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authorMatt Redfearn <matt.redfearn@imgtec.com>2016-09-07 10:45:10 +0100
committerRalf Baechle <ralf@linux-mips.org>2016-10-04 16:13:57 +0200
commitd6219420480b75258b93583caa3885fb80d83313 (patch)
treed58c4928655e95d4ef4cac1ed67234d85c82dd53 /arch/mips/kernel
parent6b89d22e742aa3fbb1878c2e6684b0bfd591f7c8 (diff)
downloadlinux-d6219420480b75258b93583caa3885fb80d83313.tar.bz2
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>
Diffstat (limited to 'arch/mips/kernel')
-rw-r--r--arch/mips/kernel/mips-cpc.c13
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();