[PATCH v2 1/3] power: add uncore API to power library

[Tadhg Kearney <tadhg.kearney@intel.com>]

Add api to allow uncore frequency adjustment. This is done through
manipulating related sysfs entries to adjust the min/max uncore values.
Seven api's are being added that are all public and experimental.

Signed-off-by: Tadhg Kearney <tadhg.kearney@intel.com>
---
 config/x86/meson.build              |   2 +
 doc/guides/prog_guide/power_man.rst |  27 ++
 lib/power/meson.build               |   2 +
 lib/power/rte_power_uncore.c        | 399 ++++++++++++++++++++++++++++
 lib/power/rte_power_uncore.h        | 159 +++++++++++
 lib/power/version.map               |   7 +
 6 files changed, 596 insertions(+)
 create mode 100644 lib/power/rte_power_uncore.c
 create mode 100644 lib/power/rte_power_uncore.h

diff --git a/config/x86/meson.build b/config/x86/meson.build
index 54345c4da3..f81103d8e3 100644
--- a/config/x86/meson.build
+++ b/config/x86/meson.build
@@ -73,3 +73,5 @@ endif
 dpdk_conf.set('RTE_CACHE_LINE_SIZE', 64)
 dpdk_conf.set('RTE_MAX_LCORE', 128)
 dpdk_conf.set('RTE_MAX_NUMA_NODES', 32)
+dpdk_conf.set('RTE_MAX_NUMA_DIE', 1)
+dpdk_conf.set('RTE_MAX_UNCORE_FREQS', 32)
diff --git a/doc/guides/prog_guide/power_man.rst b/doc/guides/prog_guide/power_man.rst
index 98cfd3c1f3..ec975a5556 100644
--- a/doc/guides/prog_guide/power_man.rst
+++ b/doc/guides/prog_guide/power_man.rst
@@ -276,6 +276,33 @@ API Overview for Ethernet PMD Power Management
 * **Set Scaling Max Freq**: Set the maximum frequency (kHz) to be used in Frequency
   Scaling mode.
 
+Uncore API
+----------
+
+Abstract
+~~~~~~~~
+Up to 60% power saving can be achieved by reducing the uncore frequency to its lowest value.
+With later kernels, there is now a sysfs entry to allow adjustment of uncore frequency.
+This manipulates the contest of MSR 0x620, which sets min/max of the uncore for the SKU.
+
+
+API Overview for Uncore
+~~~~~~~~~~~~~~~~~~~~~~~
+* **Uncore Power Init**: Initialise uncore power, populate frequency array and record
+  original min & max for pkg & die.
+
+* **Uncore Power Exit**: Exit uncore power, restoring original min & max for pkg & die.
+
+* **Get Uncore Power Freq**: Get current uncore freq index for pkg & die.
+
+* **Set Uncore Power Freq**: Set min & max uncore freq index for pkg & die (min and max will be the same).
+
+* **Uncore Power Max**: Set max uncore freq index for pkg & die.
+
+* **Uncore Power Min**: Set min uncore freq index for pkg & die.
+
+* **Get Num Freqs**: Get the number of frequencies in the index array.
