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ARM: 7773/1: PJ4B: Add support for errata 4742

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This commit fixes the regression on Armada 370 (the kernal hang during
boot) introduced by the commit: "ARM: 7691/1: mm: kill unused
TLB_CAN_READ_FROM_L1_CACHE and use ALT_SMP instead".

When coming out of either a Wait for Interrupt (WFI) or a Wait for
Event (WFE) IDLE states, a specific timing sensitivity exists between
the retiring WFI/WFE instructions and the newly issued subsequent
instructions. This sensitivity can result in a CPU hang scenario.  The
workaround is to insert either a Data Synchronization Barrier (DSB) or
Data Memory Barrier (DMB) command immediately after the WFI/WFE
instruction.

This commit was based on the work of Lior Amsalem, but heavily
modified to apply the errata fix dynamically according to the
processor type thanks to the suggestions of Russell King and Nicolas
Pitre.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Gregory CLEMENT 2013-06-23 10:17:11 +01:00 committed by Russell King
parent 63384fd0b1
commit 3e0a07f8c4
4 changed files with 59 additions and 3 deletions
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14
arch/arm/Kconfig
View File

@ -1087,6 +1087,20 @@ if !MMU
source "arch/arm/Kconfig-nommu"
endif
config PJ4B_ERRATA_4742
bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
depends on CPU_PJ4B && MACH_ARMADA_370
default y
help
When coming out of either a Wait for Interrupt (WFI) or a Wait for
Event (WFE) IDLE states, a specific timing sensitivity exists between
the retiring WFI/WFE instructions and the newly issued subsequent
instructions. This sensitivity can result in a CPU hang scenario.
Workaround:
The software must insert either a Data Synchronization Barrier (DSB)
or Data Memory Barrier (DMB) command immediately after the WFI/WFE
instruction
config ARM_ERRATA_326103
bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
depends on CPU_V6

9
arch/arm/include/asm/glue-proc.h
View File

@ -230,6 +230,15 @@
# endif
#endif
#ifdef CONFIG_CPU_PJ4B
# ifdef CPU_NAME
# undef MULTI_CPU
# define MULTI_CPU
# else
# define CPU_NAME cpu_pj4b
# endif
#endif
#ifndef MULTI_CPU
#define cpu_proc_init __glue(CPU_NAME,_proc_init)
#define cpu_proc_fin __glue(CPU_NAME,_proc_fin)

5
arch/arm/mm/proc-macros.S
View File

@ -333,3 +333,8 @@ ENTRY(\name\()_tlb_fns)
.endif
.size \name\()_tlb_fns, . - \name\()_tlb_fns
.endm
.macro globl_equ x, y
.globl \x
.equ \x, \y
.endm

34
arch/arm/mm/proc-v7.S
View File

@ -138,6 +138,29 @@ ENTRY(cpu_v7_do_resume)
mov r0, r8 @ control register
b cpu_resume_mmu
ENDPROC(cpu_v7_do_resume)
#endif
#ifdef CONFIG_CPU_PJ4B
globl_equ cpu_pj4b_switch_mm, cpu_v7_switch_mm
globl_equ cpu_pj4b_set_pte_ext, cpu_v7_set_pte_ext
globl_equ cpu_pj4b_proc_init, cpu_v7_proc_init
globl_equ cpu_pj4b_proc_fin, cpu_v7_proc_fin
globl_equ cpu_pj4b_reset, cpu_v7_reset
#ifdef CONFIG_PJ4B_ERRATA_4742
ENTRY(cpu_pj4b_do_idle)
dsb @ WFI may enter a low-power mode
wfi
dsb @barrier
mov pc, lr
ENDPROC(cpu_pj4b_do_idle)
#else
globl_equ cpu_pj4b_do_idle, cpu_v7_do_idle
#endif
globl_equ cpu_pj4b_dcache_clean_area, cpu_v7_dcache_clean_area
globl_equ cpu_pj4b_do_suspend, cpu_v7_do_suspend
globl_equ cpu_pj4b_do_resume, cpu_v7_do_resume
globl_equ cpu_pj4b_suspend_size, cpu_v7_suspend_size
#endif
__CPUINIT
@ -350,6 +373,9 @@ __v7_setup_stack:
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#ifdef CONFIG_CPU_PJ4B
define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
#endif
.section ".rodata"
@ -362,7 +388,7 @@ __v7_setup_stack:
/*
* Standard v7 proc info content
*/
.macro __v7_proc initfunc, mm_mmuflags = 0, io_mmuflags = 0, hwcaps = 0
.macro __v7_proc initfunc, mm_mmuflags = 0, io_mmuflags = 0, hwcaps = 0, proc_fns = v7_processor_functions
ALT_SMP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | \
PMD_SECT_AF | PMD_FLAGS_SMP | \mm_mmuflags)
ALT_UP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | \
@ -375,7 +401,7 @@ __v7_setup_stack:
.long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB | HWCAP_FAST_MULT | \
HWCAP_EDSP | HWCAP_TLS | \hwcaps
.long cpu_v7_name
.long v7_processor_functions
.long \proc_fns
.long v7wbi_tlb_fns
.long v6_user_fns
.long v7_cache_fns
@ -407,12 +433,14 @@ __v7_ca9mp_proc_info:
/*
* Marvell PJ4B processor.
*/
#ifdef CONFIG_CPU_PJ4B
.type __v7_pj4b_proc_info, #object
__v7_pj4b_proc_info:
.long 0x560f5800
.long 0xff0fff00
__v7_proc __v7_pj4b_setup
__v7_proc __v7_pj4b_setup, proc_fns = pj4b_processor_functions
.size __v7_pj4b_proc_info, . - __v7_pj4b_proc_info
#endif
/*
* ARM Ltd. Cortex A7 processor.