[PATCH 1/2] remove the SGI SN2 mmtimer driver

From: Christoph Hellwig
Date: Fri May 26 2017 - 05:21:56 EST

This driver supports direct system clock access on the ancient SGI SN2
IA64 systems, and implement the only non-builtin k_clock instance.
Remove it as any remaining IA64 altix user will be running just as old
distros anyway.

Note that this does not affect the never uv_mmtimer driver for x86-based
Altix systems.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/char/Kconfig | 9 -
drivers/char/Makefile | 1 -
drivers/char/mmtimer.c | 858 -------------------------------------------------
3 files changed, 868 deletions(-)
delete mode 100644 drivers/char/mmtimer.c

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 31adbebf812e..2af70014ee5a 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -539,15 +539,6 @@ config HANGCHECK_TIMER
out to lunch past a certain margin. It can reboot the system
or merely print a warning.

-config MMTIMER
- tristate "MMTIMER Memory mapped RTC for SGI Altix"
- depends on IA64_GENERIC || IA64_SGI_SN2
- depends on POSIX_TIMERS
- default y
- help
- The mmtimer device allows direct userspace access to the
- Altix system timer.
-
config UV_MMTIMER
tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
depends on X86_UV
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index 6e6c244a66a0..53e33720818c 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -10,7 +10,6 @@ obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o
obj-$(CONFIG_RAW_DRIVER) += raw.o
obj-$(CONFIG_SGI_SNSC) += snsc.o snsc_event.o
obj-$(CONFIG_MSPEC) += mspec.o
-obj-$(CONFIG_MMTIMER) += mmtimer.o
obj-$(CONFIG_UV_MMTIMER) += uv_mmtimer.o
obj-$(CONFIG_IBM_BSR) += bsr.o
obj-$(CONFIG_SGI_MBCS) += mbcs.o
diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c
deleted file mode 100644
index 0e7fcb04f01e..000000000000
--- a/drivers/char/mmtimer.c
+++ /dev/null
@@ -1,858 +0,0 @@
-/*
- * Timer device implementation for SGI SN platforms.
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (c) 2001-2006 Silicon Graphics, Inc. All rights reserved.
- *
- * This driver exports an API that should be supportable by any HPET or IA-PC
- * multimedia timer. The code below is currently specific to the SGI Altix
- * SHub RTC, however.
- *
- * 11/01/01 - jbarnes - initial revision
- * 9/10/04 - Christoph Lameter - remove interrupt support for kernel inclusion
- * 10/1/04 - Christoph Lameter - provide posix clock CLOCK_SGI_CYCLE
- * 10/13/04 - Christoph Lameter, Dimitri Sivanich - provide timer interrupt
- * support via the posix timer interface
- */
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/ioctl.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/errno.h>
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/mmtimer.h>
-#include <linux/miscdevice.h>
-#include <linux/posix-timers.h>
-#include <linux/interrupt.h>
-#include <linux/time.h>
-#include <linux/math64.h>
-#include <linux/mutex.h>
-#include <linux/slab.h>
-
-#include <linux/uaccess.h>
-#include <asm/sn/addrs.h>
-#include <asm/sn/intr.h>
-#include <asm/sn/shub_mmr.h>
-#include <asm/sn/nodepda.h>
-#include <asm/sn/shubio.h>
-
-MODULE_AUTHOR("Jesse Barnes <jbarnes@xxxxxxx>");
-MODULE_DESCRIPTION("SGI Altix RTC Timer");
-MODULE_LICENSE("GPL");
-
-/* name of the device, usually in /dev */
-#define MMTIMER_NAME "mmtimer"
-#define MMTIMER_DESC "SGI Altix RTC Timer"
-#define MMTIMER_VERSION "2.1"
-
-#define RTC_BITS 55 /* 55 bits for this implementation */
-
-static struct k_clock sgi_clock;
-
-extern unsigned long sn_rtc_cycles_per_second;
-
-#define RTC_COUNTER_ADDR ((long *)LOCAL_MMR_ADDR(SH_RTC))
-
-#define rtc_time() (*RTC_COUNTER_ADDR)
-
-static DEFINE_MUTEX(mmtimer_mutex);
-static long mmtimer_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg);
-static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
-
-/*
- * Period in femtoseconds (10^-15 s)
- */
-static unsigned long mmtimer_femtoperiod = 0;
-
-static const struct file_operations mmtimer_fops = {
- .owner = THIS_MODULE,
- .mmap = mmtimer_mmap,
- .unlocked_ioctl = mmtimer_ioctl,
- .llseek = noop_llseek,
-};
-
-/*
- * We only have comparison registers RTC1-4 currently available per
- * node. RTC0 is used by SAL.
