diff options
Diffstat (limited to 'drivers/char/hpet.c')
| -rw-r--r-- | drivers/char/hpet.c | 289 |
1 files changed, 189 insertions, 100 deletions
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c index 32b8bbf5003..d5d4cd82b9f 100644 --- a/drivers/char/hpet.c +++ b/drivers/char/hpet.c @@ -14,7 +14,6 @@ #include <linux/interrupt.h> #include <linux/module.h> #include <linux/kernel.h> -#include <linux/smp_lock.h> #include <linux/types.h> #include <linux/miscdevice.h> #include <linux/major.h> @@ -30,19 +29,17 @@ #include <linux/bcd.h> #include <linux/seq_file.h> #include <linux/bitops.h> +#include <linux/compat.h> #include <linux/clocksource.h> - +#include <linux/uaccess.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/acpi.h> +#include <linux/hpet.h> #include <asm/current.h> -#include <asm/uaccess.h> -#include <asm/system.h> -#include <asm/io.h> #include <asm/irq.h> #include <asm/div64.h> -#include <linux/acpi.h> -#include <acpi/acpi_bus.h> -#include <linux/hpet.h> - /* * The High Precision Event Timer driver. * This driver is closely modelled after the rtc.c driver. @@ -66,25 +63,24 @@ #define read_counter(MC) readl(MC) #endif +static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */ static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; /* This clocksource driver currently only works on ia64 */ #ifdef CONFIG_IA64 static void __iomem *hpet_mctr; -static cycle_t read_hpet(void) +static cycle_t read_hpet(struct clocksource *cs) { return (cycle_t)read_counter((void __iomem *)hpet_mctr); } static struct clocksource clocksource_hpet = { - .name = "hpet", - .rating = 250, - .read = read_hpet, - .mask = CLOCKSOURCE_MASK(64), - .mult = 0, /* to be calculated */ - .shift = 10, - .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .name = "hpet", + .rating = 250, + .read = read_hpet, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static struct clocksource *hpet_clocksource; #endif @@ -163,11 +159,31 @@ static irqreturn_t hpet_interrupt(int irq, void *data) * This has the effect of treating non-periodic like periodic. */ if ((devp->hd_flags & (HPET_IE | HPET_PERIODIC)) == HPET_IE) { - unsigned long m, t; + unsigned long m, t, mc, base, k; + struct hpet __iomem *hpet = devp->hd_hpet; + struct hpets *hpetp = devp->hd_hpets; t = devp->hd_ireqfreq; - m = read_counter(&devp->hd_hpet->hpet_mc); - write_counter(t + m + devp->hd_hpets->hp_delta, + m = read_counter(&devp->hd_timer->hpet_compare); + mc = read_counter(&hpet->hpet_mc); + /* The time for the next interrupt would logically be t + m, + * however, if we are very unlucky and the interrupt is delayed + * for longer than t then we will completely miss the next + * interrupt if we set t + m and an application will hang. + * Therefore we need to make a more complex computation assuming + * that there exists a k for which the following is true: + * k * t + base < mc + delta + * (k + 1) * t + base > mc + delta + * where t is the interval in hpet ticks for the given freq, + * base is the theoretical start value 0 < base < t, + * mc is the main counter value at the time of the interrupt, + * delta is the time it takes to write the a value to the + * comparator. + * k may then be computed as (mc - base + delta) / t . + */ + base = mc % t; + k = (mc - base + hpetp->hp_delta) / t; + write_counter(t * (k + 1) + base, &devp->hd_timer->hpet_compare); } @@ -216,15 +232,13 @@ static void hpet_timer_set_irq(struct hpet_dev *devp) else v &= ~0xffff; - for (irq = find_first_bit(&v, HPET_MAX_IRQ); irq < HPET_MAX_IRQ; - irq = find_next_bit(&v, HPET_MAX_IRQ, 1 + irq)) { - + for_each_set_bit(irq, &v, HPET_MAX_IRQ) { if (irq >= nr_irqs) { irq = HPET_MAX_IRQ; break; } - gsi = acpi_register_gsi(irq, ACPI_LEVEL_SENSITIVE, + gsi = acpi_register_gsi(NULL, irq, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_LOW); if (gsi > 