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ARC: mm: arc700: Don't assume 2 colours for aliasing VIPT dcache

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An ARC700 customer reported linux boot crashes when upgrading to bigger
L1 dcache (64K from 32K). Turns out they had an aliasing VIPT config and
current code only assumed 2 colours, while theirs had 4. So default to 4
colours and complain if there are fewer. Ideally this needs to be a
Kconfig option, but heck that's too much of hassle for a single user.

Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2016-12-19 11:38:38 -08:00
parent f64915be2d
commit 08fe007968
2 changed files with 12 additions and 5 deletions
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6
arch/arc/include/asm/cacheflush.h
View file

@ -85,6 +85,10 @@ void flush_anon_page(struct vm_area_struct *vma,
*/
#define PG_dc_clean PG_arch_1
#define CACHE_COLORS_NUM 4
#define CACHE_COLORS_MSK (CACHE_COLORS_NUM - 1)
#define CACHE_COLOR(addr) (((unsigned long)(addr) >> (PAGE_SHIFT)) & CACHE_COLORS_MSK)
/*
* Simple wrapper over config option
* Bootup code ensures that hardware matches kernel configuration
@ -94,8 +98,6 @@ static inline int cache_is_vipt_aliasing(void)
return IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
}
#define CACHE_COLOR(addr) (((unsigned long)(addr) >> (PAGE_SHIFT)) & 1)
/*
* checks if two addresses (after page aligning) index into same cache set
*/

11
arch/arc/mm/cache.c
View file

@ -972,11 +972,16 @@ void arc_cache_init(void)
/* check for D-Cache aliasing on ARCompact: ARCv2 has PIPT */
if (is_isa_arcompact()) {
int handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
int num_colors = dc->sz_k/dc->assoc/TO_KB(PAGE_SIZE);
if (dc->alias && !handled)
panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
else if (!dc->alias && handled)
if (dc->alias) {
if (!handled)
panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
if (CACHE_COLORS_NUM != num_colors)
panic("CACHE_COLORS_NUM not optimized for config\n");
} else if (!dc->alias && handled) {
panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
}
}
}