- */
-/* Check for an RTC interrupt pending */
-static int mmtimer_int_pending(int comparator)
-{
- if (HUB_L((unsigned long *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED)) &
- SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator)
- return 1;
- else
- return 0;
-}
-
-/* Clear the RTC interrupt pending bit */
-static void mmtimer_clr_int_pending(int comparator)
-{
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS),
- SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator);
-}
-
-/* Setup timer on comparator RTC1 */
-static void mmtimer_setup_int_0(int cpu, u64 expires)
-{
- u64 val;
-
- /* Disable interrupt */
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 0UL);
-
- /* Initialize comparator value */
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), -1L);
-
- /* Clear pending bit */
- mmtimer_clr_int_pending(0);
-
- val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC1_INT_CONFIG_IDX_SHFT) |
- ((u64)cpu_physical_id(cpu) <<
- SH_RTC1_INT_CONFIG_PID_SHFT);
-
- /* Set configuration */
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_CONFIG), val);
-
- /* Enable RTC interrupts */
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 1UL);
-
- /* Initialize comparator value */
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), expires);
-
-
-}
-
-/* Setup timer on comparator RTC2 */
-static void mmtimer_setup_int_1(int cpu, u64 expires)
-{
- u64 val;
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 0UL);
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), -1L);
-
- mmtimer_clr_int_pending(1);
-
- val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC2_INT_CONFIG_IDX_SHFT) |
- ((u64)cpu_physical_id(cpu) <<
- SH_RTC2_INT_CONFIG_PID_SHFT);
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_CONFIG), val);
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 1UL);
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), expires);
-}
-
-/* Setup timer on comparator RTC3 */
-static void mmtimer_setup_int_2(int cpu, u64 expires)
-{
- u64 val;
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 0UL);
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), -1L);
-
- mmtimer_clr_int_pending(2);
-
- val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC3_INT_CONFIG_IDX_SHFT) |
- ((u64)cpu_physical_id(cpu) <<
- SH_RTC3_INT_CONFIG_PID_SHFT);
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_CONFIG), val);
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 1UL);
-
- HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), expires);
-}
-
-/*
- * This function must be called with interrupts disabled and preemption off
- * in order to insure that the setup succeeds in a deterministic time frame.
- * It will check if the interrupt setup succeeded.
