We need to acquire pcc_lock only when we are accessing registers
that are in the PCC subspsace.
Signed-off-by: Prashanth Prakash <pprakash@xxxxxxxxxxxxxx>
---
drivers/acpi/cppc_acpi.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 28170c2..a4b2b50 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -761,7 +761,7 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf,
*nom_perf;
u64 high, low, ref, nom;
- int ret = 0;
+ int ret = 0, regs_in_pcc = 0;
if (!cpc_desc) {
pr_debug("No CPC descriptor for CPU:%d\n", cpunum);
@@ -773,13 +773,13 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
ref_perf = &cpc_desc->cpc_regs[REFERENCE_PERF];
nom_perf = &cpc_desc->cpc_regs[NOMINAL_PERF];
- spin_lock(&pcc_lock);
-
/* Are any of the regs PCC ?*/
if ((highest_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
- (lowest_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
- (ref_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
- (nom_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)) {
+ (lowest_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
+ (ref_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
+ (nom_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)) {
+ spin_lock(&pcc_lock);
+ regs_in_pcc = 1;
/* Ring doorbell once to update PCC subspace */
if (send_pcc_cmd(CMD_READ) < 0) {
ret = -EIO;
@@ -806,7 +806,8 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
ret = -EFAULT;
out_err:
- spin_unlock(&pcc_lock);
+ if (regs_in_pcc)
+ spin_unlock(&pcc_lock);
return ret;
}
EXPORT_SYMBOL_GPL(cppc_get_perf_caps);
@@ -823,7 +824,7 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
struct cpc_register_resource *delivered_reg, *reference_reg;
u64 delivered, reference;
- int ret = 0;
+ int ret = 0, regs_in_pcc = 0;
if (!cpc_desc) {
pr_debug("No CPC descriptor for CPU:%d\n", cpunum);
@@ -833,11 +834,11 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR];
reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR];
- spin_lock(&pcc_lock);
-
/* Are any of the regs PCC ?*/
if ((delivered_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
(reference_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)) {
+ spin_lock(&pcc_lock);
+ regs_in_pcc = 1;
/* Ring doorbell once to update PCC subspace */
if (send_pcc_cmd(CMD_READ) < 0) {
ret = -EIO;
@@ -863,7 +864,8 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
perf_fb_ctrs->prev_reference = reference;
out_err:
- spin_unlock(&pcc_lock);
+ if (regs_in_pcc)
+ spin_unlock(&pcc_lock);
return ret;
}
EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs);
@@ -888,10 +890,9 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF];
- spin_lock(&pcc_lock);
-
/* If this is PCC reg, check if channel is free before writing */
if (desired_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+ spin_lock(&pcc_lock);
ret = check_pcc_chan();
if (ret)
goto busy_channel;
@@ -910,7 +911,8 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
ret = -EIO;
}
busy_channel:
- spin_unlock(&pcc_lock);
+ if (desired_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)
+ spin_unlock(&pcc_lock);
return ret;
}
EXPORT_SYMBOL_GPL(cppc_set_perf);
--
Qualcomm Technologies, Inc. on behalf
of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc.
is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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