CPPC performance capabilities do not change during runtime, so we can
read perf caps for all CPUs in a single CPPC read command and cache
them locally.
Signed-off-by: Prashanth Prakash <pprakash@xxxxxxxxxxxxxx>
---
drivers/acpi/cppc_acpi.c | 103 +++++++++++++++++++++++++++++++++--------------
include/acpi/cppc_acpi.h | 1 +
2 files changed, 73 insertions(+), 31 deletions(-)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 3ca0729..45f021a 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -92,6 +92,12 @@ struct cppc_pcc_data {
*/
static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr);
+/*
+ * The cppc_perf_caps structure contains the performance capabilities
+ * as described in section 8.4.7.1 of ACPI 6.1 spec
+ */
+static DEFINE_PER_CPU(struct cppc_perf_caps, cpc_perf_caps);
+
/* pcc mapped address + header size + offset within PCC subspace */
#define GET_PCC_VADDR(offs) (pcc_data.pcc_comm_addr + 0x8 + (offs))
@@ -971,49 +977,84 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
*/
int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
{
- struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
- struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf,
- *nom_perf;
- u64 high, low, nom;
- int ret = 0, regs_in_pcc = 0;
+ static bool initialized;
+ int ret = 0, i;
+ bool regs_in_pcc = false;
+ struct cppc_perf_caps *caps;
- if (!cpc_desc) {
- pr_debug("No CPC descriptor for CPU:%d\n", cpunum);
- return -ENODEV;
+ if (initialized) {
+ caps = &per_cpu(cpc_perf_caps, cpunum);
+
+ if (!caps->highest_perf || !caps->lowest_perf ||
+ !caps->nominal_perf || !caps->lowest_non_linear_perf)
+ return -EFAULT;
+
+ memcpy(perf_caps, caps, sizeof(struct cppc_perf_caps));
+ return 0;
}
- highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF];
- lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF];
- ref_perf = &cpc_desc->cpc_regs[REFERENCE_PERF];
- nom_perf = &cpc_desc->cpc_regs[NOMINAL_PERF];
+ /* Perf caps don't change over time, so read all of them at once */
+ for_each_possible_cpu(i) {
+ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, i);
+ struct cpc_register_resource *highest_reg, *lowest_reg,
+ *nom_reg, *lowest_non_linear_reg;
+ u64 perf;
- /* Are any of the regs PCC ?*/
- if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) ||
- CPC_IN_PCC(ref_perf) || CPC_IN_PCC(nom_perf)) {
- regs_in_pcc = 1;
- down_write(&pcc_data.pcc_lock);
- /* Ring doorbell once to update PCC subspace */
- if (send_pcc_cmd(CMD_READ) < 0) {
- ret = -EIO;
- goto out_err;
+ if (!cpc_desc) {
+ pr_debug("No CPC descriptor for CPU:%d\n", i);
+ continue;
+ }
+
+ highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF];
+ lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF];
+ lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF];
+ nom_reg = &cpc_desc->cpc_regs[NOMINAL_PERF];
+
+ /* Are any of the regs in PCC ?*/
+ if (!regs_in_pcc) {
+ regs_in_pcc = CPC_IN_PCC(highest_reg) ||
+ CPC_IN_PCC(lowest_reg) ||
+ CPC_IN_PCC(lowest_non_linear_reg) ||
+ CPC_IN_PCC(nom_reg);
+ if (regs_in_pcc) {
+ down_write(&pcc_data.pcc_lock);
+ /* Skip if another CPU has completed init */
+ if (initialized)
+ goto out;
+
+ /* Ring doorbell once to update PCC subspace */
+ if (send_pcc_cmd(CMD_READ) < 0) {
+ ret = -EIO;
+ goto out;
+ }
+ }
}
- }
- cpc_read(cpunum, highest_reg, &high);
- perf_caps->highest_perf = high;
+ caps = &per_cpu(cpc_perf_caps, i);
- cpc_read(cpunum, lowest_reg, &low);
- perf_caps->lowest_perf = low;
+ cpc_read(i, highest_reg, &perf);
+ caps->highest_perf = perf;
- cpc_read(cpunum, nom_perf, &nom);
- perf_caps->nominal_perf = nom;
+ cpc_read(i, lowest_reg, &perf);
+ caps->lowest_perf = perf;
- if (!high || !low || !nom)
- ret = -EFAULT;
+ cpc_read(i, nom_reg, &perf);
+ caps->nominal_perf = perf;
-out_err:
+ cpc_read(i, lowest_non_linear_reg, &perf);
+ caps->lowest_non_linear_perf = perf;
+ }
+
+ initialized = true;
+
+out:
if (regs_in_pcc)
up_write(&pcc_data.pcc_lock);
+
+ /* Copy over the per cpu data to perf_caps if init ws successful */
+ if (!ret)
+ ret = cppc_get_perf_caps(cpunum, perf_caps);
+
return ret;
}
EXPORT_SYMBOL_GPL(cppc_get_perf_caps);
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 427a7c3..3f64660 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -103,6 +103,7 @@ struct cppc_perf_caps {
u32 highest_perf;
u32 nominal_perf;
u32 lowest_perf;
+ u32 lowest_non_linear_perf;
};
struct cppc_perf_ctrls {
--
Qualcomm Datacenter Technologies on behalf of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
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