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![Corentin Labbe](/assets/img/avatar_default.png)
Since the struct miscdevice have many members, it is dangerous to init it without members name relying only on member order. This patch add member name to the init declaration. Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
858 lines
21 KiB
C
858 lines
21 KiB
C
/*
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* Timer device implementation for SGI SN platforms.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (c) 2001-2006 Silicon Graphics, Inc. All rights reserved.
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*
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* This driver exports an API that should be supportable by any HPET or IA-PC
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* multimedia timer. The code below is currently specific to the SGI Altix
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* SHub RTC, however.
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*
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* 11/01/01 - jbarnes - initial revision
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* 9/10/04 - Christoph Lameter - remove interrupt support for kernel inclusion
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* 10/1/04 - Christoph Lameter - provide posix clock CLOCK_SGI_CYCLE
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* 10/13/04 - Christoph Lameter, Dimitri Sivanich - provide timer interrupt
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* support via the posix timer interface
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/ioctl.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/mmtimer.h>
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#include <linux/miscdevice.h>
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#include <linux/posix-timers.h>
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#include <linux/interrupt.h>
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#include <linux/time.h>
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#include <linux/math64.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <asm/sn/addrs.h>
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#include <asm/sn/intr.h>
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#include <asm/sn/shub_mmr.h>
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#include <asm/sn/nodepda.h>
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#include <asm/sn/shubio.h>
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MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>");
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MODULE_DESCRIPTION("SGI Altix RTC Timer");
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MODULE_LICENSE("GPL");
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/* name of the device, usually in /dev */
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#define MMTIMER_NAME "mmtimer"
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#define MMTIMER_DESC "SGI Altix RTC Timer"
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#define MMTIMER_VERSION "2.1"
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#define RTC_BITS 55 /* 55 bits for this implementation */
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static struct k_clock sgi_clock;
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extern unsigned long sn_rtc_cycles_per_second;
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#define RTC_COUNTER_ADDR ((long *)LOCAL_MMR_ADDR(SH_RTC))
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#define rtc_time() (*RTC_COUNTER_ADDR)
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static DEFINE_MUTEX(mmtimer_mutex);
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static long mmtimer_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg);
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static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
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/*
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* Period in femtoseconds (10^-15 s)
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*/
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static unsigned long mmtimer_femtoperiod = 0;
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static const struct file_operations mmtimer_fops = {
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.owner = THIS_MODULE,
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.mmap = mmtimer_mmap,
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.unlocked_ioctl = mmtimer_ioctl,
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.llseek = noop_llseek,
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};
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/*
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* We only have comparison registers RTC1-4 currently available per
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* node. RTC0 is used by SAL.
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*/
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/* Check for an RTC interrupt pending */
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static int mmtimer_int_pending(int comparator)
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{
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if (HUB_L((unsigned long *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED)) &
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SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator)
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return 1;
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else
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return 0;
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}
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/* Clear the RTC interrupt pending bit */
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static void mmtimer_clr_int_pending(int comparator)
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{
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_EVENT_OCCURRED_ALIAS),
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SH_EVENT_OCCURRED_RTC1_INT_MASK << comparator);
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}
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/* Setup timer on comparator RTC1 */
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static void mmtimer_setup_int_0(int cpu, u64 expires)
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{
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u64 val;
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/* Disable interrupt */
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 0UL);
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/* Initialize comparator value */
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), -1L);
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/* Clear pending bit */
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mmtimer_clr_int_pending(0);
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val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC1_INT_CONFIG_IDX_SHFT) |
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((u64)cpu_physical_id(cpu) <<
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SH_RTC1_INT_CONFIG_PID_SHFT);
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/* Set configuration */
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_CONFIG), val);
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/* Enable RTC interrupts */
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE), 1UL);
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/* Initialize comparator value */
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPB), expires);
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}
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/* Setup timer on comparator RTC2 */
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static void mmtimer_setup_int_1(int cpu, u64 expires)
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{
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u64 val;
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 0UL);
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), -1L);
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mmtimer_clr_int_pending(1);
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val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC2_INT_CONFIG_IDX_SHFT) |
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((u64)cpu_physical_id(cpu) <<
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SH_RTC2_INT_CONFIG_PID_SHFT);
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_CONFIG), val);
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE), 1UL);
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPC), expires);
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}
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/* Setup timer on comparator RTC3 */
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static void mmtimer_setup_int_2(int cpu, u64 expires)
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{
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u64 val;
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 0UL);
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), -1L);
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mmtimer_clr_int_pending(2);
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val = ((u64)SGI_MMTIMER_VECTOR << SH_RTC3_INT_CONFIG_IDX_SHFT) |
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((u64)cpu_physical_id(cpu) <<
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SH_RTC3_INT_CONFIG_PID_SHFT);
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_CONFIG), val);
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE), 1UL);
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HUB_S((u64 *)LOCAL_MMR_ADDR(SH_INT_CMPD), expires);
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}
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/*
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* This function must be called with interrupts disabled and preemption off
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* in order to insure that the setup succeeds in a deterministic time frame.