- */
-static int mmtimer_setup(int cpu, int comparator, unsigned long expires,
- u64 *set_completion_time)
-{
- switch (comparator) {
- case 0:
- mmtimer_setup_int_0(cpu, expires);
- break;
- case 1:
- mmtimer_setup_int_1(cpu, expires);
- break;
- case 2:
- mmtimer_setup_int_2(cpu, expires);
- break;
- }
- /* We might've missed our expiration time */
- *set_completion_time = rtc_time();
- if (*set_completion_time <= expires)
- return 1;
-
- /*
- * If an interrupt is already pending then its okay
- * if not then we failed
- */
- return mmtimer_int_pending(comparator);
-}
-
-static int mmtimer_disable_int(long nasid, int comparator)
-{
- switch (comparator) {
- case 0:
- nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE),
- 0UL) : REMOTE_HUB_S(nasid, SH_RTC1_INT_ENABLE, 0UL);
- break;
- case 1:
- nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE),
- 0UL) : REMOTE_HUB_S(nasid, SH_RTC2_INT_ENABLE, 0UL);
- break;
- case 2:
- nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE),
- 0UL) : REMOTE_HUB_S(nasid, SH_RTC3_INT_ENABLE, 0UL);
- break;
- default:
- return -EFAULT;
- }
- return 0;
-}
-
-#define COMPARATOR 1 /* The comparator to use */
-
-#define TIMER_OFF 0xbadcabLL /* Timer is not setup */
-#define TIMER_SET 0 /* Comparator is set for this timer */
-
-#define MMTIMER_INTERVAL_RETRY_INCREMENT_DEFAULT 40
-
-/* There is one of these for each timer */
-struct mmtimer {
- struct rb_node list;
- struct k_itimer *timer;
- int cpu;
-};
-
-struct mmtimer_node {
- spinlock_t lock ____cacheline_aligned;
- struct rb_root timer_head;
- struct rb_node *next;
- struct tasklet_struct tasklet;
-};
-static struct mmtimer_node *timers;
-
-static unsigned mmtimer_interval_retry_increment =
- MMTIMER_INTERVAL_RETRY_INCREMENT_DEFAULT;
-module_param(mmtimer_interval_retry_increment, uint, 0644);
-MODULE_PARM_DESC(mmtimer_interval_retry_increment,
- "RTC ticks to add to expiration on interval retry (default 40)");
-
-/*
- * Add a new mmtimer struct to the node's mmtimer list.
- * This function assumes the struct mmtimer_node is locked.
- */
-static void mmtimer_add_list(struct mmtimer *n)
-{
- int nodeid = n->timer->it.mmtimer.node;
- unsigned long expires = n->timer->it.mmtimer.expires;
- struct rb_node **link = &timers[nodeid].timer_head.rb_node;
- struct rb_node *parent = NULL;
- struct mmtimer *x;
-
- /*
- * Find the right place in the rbtree:
- */
- while (*link) {
- parent = *link;
- x = rb_entry(parent, struct mmtimer, list);
-
- if (expires < x->timer->it.mmtimer.expires)
- link = &(*link)->rb_left;
- else
- link = &(*link)->rb_right;
- }
-
- /*
- * Insert the timer to the rbtree and check whether it
- * replaces the first pending timer
- */
- rb_link_node(&n->list, parent, link);
- rb_insert_color(&n->list, &timers[nodeid].timer_head);
-
- if (!timers[nodeid].next || expires < rb_entry(timers[nodeid].next,
- struct mmtimer, list)->timer->it.mmtimer.expires)
- timers[nodeid].next = &n->list;
-}
-
-/*
- * Set the comparator for the next timer.
- * This function assumes the struct mmtimer_node is locked.
- */
-static void mmtimer_set_next_timer(int nodeid)
-{
- struct mmtimer_node *n = &timers[nodeid];
- struct mmtimer *x;
- struct k_itimer *t;
- u64 expires, exp, set_completion_time;
- int i;
-
-restart:
- if (n->next == NULL)
- return;
-
- x = rb_entry(n->next, struct mmtimer, list);
- t = x->timer;
- if (!t->it.mmtimer.incr) {
- /* Not an interval timer */
- if (!mmtimer_setup(x->cpu, COMPARATOR,
- t->it.mmtimer.expires,
- &set_completion_time)) {
- /* Late setup, fire now */
- tasklet_schedule(&n->tasklet);
- }
- return;
- }
-
- /* Interval timer */
- i = 0;
- expires = exp = t->it.mmtimer.expires;
- while (!mmtimer_setup(x->cpu, COMPARATOR, expires,
- &set_completion_time)) {
- int to;
-
- i++;
- expires = set_completion_time +
- mmtimer_interval_retry_increment + (1 << i);
- /* Calculate overruns as we go. */
- to = ((u64)(expires - exp) / t->it.mmtimer.incr);
- if (to) {
- t->it_overrun += to;
- t->it.mmtimer.expires += t->it.mmtimer.incr * to;
- exp = t->it.mmtimer.expires;
- }
- if (i > 20) {
- printk(KERN_ALERT "mmtimer: cannot reschedule timer\n");
- t->it.mmtimer.clock = TIMER_OFF;
- n->next = rb_next(&x->list);
- rb_erase(&x->list, &n->timer_head);
- kfree(x);
- goto restart;
- }
- }
-}
-
-/**
- * mmtimer_ioctl - ioctl interface for /dev/mmtimer
- * @file: file structure for the device
- * @cmd: command to execute
- * @arg: optional argument to command
- *
- * Executes the command specified by @cmd. Returns 0 for success, < 0 for
- * failure.
