--- /dev/null
+/*
+ * thermal support for the cell processor
+ *
+ * This module adds some sysfs attributes to cpu and spu nodes.
+ * Base for measurements are the digital thermal sensors (DTS)
+ * located on the chip.
+ * The accuracy is 2 degrees, starting from 65 up to 125 degrees celsius
+ * The attributes can be found under
+ * /sys/devices/system/cpu/cpuX/thermal
+ * /sys/devices/system/spu/spuX/thermal
+ *
+ * The following attributes are added for each node:
+ * temperature:
+ * contains the current temperature measured by the DTS
+ * throttle_begin:
+ * throttling begins when temperature is greater or equal to
+ * throttle_begin. Setting this value to 125 prevents throttling.
+ * throttle_end:
+ * throttling is being ceased, if the temperature is lower than
+ * throttle_end. Due to a delay between applying throttling and
+ * a reduced temperature this value should be less than throttle_begin.
+ * A value equal to throttle_begin provides only a very little hysteresis.
+ * throttle_full_stop:
+ * If the temperatrue is greater or equal to throttle_full_stop,
+ * full throttling is applied to the cpu or spu. This value should be
+ * greater than throttle_begin and throttle_end. Setting this value to
+ * 65 prevents the unit from running code at all.
+ *
+ * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
+ *
+ * Author: Christian Krafft <krafft@de.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/cpu.h>
+#include <asm/spu.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/cell-regs.h>
+
+#include "spu_priv1_mmio.h"
+
+#define TEMP_MIN 65
+#define TEMP_MAX 125
+
+#define DEVICE_PREFIX_ATTR(_prefix,_name,_mode) \
+struct device_attribute attr_ ## _prefix ## _ ## _name = { \
+ .attr = { .name = __stringify(_name), .mode = _mode }, \
+ .show = _prefix ## _show_ ## _name, \
+ .store = _prefix ## _store_ ## _name, \
+};
+
+static inline u8 reg_to_temp(u8 reg_value)
+{
+ return ((reg_value & 0x3f) << 1) + TEMP_MIN;
+}
+
+static inline u8 temp_to_reg(u8 temp)
+{
+ return ((temp - TEMP_MIN) >> 1) & 0x3f;
+}
+
+static struct cbe_pmd_regs __iomem *get_pmd_regs(struct device *dev)
+{
+ struct spu *spu;
+
+ spu = container_of(dev, struct spu, dev);
+
+ return cbe_get_pmd_regs(spu_devnode(spu));
+}
+
+/* returns the value for a given spu in a given register */
+static u8 spu_read_register_value(struct device *dev, union spe_reg __iomem *reg)
+{
+ union spe_reg value;
+ struct spu *spu;
+
+ spu = container_of(dev, struct spu, dev);
+ value.val = in_be64(®->val);
+
+ return value.spe[spu->spe_id];
+}
+
+static ssize_t spu_show_temp(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ u8 value;
+ struct cbe_pmd_regs __iomem *pmd_regs;
+
+ pmd_regs = get_pmd_regs(dev);
+
+ value = spu_read_register_value(dev, &pmd_regs->ts_ctsr1);
+
+ return sprintf(buf, "%d\n", reg_to_temp(value));
+}
+
+static ssize_t show_throttle(struct cbe_pmd_regs __iomem *pmd_regs, char *buf, int pos)
+{
+ u64 value;
+
+ value = in_be64(&pmd_regs->tm_tpr.val);
+ /* access the corresponding byte */
+ value >>= pos;
+ value &= 0x3F;
+
+ return sprintf(buf, "%d\n", reg_to_temp(value));
+}
+
+static ssize_t store_throttle(struct cbe_pmd_regs __iomem *pmd_regs, const char *buf, size_t size, int pos)
+{
+ u64 reg_value;
+ unsigned int temp;
+ u64 new_value;
+ int ret;
+
+ ret = sscanf(buf, "%u", &temp);
+
+ if (ret != 1 || temp < TEMP_MIN || temp > TEMP_MAX)
+ return -EINVAL;
+
+ new_value = temp_to_reg(temp);
+
+ reg_value = in_be64(&pmd_regs->tm_tpr.val);
+
+ /* zero out bits for new value */
+ reg_value &= ~(0xffull << pos);
+ /* set bits to new value */
+ reg_value |= new_value << pos;
+
+ out_be64(&pmd_regs->tm_tpr.val, reg_value);
+ return size;
+}
+
+static ssize_t spu_show_throttle_end(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return show_throttle(get_pmd_regs(dev), buf, 0);
+}
+
+static ssize_t spu_show_throttle_begin(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return show_throttle(get_pmd_regs(dev), buf, 8);
+}
+
+static ssize_t spu_show_throttle_full_stop(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return show_throttle(get_pmd_regs(dev), buf, 16);
+}
+
+static ssize_t spu_store_throttle_end(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ return store_throttle(get_pmd_regs(dev), buf, size, 0);
+}
+
+static ssize_t spu_store_throttle_begin(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ return store_throttle(get_pmd_regs(dev), buf, size, 8);
+}
+
+static ssize_t spu_store_throttle_full_stop(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ return store_throttle(get_pmd_regs(dev), buf, size, 16);
+}
+
+static ssize_t ppe_show_temp(struct device *dev, char *buf, int pos)
+{
+ struct cbe_pmd_regs __iomem *pmd_regs;
+ u64 value;
+