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* It will check if the interrupt setup succeeded.
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*/
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static int mmtimer_setup(int cpu, int comparator, unsigned long expires,
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u64 *set_completion_time)
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{
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switch (comparator) {
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case 0:
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mmtimer_setup_int_0(cpu, expires);
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break;
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case 1:
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mmtimer_setup_int_1(cpu, expires);
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break;
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case 2:
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mmtimer_setup_int_2(cpu, expires);
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break;
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}
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/* We might've missed our expiration time */
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*set_completion_time = rtc_time();
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if (*set_completion_time <= expires)
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return 1;
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/*
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* If an interrupt is already pending then its okay
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* if not then we failed
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*/
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return mmtimer_int_pending(comparator);
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}
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static int mmtimer_disable_int(long nasid, int comparator)
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{
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switch (comparator) {
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case 0:
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nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC1_INT_ENABLE),
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0UL) : REMOTE_HUB_S(nasid, SH_RTC1_INT_ENABLE, 0UL);
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break;
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case 1:
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nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC2_INT_ENABLE),
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0UL) : REMOTE_HUB_S(nasid, SH_RTC2_INT_ENABLE, 0UL);
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break;
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case 2:
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nasid == -1 ? HUB_S((u64 *)LOCAL_MMR_ADDR(SH_RTC3_INT_ENABLE),
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0UL) : REMOTE_HUB_S(nasid, SH_RTC3_INT_ENABLE, 0UL);
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break;
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default:
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return -EFAULT;
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}
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return 0;
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}
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#define COMPARATOR 1 /* The comparator to use */
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#define TIMER_OFF 0xbadcabLL /* Timer is not setup */
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#define TIMER_SET 0 /* Comparator is set for this timer */
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#define MMTIMER_INTERVAL_RETRY_INCREMENT_DEFAULT 40
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/* There is one of these for each timer */
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struct mmtimer {
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struct rb_node list;
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struct k_itimer *timer;
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int cpu;
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};
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struct mmtimer_node {
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spinlock_t lock ____cacheline_aligned;
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struct rb_root timer_head;
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struct rb_node *next;
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struct tasklet_struct tasklet;
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};
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static struct mmtimer_node *timers;
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static unsigned mmtimer_interval_retry_increment =
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MMTIMER_INTERVAL_RETRY_INCREMENT_DEFAULT;
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module_param(mmtimer_interval_retry_increment, uint, 0644);
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MODULE_PARM_DESC(mmtimer_interval_retry_increment,
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"RTC ticks to add to expiration on interval retry (default 40)");
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/*
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* Add a new mmtimer struct to the node's mmtimer list.
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* This function assumes the struct mmtimer_node is locked.
