diff options
Diffstat (limited to 'drivers/idle/i7300_idle.c')
| -rw-r--r-- | drivers/idle/i7300_idle.c | 612 |
1 files changed, 0 insertions, 612 deletions
diff --git a/drivers/idle/i7300_idle.c b/drivers/idle/i7300_idle.c deleted file mode 100644 index ffeebc7e9f1c..000000000000 --- a/drivers/idle/i7300_idle.c +++ /dev/null @@ -1,612 +0,0 @@ -/* - * (C) Copyright 2008 Intel Corporation - * Authors: - * Andy Henroid <andrew.d.henroid@intel.com> - * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> - */ - -/* - * Save DIMM power on Intel 7300-based platforms when all CPUs/cores - * are idle, using the DIMM thermal throttling capability. - * - * This driver depends on the Intel integrated DMA controller (I/O AT). - * If the driver for I/O AT (drivers/dma/ioatdma*) is also enabled, - * this driver should work cooperatively. - */ - -/* #define DEBUG */ - -#include <linux/module.h> -#include <linux/pci.h> -#include <linux/gfp.h> -#include <linux/sched.h> -#include <linux/notifier.h> -#include <linux/cpumask.h> -#include <linux/ktime.h> -#include <linux/delay.h> -#include <linux/debugfs.h> -#include <linux/stop_machine.h> -#include <linux/i7300_idle.h> - -#include <asm/idle.h> - -#include "../dma/ioat/hw.h" -#include "../dma/ioat/registers.h" - -#define I7300_IDLE_DRIVER_VERSION "1.55" -#define I7300_PRINT "i7300_idle:" - -#define MAX_STOP_RETRIES 10 - -static int debug; -module_param_named(debug, debug, uint, 0644); -MODULE_PARM_DESC(debug, "Enable debug printks in this driver"); - -static int forceload; -module_param_named(forceload, forceload, uint, 0644); -MODULE_PARM_DESC(debug, "Enable driver testing on unvalidated i5000"); - -#define dprintk(fmt, arg...) \ - do { if (debug) printk(KERN_INFO I7300_PRINT fmt, ##arg); } while (0) - -/* - * Value to set THRTLOW to when initiating throttling - * 0 = No throttling - * 1 = Throttle when > 4 activations per eval window (Maximum throttling) - * 2 = Throttle when > 8 activations - * 168 = Throttle when > 672 activations (Minimum throttling) - */ -#define MAX_THROTTLE_LOW_LIMIT 168 -static uint throttle_low_limit = 1; -module_param_named(throttle_low_limit, throttle_low_limit, uint, 0644); -MODULE_PARM_DESC(throttle_low_limit, - "Value for THRTLOWLM activation field " - "(0 = disable throttle, 1 = Max throttle, 168 = Min throttle)"); - -/* - * simple invocation and duration statistics - */ -static unsigned long total_starts; -static unsigned long total_us; - -#ifdef DEBUG -static unsigned long past_skip; -#endif - -static struct pci_dev *fbd_dev; - -static raw_spinlock_t i7300_idle_lock; -static int i7300_idle_active; - -static u8 i7300_idle_thrtctl_saved; -static u8 i7300_idle_thrtlow_saved; -static u32 i7300_idle_mc_saved; - -static cpumask_var_t idle_cpumask; -static ktime_t start_ktime; -static unsigned long avg_idle_us; - -static struct dentry *debugfs_dir; - -/* Begin: I/O AT Helper routines */ - -#define IOAT_CHANBASE(ioat_ctl, chan) (ioat_ctl + 0x80 + 0x80 * chan) -/* Snoop control (disable snoops when coherency is not important) */ -#define IOAT_DESC_SADDR_SNP_CTL (1UL << 1) -#define IOAT_DESC_DADDR_SNP_CTL (1UL << 2) - -static struct pci_dev *ioat_dev; -static struct ioat_dma_descriptor *ioat_desc; /* I/O AT desc & data (1 page) */ -static unsigned long ioat_desc_phys; -static u8 *ioat_iomap; /* I/O AT memory-mapped control regs (aka CB_BAR) */ -static