+ pmd_regs = cbe_get_cpu_pmd_regs(dev->id);
+ value = in_be64(&pmd_regs->ts_ctsr2);
+
+ value = (value >> pos) & 0x3f;
+
+ return sprintf(buf, "%d\n", reg_to_temp(value));
+}
+
+
+/* shows the temperature of the DTS on the PPE,
+ * located near the linear thermal sensor */
+static ssize_t ppe_show_temp0(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return ppe_show_temp(dev, buf, 32);
+}
+
+/* shows the temperature of the second DTS on the PPE */
+static ssize_t ppe_show_temp1(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return ppe_show_temp(dev, buf, 0);
+}
+
+static ssize_t ppe_show_throttle_end(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 32);
+}
+
+static ssize_t ppe_show_throttle_begin(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 40);
+}
+
+static ssize_t ppe_show_throttle_full_stop(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return show_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, 48);
+}
+
+static ssize_t ppe_store_throttle_end(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 32);
+}
+
+static ssize_t ppe_store_throttle_begin(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 40);
+}
+
+static ssize_t ppe_store_throttle_full_stop(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ return store_throttle(cbe_get_cpu_pmd_regs(dev->id), buf, size, 48);
+}
+
+
+static struct device_attribute attr_spu_temperature = {
+ .attr = {.name = "temperature", .mode = 0400 },
+ .show = spu_show_temp,
+};
+
+static DEVICE_PREFIX_ATTR(spu, throttle_end, 0600);
+static DEVICE_PREFIX_ATTR(spu, throttle_begin, 0600);
+static DEVICE_PREFIX_ATTR(spu, throttle_full_stop, 0600);
+
+
+static struct attribute *spu_attributes[] = {
+ &attr_spu_temperature.attr,
+ &attr_spu_throttle_end.attr,
+ &attr_spu_throttle_begin.attr,
+ &attr_spu_throttle_full_stop.attr,
+ NULL,
+};
+
+static struct attribute_group spu_attribute_group = {
+ .name = "thermal",
+ .attrs = spu_attributes,
+};
+
+static struct device_attribute attr_ppe_temperature0 = {
+ .attr = {.name = "temperature0", .mode = 0400 },
+ .show = ppe_show_temp0,
+};
+
+static struct device_attribute attr_ppe_temperature1 = {
+ .attr = {.name = "temperature1", .mode = 0400 },
+ .show = ppe_show_temp1,
+};
+
+static DEVICE_PREFIX_ATTR(ppe, throttle_end, 0600);
+static DEVICE_PREFIX_ATTR(ppe, throttle_begin, 0600);
+static DEVICE_PREFIX_ATTR(ppe, throttle_full_stop, 0600);
+
+static struct attribute *ppe_attributes[] = {
+ &attr_ppe_temperature0.attr,
+ &attr_ppe_temperature1.attr,
+ &attr_ppe_throttle_end.attr,
+ &attr_ppe_throttle_begin.attr,
+ &attr_ppe_throttle_full_stop.attr,
+ NULL,
+};
+
+static struct attribute_group ppe_attribute_group = {
+ .name = "thermal",
+ .attrs = ppe_attributes,
+};
+
+/*
+ * initialize throttling with default values
+ */
+static int __init init_default_values(void)
+{
+ int cpu;
+ struct cbe_pmd_regs __iomem *pmd_regs;
+ struct device *dev;
+ union ppe_spe_reg tpr;
+ union spe_reg str1;
+ u64 str2;
+ union spe_reg cr1;
+ u64 cr2;
+
+ /* TPR defaults */
+ /* ppe
+ * 1F - no full stop
+ * 08 - dynamic throttling starts if over 80 degrees
+ * 03 - dynamic throttling ceases if below 70 degrees */
+ tpr.ppe = 0x1F0803;
+ /* spe
+ * 10 - full stopped when over 96 degrees
+ * 08 - dynamic throttling starts if over 80 degrees
+ * 03 - dynamic throttling ceases if below 70 degrees
+ */
+ tpr.spe = 0x100803;
+
+ /* STR defaults */
+ /* str1
+ * 10 - stop 16 of 32 cycles
+ */
+ str1.val = 0x1010101010101010ull;
+ /* str2
+ * 10 - stop 16 of 32 cycles
+ */
+ str2 = 0x10;
+
+ /* CR defaults */
+ /* cr1
+ * 4 - normal operation
+ */
+ cr1.val = 0x0404040404040404ull;
+ /* cr2
+ * 4 - normal operation
+ */
+ cr2 = 0x04;
+
+ for_each_possible_cpu (cpu) {
+ pr_debug("processing cpu %d\n", cpu);
+ dev = get_cpu_device(cpu);
+
+ if (!dev) {
+ pr_info("invalid dev pointer for cbe_thermal\n");
+ return -EINVAL;
+ }
+
+ pmd_regs = cbe_get_cpu_pmd_regs(dev->id);
+
+ if (!pmd_regs) {
+ pr_info("invalid CBE regs pointer for cbe_thermal\n");
+ return -EINVAL;
+ }
+
+ out_be64(&pmd_regs->tm_str2, str2);
+ out_be64(&pmd_regs->tm_str1.val, str1.val);
+ out_be64(&pmd_regs->tm_tpr.val, tpr.val);
+ out_be64(&pmd_regs->tm_cr1.val, cr1.val);
+ out_be64(&pmd_regs->tm_cr2, cr2);
+ }
+
+ return 0;
+}
+
+
+static int __init thermal_init(void)
+{
+ int rc = init_default_values();
+
+ if (rc == 0) {
+ spu_add_dev_attr_group(&spu_attribute_group);
+ cpu_add_dev_attr_group(&ppe_attribute_group);
+ }
+
+ return rc;
+}
+module_init(thermal_init);
+
+static void __exit thermal_exit(void)
+{
+ spu_remove_dev_attr_group(&spu_attribute_group);
+ cpu_remove_dev_attr_group(&ppe_attribute_group);
+}
+module_exit(thermal_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
+
Code Review / kvmfornfv.git / blobdiff