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ARM: 8607/1: V7M: Wire up caches for V7M processors with cache support.

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This patch does the plumbing required to invoke the V7M cache code added
in earlier patches in this series, although there is no users for that
yet.

In order to honour the I/D cache disable config options, this patch changes
the mechanism by which the CCR is set on boot, to be more like V7A/R.

Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Andras Szemzo <sza@esh.hu>
Tested-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Jonathan Austin 2016-08-30 17:31:22 +01:00 committed by Russell King
parent 9a1af5f220
commit bc0ee9d24a
5 changed files with 26 additions and 11 deletions
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4
arch/arm/include/asm/glue-cache.h
View file

@ -118,11 +118,7 @@
#endif
#if defined(CONFIG_CPU_V7M)
# ifdef _CACHE
# define MULTI_CACHE 1
# else
# define _CACHE nop
# endif
#endif
#if !defined(_CACHE) && !defined(MULTI_CACHE)

16
arch/arm/kernel/head-nommu.S
View file

@ -158,7 +158,21 @@ __after_proc_init:
bic r0, r0, #CR_V
#endif
mcr p15, 0, r0, c1, c0, 0 @ write control reg
#endif /* CONFIG_CPU_CP15 */
#elif defined (CONFIG_CPU_V7M)
/* For V7M systems we want to modify the CCR similarly to the SCTLR */
#ifdef CONFIG_CPU_DCACHE_DISABLE
bic r0, r0, #V7M_SCB_CCR_DC
#endif
#ifdef CONFIG_CPU_BPREDICT_DISABLE
bic r0, r0, #V7M_SCB_CCR_BP
#endif
#ifdef CONFIG_CPU_ICACHE_DISABLE
bic r0, r0, #V7M_SCB_CCR_IC
#endif
movw r3, #:lower16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
movt r3, #:upper16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
str r0, [r3]
#endif /* CONFIG_CPU_CP15 elif CONFIG_CPU_V7M */
ret lr
ENDPROC(__after_proc_init)
.ltorg

10
arch/arm/mm/Kconfig
View file

@ -403,6 +403,7 @@ config CPU_V7M
bool
select CPU_32v7M
select CPU_ABRT_NOMMU
select CPU_CACHE_V7M
select CPU_CACHE_NOP
select CPU_PABRT_LEGACY
select CPU_THUMBONLY
@ -518,6 +519,9 @@ config CPU_CACHE_VIPT
config CPU_CACHE_FA
bool
config CPU_CACHE_V7M
bool
if MMU
# The copy-page model
config CPU_COPY_V4WT
@ -750,14 +754,14 @@ config CPU_HIGH_VECTOR
config CPU_ICACHE_DISABLE
bool "Disable I-Cache (I-bit)"
depends on CPU_CP15 && !(CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)
depends on (CPU_CP15 && !(CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)) || CPU_V7M
help
Say Y here to disable the processor instruction cache. Unless
you have a reason not to or are unsure, say N.
config CPU_DCACHE_DISABLE
bool "Disable D-Cache (C-bit)"
depends on CPU_CP15 && !SMP
depends on (CPU_CP15 && !SMP) || CPU_V7M
help
Say Y here to disable the processor data cache. Unless
you have a reason not to or are unsure, say N.
@ -792,7 +796,7 @@ config CPU_CACHE_ROUND_ROBIN
config CPU_BPREDICT_DISABLE
bool "Disable branch prediction"
depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526
depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526 || CPU_V7M
help
Say Y here to disable branch prediction. If unsure, say N.

2
arch/arm/mm/Makefile
View file

@ -43,9 +43,11 @@ obj-$(CONFIG_CPU_CACHE_V6) += cache-v6.o
obj-$(CONFIG_CPU_CACHE_V7) += cache-v7.o
obj-$(CONFIG_CPU_CACHE_FA) += cache-fa.o
obj-$(CONFIG_CPU_CACHE_NOP) += cache-nop.o
obj-$(CONFIG_CPU_CACHE_V7M) += cache-v7m.o
AFLAGS_cache-v6.o :=-Wa,-march=armv6
AFLAGS_cache-v7.o :=-Wa,-march=armv7-a
AFLAGS_cache-v7m.o :=-Wa,-march=armv7-m
obj-$(CONFIG_CPU_COPY_V4WT) += copypage-v4wt.o
obj-$(CONFIG_CPU_COPY_V4WB) += copypage-v4wb.o

5
arch/arm/mm/proc-v7m.S
View file

@ -118,9 +118,8 @@ __v7m_setup:
@ Configure the System Control Register to ensure 8-byte stack alignment
@ Note the STKALIGN bit is either RW or RAO.
ldr r12, [r0, V7M_SCB_CCR] @ system control register
orr r12, #V7M_SCB_CCR_STKALIGN
str r12, [r0, V7M_SCB_CCR]
ldr r0, [r0, V7M_SCB_CCR] @ system control register
orr r0, #V7M_SCB_CCR_STKALIGN
ret lr
ENDPROC(__v7m_setup)