- *
- * Valid commands:
- *
- * %MMTIMER_GETOFFSET - Should return the offset (relative to the start
- * of the page where the registers are mapped) for the counter in question.
- *
- * %MMTIMER_GETRES - Returns the resolution of the clock in femto (10^-15)
- * seconds
- *
- * %MMTIMER_GETFREQ - Copies the frequency of the clock in Hz to the address
- * specified by @arg
- *
- * %MMTIMER_GETBITS - Returns the number of bits in the clock's counter
- *
- * %MMTIMER_MMAPAVAIL - Returns 1 if the registers can be mmap'd into userspace
- *
- * %MMTIMER_GETCOUNTER - Gets the current value in the counter and places it
- * in the address specified by @arg.
- */
-static long mmtimer_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- int ret = 0;
-
- mutex_lock(&mmtimer_mutex);
-
- switch (cmd) {
- case MMTIMER_GETOFFSET: /* offset of the counter */
- /*
- * SN RTC registers are on their own 64k page
- */
- if(PAGE_SIZE <= (1 << 16))
- ret = (((long)RTC_COUNTER_ADDR) & (PAGE_SIZE-1)) / 8;
- else
- ret = -ENOSYS;
- break;
-
- case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */
- if(copy_to_user((unsigned long __user *)arg,
- &mmtimer_femtoperiod, sizeof(unsigned long)))
- ret = -EFAULT;
- break;
-
- case MMTIMER_GETFREQ: /* frequency in Hz */
- if(copy_to_user((unsigned long __user *)arg,
- &sn_rtc_cycles_per_second,
- sizeof(unsigned long)))
- ret = -EFAULT;
- break;
-
- case MMTIMER_GETBITS: /* number of bits in the clock */
- ret = RTC_BITS;
- break;
-
- case MMTIMER_MMAPAVAIL: /* can we mmap the clock into userspace? */
- ret = (PAGE_SIZE <= (1 << 16)) ? 1 : 0;
- break;
-
- case MMTIMER_GETCOUNTER:
- if(copy_to_user((unsigned long __user *)arg,
- RTC_COUNTER_ADDR, sizeof(unsigned long)))
- ret = -EFAULT;
- break;
- default:
- ret = -ENOTTY;
- break;
- }
- mutex_unlock(&mmtimer_mutex);
- return ret;
-}
-
-/**
- * mmtimer_mmap - maps the clock's registers into userspace
- * @file: file structure for the device
- * @vma: VMA to map the registers into
- *
- * Calls remap_pfn_range() to map the clock's registers into
- * the calling process' address space.