+
 References
 ----------
 
diff --git a/lib/power/meson.build b/lib/power/meson.build
index ba8d66074b..80cdeb72d4 100644
--- a/lib/power/meson.build
+++ b/lib/power/meson.build
@@ -21,12 +21,14 @@ sources = files(
         'rte_power.c',
         'rte_power_empty_poll.c',
         'rte_power_pmd_mgmt.c',
+        'rte_power_uncore.c',
 )
 headers = files(
         'rte_power.h',
         'rte_power_empty_poll.h',
         'rte_power_pmd_mgmt.h',
         'rte_power_guest_channel.h',
+        'rte_power_uncore.h',
 )
 if cc.has_argument('-Wno-cast-qual')
     cflags += '-Wno-cast-qual'
diff --git a/lib/power/rte_power_uncore.c b/lib/power/rte_power_uncore.c
new file mode 100644
index 0000000000..184df7013b
--- /dev/null
+++ b/lib/power/rte_power_uncore.c
@@ -0,0 +1,399 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2022 Intel Corporation
+ */
+
+#include <errno.h>
+
+#include <rte_memcpy.h>
+
+#include "rte_power_uncore.h"
+#include "power_common.h"
+
+#define BUS_FREQ     100000
+
+#define POWER_GOVERNOR_PERF "performance"
+#define POWER_UNCORE_SYSFILE_MAX_FREQ \
+		"/sys/devices/system/cpu/intel_uncore_frequency/package_%02u_die_%02u/max_freq_khz"
+#define POWER_UNCORE_SYSFILE_MIN_FREQ  \
+		"/sys/devices/system/cpu/intel_uncore_frequency/package_%02u_die_%02u/min_freq_khz"
+#define POWER_UNCORE_SYSFILE_BASE_MAX_FREQ \
+		"/sys/devices/system/cpu/intel_uncore_frequency/package_%02u_die_%02u/initial_max_freq_khz"
+#define POWER_UNCORE_SYSFILE_BASE_MIN_FREQ  \
+		"/sys/devices/system/cpu/intel_uncore_frequency/package_%02u_die_%02u/initial_min_freq_khz"
+
+
+struct uncore_power_info {
+	unsigned int die;                    /**< Core die id */
+	unsigned int pkg;                    /**< Package id */
+	uint32_t freqs[RTE_MAX_UNCORE_FREQS];/**< Frequency array */
+	uint32_t nb_freqs;                   /**< Number of available freqs */
+	FILE *f_cur_min;                     /**< FD of scaling_min */
+	FILE *f_cur_max;                     /**< FD of scaling_max */
+	FILE *f_base_min;                    /**< FD of initial min */
+	FILE *f_base_max;                    /**< FD of initial max */
+	int cur_idx;                         /**< Freq index in freqs array */
+	uint32_t init_max_freq;              /**< Initial max frequency */
+	uint32_t init_min_freq;              /**< Initial min frequency */
+} __rte_cache_aligned;
+
+
+static struct uncore_power_info uncore_info[RTE_MAX_NUMA_NODES][RTE_MAX_NUMA_DIE];
+
+static int
+set_uncore_freq_internal(struct uncore_power_info *ui, uint32_t idx)
+{
+	uint32_t target_uncore_freq, curr_max_freq;
+	int ret;
+
+	if (idx >= RTE_MAX_UNCORE_FREQS || idx >= ui->nb_freqs) {
+		RTE_LOG(ERR, POWER, "Invalid uncore frequency index %u, which "
+				"should be less than %u\n", idx, ui->nb_freqs);
+		return -1;
+	}
+
+	target_uncore_freq = ui->freqs[idx];
+
+	if (fprintf(ui->f_cur_min, "%u", target_uncore_freq) < 0) {
+		RTE_LOG(ERR, POWER, "Fail to write new uncore frequency for "
+				"pkg %02u die %02u\n", ui->pkg, ui->die);
+		return -1;
+	}
+
+	if (fprintf(ui->f_cur_max, "%u", target_uncore_freq) < 0) {
+		RTE_LOG(ERR, POWER, "Fail to write new uncore frequency for "
+				"pkg %02u die %02u\n", ui->pkg, ui->die);
+		return -1;
+	}
+
+	POWER_DEBUG_TRACE("Uncore requency '%u' to be set for pkg %02u die %02u\n",
+				target_uncore_freq, ui->pkg, ui->die);
+
+	open_core_sysfs_file(&ui->f_cur_max, "rw+", POWER_UNCORE_SYSFILE_MAX_FREQ,
+			ui->pkg, ui->die);
+	if (ui->f_cur_max == NULL) {
+		RTE_LOG(DEBUG, POWER, "failed to open %s\n",
+				POWER_UNCORE_SYSFILE_MAX_FREQ);
+		return -1;
+	}
+	ret = read_core_sysfs_u32(ui->f_cur_max, &curr_max_freq);
+		if (ret < 0) {
+			RTE_LOG(DEBUG, POWER, "Failed to read %s\n",
+					POWER_UNCORE_SYSFILE_MAX_FREQ);
+			fclose(ui->f_cur_max);
+			return -1;
+		}
+
+	if (target_uncore_freq <= curr_max_freq) {
+		fflush(ui->f_cur_min);
+		fflush(ui->f_cur_max);
+	} else {
+		fflush(ui->f_cur_max);
+		fflush(ui->f_cur_min);
+	}
+
+	ui->cur_idx = idx;
+
+	return 0;
+}
+
+/**
+ * Fopen the sys file for the future setting of the uncore die frequency.
