This driver memory maps the UV Hub RTC.
Signed-off-by: Dimitri Sivanich <[email protected]>
---
drivers/char/Kconfig | 8 +
drivers/char/Makefile | 1
drivers/char/uv_mmtimer.c | 214 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 223 insertions(+)
Index: linux/drivers/char/Kconfig
===================================================================
--- linux.orig/drivers/char/Kconfig 2009-09-10 12:38:30.000000000 -0500
+++ linux/drivers/char/Kconfig 2009-09-10 12:40:12.000000000 -0500
@@ -1087,6 +1087,14 @@ config MMTIMER
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
+ default m
+ help
+ The uv_mmtimer device allows direct userspace access to the
+ UV system timer.
+
source "drivers/char/tpm/Kconfig"
config TELCLOCK
Index: linux/drivers/char/Makefile
===================================================================
--- linux.orig/drivers/char/Makefile 2009-09-10 12:38:30.000000000 -0500
+++ linux/drivers/char/Makefile 2009-09-10 12:40:12.000000000 -0500
@@ -58,6 +58,7 @@ 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_VIOTAPE) += viotape.o
obj-$(CONFIG_HVCS) += hvcs.o
obj-$(CONFIG_IBM_BSR) += bsr.o
Index: linux/drivers/char/uv_mmtimer.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux/drivers/char/uv_mmtimer.c 2009-09-10 14:09:35.000000000 -0500
@@ -0,0 +1,214 @@
+/*
+ * Timer device implementation for SGI UV platform.
+ *
+ * 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) 2009 Silicon Graphics, Inc. All rights reserved.
+ *
+ */
+
+#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/smp_lock.h>
+
+#include <asm/genapic.h>
+#include <asm/uv/uv_hub.h>
+#include <asm/uv/bios.h>
+#include <asm/uv/uv.h>
+
+MODULE_AUTHOR("Dimitri Sivanich <[email protected]>");
+MODULE_DESCRIPTION("SGI UV Memory Mapped RTC Timer");
+MODULE_LICENSE("GPL");
+
+/* name of the device, usually in /dev */
+#define UV_MMTIMER_NAME "mmtimer"
+#define UV_MMTIMER_DESC "SGI UV Memory Mapped RTC Timer"
+#define UV_MMTIMER_VERSION "1.0"
+
+static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg);
+static int uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
+
+/*
+ * Period in femtoseconds (10^-15 s)
+ */
+static unsigned long uv_mmtimer_femtoperiod;
+
+static const struct file_operations uv_mmtimer_fops = {
+ .owner = THIS_MODULE,
+ .mmap = uv_mmtimer_mmap,
+ .unlocked_ioctl = uv_mmtimer_ioctl,
+};
+
+/**
+ * uv_mmtimer_ioctl - ioctl interface for /dev/uv_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 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 uv_mmtimer_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int ret = 0;
+
+ switch (cmd) {
+ case MMTIMER_GETOFFSET: /* offset of the counter */
+ /*
+ * UV RTC register is on it's own page
+ */
+ if (PAGE_SIZE <= (1 << 16))
+ ret = ((UV_LOCAL_MMR_BASE | UVH_RTC) & (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,
+ &uv_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 = hweight64(UVH_RTC_REAL_TIME_CLOCK_MASK);
+ 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,
+ (unsigned long *)uv_local_mmr_address(UVH_RTC),
+ sizeof(unsigned long)))
+ ret = -EFAULT;
+ break;
+ default:
+ ret = -ENOTTY;
+ break;
+ }
+ return ret;
+}
+
+/**
+ * uv_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 uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ unsigned long uv_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);
+
+ uv_mmtimer_addr = UV_LOCAL_MMR_BASE | UVH_RTC;
+ uv_mmtimer_addr &= ~(PAGE_SIZE - 1);
+ uv_mmtimer_addr &= 0xfffffffffffffffUL;
+
+ if (remap_pfn_range(vma, vma->vm_start, uv_mmtimer_addr >> PAGE_SHIFT,
+ PAGE_SIZE, vma->vm_page_prot)) {
+ printk(KERN_ERR "remap_pfn_range failed in uv_mmtimer_mmap\n");
+ return -EAGAIN;
+ }
+
+ return 0;
+}
+
+static struct miscdevice uv_mmtimer_miscdev = {
+ MISC_DYNAMIC_MINOR,
+ UV_MMTIMER_NAME,
+ &uv_mmtimer_fops
+};
+
+
+/**
+ * uv_mmtimer_init - device initialization routine
+ *
+ * Does initial setup for the uv_mmtimer device.