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*/
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static void mmtimer_add_list(struct mmtimer *n)
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{
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int nodeid = n->timer->it.mmtimer.node;
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unsigned long expires = n->timer->it.mmtimer.expires;
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struct rb_node **link = &timers[nodeid].timer_head.rb_node;
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struct rb_node *parent = NULL;
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struct mmtimer *x;
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/*
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* Find the right place in the rbtree:
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*/
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while (*link) {
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parent = *link;
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x = rb_entry(parent, struct mmtimer, list);
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if (expires < x->timer->it.mmtimer.expires)
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link = &(*link)->rb_left;
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else
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link = &(*link)->rb_right;
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}
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/*
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* Insert the timer to the rbtree and check whether it
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* replaces the first pending timer
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*/
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rb_link_node(&n->list, parent, link);
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rb_insert_color(&n->list, &timers[nodeid].timer_head);
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if (!timers[nodeid].next || expires < rb_entry(timers[nodeid].next,
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struct mmtimer, list)->timer->it.mmtimer.expires)
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timers[nodeid].next = &n->list;
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}
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/*
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* Set the comparator for the next timer.
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* This function assumes the struct mmtimer_node is locked.
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*/
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static void mmtimer_set_next_timer(int nodeid)
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{
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struct mmtimer_node *n = &timers[nodeid];
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struct mmtimer *x;
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struct k_itimer *t;
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u64 expires, exp, set_completion_time;
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int i;
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restart:
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if (n->next == NULL)
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return;
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x = rb_entry(n->next, struct mmtimer, list);
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t = x->timer;
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if (!t->it.mmtimer.incr) {
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/* Not an interval timer */
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if (!mmtimer_setup(x->cpu, COMPARATOR,
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t->it.mmtimer.expires,
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&set_completion_time)) {
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/* Late setup, fire now */
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tasklet_schedule(&n->tasklet);
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}
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return;
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}
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/* Interval timer */
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i = 0;
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expires = exp = t->it.mmtimer.expires;
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while (!mmtimer_setup(x->cpu, COMPARATOR, expires,
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&set_completion_time)) {
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int to;
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i++;
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expires = set_completion_time +
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mmtimer_interval_retry_increment + (1 << i);
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/* Calculate overruns as we go. */
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to = ((u64)(expires - exp) / t->it.mmtimer.incr);
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if (to) {
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t->it_overrun += to;
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t->it.mmtimer.expires += t->it.mmtimer.incr * to;
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exp = t->it.mmtimer.expires;
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}
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if (i > 20) {
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printk(KERN_ALERT "mmtimer: cannot reschedule timer\n");
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t->it.mmtimer.clock = TIMER_OFF;
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n->next = rb_next(&x->list);
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rb_erase(&x->list, &n->timer_head);
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kfree(x);
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goto restart;
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}
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}
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}
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/**
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* mmtimer_ioctl - ioctl interface for /dev/mmtimer
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* @file: file structure for the device
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* @cmd: command to execute
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* @arg: optional argument to command
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*
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* Executes the command specified by @cmd. Returns 0 for success, < 0 for
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* failure.
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*
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* Valid commands:
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*
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* %MMTIMER_GETOFFSET - Should return the offset (relative to the start
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* of the page where the registers are mapped) for the counter in question.
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*
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* %MMTIMER_GETRES - Returns the resolution of the clock in femto (10^-15)
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* seconds
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*
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* %MMTIMER_GETFREQ - Copies the frequency of the clock in Hz to the address
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* specified by @arg
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*
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* %MMTIMER_GETBITS - Returns the number of bits in the clock's counter
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*
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* %MMTIMER_MMAPAVAIL - Returns 1 if the registers can be mmap'd into userspace
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*
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* %MMTIMER_GETCOUNTER - Gets the current value in the counter and places it
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* in the address specified by @arg.
