+++ /dev/null
-/*
- * (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");
projects / linux-beck.git / commitdiff