0) break; @@ -252,7 +266,7 @@ static int hpet_open(struct inode *inode, struct file *file) if (file->f_mode & FMODE_WRITE) return -EINVAL; - lock_kernel(); + mutex_lock(&hpet_mutex); spin_lock_irq(&hpet_lock); for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next) @@ -266,7 +280,7 @@ static int hpet_open(struct inode *inode, struct file *file) if (!devp) { spin_unlock_irq(&hpet_lock); - unlock_kernel(); + mutex_unlock(&hpet_mutex); return -EBUSY; } @@ -274,7 +288,7 @@ static int hpet_open(struct inode *inode, struct file *file) devp->hd_irqdata = 0; devp->hd_flags |= HPET_OPEN; spin_unlock_irq(&hpet_lock); - unlock_kernel(); + mutex_unlock(&hpet_mutex); hpet_timer_set_irq(devp); @@ -350,14 +364,28 @@ static unsigned int hpet_poll(struct file *file, poll_table * wait) return 0; } +#ifdef CONFIG_HPET_MMAP +#ifdef CONFIG_HPET_MMAP_DEFAULT +static int hpet_mmap_enabled = 1; +#else +static int hpet_mmap_enabled = 0; +#endif + +static __init int hpet_mmap_enable(char *str) +{ + get_option(&str, &hpet_mmap_enabled); + pr_info("HPET mmap %s\n", hpet_mmap_enabled ? "enabled" : "disabled"); + return 1; +} +__setup("hpet_mmap", hpet_mmap_enable); + static int hpet_mmap(struct file *file, struct vm_area_struct *vma) { -#ifdef CONFIG_HPET_MMAP struct hpet_dev *devp; unsigned long addr; - if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff) - return -EINVAL; + if (!hpet_mmap_enabled) + return -EACCES; devp = file->private_data; addr = devp->hd_hpets->hp_hpet_phys; @@ -365,21 +393,15 @@ static int hpet_mmap(struct file *file, struct vm_area_struct *vma) if (addr & (PAGE_SIZE - 1)) return -ENOSYS; - vma->vm_flags |= VM_IO; vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - - if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, - PAGE_SIZE, vma->vm_page_prot)) { - printk(KERN_ERR "%s: io_remap_pfn_range failed\n", - __func__); - return -EAGAIN; - } - - return 0; + return vm_iomap_memory(vma, addr, PAGE_SIZE); +} #else +static int hpet_mmap(struct file *file, struct vm_area_struct *vma) +{ return -ENOSYS; -#endif } +#endif static int hpet_fasync(int fd, struct file *file, int on) { @@ -431,18 +453,6 @@ static int hpet_release(struct inode *inode, struct file *file) return 0; } -static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int); - -static int -hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd, - unsigned long arg) -{ - struct hpet_dev *devp; - - devp = file->private_data; - return hpet_ioctl_common(devp, cmd, arg, 0); -} - static int hpet_ioctl_ieon(struct hpet_dev *devp) { struct hpet_timer __iomem *timer; @@ -477,9 +487,23 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp) if (irq) { unsigned long irq_flags; + if (devp->hd_flags & HPET_SHARED_IRQ) { + /* + * To prevent the interrupt handler from seeing an + * unwanted interrupt status bit, program the timer + * so that it will not fire in the near future ... + */ + writel(readl(&timer->hpet_config) & ~Tn_TYPE_CNF_MASK, + &timer->hpet_config); + write_counter(read_counter(&hpet->hpet_mc), + &timer->hpet_compare); + /* ... and clear any left-over status. */ + isr = 1 << (devp - devp->hd_hpets->hp_dev); + writel(isr, &hpet->hpet_isr); + } + sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev)); - irq_flags = devp->hd_flags & HPET_SHARED_IRQ - ? IRQF_SHARED : IRQF_DISABLED; + irq_flags = devp->hd_flags & HPET_SHARED_IRQ ? IRQF_SHARED : 0; if (request_irq(irq, hpet_interrupt, irq_flags, devp->hd_name, (void *)devp)) { printk(KERN_ERR "hpet: IRQ %d is not free\n", irq); @@ -504,21 +528,25 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp) g = v | Tn_32MODE_CNF_MASK | Tn_INT_ENB_CNF_MASK; if (devp->hd_flags & HPET_PERIODIC) { - write_counter(t, &timer->hpet_compare); g |= Tn_TYPE_CNF_MASK; - v |= Tn_TYPE_CNF_MASK; - writeq(v, &timer->hpet_config); - v |= Tn_VAL_SET_CNF_MASK; + v |= Tn_TYPE_CNF_MASK | Tn_VAL_SET_CNF_MASK; writeq(v, &timer->hpet_config); local_irq_save(flags); - /* NOTE: what we modify here is a hidden accumulator + /* + * NOTE: First we modify the hidden accumulator * register supported by periodic-capable comparators. * We never want to modify the (single) counter; that - * would affect all the comparators. + * would affect all the comparators. The value written + * is the counter value when the first interrupt is due. */ m = read_counter(&hpet->hpet_mc); write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare); + /* + * Then we modify the comparator, indicating the period + * for subsequent interrupt. + */ + write_counter(t, &timer->hpet_compare); } else { local_irq_save(flags); m = read_counter(&hpet->hpet_mc); @@ -547,7 +575,8 @@ static inline unsigned long hpet_time_div(struct hpets *hpets, } static int -hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) +hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, + struct hpet_info *info) { struct hpet_timer __iomem *timer; struct hpet __iomem *hpet; @@ -588,23 +617,14 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) break; case HPET_INFO: { - struct hpet_info info; - + memset(info, 0, sizeof(*info)); if (devp->hd_ireqfreq) - info.hi_ireqfreq = + info->hi_ireqfreq = hpet_time_div(hpetp, devp->hd_ireqfreq); - else - info.hi_ireqfreq = 0; - info.hi_flags = + info->hi_flags = readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK; - info.hi_hpet = hpetp->hp_which; - info.hi_timer = devp - hpetp->hp_dev; - if (kernel) - memcpy((void *)arg, &info, sizeof(info)); - else - if (copy_to_user((void __user *)arg, &info, - sizeof(info))) - err = -EFAULT; + info->hi_hpet = hpetp->hp_which; + info->hi_timer = devp - hpetp->hp_dev; break; } case HPET_EPI: @@ -630,7 +650,7 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) devp->hd_flags &= ~HPET_PERIODIC; break; case HPET_IRQFREQ: - if (!kernel && (arg > hpet_max_freq) && + if ((arg > hpet_max_freq) && !capable(CAP_SYS_RESOURCE)) { err = -EACCES; break; @@ -647,12 +667,63 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) return err; } +static long +hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct hpet_info info; + int err; + + mutex_lock(&hpet_mutex); + err = hpet_ioctl_common(file->private_data, cmd, arg, &info); + mutex_unlock(&hpet_mutex); + + if ((cmd == HPET_INFO) && !err && + (copy_to_user((void __user *)arg, &info, sizeof(info)))) + err = -EFAULT; + + return err; +} + +#ifdef CONFIG_COMPAT +struct compat_hpet_info { + compat_ulong_t hi_ireqfreq; /* Hz */ + compat_ulong_t hi_flags; /* information */ + unsigned short hi_hpet; + unsigned short hi_timer; +}; + +static long +hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct hpet_info info; + int err; + + mutex_lock(&hpet_mutex); + err = hpet_ioctl_common(file->private_data, cmd, arg, &info); + mutex_unlock(&hpet_mutex); + + if ((cmd == HPET_INFO) && !err) { + struct compat_hpet_info __user *u = compat_ptr(arg); + if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) || + put_user(info.hi_flags, &u->hi_flags) || + put_user(info.hi_hpet, &u->hi_hpet) || + put_user(info.hi_timer, &u->hi_timer)) + err = -EFAULT; + } + + return err; +} +#endif + static const struct file_operations hpet_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .read = hpet_read, .poll = hpet_poll, - .ioctl = hpet_ioctl, + .unlocked_ioctl = hpet_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = hpet_compat_ioctl, +#endif .open = hpet_open, .release = hpet_release, .fasync = hpet_fasync, @@ -670,38 +741,35 @@ static int hpet_is_known(struct hpet_data *hdp) return 0; } -static ctl_table hpet_table[] = { +static struct ctl_table hpet_table[] = { { - .ctl_name = CTL_UNNUMBERED, .procname = "max-user-freq", .data = &hpet_max_freq, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = &proc_dointvec, + .proc_handler = proc_dointvec, }, - {.ctl_name = 0} + {} }; -static ctl_table hpet_root[] = { +static struct ctl_table hpet_root[] = { { - .ctl_name = CTL_UNNUMBERED, .procname = "hpet", .maxlen = 0, .mode = 0555, .child = hpet_table, }, - {.ctl_name = 0} + {} }; -static ctl_table dev_root[] = { +static struct ctl_table dev_root[] = { { - .ctl_name = CTL_DEV, .procname = "dev", .maxlen = 0, .mode = 0555, .child = hpet_root, }, - {.ctl_name = 0} + {} }; static struct ctl_table_header *sysctl_header; @@ -713,7 +781,7 @@ static struct ctl_table_header *sysctl_header; */ #define TICK_CALIBRATE (1000UL) -static unsigned long hpet_calibrate(struct hpets *hpetp) +static unsigned long __hpet_calibrate(struct hpets *hpetp) { struct hpet_timer __iomem *timer = NULL; unsigned long t, m, count, i, flags, start; @@ -750,6 +818,26 @@ static unsigned long hpet_calibrate(struct hpets *hpetp) return (m - start) / i; } +static unsigned long hpet_calibrate(struct hpets *hpetp) +{ + unsigned long ret = ~0UL; + unsigned long tmp; + + /* + * Try to calibrate until return value becomes stable small value. + * If SMI interruption occurs in calibration loop, the return value + * will be big. This avoids its impact. + */ + for ( ; ; ) { + tmp = __hpet_calibrate(hpetp); + if (ret <= tmp) + break; + ret = tmp; + } + + return ret; +} + int hpet_alloc(struct hpet_data *hdp) { u64 cap, mcfg; @@ -758,7 +846,7 @@ int hpet_alloc(struct hpet_data *hdp) struct hpets *hpetp; size_t siz; struct hpet __iomem *hpet; - static struct hpets *last = NULL; + static struct hpets *last; unsigned long period; unsigned long long temp; u32 remainder; @@ -822,8 +910,8 @@ int hpet_alloc(struct hpet_data *hdp) hpetp->hp_which, hdp->hd_phys_address, hpetp->hp_ntimer > 1 ? "s" : ""); for (i = 0; i < hpetp->hp_ntimer; i++) - printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); - printk("\n"); + printk(KERN_CONT "%s %d", i > 0 ? "," : "", hdp->hd_irq[i]); + printk(KERN_CONT "\n"); temp = hpetp->hp_tick_freq; remainder = do_div(temp, 1000000); @@ -867,10 +955,8 @@ int hpet_alloc(struct hpet_data *hdp) #ifdef CONFIG_IA64 if (!hpet_clocksource) { hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; - CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); - clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq, - clocksource_hpet.shift); - clocksource_register(&clocksource_hpet); + clocksource_hpet.archdata.fsys_mmio = hpet_mctr; + clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq); hpetp->hp_clocksource = &clocksource_hpet; hpet_clocksource = &clocksource_hpet; } @@ -901,8 +987,6 @@ static acpi_status hpet_resources(struct acpi_resource *res, void *data) struct acpi_resource_fixed_memory32 *fixmem32; fixmem32 = &res->data.fixed_memory32; - if (!fixmem32) - return AE_NO_MEMORY; hdp->hd_phys_address = fixmem32->address; hdp->hd_address = ioremap(fixmem32->address, @@ -919,7 +1003,10 @@ static acpi_status hpet_resources(struct acpi_resource *res, void *data) irqp = &res->data.extended_irq; for (i = 0; i < irqp->interrupt_count; i++) { - irq = acpi_register_gsi(irqp->interrupts[i], + if (hdp->hd_nirqs >= HPET_MAX_TIMERS) + break; + + irq = acpi_register_gsi(NULL, irqp->interrupts[i], irqp->triggering, irqp->polarity); if (irq < 0) return AE_ERROR; @@ -947,6 +1034,8 @@ static int hpet_acpi_add(struct acpi_device *device) return -ENODEV; if (!data.hd_address || !data.hd_nirqs) { + if (data.hd_address) + iounmap(data.hd_address); printk("%s: no address or irqs in _CRS\n", __func__); return -ENODEV; } @@ -954,7 +1043,7 @@ static int hpet_acpi_add(struct acpi_device *device) return hpet_alloc(&data); } -static int hpet_acpi_remove(struct acpi_device *device, int type) +static int hpet_acpi_remove(struct acpi_device *device) { /* XXX need to unregister clocksource, dealloc mem, etc */ return -EINVAL; |
