed, 67 insertions(+)
diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S index 4b11aa4..d5bcf12 100644 --- a/arch/arm/cpu/armv8/start.S +++ b/arch/arm/cpu/armv8/start.S @@ -100,6 +100,8 @@ master_cpu: WEAK(lowlevel_init) mov x29, lr /* Save LR */
- bl apply_core_errata
#if defined(CONFIG_GICV2) || defined(CONFIG_GICV3) branch_if_slave x0, 1f ldr x0, =GICD_BASE @@ -155,6 +157,51 @@ ENDPROC(smp_kick_all_cpus)
/*-----------------------------------------------------------------------*/
+WEAK(apply_core_errata)
- mov x29, lr /* Save LR */
- /* For now, we support Cortex-A57 specific errata only */
- /* Check if we are running on a Cortex-A57 core */
- branch_if_a57_core x0, 1f
- b 2f
+1:
- bl apply_a57_core_errata
+2:
- mov lr, x29 /* Restore LR */
- ret
+ENDPROC(apply_core_errata)
+/*-----------------------------------------------------------------------*/
+WEAK(apply_a57_core_errata)
- mov x29, lr /* Save LR */
+#ifdef CONFIG_ARM_ERRATA_828024
- mrs x0, S3_1_c15_c2_0 /* cpuactlr_el1 */
- /* Disable non-allocate hint of w-b-n-a memory type */
- mov x0, #0x1 << 49
- /* Disable write streaming no L1-allocate threshold */
- mov x0, #0x3 << 25
- /* Disable write streaming no-allocate threshold */
- mov x0, #0x3 << 27
- msr S3_1_c15_c2_0, x0 /* cpuactlr_el1 */
+#endif
+#ifdef CONFIG_ARM_ERRATA_826974
- mrs x0, S3_1_c15_c2_0 /* cpuactlr_el1 */
- /* Disable speculative load execution ahead of a DMB */
- mov x0, #0x1 << 59
- msr S3_1_c15_c2_0, x0 /* cpuactlr_el1 */
+#endif
- mov lr, x29 /* Restore LR */
- ret
+ENDPROC(apply_a57_core_errata)
Bhupesh,
Have you tested your patch on simulator/emulator? It seems you use x29 recursively. x29 holds the return address for function lowlevel_init. You use it multiple times, so the program will not run correctly.
Beside, you implement this framework in lowlevel_init function, which is a weak function. I guess you may have tested for LS2085A simulator, but we have a different lowlevel_init function implemented. You may want to add a new function call before "bl lowlevel_init".
York