+ */
+static int
+power_init_for_setting_uncore_freq(struct uncore_power_info *ui)
+{
+	FILE *f_base_min = NULL, *f_base_max = NULL, *f_min = NULL, *f_max = NULL;
+	uint32_t base_min_freq, base_max_freq, min_freq, max_freq;
+	int ret;
+
+	/* open and read all uncore sys files */
+	/* Base_max */
+	open_core_sysfs_file(&f_base_max, "r", POWER_UNCORE_SYSFILE_BASE_MAX_FREQ,
+			ui->pkg, ui->die);
+	if (f_base_max == NULL) {
+		RTE_LOG(DEBUG, POWER, "failed to open %s\n",
+				POWER_UNCORE_SYSFILE_BASE_MAX_FREQ);
+		goto err;
+	}
+	ret = read_core_sysfs_u32(f_base_max, &base_max_freq);
+	if (ret < 0) {
+		RTE_LOG(DEBUG, POWER, "Failed to read %s\n",
+				POWER_UNCORE_SYSFILE_BASE_MAX_FREQ);
+		goto err;
+	}
+
+	/* Base min */
+	open_core_sysfs_file(&f_base_min, "r", POWER_UNCORE_SYSFILE_BASE_MIN_FREQ,
+		ui->pkg, ui->die);
+	if (f_base_min == NULL) {
+		RTE_LOG(DEBUG, POWER, "failed to open %s\n",
+				POWER_UNCORE_SYSFILE_BASE_MIN_FREQ);
+		goto err;
+	}
+	if (f_base_min != NULL) {
+		ret = read_core_sysfs_u32(f_base_min, &base_min_freq);
+		if (ret < 0) {
+			RTE_LOG(DEBUG, POWER, "Failed to read %s\n",
+					POWER_UNCORE_SYSFILE_BASE_MIN_FREQ);
+			goto err;
+		}
+	}
+
+	/* Curr min */
+	open_core_sysfs_file(&f_min, "rw+", POWER_UNCORE_SYSFILE_MIN_FREQ,
+			ui->pkg, ui->die);
+	if (f_min == NULL) {
+		RTE_LOG(DEBUG, POWER, "failed to open %s\n",
+				POWER_UNCORE_SYSFILE_MIN_FREQ);
+		goto err;
+	}
+	if (f_min != NULL) {
+		ret = read_core_sysfs_u32(f_min, &min_freq);
+		if (ret < 0) {
+			RTE_LOG(DEBUG, POWER, "Failed to read %s\n",
+					POWER_UNCORE_SYSFILE_MIN_FREQ);
+			goto err;
+		}
+	}
+
+	/* Curr max */
+	open_core_sysfs_file(&f_max, "rw+", POWER_UNCORE_SYSFILE_MAX_FREQ,
+			ui->pkg, ui->die);
+	if (f_max == NULL) {
+		RTE_LOG(DEBUG, POWER, "failed to open %s\n",
+				POWER_UNCORE_SYSFILE_MAX_FREQ);
+		goto err;
+	}
+	if (f_max != NULL) {
+		ret = read_core_sysfs_u32(f_max, &max_freq);
+		if (ret < 0) {
+			RTE_LOG(DEBUG, POWER, "Failed to read %s\n",
+					POWER_UNCORE_SYSFILE_MAX_FREQ);
+			goto err;
+		}
+	}
+
+	/* assign file handles */
+	ui->f_cur_min = f_min;
+	ui->f_cur_max = f_max;
+	ui->f_base_max = f_base_max;
+	ui->f_base_min = f_base_min;
+	ui->init_max_freq = base_max_freq;
+	ui->init_min_freq = base_min_freq;
+
+	return 0;
+
+err:
+	if (f_base_min != NULL)
+		fclose(f_base_min);
+	if (f_base_max != NULL)
+		fclose(f_base_max);
+	if (f_min != NULL)
+		fclose(f_min);
+	if (f_max != NULL)
+		fclose(f_max);
+	return -1;
+}
+
+/**
+ * Get the available uncore frequencies of the specific die by reading the
+ * sys file.
