From 38e0e8c0550eaed1af48ec5ad9ddb8a25e8b04ae Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Mon, 10 Jul 2006 04:45:30 -0700 Subject: [PATCH] char/rtc: Handle memory-mapped chips properly Handle memory-mapped chips properly, needed for example on DECstations. This support was in Linux 2.4 but for some reason got lost in 2.6. This patch is taken directly from the linux-mips repository. [akpm@osdl.org: cleanup] Signed-off-by: Maciej W. Rozycki Signed-off-by: Martin Michlmayr Cc: Paul Gortmaker Cc: Ralf Baechle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/rtc.c | 41 ++++++++++++++++++++++++++++++++--------- 1 file changed, 32 insertions(+), 9 deletions(-) (limited to 'drivers/char/rtc.c') diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c index cc7bd1a3095b..6ccc364c08df 100644 --- a/drivers/char/rtc.c +++ b/drivers/char/rtc.c @@ -46,13 +46,12 @@ * 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init * 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer * CONFIG_HPET_EMULATE_RTC + * 1.12a Maciej W. Rozycki: Handle memory-mapped chips properly. * 1.12ac Alan Cox: Allow read access to the day of week register */ #define RTC_VERSION "1.12ac" -#define RTC_IO_EXTENT 0x8 - /* * Note that *all* calls to CMOS_READ and CMOS_WRITE are done with * interrupts disabled. Due to the index-port/data-port (0x70/0x71) @@ -337,7 +336,15 @@ static ssize_t rtc_read(struct file *file, char __user *buf, if (rtc_has_irq == 0) return -EIO; - if (count < sizeof(unsigned)) + /* + * Historically this function used to assume that sizeof(unsigned long) + * is the same in userspace and kernelspace. This lead to problems + * for configurations with multiple ABIs such a the MIPS o32 and 64 + * ABIs supported on the same kernel. So now we support read of both + * 4 and 8 bytes and assume that's the sizeof(unsigned long) in the + * userspace ABI. + */ + if (count != sizeof(unsigned int) && count != sizeof(unsigned long)) return -EINVAL; add_wait_queue(&rtc_wait, &wait); @@ -368,10 +375,12 @@ static ssize_t rtc_read(struct file *file, char __user *buf, schedule(); } while (1); - if (count < sizeof(unsigned long)) - retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int); + if (count == sizeof(unsigned int)) + retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int); else retval = put_user(data, (unsigned long __user *)buf) ?: sizeof(long); + if (!retval) + retval = count; out: current->state = TASK_RUNNING; remove_wait_queue(&rtc_wait, &wait); @@ -923,6 +932,9 @@ static int __init rtc_init(void) struct sparc_isa_device *isa_dev; #endif #endif +#ifndef __sparc__ + void *r; +#endif #ifdef __sparc__ for_each_ebus(ebus) { @@ -964,8 +976,13 @@ found: } no_irq: #else - if (!request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc")) { - printk(KERN_ERR "rtc: I/O port %d is not free.\n", RTC_PORT (0)); + if (RTC_IOMAPPED) + r = request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc"); + else + r = request_mem_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc"); + if (!r) { + printk(KERN_ERR "rtc: I/O resource %lx is not free.\n", + (long)(RTC_PORT(0))); return -EIO; } @@ -979,7 +996,10 @@ no_irq: if(request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED, "rtc", NULL)) { /* Yeah right, seeing as irq 8 doesn't even hit the bus. */ printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ); - release_region(RTC_PORT(0), RTC_IO_EXTENT); + if (RTC_IOMAPPED) + release_region(RTC_PORT(0), RTC_IO_EXTENT); + else + release_mem_region(RTC_PORT(0), RTC_IO_EXTENT); return -EIO; } hpet_rtc_timer_init(); @@ -1079,7 +1099,10 @@ static void __exit rtc_exit (void) if (rtc_has_irq) free_irq (rtc_irq, &rtc_port); #else - release_region (RTC_PORT (0), RTC_IO_EXTENT); + if (RTC_IOMAPPED) + release_region(RTC_PORT(0), RTC_IO_EXTENT); + else + release_mem_region(RTC_PORT(0), RTC_IO_EXTENT); #ifdef RTC_IRQ if (rtc_has_irq) free_irq (RTC_IRQ, NULL); -- cgit v1.2.2 From 0f74964627e0ece4ac8da0e2cd01906ec322b4fe Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 12 Jul 2006 09:03:10 -0700 Subject: [PATCH] lockdep: HPET/RTC fix Joseph Fannin reported that hpet_rtc_interrupt() enables hardirqs in irq context: [ 25.628000] [] trace_hardirqs_on+0xce/0x200 [ 25.628000] [] _spin_unlock_irq+0x31/0x70 [ 25.628000] [] rtc_get_rtc_time+0x44/0x1a0 [ 25.628000] [] hpet_rtc_interrupt+0x21b/0x280 [ 25.628000] [] handle_IRQ_event+0x31/0x70 [ 25.628000] [] handle_edge_irq+0xe7/0x210 [ 25.628000] [] do_IRQ+0x92/0x120 [ 25.628000] [] common_interrupt+0x25/0x2c the call of rtc_get_rtc_time() is highly suspect. At a minimum we need the patch below to save/restore hardirq state. Signed-off-by: Ingo Molnar Cc: Joseph Fannin Cc: John Stultz Cc: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/rtc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/char/rtc.c') diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c index 6ccc364c08df..6e6a7c7a7eff 100644 --- a/drivers/char/rtc.c +++ b/drivers/char/rtc.c @@ -1245,7 +1245,7 @@ static int rtc_proc_open(struct inode *inode, struct file *file) void rtc_get_rtc_time(struct rtc_time *rtc_tm) { - unsigned long uip_watchdog = jiffies; + unsigned long uip_watchdog = jiffies, flags; unsigned char ctrl; #ifdef CONFIG_MACH_DECSTATION unsigned int real_year; @@ -1272,7 +1272,7 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm) * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is * only updated by the RTC when initially set to a non-zero value. */ - spin_lock_irq(&rtc_lock); + spin_lock_irqsave(&rtc_lock, flags); rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS); rtc_tm->tm_min = CMOS_READ(RTC_MINUTES); rtc_tm->tm_hour = CMOS_READ(RTC_HOURS); @@ -1286,7 +1286,7 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm) real_year = CMOS_READ(RTC_DEC_YEAR); #endif ctrl = CMOS_READ(RTC_CONTROL); - spin_unlock_irq(&rtc_lock); + spin_unlock_irqrestore(&rtc_lock, flags); if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { -- cgit v1.2.2