Add new auxiliary driver that exposes the SoC performance limit reasons
via debugfs interface.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Signed-off-by: Tero Kristo <tero.kristo@xxxxxxxxxxxxxxx>
---
drivers/platform/x86/intel/Kconfig | 7 +
drivers/platform/x86/intel/Makefile | 1 +
drivers/platform/x86/intel/intel_plr_tpmi.c | 205 ++++++++++++++++++++
3 files changed, 213 insertions(+)
create mode 100644 drivers/platform/x86/intel/intel_plr_tpmi.c
diff --git a/drivers/platform/x86/intel/Kconfig b/drivers/platform/x86/intel/Kconfig
index e97a97355d5a..ad50bbabec61 100644
--- a/drivers/platform/x86/intel/Kconfig
+++ b/drivers/platform/x86/intel/Kconfig
@@ -209,6 +209,13 @@ config INTEL_TPMI
To compile this driver as a module, choose M here: the module will
be called intel_vsec_tpmi.
+config INTEL_PLR_TPMI
+ tristate "Intel SoC TPMI Power Limit Reasons driver"
+ depends on INTEL_TPMI
+ help
+ This driver provides the TPMI power limit reasons status information
+ via debugfs files.
+
config INTEL_TURBO_MAX_3
bool "Intel Turbo Boost Max Technology 3.0 enumeration driver"
depends on X86_64 && SCHED_MC_PRIO
diff --git a/drivers/platform/x86/intel/Makefile b/drivers/platform/x86/intel/Makefile
index 10437e56027d..74db065c82d6 100644
--- a/drivers/platform/x86/intel/Makefile
+++ b/drivers/platform/x86/intel/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_INTEL_PUNIT_IPC) += intel_punit_ipc.o
# TPMI drivers
intel_vsec_tpmi-y := tpmi.o
obj-$(CONFIG_INTEL_TPMI) += intel_vsec_tpmi.o
+obj-$(CONFIG_INTEL_PLR_TPMI) += intel_plr_tpmi.o
intel_tpmi_power_domains-y := tpmi_power_domains.o
obj-$(CONFIG_INTEL_TPMI_POWER_DOMAINS) += intel_tpmi_power_domains.o
diff --git a/drivers/platform/x86/intel/intel_plr_tpmi.c b/drivers/platform/x86/intel/intel_plr_tpmi.c
new file mode 100644
index 000000000000..5fd45dd3c396
--- /dev/null
+++ b/drivers/platform/x86/intel/intel_plr_tpmi.c
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Performance Limit Reasons via TPMI
+ *
+ * Copyright (c) 2024, Intel Corporation.
+ * All Rights Reserved.
+ */
+
+#include <linux/array_size.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/bitmap.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gfp_types.h>
+#include <linux/intel_tpmi.h>
+#include <linux/io.h>
+#include <linux/kstrtox.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/seq_file.h>
+#include <linux/sprintf.h>
+#include <linux/types.h>
+
+#define PLR_HEADER 0x00
+#define PLR_DIE_LEVEL 0x18
+
+#define PLR_INVALID GENMASK_ULL(63, 0)
+
+struct tpmi_plr_die {
+ void __iomem *base;
+};
+
+struct tpmi_plr {
+ struct dentry *dbgfs_dir;
+ struct tpmi_plr_die *die_info;
+ int num_dies;
+};
+
+static const char * const plr_coarse_reasons[] = {
+ "FREQUENCY",
+ "CURRENT",
+ "POWER",
+ "THERMAL",
+ "PLATFORM",
+ "MCP",
+ "RAS",
+ "MISC",
+ "QOS",
+ "DFC",
+};
+
+static u64 plr_read(struct tpmi_plr_die *plr_die, int offset)
+{
+ return readq(plr_die->base + offset);
+}
+
+static void plr_write(u64 val, struct tpmi_plr_die *plr_die, int offset)
+{
+ writeq(val, plr_die->base + offset);
+}
+
+static void plr_print_bits(struct seq_file *s, u64 val, int bits)
+{
+ const unsigned long mask[] = { BITMAP_FROM_U64(val) };
+ int bit;
+
+ for_each_set_bit(bit, mask, bits) {