u8 *ioat_chanbase; - -/* Start I/O AT memory copy */ -static int i7300_idle_ioat_start(void) -{ - u32 err; - /* Clear error (due to circular descriptor pointer) */ - err = readl(ioat_chanbase + IOAT_CHANERR_OFFSET); - if (err) - writel(err, ioat_chanbase + IOAT_CHANERR_OFFSET); - - writeb(IOAT_CHANCMD_START, ioat_chanbase + IOAT1_CHANCMD_OFFSET); - return 0; -} - -/* Stop I/O AT memory copy */ -static void i7300_idle_ioat_stop(void) -{ - int i; - u64 sts; - - for (i = 0; i < MAX_STOP_RETRIES; i++) { - writeb(IOAT_CHANCMD_RESET, - ioat_chanbase + IOAT1_CHANCMD_OFFSET); - - udelay(10); - - sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) & - IOAT_CHANSTS_STATUS; - - if (sts != IOAT_CHANSTS_ACTIVE) - break; - - } - - if (i == MAX_STOP_RETRIES) { - dprintk("failed to stop I/O AT after %d retries\n", - MAX_STOP_RETRIES); - } -} - -/* Test I/O AT by copying 1024 byte from 2k to 1k */ -static int __init i7300_idle_ioat_selftest(u8 *ctl, - struct ioat_dma_descriptor *desc, unsigned long desc_phys) -{ - u64 chan_sts; - - memset(desc, 0, 2048); - memset((u8 *) desc + 2048, 0xab, 1024); - - desc[0].size = 1024; - desc[0].ctl = 0; - desc[0].src_addr = desc_phys + 2048; - desc[0].dst_addr = desc_phys + 1024; - desc[0].next = 0; - - writeb(IOAT_CHANCMD_RESET, ioat_chanbase + IOAT1_CHANCMD_OFFSET); - writeb(IOAT_CHANCMD_START, ioat_chanbase + IOAT1_CHANCMD_OFFSET); - - udelay(1000); - - chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) & - IOAT_CHANSTS_STATUS; - - if (chan_sts != IOAT_CHANSTS_DONE) { - /* Not complete, reset the channel */ - writeb(IOAT_CHANCMD_RESET, - ioat_chanbase + IOAT1_CHANCMD_OFFSET); - return -1; - } - - if (*(u32 *) ((u8 *) desc + 3068) != 0xabababab || - *(u32 *) ((u8 *) desc + 2044) != 0xabababab) { - dprintk("Data values src 0x%x, dest 0x%x, memset 0x%x\n", - *(u32 *) ((u8 *) desc + 2048), - *(u32 *) ((u8 *) desc + 1024), - *(u32 *) ((u8 *) desc + 3072)); - return -1; - } - return 0; -} - -static struct device dummy_dma_dev = { - .init_name = "fallback device", - .coherent_dma_mask = DMA_BIT_MASK(64), - .dma_mask = &dummy_dma_dev.coherent_dma_mask, -}; - -/* Setup and initialize I/O AT */ -/* This driver needs I/O AT as the throttling takes effect only when there is - * some memory activity. We use I/O AT to set up a dummy copy, while all CPUs - * go idle and memory is throttled. - */ -static int __init i7300_idle_ioat_init(void) -{ - u8 ver, chan_count, ioat_chan; - u16 chan_ctl; - - ioat_iomap = (u8 *) ioremap_nocache(pci_resource_start(ioat_dev, 0), - pci_resource_len(ioat_dev, 0)); - - if (!ioat_iomap) { - printk(KERN_ERR I7300_PRINT "failed to map I/O AT registers\n"); - goto err_ret; - } - - ver = readb(ioat_iomap + IOAT_VER_OFFSET); - if (ver != IOAT_VER_1_2) { - printk(KERN_ERR I7300_PRINT "unknown I/O AT version (%u.%u)\n", - ver >> 4, ver & 0xf); - goto err_unmap; - } - - chan_count = readb(ioat_iomap + IOAT_CHANCNT_OFFSET); - if (!chan_count) { - printk(KERN_ERR I7300_PRINT "unexpected # of I/O AT channels " - "(%u)\n", - chan_count); - goto err_unmap; - } - - ioat_chan = chan_count - 1; - ioat_chanbase = IOAT_CHANBASE(ioat_iomap, ioat_chan); - - chan_ctl = readw(ioat_chanbase + IOAT_CHANCTRL_OFFSET); - if (chan_ctl & IOAT_CHANCTRL_CHANNEL_IN_USE) { - printk(KERN_ERR I7300_PRINT "channel %d in use\n", ioat_chan); - goto err_unmap; - } - - writew(IOAT_CHANCTRL_CHANNEL_IN_USE, - ioat_chanbase + IOAT_CHANCTRL_OFFSET); - - ioat_desc = (struct ioat_dma_descriptor *)dma_alloc_coherent( - &dummy_dma_dev, 4096, - (dma_addr_t *)&ioat_desc_phys, GFP_KERNEL); - if (!ioat_desc) { - printk(KERN_ERR I7300_PRINT "failed to allocate I/O AT desc\n"); - goto err_mark_unused; - } - - writel(ioat_desc_phys & 0xffffffffUL, - ioat_chanbase + IOAT1_CHAINADDR_OFFSET_LOW); - writel(ioat_desc_phys >> 32, - ioat_chanbase + IOAT1_CHAINADDR_OFFSET_HIGH); - - if (i7300_idle_ioat_selftest(ioat_iomap, ioat_desc, ioat_desc_phys)) { - printk(KERN_ERR I7300_PRINT "I/O AT self-test failed\n"); - goto err_free; - } - - /* Setup circular I/O AT descriptor chain */ - ioat_desc[0].ctl = IOAT_DESC_SADDR_SNP_CTL | IOAT_DESC_DADDR_SNP_CTL; - ioat_desc[0].src_addr = ioat_desc_phys + 2048; - ioat_desc[0].dst_addr = ioat_desc_phys + 3072; - ioat_desc[0].size = 128; - ioat_desc[0].next = ioat_desc_phys + sizeof(struct ioat_dma_descriptor); - - ioat_desc[1].ctl = ioat_desc[0].ctl; - ioat_desc[1].src_addr = ioat_desc[0].src_addr; - ioat_desc[1].dst_addr = ioat_desc[0].dst_addr; - ioat_desc[1].size = ioat_desc[0].size; - ioat_desc[1].next = ioat_desc_phys; - - return 0; - -err_free: - dma_free_coherent(&dummy_dma_dev, 4096, (void *)ioat_desc, 0); -err_mark_unused: - writew(0, ioat_chanbase + IOAT_CHANCTRL_OFFSET); -err_unmap: - iounmap(ioat_iomap); -err_ret: - return -ENODEV; -} - -/* Cleanup I/O AT */ -static void __exit i7300_idle_ioat_exit(void) -{ - int i; - u64 chan_sts; - - i7300_idle_ioat_stop(); - - /* Wait for a while for the channel to halt before releasing */ - for (i = 0; i < MAX_STOP_RETRIES; i++) { - writeb(IOAT_CHANCMD_RESET, - ioat_chanbase + IOAT1_CHANCMD_OFFSET); - - chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) & - IOAT_CHANSTS_STATUS; - - if (chan_sts != IOAT_CHANSTS_ACTIVE) { - writew(0, ioat_chanbase + IOAT_CHANCTRL_OFFSET); - break; - } - udelay(1000); - } - - chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) & - IOAT_CHANSTS_STATUS; - - /* - * We tried to reset multiple times. If IO A/T channel is still active - * flag an error and return without cleanup. Memory leak is better - * than random corruption in that extreme error situation. - */ - if (chan_sts == IOAT_CHANSTS_ACTIVE) { - printk(KERN_ERR I7300_PRINT "Unable to stop IO A/T channels." - " Not freeing resources\n"); - return; - } - - dma_free_coherent(&dummy_dma_dev, 4096, (void *)ioat_desc, 0); - iounmap(ioat_iomap); -} - -/* End: I/O AT Helper routines */ - -#define DIMM_THRTLOW 0x64 -#define DIMM_THRTCTL 0x67 -#define DIMM_THRTCTL_THRMHUNT (1UL << 0) -#define DIMM_MC 0x40 -#define DIMM_GTW_MODE (1UL << 17) -#define DIMM_GBLACT 0x60 - -/* - * Keep track of an exponential-decaying average of recent idle durations. - * The latest duration gets DURATION_WEIGHT_PCT percentage weight - * in this average, with the old average getting the remaining weight. - * - * High weights emphasize recent history, low weights include long history. - */ -#define DURATION_WEIGHT_PCT 55 - -/* - * When the decaying average of recent durations or the predicted duration - * of the next timer interrupt is shorter than duration_threshold, the - * driver will decline to throttle. - */ -#define DURATION_THRESHOLD_US 100 - - -/* Store DIMM thermal throttle configuration */ -static int i7300_idle_thrt_save(void) -{ - u32 new_mc_val; - u8 