+ */
+static int
+power_get_available_uncore_freqs(struct uncore_power_info *ui)
+{
+	int ret = -1;
+	uint32_t i, num_uncore_freqs = 0;
+
+	num_uncore_freqs = (ui->init_max_freq - ui->init_min_freq) / BUS_FREQ + 1;
+	if (num_uncore_freqs >= RTE_MAX_UNCORE_FREQS) {
+		RTE_LOG(ERR, POWER, "Too many available uncore frequencies: %d\n",
+				num_uncore_freqs);
+		goto out;
+	}
+
+	/* Generate the uncore freq bucket array. */
+	for (i = 0; i < num_uncore_freqs; i++)
+		ui->freqs[i] = ui->init_max_freq - (i) * BUS_FREQ;
+
+	ui->nb_freqs = num_uncore_freqs;
+
+	ret = 0;
+
+	POWER_DEBUG_TRACE("%d uncore frequency(s) of pkg %02u die %02u are available\n",
+			num_uncore_freqs, ui->pkg, ui->die);
+
+out:
+	return ret;
+}
+
+
+int
+rte_power_uncore_init(unsigned int pkg, unsigned int die)
+{
+	struct uncore_power_info *ui;
+
+	/* Check if pkg and die values are viable */
+	if (pkg >= RTE_MAX_NUMA_NODES) {
+		RTE_LOG(DEBUG, POWER, "Package number %02u can not exceed %u\n",
+				pkg, RTE_MAX_NUMA_NODES - 1U);
+		return -1;
+	}
+
+	if (die >= RTE_MAX_NUMA_DIE) {
+		RTE_LOG(DEBUG, POWER, "Die number %02u can not exceed %u\n",
+				die, RTE_MAX_NUMA_DIE - 1U);
+		return -1;
+	}
+
+	ui = &uncore_info[pkg][die];
+	ui->die = die;
+	ui->pkg = pkg;
+
+	/* Init for setting unocre die frequency */
+	if (power_init_for_setting_uncore_freq(ui) < 0) {
+		RTE_LOG(DEBUG, POWER, "Cannot init for setting uncore frequency for "
+				"pkg %02u die %02u\n", pkg, die);
+		return -1;
+	}
+
+	/* Get the available frequencies */
+	if (power_get_available_uncore_freqs(ui) < 0) {
+		RTE_LOG(DEBUG, POWER, "Cannot get available uncore frequencies of "
+				"pkg %02u die %02u\n", pkg, die);
+		return -1;
+	}
+
+	return 0;
+}
+
+int
+rte_power_uncore_exit(unsigned int pkg, unsigned int die)
+{
+	struct uncore_power_info *ui;
+
+	if (pkg >= RTE_MAX_NUMA_NODES) {
+		RTE_LOG(DEBUG, POWER, "Package number %02u can not exceed %u\n",
+				pkg, RTE_MAX_NUMA_NODES - 1U);
+		return -1;
+	}
+
+	if (die >= RTE_MAX_NUMA_DIE) {
+		RTE_LOG(DEBUG, POWER, "Die number %02u can not exceed %u\n",
+				die, RTE_MAX_NUMA_DIE - 1U);
+		return -1;
+	}
+
+	ui = &uncore_info[pkg][die];
+
+	/* Close FD of setting freq */
+	fclose(ui->f_cur_min);
+	fclose(ui->f_cur_max);
+	fclose(ui->f_base_max);
+	fclose(ui->f_base_min);
+	ui->f_cur_min = NULL;
+	ui->f_cur_max = NULL;
+	ui->f_base_min = NULL;
+	ui->f_base_max = NULL;
+
+	return 0;
+}
+
+int
+rte_power_get_uncore_freq(unsigned int pkg, unsigned int die)
+{
+	if (pkg >= RTE_MAX_NUMA_NODES) {
+		RTE_LOG(DEBUG, POWER, "Invalid package number\n");
+		return -1;
+	}
+
+	if (die >= RTE_MAX_NUMA_DIE) {
