diff options
| author | Matt Redfearn <matt.redfearn@imgtec.com> | 2016-09-07 12:45:10 +0300 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2016-10-04 17:13:57 +0300 |
| commit | d6219420480b75258b93583caa3885fb80d83313 (patch) | |
| tree | d58c4928655e95d4ef4cac1ed67234d85c82dd53 | |
| parent | 6b89d22e742aa3fbb1878c2e6684b0bfd591f7c8 (diff) | |
| download | linux-d6219420480b75258b93583caa3885fb80d83313.tar.xz | |
MIPS: CPC: Avoid lock when MIPS CM >= 3 is present
MIPS CM version 3 removed the CPC_CL_OTHER register and instead the
CM_CL_OTHER register is used to redirect the CPC_OTHER region. As such,
we should not write the unimplmented register and can avoid the
spinlock as well.
These lock functions should aleady be called within the context of a
mips_cm_{lock,unlock}_other pair ensuring the correct CPC_OTHER region
will be accessed.
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14219/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| -rw-r--r-- | arch/mips/kernel/mips-cpc.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c index 0e337f55ac60..2a45867d3b4f 100644 --- a/arch/mips/kernel/mips-cpc.c +++ b/arch/mips/kernel/mips-cpc.c @@ -71,6 +71,11 @@ int mips_cpc_probe(void) void mips_cpc_lock_other(unsigned int core) { unsigned int curr_core; + + if (mips_cm_revision() >= CM_REV_CM3) + /* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */ + return; + preempt_disable(); curr_core = current_cpu_data.core; spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core), @@ -86,7 +91,13 @@ void mips_cpc_lock_other(unsigned int core) void mips_cpc_unlock_other(void) { - unsigned int curr_core = current_cpu_data.core; + unsigned int curr_core; + + if (mips_cm_revision() >= CM_REV_CM3) + /* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */ + return; + + curr_core = current_cpu_data.core; spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core), per_cpu(cpc_core_lock_flags, curr_core)); preempt_enable(); |