[PATCH 12/16] cell: add temperature to SPU and CPU sysfs entries

arnd
2006-10-24T16:40:43Z

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From: Christian Krafft <krafft@de.ibm.com>

This patch adds a module that registers sysfs attributes to CPU and SPU
containing the temperature of the CBE.

They can be found under
/sys/devices/system/spu/cpuX/thermal/temperature[0|1]
/sys/devices/system/spu/spuX/thermal/temperature

The temperature is read from the on-chip temperature sensors.

Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

Index: linux-2.6/arch/powerpc/platforms/cell/Kconfig
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/Kconfig
+++ linux-2.6/arch/powerpc/platforms/cell/Kconfig
@@ -20,4 +20,9 @@ config CBE_RAS
bool "RAS features for bare metal Cell BE"
default y

+config CBE_THERM
+ tristate "CBE thermal support"
+ default m
+ depends on CBE_RAS
+
endmenu
Index: linux-2.6/arch/powerpc/platforms/cell/Makefile
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/Makefile
+++ linux-2.6/arch/powerpc/platforms/cell/Makefile
@@ -3,6 +3,8 @@ obj-$(CONFIG_PPC_CELL_NATIVE) += interr
pmu.o
obj-$(CONFIG_CBE_RAS) += ras.o

+obj-$(CONFIG_CBE_THERM) += cbe_thermal.o
+
ifeq ($(CONFIG_SMP),y)
obj-$(CONFIG_PPC_CELL_NATIVE) += smp.o
endif
Index: linux-2.6/arch/powerpc/configs/cell_defconfig
===================================================================
--- linux-2.6.orig/arch/powerpc/configs/cell_defconfig
+++ linux-2.6/arch/powerpc/configs/cell_defconfig
@@ -149,6 +149,7 @@ CONFIG_MMIO_NVRAM=y
CONFIG_SPU_FS=m
CONFIG_SPU_BASE=y
CONFIG_CBE_RAS=y
+CONFIG_CBE_THERM=m

#
# Kernel options
Index: linux-2.6/arch/powerpc/platforms/cell/cbe_thermal.c
===================================================================
--- /dev/null
+++ linux-2.6/arch/powerpc/platforms/cell/cbe_thermal.c
@@ -0,0 +1,225 @@
+/*
+ * thermal support for the cell processor
+ *
+ * (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/sysdev.h>
+#include <linux/kernel.h>
+#include <linux/cpu.h>
+#include <asm/spu.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+
+#include "cbe_regs.h"
+
+static struct cbe_pmd_regs __iomem *get_pmd_regs(struct sys_device *sysdev)
+{
+ struct spu *spu;
+
+ spu = container_of(sysdev, struct spu, sysdev);
+
+ return cbe_get_pmd_regs(spu->devnode);
+}
+
+/* returns the value for a given spu in a given register */
+static u8 spu_read_register_value(struct sys_device *sysdev, union spe_reg __iomem *reg)
+{
+ unsigned int *id;
+ union spe_reg value;
+ struct spu *spu;
+
+ /* getting the id from the reg attribute will not work on future device-tree layouts
+ * in future we should store the id to the spu struct and use it here */
+ spu = container_of(sysdev, struct spu, sysdev);
+ id = (unsigned int *)get_property(spu->devnode, "reg", NULL);
+ value.val = in_be64(&reg->val);
+
+ return value.spe[*id];
+}
+
+static ssize_t spu_show_temp(struct sys_device *sysdev, char *buf)
+{
+ int value;
+ struct cbe_pmd_regs __iomem *pmd_regs;
+
+ pmd_regs = get_pmd_regs(sysdev);
+
+ value = spu_read_register_value(sysdev, &pmd_regs->ts_ctsr1);
+ /* clear all other bits */
+ value &= 0x3F;
+ /* temp is stored in steps of 2 degrees */
+ value *= 2;
+ /* base temp is 65 degrees */
+ value += 65;
+
+ return sprintf(buf, "%d\n", (int) value);
+}
+
+static ssize_t ppe_show_temp(struct sys_device *sysdev, char *buf, int pos)
+{
+ struct cbe_pmd_regs __iomem *pmd_regs;
+ u64 value;
+
+ pmd_regs = cbe_get_cpu_pmd_regs(sysdev->id);
+ value = in_be64(&pmd_regs->ts_ctsr2);
+
+ /* access the corresponding byte */
+ value >>= pos;
+ /* clear all other bits */
+ value &= 0x3F;
+ /* temp is stored in steps of 2 degrees */
+ value *= 2;
+ /* base temp is 65 degrees */
+ value += 65;
+
+ return sprintf(buf, "%d\n", (int) value);
+}
+
+
+/* shows the temperature of the DTS on the PPE,
+ * located near the linear thermal sensor */
+static ssize_t ppe_show_temp0(struct sys_device *sysdev, char *buf)
+{
+ return ppe_show_temp(sysdev, buf, 32);
+}
+
+/* shows the temperature of the second DTS on the PPE */
+static ssize_t ppe_show_temp1(struct sys_device *sysdev, char *buf)
+{
+ return ppe_show_temp(sysdev, buf, 0);
+}
+
+static struct sysdev_attribute attr_spu_temperature = {
+ .attr = {.name = "temperature", .mode = 0400 },
+ .show = spu_show_temp,
+};
+
+static struct attribute *spu_attributes[] = {
+ &attr_spu_temperature.attr,
+};
+
+static struct attribute_group spu_attribute_group = {
+ .name = "thermal",
+ .attrs = spu_attributes,
+};
+
+static struct sysdev_attribute attr_ppe_temperature0 = {
+ .attr = {.name = "temperature0", .mode = 0400 },
+ .show = ppe_show_temp0,
+};
+
+static struct sysdev_attribute attr_ppe_temperature1 = {
+ .attr = {.name = "temperature1", .mode = 0400 },
+ .show = ppe_show_temp1,
+};
+
+static struct attribute *ppe_attributes[] = {
+ &attr_ppe_temperature0.attr,
+ &attr_ppe_temperature1.attr,
+};
+
+static struct attribute_group ppe_attribute_group = {
+ .name = "thermal",
+ .attrs = ppe_attributes,
+};
+
+/*
+ * initialize throttling with default values
+ */
+static void __init init_default_values(void)
+{
+ int cpu;
+ struct cbe_pmd_regs __iomem *pmd_regs;
+ struct sys_device *sysdev;
+ 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);
+ sysdev = get_cpu_sysdev(cpu);
+ pmd_regs = cbe_get_cpu_pmd_regs(sysdev->id);
+
+ 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);
+ }
+}
+
+
+static int __init thermal_init(void)
+{
+ init_default_values();
+
+ spu_add_sysdev_attr_group(&spu_attribute_group);
+ cpu_add_sysdev_attr_group(&ppe_attribute_group);
+
+ return 0;
+}
+module_init(thermal_init);
+
+static void __exit thermal_exit(void)
+{
+ spu_remove_sysdev_attr_group(&spu_attribute_group);
+ cpu_remove_sysdev_attr_group(&ppe_attribute_group);
+}
+module_exit(thermal_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Christian Krafft <krafft@de.ibm.com>");
+

--