+		RTE_LOG(DEBUG, POWER, "Invalid die number\n");
+		return -1;
+	}
+
+	return uncore_info[pkg][die].cur_idx;
+}
+
+int
+rte_power_set_uncore_freq(unsigned int pkg, unsigned int die, uint32_t index)
+{
+	if (pkg >= RTE_MAX_NUMA_NODES) {
+		RTE_LOG(DEBUG, POWER, "Invalid package number\n");
+		return -1;
+	}
+
+	if (die >= RTE_MAX_NUMA_DIE) {
+		RTE_LOG(DEBUG, POWER, "Invalid die number\n");
+		return -1;
+	}
+
+	return set_uncore_freq_internal(&(uncore_info[pkg][die]), index);
+}
+
+int
+rte_power_uncore_freq_max(unsigned int pkg, unsigned int die)
+{
+	if (pkg >= RTE_MAX_NUMA_NODES) {
+		RTE_LOG(DEBUG, POWER, "Invalid package number\n");
+		return -1;
+	}
+
+	if (die >= RTE_MAX_NUMA_DIE) {
+		RTE_LOG(DEBUG, POWER, "Invalid die number\n");
+		return -1;
+	}
+
+	struct uncore_power_info *ui = &uncore_info[pkg][die];
+
+	if (fprintf(ui->f_cur_max, "%u", 0) < 0) {
+		RTE_LOG(ERR, POWER, "Fail to write new uncore frequency for "
+				"pkg %02u die %02u\n", ui->pkg, ui->die);
+		return -1;
+	}
+
+	fflush(ui->f_cur_max);
+	return 0;
+}
+
+
+int
+rte_power_uncore_freq_min(unsigned int pkg, unsigned int die)
+{
+	if (pkg >= RTE_MAX_NUMA_NODES) {
+		RTE_LOG(DEBUG, POWER, "Invalid package number\n");
+		return -1;
+	}
+
+	if (die >= RTE_MAX_NUMA_DIE) {
+		RTE_LOG(DEBUG, POWER, "Invalid die number\n");
+		return -1;
+	}
+
+	struct uncore_power_info *ui = &uncore_info[pkg][die];
+
+	if (fprintf(ui->f_cur_min, "%u",  ui->freqs[ui->nb_freqs - 1]) < 0) {
+		RTE_LOG(ERR, POWER, "Fail to write new uncore frequency for "
+				"pkg %02u die %02u\n", ui->pkg, ui->die);
+		return -1;
+	}
+
+	fflush(ui->f_cur_min);
+	return 0;
+}
+
+int
+rte_power_uncore_get_num_freqs(unsigned int pkg, unsigned int die)
+{
+	if (pkg >= RTE_MAX_NUMA_NODES) {
+		RTE_LOG(DEBUG, POWER, "Invalid package number\n");
+		return -1;
+	}
+
+	if (die >= RTE_MAX_NUMA_DIE) {
+		RTE_LOG(DEBUG, POWER, "Invalid die number\n");
+		return -1;
+	}
+
+	return uncore_info[pkg][die].nb_freqs;
+}
diff --git a/lib/power/rte_power_uncore.h b/lib/power/rte_power_uncore.h
new file mode 100644
index 0000000000..6376c3da11
--- /dev/null
+++ b/lib/power/rte_power_uncore.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2022 Intel Corporation
+ */
+
+#ifndef _RTE_POWER_UNCORE_H
+#define _RTE_POWER_UNCORE_H
+
+/**
+ * @file
+ * RTE Uncore Frequency Management
+ */
+
+#include "rte_power.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Initialize uncore frequency management for specific die on a package. It will check and set the
+ * governor to performance for the die, get the available frequencies, and
+ * prepare to set new die frequency.