- */
-static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
-{
- unsigned long mmtimer_addr;
-
- if (vma->vm_end - vma->vm_start != PAGE_SIZE)
- return -EINVAL;
-
- if (vma->vm_flags & VM_WRITE)
- return -EPERM;
-
- if (PAGE_SIZE > (1 << 16))
- return -ENOSYS;
-
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
- mmtimer_addr = __pa(RTC_COUNTER_ADDR);
- mmtimer_addr &= ~(PAGE_SIZE - 1);
- mmtimer_addr &= 0xfffffffffffffffUL;
-
- if (remap_pfn_range(vma, vma->vm_start, mmtimer_addr >> PAGE_SHIFT,
- PAGE_SIZE, vma->vm_page_prot)) {
- printk(KERN_ERR "remap_pfn_range failed in mmtimer.c\n");
- return -EAGAIN;
- }
-
- return 0;
-}
-
-static struct miscdevice mmtimer_miscdev = {
- .minor = SGI_MMTIMER,
- .name = MMTIMER_NAME,
- .fops = &mmtimer_fops
-};
-
-static struct timespec sgi_clock_offset;
-static int sgi_clock_period;
-
-/*
- * Posix Timer Interface
- */
-
-static struct timespec sgi_clock_offset;
-static int sgi_clock_period;
-
-static int sgi_clock_get(clockid_t clockid, struct timespec64 *tp)
-{
- u64 nsec;
-
- nsec = rtc_time() * sgi_clock_period
- + sgi_clock_offset.tv_nsec;
- *tp = ns_to_timespec64(nsec);
- tp->tv_sec += sgi_clock_offset.tv_sec;
- return 0;
-};
-
-static int sgi_clock_set(const clockid_t clockid, const struct timespec64 *tp)
-{
-
- u64 nsec;
- u32 rem;
-
- nsec = rtc_time() * sgi_clock_period;
-
- sgi_clock_offset.tv_sec = tp->tv_sec - div_u64_rem(nsec, NSEC_PER_SEC, &rem);
-
- if (rem <= tp->tv_nsec)
- sgi_clock_offset.tv_nsec = tp->tv_sec - rem;
- else {
- sgi_clock_offset.tv_nsec = tp->tv_sec + NSEC_PER_SEC - rem;
- sgi_clock_offset.tv_sec--;
- }
- return 0;
-}
-
-/**
- * mmtimer_interrupt - timer interrupt handler
- * @irq: irq received
- * @dev_id: device the irq came from
- *
- * Called when one of the comarators matches the counter, This
- * routine will send signals to processes that have requested
- * them.
- *
- * This interrupt is run in an interrupt context
- * by the SHUB. It is therefore safe to locally access SHub
- * registers.
- */
-static irqreturn_t
-mmtimer_interrupt(int irq, void *dev_id)
-{
- unsigned long expires = 0;
- int result = IRQ_NONE;
- unsigned indx = cpu_to_node(smp_processor_id());
- struct mmtimer *base;
-
- spin_lock(&timers[indx].lock);
- base = rb_entry(timers[indx].next, struct mmtimer, list);
- if (base == NULL) {
- spin_unlock(&timers[indx].lock);
- return result;
- }
-
- if (base->cpu == smp_processor_id()) {
- if (base->timer)
- expires = base->timer->it.mmtimer.expires;
- /* expires test won't work with shared irqs */
- if ((mmtimer_int_pending(COMPARATOR) > 0) ||
- (expires && (expires <= rtc_time()))) {
- mmtimer_clr_int_pending(COMPARATOR);
- tasklet_schedule(&timers[indx].tasklet);
- result = IRQ_HANDLED;
- }
- }
- spin_unlock(&timers[indx].lock);
- return result;
-}
-
-static void mmtimer_tasklet(unsigned long data)
-{
- int nodeid = data;
- struct mmtimer_node *mn = &timers[nodeid];
- struct mmtimer *x;
- struct k_itimer *t;
- unsigned long flags;
-
- /* Send signal and deal with periodic signals */
- spin_lock_irqsave(&mn->lock, flags);
- if (!mn->next)
- goto out;
-
- x = rb_entry(mn->next, struct mmtimer, list);
- t = x->timer;
-
- if (t->it.mmtimer.clock == TIMER_OFF)
- goto out;
-
- t->it_overrun = 0;
-
- mn->next = rb_next(&x->list);
- rb_erase(&x->list, &mn->timer_head);
-
- if (posix_timer_event(t, 0) != 0)
- t->it_overrun++;
-
- if(t->it.mmtimer.incr) {
- t->it.mmtimer.expires += t->it.mmtimer.incr;
- mmtimer_add_list(x);
- } else {
- /* Ensure we don't false trigger in mmtimer_interrupt */