gblactlm; - - pci_read_config_byte(fbd_dev, DIMM_THRTCTL, &i7300_idle_thrtctl_saved); - pci_read_config_byte(fbd_dev, DIMM_THRTLOW, &i7300_idle_thrtlow_saved); - pci_read_config_dword(fbd_dev, DIMM_MC, &i7300_idle_mc_saved); - /* - * Make sure we have Global Throttling Window Mode set to have a - * "short" window. This (mostly) works around an issue where - * throttling persists until the end of the global throttling window - * size. On the tested system, this was resulting in a maximum of - * 64 ms to exit throttling (average 32 ms). The actual numbers - * depends on system frequencies. Setting the short window reduces - * this by a factor of 4096. - * - * We will only do this only if the system is set for - * unlimited-activations while in open-loop throttling (i.e., when - * Global Activation Throttle Limit is zero). - */ - pci_read_config_byte(fbd_dev, DIMM_GBLACT, &gblactlm); - dprintk("thrtctl_saved = 0x%02x, thrtlow_saved = 0x%02x\n", - i7300_idle_thrtctl_saved, - i7300_idle_thrtlow_saved); - dprintk("mc_saved = 0x%08x, gblactlm = 0x%02x\n", - i7300_idle_mc_saved, - gblactlm); - if (gblactlm == 0) { - new_mc_val = i7300_idle_mc_saved | DIMM_GTW_MODE; - pci_write_config_dword(fbd_dev, DIMM_MC, new_mc_val); - return 0; - } else { - dprintk("could not set GTW_MODE = 1 (OLTT enabled)\n"); - return -ENODEV; - } -} - -/* Restore DIMM thermal throttle configuration */ -static void i7300_idle_thrt_restore(void) -{ - pci_write_config_dword(fbd_dev, DIMM_MC, i7300_idle_mc_saved); - pci_write_config_byte(fbd_dev, DIMM_THRTLOW, i7300_idle_thrtlow_saved); - pci_write_config_byte(fbd_dev, DIMM_THRTCTL, i7300_idle_thrtctl_saved); -} - -/* Enable DIMM thermal throttling */ -static void i7300_idle_start(void) -{ - u8 new_ctl; - u8 limit; - - new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT; - pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl); - - limit = throttle_low_limit; - if (unlikely(limit > MAX_THROTTLE_LOW_LIMIT)) - limit = MAX_THROTTLE_LOW_LIMIT; - - pci_write_config_byte(fbd_dev, DIMM_THRTLOW, limit); - - new_ctl = i7300_idle_thrtctl_saved | DIMM_THRTCTL_THRMHUNT; - pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl); -} - -/* Disable DIMM thermal throttling */ -static void i7300_idle_stop(void) -{ - u8 new_ctl; - u8 got_ctl; - - new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT; - pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl); - - pci_write_config_byte(fbd_dev, DIMM_THRTLOW, i7300_idle_thrtlow_saved); - pci_write_config_byte(fbd_dev, DIMM_THRTCTL, i7300_idle_thrtctl_saved); - pci_read_config_byte(fbd_dev, DIMM_THRTCTL, &got_ctl); - WARN_ON_ONCE(got_ctl != i7300_idle_thrtctl_saved); -} - - -/* - * i7300_avg_duration_check() - * return 0 if the decaying average of recent idle durations is - * more than DURATION_THRESHOLD_US - */ -static int i7300_avg_duration_check(void) -{ - if (avg_idle_us >= DURATION_THRESHOLD_US) - return 0; - -#ifdef DEBUG - past_skip++; -#endif - return 1; -} - -/* Idle notifier to look at idle CPUs */ -static int i7300_idle_notifier(struct notifier_block *nb, unsigned long val, - void *data) -{ - unsigned long flags; - ktime_t now_ktime; - static ktime_t idle_begin_time; - static int time_init = 1; - - if (!throttle_low_limit) - return 0; - - if (unlikely(time_init)) { - time_init = 0; - idle_begin_time = ktime_get(); - } - - raw_spin_lock_irqsave(&i7300_idle_lock, flags); - if (val == IDLE_START) { - - cpumask_set_cpu(smp_processor_id(), idle_cpumask); - - if (cpumask_weight(idle_cpumask) != num_online_cpus()) - goto end; - - now_ktime = ktime_get(); - idle_begin_time = now_ktime; - - if (i7300_avg_duration_check()) - goto end; - - i7300_idle_active = 1; - total_starts++; - start_ktime = now_ktime; - - i7300_idle_start(); - i7300_idle_ioat_start(); - - } else if (val == IDLE_END) { - cpumask_clear_cpu(smp_processor_id(), idle_cpumask); - if (cpumask_weight(idle_cpumask) == (num_online_cpus() - 1)) { - /* First CPU coming out of idle */ - u64 idle_duration_us; - - now_ktime = ktime_get(); - - idle_duration_us = ktime_to_us(ktime_sub - (now_ktime, idle_begin_time)); - - avg_idle_us = - ((100 - DURATION_WEIGHT_PCT) * avg_idle_us + - DURATION_WEIGHT_PCT * idle_duration_us) / 100; - - if (i7300_idle_active) { - ktime_t idle_ktime; - - idle_ktime = ktime_sub(now_ktime, start_ktime); - total_us += ktime_to_us(idle_ktime); - - i7300_idle_ioat_stop(); - i7300_idle_stop(); - i7300_idle_active = 0; - } - } - } -end: - raw_spin_unlock_irqrestore(&i7300_idle_lock, flags); - return 0; -} - -static struct notifier_block i7300_idle_nb = { - .notifier_call = i7300_idle_notifier, -}; - -MODULE_DEVICE_TABLE(pci, pci_tbl); - -static ssize_t stats_read_ul(struct file *fp, char __user *ubuf, size_t count, - loff_t *off) -{ - unsigned long *p = fp->private_data; - char buf[32]; - int len; - - len = snprintf(buf, 32, "%lu\n", *p); - return simple_read_from_buffer(ubuf, count, off, buf, len); -} - -static const struct file_operations idle_fops = { - .open = simple_open, - .read = stats_read_ul, - .llseek = default_llseek, -}; - -struct debugfs_file_info { - void *ptr; - char name[32]; - struct dentry *file; -} debugfs_file_list[] = { - {&total_starts, "total_starts", NULL}, - {&total_us, "total_us", NULL}, -#ifdef DEBUG - {&past_skip, "past_skip", NULL}, -#endif - {NULL, "", NULL} - }; - -static int __init i7300_idle_init(void) -{ - raw_spin_lock_init(&i7300_idle_lock); - total_us = 0; - - if (i7300_idle_platform_probe(&fbd_dev, &ioat_dev, forceload)) - return -ENODEV; - - if (i7300_idle_thrt_save()) - return -ENODEV; - - if (i7300_idle_ioat_init()) - return -ENODEV; - - if (!zalloc_cpumask_var(&idle_cpumask, GFP_KERNEL)) - return -ENOMEM; - - debugfs_dir = debugfs_create_dir("i7300_idle", NULL); - if (debugfs_dir) { - int i = 0; - - while (debugfs_file_list[i].ptr != NULL) { - debugfs_file_list[i].file = debugfs_create_file( - debugfs_file_list[i].name, - S_IRUSR, - debugfs_dir, - debugfs_file_list[i].ptr, - &idle_fops); - i++; - } - } - - idle_notifier_register(&i7300_idle_nb); - - printk(KERN_INFO "i7300_idle: loaded v%s\n", I7300_IDLE_DRIVER_VERSION); - return 0; -} - -static void __exit i7300_idle_exit(void) -{ - idle_notifier_unregister(&i7300_idle_nb); - free_cpumask_var(idle_cpumask); - - if (debugfs_dir) { - int i = 0; - - while (debugfs_file_list[i].file != NULL) { - debugfs_remove(debugfs_file_list[i].file); - i++; - } - - debugfs_remove(debugfs_dir); - } - i7300_idle_thrt_restore(); - i7300_idle_ioat_exit(); -} - -module_init(i7300_idle_init); -module_exit(i7300_idle_exit); - -MODULE_AUTHOR("Andy Henroid <andrew.d.henroid@intel.com>"); -MODULE_DESCRIPTION("Intel Chipset DIMM Idle Power Saving Driver v" - I7300_IDLE_DRIVER_VERSION); -MODULE_LICENSE("GPL"); |