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*/
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static long mmtimer_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret = 0;
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mutex_lock(&mmtimer_mutex);
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switch (cmd) {
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case MMTIMER_GETOFFSET: /* offset of the counter */
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/*
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* SN RTC registers are on their own 64k page
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*/
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if(PAGE_SIZE <= (1 << 16))
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ret = (((long)RTC_COUNTER_ADDR) & (PAGE_SIZE-1)) / 8;
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else
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ret = -ENOSYS;
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break;
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case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */
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if(copy_to_user((unsigned long __user *)arg,
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&mmtimer_femtoperiod, sizeof(unsigned long)))
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ret = -EFAULT;
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break;
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case MMTIMER_GETFREQ: /* frequency in Hz */
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if(copy_to_user((unsigned long __user *)arg,
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&sn_rtc_cycles_per_second,
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sizeof(unsigned long)))
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ret = -EFAULT;
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break;
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case MMTIMER_GETBITS: /* number of bits in the clock */
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ret = RTC_BITS;
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break;
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case MMTIMER_MMAPAVAIL: /* can we mmap the clock into userspace? */
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ret = (PAGE_SIZE <= (1 << 16)) ? 1 : 0;
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break;
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case MMTIMER_GETCOUNTER:
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if(copy_to_user((unsigned long __user *)arg,
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RTC_COUNTER_ADDR, sizeof(unsigned long)))
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ret = -EFAULT;
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break;
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default:
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ret = -ENOTTY;
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break;
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}
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mutex_unlock(&mmtimer_mutex);
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return ret;
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}
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/**
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* mmtimer_mmap - maps the clock's registers into userspace
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* @file: file structure for the device
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* @vma: VMA to map the registers into
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*
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* Calls remap_pfn_range() to map the clock's registers into
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* the calling process' address space.
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*/
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static int mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
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{
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unsigned long mmtimer_addr;
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if (vma->vm_end - vma->vm_start != PAGE_SIZE)
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return -EINVAL;
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if (vma->vm_flags & VM_WRITE)
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return -EPERM;
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if (PAGE_SIZE > (1 << 16))
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return -ENOSYS;
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vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
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mmtimer_addr = __pa(RTC_COUNTER_ADDR);
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mmtimer_addr &= ~(PAGE_SIZE - 1);
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mmtimer_addr &= 0xfffffffffffffffUL;
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if (remap_pfn_range(vma, vma->vm_start, mmtimer_addr >> PAGE_SHIFT,
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PAGE_SIZE, vma->vm_page_prot)) {
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printk(KERN_ERR "remap_pfn_range failed in mmtimer.c\n");
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return -EAGAIN;
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}
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return 0;
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}
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static struct miscdevice mmtimer_miscdev = {
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.minor = SGI_MMTIMER,
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.name = MMTIMER_NAME,
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.fops = &mmtimer_fops
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};
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static struct timespec sgi_clock_offset;
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static int sgi_clock_period;
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/*
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* Posix Timer Interface
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*/
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static struct timespec sgi_clock_offset;
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static int sgi_clock_period;
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static int sgi_clock_get(clockid_t clockid, struct timespec *tp)
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{
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u64 nsec;
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nsec = rtc_time() * sgi_clock_period
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+ sgi_clock_offset.tv_nsec;
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*tp = ns_to_timespec(nsec);
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tp->tv_sec += sgi_clock_offset.tv_sec;
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return 0;
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};
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static int sgi_clock_set(const clockid_t clockid, const struct timespec *tp)
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{
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u64 nsec;
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u32 rem;
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nsec = rtc_time() * sgi_clock_period;
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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 itimerspec *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_timespec(timr->it.mmtimer.incr * sgi_clock_period);
|
|
cur_setting->it_value = ns_to_timespec((timr->it.mmtimer.expires - rtc_time()) * sgi_clock_period);
|
|
}
|
|
|
|
|
|
static int sgi_timer_set(struct k_itimer *timr, int flags,
|
|
struct itimerspec * new_setting,
|
|
struct itimerspec * 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 = timespec_to_ns(&new_setting->it_value);
|
|
period = timespec_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 timespec n;
|
|
unsigned long now;
|
|
|
|
getnstimeofday(&n);
|
|
now = timespec_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 timespec *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);
|