- t->it.mmtimer.clock = TIMER_OFF;
- t->it.mmtimer.expires = 0;
- kfree(x);
- }
- /* Set comparator for next timer, if there is one */
- mmtimer_set_next_timer(nodeid);
-
- t->it_overrun_last = t->it_overrun;
-out:
- spin_unlock_irqrestore(&mn->lock, flags);
-}
-
-static int sgi_timer_create(struct k_itimer *timer)
-{
- /* Insure that a newly created timer is off */
- timer->it.mmtimer.clock = TIMER_OFF;
- return 0;
-}
-
-/* This does not really delete a timer. It just insures
- * that the timer is not active
- *
- * Assumption: it_lock is already held with irq's disabled
- */
-static int sgi_timer_del(struct k_itimer *timr)
-{
- cnodeid_t nodeid = timr->it.mmtimer.node;
- unsigned long irqflags;
-
- spin_lock_irqsave(&timers[nodeid].lock, irqflags);
- if (timr->it.mmtimer.clock != TIMER_OFF) {
- unsigned long expires = timr->it.mmtimer.expires;
- struct rb_node *n = timers[nodeid].timer_head.rb_node;
- struct mmtimer *uninitialized_var(t);
- int r = 0;
-
- timr->it.mmtimer.clock = TIMER_OFF;
- timr->it.mmtimer.expires = 0;
-
- while (n) {
- t = rb_entry(n, struct mmtimer, list);
- if (t->timer == timr)
- break;
-
- if (expires < t->timer->it.mmtimer.expires)
- n = n->rb_left;
- else
- n = n->rb_right;
- }
-
- if (!n) {
- spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
- return 0;
- }
-
- if (timers[nodeid].next == n) {
- timers[nodeid].next = rb_next(n);
- r = 1;
- }
-
- rb_erase(n, &timers[nodeid].timer_head);
- kfree(t);
-
- if (r) {
- mmtimer_disable_int(cnodeid_to_nasid(nodeid),
- COMPARATOR);
- mmtimer_set_next_timer(nodeid);
- }
- }
- spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
- return 0;
-}
-
-/* Assumption: it_lock is already held with irq's disabled */
-static void sgi_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
-{
-
- if (timr->it.mmtimer.clock == TIMER_OFF) {
- cur_setting->it_interval.tv_nsec = 0;
- cur_setting->it_interval.tv_sec = 0;
- cur_setting->it_value.tv_nsec = 0;
- cur_setting->it_value.tv_sec =0;
- return;
- }
-
- cur_setting->it_interval = ns_to_timespec64(timr->it.mmtimer.incr * sgi_clock_period);
- cur_setting->it_value = ns_to_timespec64((timr->it.mmtimer.expires - rtc_time()) * sgi_clock_period);
-}
-
-
-static int sgi_timer_set(struct k_itimer *timr, int flags,
- struct itimerspec64 *new_setting,
- struct itimerspec64 *old_setting)
-{
- unsigned long when, period, irqflags;
- int err = 0;
- cnodeid_t nodeid;
- struct mmtimer *base;
- struct rb_node *n;
-
- if (old_setting)
- sgi_timer_get(timr, old_setting);
-
- sgi_timer_del(timr);
- when = timespec64_to_ns(&new_setting->it_value);
- period = timespec64_to_ns(&new_setting->it_interval);
-
- if (when == 0)
- /* Clear timer */
- return 0;
-
- base = kmalloc(sizeof(struct mmtimer), GFP_KERNEL);
- if (base == NULL)
- return -ENOMEM;
-
- if (flags & TIMER_ABSTIME) {
- struct timespec64 n;
- unsigned long now;
-
- getnstimeofday64(&n);
- now = timespec64_to_ns(&n);
- if (when > now)
- when -= now;
- else
- /* Fire the timer immediately */
- when = 0;
- }
-
- /*
- * Convert to sgi clock period. Need to keep rtc_time() as near as possible
- * to getnstimeofday() in order to be as faithful as possible to the time
- * specified.
- */
- when = (when + sgi_clock_period - 1) / sgi_clock_period + rtc_time();
- period = (period + sgi_clock_period - 1) / sgi_clock_period;
-
- /*
- * We are allocating a local SHub comparator. If we would be moved to another
- * cpu then another SHub may be local to us. Prohibit that by switching off
- * preemption.
