diff --git a/README b/README index 08283f52af..e918af73f9 100644 --- a/README +++ b/README @@ -690,6 +690,11 @@ The following options need to be configured: exists, unlike the similar options in the Linux kernel. Do not set these options unless they apply! + NOTE: The following can be machine specific errata. These + do have ability to provide rudimentary version and machine + specific checks, but expect no product checks. + CONFIG_ARM_ERRATA_798870 + - Tegra SoC options: CONFIG_TEGRA_SUPPORT_NON_SECURE diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile index ad22489e1a..1312a9db9e 100644 --- a/arch/arm/cpu/armv7/Makefile +++ b/arch/arm/cpu/armv7/Makefile @@ -9,7 +9,7 @@ extra-y := start.o obj-y += cache_v7.o -obj-y += cpu.o +obj-y += cpu.o cp15.o obj-y += syslib.o ifneq ($(CONFIG_AM43XX)$(CONFIG_AM33XX)$(CONFIG_OMAP44XX)$(CONFIG_OMAP54XX)$(CONFIG_TEGRA)$(CONFIG_MX6)$(CONFIG_TI81XX)$(CONFIG_AT91FAMILY)$(CONFIG_SUNXI),) diff --git a/arch/arm/cpu/armv7/cp15.c b/arch/arm/cpu/armv7/cp15.c new file mode 100644 index 0000000000..8ac81c9ba1 --- /dev/null +++ b/arch/arm/cpu/armv7/cp15.c @@ -0,0 +1,23 @@ +/* + * (C) Copyright 2015 Texas Insturments + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +/* + * CP15 specific code + */ + +#include +#include +#include +#include +#include +#include + +void __weak v7_arch_cp15_set_l2aux_ctrl(u32 l2actlr, u32 cpu_midr, + u32 cpu_rev_comb, u32 cpu_variant, + u32 cpu_rev) +{ + asm volatile ("mcr p15, 1, %0, c15, c0, 0\n\t" : : "r"(l2actlr)); +} diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S index 9b49ece2d6..89637e2639 100644 --- a/arch/arm/cpu/armv7/start.S +++ b/arch/arm/cpu/armv7/start.S @@ -166,7 +166,30 @@ ENTRY(cpu_init_cp15) mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register #endif - mov pc, lr @ back to my caller + mov r5, lr @ Store my Caller + mrc p15, 0, r1, c0, c0, 0 @ r1 has Read Main ID Register (MIDR) + mov r3, r1, lsr #20 @ get variant field + and r3, r3, #0xf @ r3 has CPU variant + and r4, r1, #0xf @ r4 has CPU revision + mov r2, r3, lsl #4 @ shift variant field for combined value + orr r2, r4, r2 @ r2 has combined CPU variant + revision + +#ifdef CONFIG_ARM_ERRATA_798870 + cmp r2, #0x30 @ Applies to lower than R3p0 + bge skip_errata_798870 @ skip if not affected rev + cmp r2, #0x20 @ Applies to including and above R2p0 + blt skip_errata_798870 @ skip if not affected rev + + mrc p15, 1, r0, c15, c0, 0 @ read l2 aux ctrl reg + orr r0, r0, #1 << 7 @ Enable hazard-detect timeout + push {r1-r5} @ Save the cpu info registers + bl v7_arch_cp15_set_l2aux_ctrl + isb @ Recommended ISB after l2actlr update + pop {r1-r5} @ Restore the cpu info - fall through +skip_errata_798870: +#endif + + mov pc, r5 @ back to my caller ENDPROC(cpu_init_cp15) #ifndef CONFIG_SKIP_LOWLEVEL_INIT diff --git a/arch/arm/include/asm/armv7.h b/arch/arm/include/asm/armv7.h index c3cc5088ea..cd4091208c 100644 --- a/arch/arm/include/asm/armv7.h +++ b/arch/arm/include/asm/armv7.h @@ -137,6 +137,9 @@ extern char __secure_end[]; #endif /* CONFIG_ARMV7_NONSEC || CONFIG_ARMV7_VIRT */ +void v7_arch_cp15_set_l2aux_ctrl(u32 l2auxctrl, u32 cpu_midr, + u32 cpu_rev_comb, u32 cpu_variant, + u32 cpu_rev); #endif /* ! __ASSEMBLY__ */ #endif