From: "Natarajan, Janakarajan" <Janakarajan.Natarajan@amd.com>
To: "linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
"devel@acpica.org" <devel@acpica.org>
Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
Robert Moore <robert.moore@intel.com>,
Erik Schmauss <erik.schmauss@intel.com>,
"Ghannam, Yazen" <Yazen.Ghannam@amd.com>,
"Natarajan, Janakarajan" <Janakarajan.Natarajan@amd.com>
Subject: [PATCH 6/6] acpi/cppc: Add support for CPPC Enable register
Date: Fri, 22 Mar 2019 20:26:13 +0000 [thread overview]
Message-ID: <7e20fe2349bff1dc14c477c5bb456b8b1cde2994.1553285718.git.Janakarajan.Natarajan@amd.com> (raw)
In-Reply-To: <cover.1553285718.git.Janakarajan.Natarajan@amd.com>
From: Yazen Ghannam <Yazen.Ghannam@amd.com>
To enable CPPC on a processor, the OS should write a value "1" to the
CPPC Enable register. Add support for this register.
Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
[ carved out into a patch, cleaned up, productized ]
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
---
drivers/acpi/cppc_acpi.c | 96 ++++++++++++++++++++++++++++++++++++++++
include/acpi/cppc_acpi.h | 1 +
2 files changed, 97 insertions(+)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index f8827ba7015d..8c6804976bb8 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -224,6 +224,43 @@ static ssize_t show_feedback_ctrs(struct kobject *kobj,
}
define_one_cppc_ro(feedback_ctrs);
+/* Used to move ENABLE register value between userspace and platform */
+static bool cppc_cpu_enable;
+
+static ssize_t show_enable(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
+ int ret;
+
+ ret = cppc_get_enable(cpc_ptr->cpu_id);
+ if (ret)
+ return ret;
+
+ return scnprintf(buf, PAGE_SIZE, "%d\n", cppc_cpu_enable);
+}
+
+static ssize_t store_enable(struct kobject *kobj,
+ struct attribute *attr,
+ const char *c, ssize_t count)
+{
+ struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
+ int ret;
+
+ ret = kstrtobool(c, &cppc_cpu_enable);
+ if (ret)
+ return ret;
+
+ ret = cppc_set_reg(cpc_ptr->cpu_id, NULL, ENABLE);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+define_one_cppc_rw(enable);
+
static struct kobj_type cppc_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
};
@@ -794,6 +831,9 @@ int set_cppc_attrs(struct cpc_desc *cpc, int entries)
case DESIRED_PERF:
cppc_attrs[attr_i++] = &desired_perf.attr;
break;
+ case ENABLE:
+ cppc_attrs[attr_i++] = &enable.attr;
+ break;
}
}
@@ -1383,6 +1423,9 @@ int cppc_set_reg(int cpu, struct cppc_perf_ctrls *perf_ctrls,
}
switch (reg_idx) {
+ case ENABLE:
+ value = cppc_cpu_enable;
+ break;
case DESIRED_PERF:
value = perf_ctrls->desired_perf;
break;
@@ -1572,6 +1615,59 @@ int cppc_get_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
}
EXPORT_SYMBOL_GPL(cppc_get_perf);
+/**
+ * cppc_get_enable - Read a CPUs enable register.
+ * @cpu: CPU from which to read control values.
+ *
+ * Return: 0 for success.
+ */
+int cppc_get_enable(int cpu)
+{
+ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
+ int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
+ struct cpc_register_resource *enable_reg;
+ struct cppc_pcc_data *pcc_ss_data = NULL;
+ int ret = 0, regs_in_pcc = 0;
+ u64 enable;
+
+ if (!cpc_desc) {
+ pr_debug("No CPC descriptor for CPU: %d\n", cpu);
+ return -ENODEV;
+ }
+
+ enable_reg = &cpc_desc->cpc_regs[ENABLE];
+
+ if (!CPC_SUPPORTED(enable_reg)) {
+ pr_warn("CPC ENABLE register not supported.\n");
+ return -ENOTSUPP;
+ }
+
+ if (CPC_IN_PCC(enable_reg)) {
+ pcc_ss_data = pcc_data[pcc_ss_id];
+ down_write(&pcc_ss_data->pcc_lock);
+ regs_in_pcc = 1;
+ /* Ring doorbell once to update PCC subspace */
+ if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) {
+ ret = -EIO;
+ goto out_err;
+ }
+ }
+
+ if (cpc_read(cpu, enable_reg, &enable)) {
+ ret = -EFAULT;
+ goto out_err;
+ }
+
+ cppc_cpu_enable = enable;
+
+out_err:
+ if (regs_in_pcc)
+ up_write(&pcc_ss_data->pcc_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cppc_get_enable);
+
/**
* cppc_get_transition_latency - returns frequency transition latency in ns
*
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 6f651235933c..fcdedff8e6bd 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -139,6 +139,7 @@ struct cppc_cpudata {
cpumask_var_t shared_cpu_map;
};
+extern int cppc_get_enable(int cpu);
extern int cppc_get_desired_perf(int cpunum, u64 *desired_perf);
extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
extern int cppc_set_reg(int cpu, struct cppc_perf_ctrls *perf_ctrls, enum cppc_regs reg_idx);
--
2.17.1
prev parent reply other threads:[~2019-03-22 20:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-22 20:25 [PATCH 0/6] CPPC optional registers AMD support Natarajan, Janakarajan
2019-03-22 20:25 ` [PATCH 1/6] acpi/cppc: Ensure only supported CPPC sysfs entries are created Natarajan, Janakarajan
2019-03-22 20:26 ` [PATCH 2/6] acpi/cppc: Modify show_cppc_data macro Natarajan, Janakarajan
2019-03-22 20:26 ` [PATCH 3/6] acpi/cppc: Rework cppc_set_perf() to use cppc_regs index Natarajan, Janakarajan
2019-03-22 20:26 ` [PATCH 4/6] acpi/cppc: Add macros to define a R/W sysfs entry for CPPC registers Natarajan, Janakarajan
2019-03-22 20:26 ` [PATCH 5/6] acpi/cppc: Add support for optional " Natarajan, Janakarajan
2019-03-27 15:47 ` Pandruvada, Srinivas
2019-03-29 20:18 ` Ghannam, Yazen
2019-03-29 23:02 ` Rafael J. Wysocki
2019-03-30 2:40 ` Pandruvada, Srinivas
2019-03-22 20:26 ` Natarajan, Janakarajan [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7e20fe2349bff1dc14c477c5bb456b8b1cde2994.1553285718.git.Janakarajan.Natarajan@amd.com \
--to=janakarajan.natarajan@amd.com \
--cc=Yazen.Ghannam@amd.com \
--cc=devel@acpica.org \
--cc=erik.schmauss@intel.com \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=rjw@rjwysocki.net \
--cc=robert.moore@intel.com \
--cc=viresh.kumar@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).