+ if (bit >= ARRAY_SIZE(plr_coarse_reasons))
+ seq_printf(s, " UNKNOWN(%d)", bit);
+ else
+ seq_printf(s, " %s", plr_coarse_reasons[bit]);
+ }
+
+ if (!val)
+ seq_puts(s, " none");
+
+ seq_putc(s, '\n');
+}
+
+static int plr_status_show(struct seq_file *s, void *unused)
+{
+ struct tpmi_plr_die *plr_die = s->private;
+ u64 val;
+
+ val = plr_read(plr_die, PLR_DIE_LEVEL);
+ seq_puts(s, "cpus");
+ plr_print_bits(s, val, 32);
+
+ return 0;
+}
+
+static ssize_t plr_status_write(struct file *filp, const char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ struct seq_file *s = filp->private_data;
+ struct tpmi_plr_die *plr_die = s->private;
+ bool val;
+ int ret;
+
+ ret = kstrtobool_from_user(ubuf, count, &val);
+ if (ret)
+ return ret;
+
+ if (val != 0)
+ return -EINVAL;
+
+ plr_write(0, plr_die, PLR_DIE_LEVEL);
+
+ return count;
+}
+DEFINE_SHOW_STORE_ATTRIBUTE(plr_status);
+
+static int intel_plr_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id)
+{
+ struct intel_tpmi_plat_info *plat_info;
+ struct dentry *dentry;
+ int i, num_resources;
+ struct resource *res;
+ struct tpmi_plr *plr;
+ void __iomem *base;
+ char name[16];
+ int err;
+
+ plat_info = tpmi_get_platform_data(auxdev);
+ if (!plat_info)
+ return dev_err_probe(&auxdev->dev, -EINVAL, "No platform info\n");
+
+ dentry = tpmi_get_debugfs_dir(auxdev);
+ if (!dentry)
+ return dev_err_probe(&auxdev->dev, -ENODEV, "No TPMI debugfs directory.\n");
+
+ num_resources = tpmi_get_resource_count(auxdev);
+ if (!num_resources)
+ return -EINVAL;
+
+ plr = devm_kzalloc(&auxdev->dev, sizeof(*plr), GFP_KERNEL);
+ if (!plr)
+ return -ENOMEM;
+
+ plr->die_info = devm_kcalloc(&auxdev->dev, num_resources, sizeof(*plr->die_info),
+ GFP_KERNEL);
+ if (!plr->die_info)
+ return -ENOMEM;
+
+ plr->num_dies = num_resources;
+ plr->dbgfs_dir = debugfs_create_dir("plr", dentry);
+
+ for (i = 0; i < num_resources; i++) {
+ res = tpmi_get_resource_at_index(auxdev, i);
+ if (!res) {
+ err = dev_err_probe(&auxdev->dev, -EINVAL, "No resource\n");
+ goto err;
+ }
+
+ base = devm_ioremap_resource(&auxdev->dev, res);
+ if (IS_ERR(base)) {
+ err = PTR_ERR(base);
+ goto err;
+ }
+
+ plr->die_info[i].base = base;
+
+ if (plr_read(&plr->die_info[i], PLR_HEADER) == PLR_INVALID)
+ continue;
+
+ snprintf(name, sizeof(name), "domain%d", i);
+
+ dentry = debugfs_create_dir(name, plr->dbgfs_dir);
+ debugfs_create_file("status", 0444, dentry, &plr->die_info[i],
+ &plr_status_fops);
+ }
+
+ auxiliary_set_drvdata(auxdev, plr);
+
+ return 0;
+
+err:
+ debugfs_remove_recursive(plr->dbgfs_dir);
+ return err;
+}
+
+static void intel_plr_remove(struct auxiliary_device *auxdev)
+{
+ struct tpmi_plr *plr = auxiliary_get_drvdata(auxdev);
+
+ debugfs_remove_recursive(plr->dbgfs_dir);
+}
+
+static const struct auxiliary_device_id intel_plr_id_table[] = {
+ { .name = "intel_vsec.tpmi-plr" },
+ {}
+};
+MODULE_DEVICE_TABLE(auxiliary, intel_plr_id_table);
+
+static struct auxiliary_driver intel_plr_aux_driver = {
+ .id_table = intel_plr_id_table,
+ .remove = intel_plr_remove,
+ .probe = intel_plr_probe,
+};
+module_auxiliary_driver(intel_plr_aux_driver);
+
+MODULE_IMPORT_NS(INTEL_TPMI);
+MODULE_DESCRIPTION("Intel TPMI PLR Driver");
+MODULE_LICENSE("GPL");
--
2.43.1
