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| author | Govindraj Raja <govindraj.raja@imgtec.com> | 2016-02-29 11:41:20 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-03-09 15:34:55 -0800 |
| commit | 75d46a71e0b86770c9f0f81d9745e16e04a27239 (patch) | |
| tree | 95ed78597282c560280c29470707d7263727eb39 | |
| parent | 760b02ed4e71d2f0b48de6c1e7edc1a708f6cbbc (diff) | |
| download | lwn-75d46a71e0b86770c9f0f81d9745e16e04a27239.tar.gz lwn-75d46a71e0b86770c9f0f81d9745e16e04a27239.zip | |
MIPS: scache: Fix scache init with invalid line size.
commit 56fa81fc9a5445938f3aa2e63d15ab63dc938ad6 upstream.
In current scache init cache line_size is determined from
cpu config register, however if there there no scache
then mips_sc_probe_cm3 function populates a invalid line_size of 2.
The invalid line_size can cause a NULL pointer deference
during r4k_dma_cache_inv as r4k_blast_scache is populated
based on line_size. Scache line_size of 2 is invalid option in
r4k_blast_scache_setup.
This issue was faced during a MIPS I6400 based virtual platform bring up
where scache was not available in virtual platform model.
Signed-off-by: Govindraj Raja <Govindraj.Raja@imgtec.com>
Fixes: 7d53e9c4cd21("MIPS: CM3: Add support for CM3 L2 cache.")
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hartley <James.Hartley@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12710/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/mips/mm/sc-mips.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/mips/mm/sc-mips.c b/arch/mips/mm/sc-mips.c index 3bd0597d9c3d..ddb8154610cc 100644 --- a/arch/mips/mm/sc-mips.c +++ b/arch/mips/mm/sc-mips.c @@ -164,11 +164,13 @@ static int __init mips_sc_probe_cm3(void) sets = cfg & CM_GCR_L2_CONFIG_SET_SIZE_MSK; sets >>= CM_GCR_L2_CONFIG_SET_SIZE_SHF; - c->scache.sets = 64 << sets; + if (sets) + c->scache.sets = 64 << sets; line_sz = cfg & CM_GCR_L2_CONFIG_LINE_SIZE_MSK; line_sz >>= CM_GCR_L2_CONFIG_LINE_SIZE_SHF; - c->scache.linesz = 2 << line_sz; + if (line_sz) + c->scache.linesz = 2 << line_sz; assoc = cfg & CM_GCR_L2_CONFIG_ASSOC_MSK; assoc >>= CM_GCR_L2_CONFIG_ASSOC_SHF; @@ -176,9 +178,12 @@ static int __init mips_sc_probe_cm3(void) c->scache.waysize = c->scache.sets * c->scache.linesz; c->scache.waybit = __ffs(c->scache.waysize); - c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT; + if (c->scache.linesz) { + c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT; + return 1; + } - return 1; + return 0; } void __weak platform_early_l2_init(void) |