Subject: cbe_thermal: add throttling attributes to cpu and spu nodes From: Christian Krafft This patch adds some attributes the cpu and spu nodes: /sys/devices/system/[c|s]pu/[c|s]pu*/thermal/throttle_begin /sys/devices/system/[c|s]pu/[c|s]pu*/thermal/throttle_end /sys/devices/system/[c|s]pu/[c|s]pu*/thermal/throttle_full_stop Signed-off-by: Christian Krafft Signed-off-by: Arnd Bergmann Index: linux-2.6/arch/powerpc/platforms/cell/cbe_thermal.c =================================================================== --- linux-2.6.orig/arch/powerpc/platforms/cell/cbe_thermal.c +++ linux-2.6/arch/powerpc/platforms/cell/cbe_thermal.c @@ -1,6 +1,31 @@ /* * 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 @@ -31,9 +56,24 @@ #include "cbe_regs.h" #include "spu_priv1_mmio.h" +#define TEMP_MIN 65 +#define TEMP_MAX 125 + +#define SYSDEV_PREFIX_ATTR(_prefix,_name,_mode) \ +struct sysdev_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) + 65; + 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 sys_device *sysdev) @@ -73,6 +113,73 @@ static ssize_t spu_show_temp(struct sys_ 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; + 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 sys_device *sysdev, char *buf) +{ + return show_throttle(get_pmd_regs(sysdev), buf, 0); +} + +static ssize_t spu_show_throttle_begin(struct sys_device *sysdev, char *buf) +{ + return show_throttle(get_pmd_regs(sysdev), buf, 8); +} + +static ssize_t spu_show_throttle_full_stop(struct sys_device *sysdev, char *buf) +{ + return show_throttle(get_pmd_regs(sysdev), buf, 16); +} + +static ssize_t spu_store_throttle_end(struct sys_device *sysdev, const char *buf, size_t size) +{ + return store_throttle(get_pmd_regs(sysdev), buf, size, 0); +} + +static ssize_t spu_store_throttle_begin(struct sys_device *sysdev, const char *buf, size_t size) +{ + return store_throttle(get_pmd_regs(sysdev), buf, size, 8); +} + +static ssize_t spu_store_throttle_full_stop(struct sys_device *sysdev, const char *buf, size_t size) +{ + return store_throttle(get_pmd_regs(sysdev), buf, size, 16); +} + static ssize_t ppe_show_temp(struct sys_device *sysdev, char *buf, int pos) { struct cbe_pmd_regs __iomem *pmd_regs; @@ -100,13 +207,52 @@ static ssize_t ppe_show_temp1(struct sys return ppe_show_temp(sysdev, buf, 0); } +static ssize_t ppe_show_throttle_end(struct sys_device *sysdev, char *buf) +{ + return show_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, 32); +} + +static ssize_t ppe_show_throttle_begin(struct sys_device *sysdev, char *buf) +{ + return show_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, 40); +} + +static ssize_t ppe_show_throttle_full_stop(struct sys_device *sysdev, char *buf) +{ + return show_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, 48); +} + +static ssize_t ppe_store_throttle_end(struct sys_device *sysdev, const char *buf, size_t size) +{ + return store_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, size, 32); +} + +static ssize_t ppe_store_throttle_begin(struct sys_device *sysdev, const char *buf, size_t size) +{ + return store_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, size, 40); +} + +static ssize_t ppe_store_throttle_full_stop(struct sys_device *sysdev, const char *buf, size_t size) +{ + return store_throttle(cbe_get_cpu_pmd_regs(sysdev->id), buf, size, 48); +} + + static struct sysdev_attribute attr_spu_temperature = { .attr = {.name = "temperature", .mode = 0400 }, .show = spu_show_temp, }; +static SYSDEV_PREFIX_ATTR(spu, throttle_end, 0600); +static SYSDEV_PREFIX_ATTR(spu, throttle_begin, 0600); +static SYSDEV_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, }; @@ -125,9 +271,16 @@ static struct sysdev_attribute attr_ppe_ .show = ppe_show_temp1, }; +static SYSDEV_PREFIX_ATTR(ppe, throttle_end, 0600); +static SYSDEV_PREFIX_ATTR(ppe, throttle_begin, 0600); +static SYSDEV_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, };