- */
- preempt_disable();
-
- nodeid = cpu_to_node(smp_processor_id());
-
- /* Lock the node timer structure */
- spin_lock_irqsave(&timers[nodeid].lock, irqflags);
-
- base->timer = timr;
- base->cpu = smp_processor_id();
-
- timr->it.mmtimer.clock = TIMER_SET;
- timr->it.mmtimer.node = nodeid;
- timr->it.mmtimer.incr = period;
- timr->it.mmtimer.expires = when;
-
- n = timers[nodeid].next;
-
- /* Add the new struct mmtimer to node's timer list */
- mmtimer_add_list(base);
-
- if (timers[nodeid].next == n) {
- /* No need to reprogram comparator for now */
- spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
- preempt_enable();
- return err;
- }
-
- /* We need to reprogram the comparator */
- if (n)
- mmtimer_disable_int(cnodeid_to_nasid(nodeid), COMPARATOR);
-
- mmtimer_set_next_timer(nodeid);
-
- /* Unlock the node timer structure */
- spin_unlock_irqrestore(&timers[nodeid].lock, irqflags);
-
- preempt_enable();
-
- return err;
-}
-
-static int sgi_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
-{
- tp->tv_sec = 0;
- tp->tv_nsec = sgi_clock_period;
- return 0;
-}
-
-static struct k_clock sgi_clock = {
- .clock_set = sgi_clock_set,
- .clock_get = sgi_clock_get,
- .clock_getres = sgi_clock_getres,
- .timer_create = sgi_timer_create,
- .timer_set = sgi_timer_set,
- .timer_del = sgi_timer_del,
- .timer_get = sgi_timer_get
-};
-
-/**
- * mmtimer_init - device initialization routine
- *
- * Does initial setup for the mmtimer device.
- */
-static int __init mmtimer_init(void)
-{
- cnodeid_t node, maxn = -1;
-
- if (!ia64_platform_is("sn2"))
- return 0;
-
- /*
- * Sanity check the cycles/sec variable
- */
- if (sn_rtc_cycles_per_second < 100000) {
- printk(KERN_ERR "%s: unable to determine clock frequency\n",
- MMTIMER_NAME);
- goto out1;
- }
-
- mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second /
- 2) / sn_rtc_cycles_per_second;
-
- if (request_irq(SGI_MMTIMER_VECTOR, mmtimer_interrupt, IRQF_PERCPU, MMTIMER_NAME, NULL)) {
- printk(KERN_WARNING "%s: unable to allocate interrupt.",
- MMTIMER_NAME);
- goto out1;
- }
-
- if (misc_register(&mmtimer_miscdev)) {
- printk(KERN_ERR "%s: failed to register device\n",
- MMTIMER_NAME);
- goto out2;
- }
-
- /* Get max numbered node, calculate slots needed */
- for_each_online_node(node) {
- maxn = node;
- }
- maxn++;
-
- /* Allocate list of node ptrs to mmtimer_t's */
- timers = kzalloc(sizeof(struct mmtimer_node)*maxn, GFP_KERNEL);
- if (!timers) {
- printk(KERN_ERR "%s: failed to allocate memory for device\n",
- MMTIMER_NAME);
- goto out3;
- }
-
- /* Initialize struct mmtimer's for each online node */
- for_each_online_node(node) {
- spin_lock_init(&timers[node].lock);
- tasklet_init(&timers[node].tasklet, mmtimer_tasklet,
- (unsigned long) node);
- }
-
- sgi_clock_period = NSEC_PER_SEC / sn_rtc_cycles_per_second;
- posix_timers_register_clock(CLOCK_SGI_CYCLE, &sgi_clock);
-
- printk(KERN_INFO "%s: v%s, %ld MHz\n", MMTIMER_DESC, MMTIMER_VERSION,
- sn_rtc_cycles_per_second/(unsigned long)1E6);
-
- return 0;
-
-out3:
- misc_deregister(&mmtimer_miscdev);
-out2:
- free_irq(SGI_MMTIMER_VECTOR, NULL);
-out1:
- return -1;
-}
-
-module_init(mmtimer_init);
--
2.11.0