+ *
+ * This function should NOT be called in the fast path.
+ *
+ * @param pkg
+ *  Package number.
+ * @param die
+ *  Die number.
+ *
+ * @return
+ *  - 0 on success.
+ *  - Negative on error.
+ */
+__rte_experimental
+int
+rte_power_uncore_init(unsigned int pkg, unsigned int die);
+
+/**
+ * Exit uncore frequency management on a specific die on a package. It will set the governor to
+ * which is before initialized.
+ *
+ * This function should NOT be called in the fast path.
+ *
+ * @param pkg
+ *  Package number.
+ * @param die
+ *  Die number.
+ *
+ * @return
+ *  - 0 on success.
+ *  - Negative on error.
+ */
+__rte_experimental
+int
+rte_power_uncore_exit(unsigned int pkg, unsigned int die);
+
+/**
+ * Return the current index of available frequencies of a specific die on a package.
+ * It should be protected outside of this function for threadsafe.
+ *
+ * This function should NOT be called in the fast path.
+ *
+ * @param pkg
+ *  Package number.
+ * @param die
+ *  Die number.
+ *
+ * @return
+ *  - The current index of available frequencies.
+ *  - Negative on error.
+ */
+__rte_experimental
+int
+rte_power_get_uncore_freq(unsigned int pkg, unsigned int die);
+
+/**
+ * Set the new frequency for a specific die on a package by indicating the index of
+ * available frequencies.
+ * It should be protected outside of this function for threadsafe.
+ *
+ * This function should NOT be called in the fast path.
+ *
+ * @param pkg
+ *  Package number.
+ * @param die
+ *  Die number.
+ * @param index
+ *  The index of available frequencies.
+ *
+ * @return
+ *  - 0 on success.
+ *  - Negative on error.
+ */
+__rte_experimental
+int
+rte_power_set_uncore_freq(unsigned int pkg, unsigned int die, uint32_t index);
+
+/**
+ * Scale up the frequency of a specific die on a package to the highest according to the
+ * available frequencies.
+ * It should be protected outside of this function for threadsafe.
+ *
+ * This function should NOT be called in the fast path.
+ *
+ * @param pkg
+ *  Package number.
+ * @param die
+ *  Die number.
+ *
+ * @return
+ *  - 0 on success.
+ *  - Negative on error.
+ */
+__rte_experimental
+int
+rte_power_uncore_freq_max(unsigned int pkg, unsigned int die);
+
+/**
+ * Scale down the frequency of a specific die on a package to the lowest according to the
+ * available frequencies.
+ * It should be protected outside of this function for threadsafe.
+ *
+ * This function should NOT be called in the fast path.
+ *
+ * @param pkg
+ *  Package number.
+ * @param die
+ *  Die number.
+ *
+ * @return
+ *  - 0 on success.
+ *  - Negative on error.
+ */
+__rte_experimental
+int
+rte_power_uncore_freq_min(unsigned int pkg, unsigned int die);
+
+/**
+ * Return the list length of available frequencies in the index array
+ *
+ * @param pkg
+ *  Package number.
+ * @param die
+ *  Die number.
+ *
+ * @return
+ *  - The number of available index's in frequency array
+ *  - Negative on error
+ */
+__rte_experimental
+int
+rte_power_uncore_get_num_freqs(unsigned int pkg, unsigned int die);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/lib/power/version.map b/lib/power/version.map
index a687754f4a..e9681df291 100644
--- a/lib/power/version.map
+++ b/lib/power/version.map
@@ -48,4 +48,11 @@ EXPERIMENTAL {
 	rte_power_pmd_mgmt_set_pause_duration;
 	rte_power_pmd_mgmt_set_scaling_freq_max;
 	rte_power_pmd_mgmt_set_scaling_freq_min;
+	rte_power_uncore_init;
+	rte_power_uncore_exit;
+	rte_power_get_uncore_freq;
+	rte_power_set_uncore_freq;
+	rte_power_uncore_freq_max;
+	rte_power_uncore_freq_min;
+	rte_power_uncore_get_num_freqs;
 };
-- 
2.25.1