[PATCH v1 1/4] power: add uncore api to power library

[tadhgkearney <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. Power man docs updated to reflect this.

Signed-off-by: tadhgkearney <tadhg.kearney@intel.com>
---
 doc/guides/prog_guide/power_man.rst |  27 ++
 lib/power/meson.build               |   2 +
 lib/power/rte_power_uncore.c        | 401 ++++++++++++++++++++++++++++
 lib/power/rte_power_uncore.h        | 151 +++++++++++
 lib/power/version.map               |   7 +
 5 files changed, 588 insertions(+)
 create mode 100644 lib/power/rte_power_uncore.c
 create mode 100644 lib/power/rte_power_uncore.h

diff --git a/doc/guides/prog_guide/power_man.rst b/doc/guides/prog_guide/power_man.rst
index 98cfd3c1f3..a512bca0b6 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..5fd8313b03
--- /dev/null
+++ b/lib/power/rte_power_uncore.c
@@ -0,0 +1,401 @@
+/* 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..9a8917ed8b
--- /dev/null
+++ b/lib/power/rte_power_uncore.h
@@ -0,0 +1,151 @@
+/* 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 managment 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