+ */
+static int __init uv_mmtimer_init(void)
+{
+ if (!is_uv_system())
+ 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",
+ UV_MMTIMER_NAME);
+ return -1;
+ }
+
+ uv_mmtimer_femtoperiod = ((unsigned long)1E15 +
+ sn_rtc_cycles_per_second / 2) /
+ sn_rtc_cycles_per_second;
+
+ if (misc_register(&uv_mmtimer_miscdev)) {
+ printk(KERN_ERR "%s: failed to register device\n",
+ UV_MMTIMER_NAME);
+ return -1;
+ }
+
+ printk(KERN_INFO "%s: v%s, %ld MHz\n", UV_MMTIMER_DESC,
+ UV_MMTIMER_VERSION,
+ sn_rtc_cycles_per_second/(unsigned long)1E6);
+
+ return 0;
+}
+
+module_init(uv_mmtimer_init);
On Thu, 10 Sep 2009 20:30:54 -0500 Dimitri Sivanich <[email protected]> wrote:
> This driver memory maps the UV Hub RTC.
>
> ...
>
> +/**
> + * uv_mmtimer_ioctl - ioctl interface for /dev/uv_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 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.
Are these % thingies part of kerneldoc?
> + */
> +static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd,
> + unsigned long arg)
> +{
> + int ret = 0;
> +
> + switch (cmd) {
> + case MMTIMER_GETOFFSET: /* offset of the counter */
> + /*
> + * UV RTC register is on it's own page
"its" ;)
> + */
> + if (PAGE_SIZE <= (1 << 16))
> + ret = ((UV_LOCAL_MMR_BASE | UVH_RTC) & (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,
> + &uv_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 = hweight64(UVH_RTC_REAL_TIME_CLOCK_MASK);
> + 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,
> + (unsigned long *)uv_local_mmr_address(UVH_RTC),
> + sizeof(unsigned long)))
> + ret = -EFAULT;
> + break;
> + default:
> + ret = -ENOTTY;
> + break;
> + }
> + return ret;
> +}
> +
> +/**
> + * uv_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 uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
> +{
> + unsigned long uv_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);
> +
> + uv_mmtimer_addr = UV_LOCAL_MMR_BASE | UVH_RTC;
> + uv_mmtimer_addr &= ~(PAGE_SIZE - 1);
> + uv_mmtimer_addr &= 0xfffffffffffffffUL;
> +
> + if (remap_pfn_range(vma, vma->vm_start, uv_mmtimer_addr >> PAGE_SHIFT,
> + PAGE_SIZE, vma->vm_page_prot)) {
> + printk(KERN_ERR "remap_pfn_range failed in uv_mmtimer_mmap\n");
> + return -EAGAIN;
> + }
> +
> + return 0;
> +}
Methinks we should be setting vma->vm_flags's VM_IO here and perhaps
also VM_RESERVED.
> +static struct miscdevice uv_mmtimer_miscdev = {
> + MISC_DYNAMIC_MINOR,
> + UV_MMTIMER_NAME,
> + &uv_mmtimer_fops
> +};
> +
> +
> +/**
> + * uv_mmtimer_init - device initialization routine
> + *
> + * Does initial setup for the uv_mmtimer device.
> + */
> +static int __init uv_mmtimer_init(void)
> +{
> + if (!is_uv_system())
> + return 0;
This will leave the module loaded but inactive. Would it make more
sense to return an error code in this case so that a) the user
discovers that he wasted his time and b) the module will get booted out
again?
> + /*
> + * Sanity check the cycles/sec variable
> + */
> + if (sn_rtc_cycles_per_second < 100000) {
> + printk(KERN_ERR "%s: unable to determine clock frequency\n",
> + UV_MMTIMER_NAME);
> + return -1;
> + }
> +
> + uv_mmtimer_femtoperiod = ((unsigned long)1E15 +
> + sn_rtc_cycles_per_second / 2) /
> + sn_rtc_cycles_per_second;
> +
> + if (misc_register(&uv_mmtimer_miscdev)) {
> + printk(KERN_ERR "%s: failed to register device\n",
> + UV_MMTIMER_NAME);
> + return -1;
> + }
> +
> + printk(KERN_INFO "%s: v%s, %ld MHz\n", UV_MMTIMER_DESC,
> + UV_MMTIMER_VERSION,
> + sn_rtc_cycles_per_second/(unsigned long)1E6);
> +
> + return 0;
> +}
> +
> +module_init(uv_mmtimer_init);
On Fri, Sep 11, 2009 at 2:52 PM, Andrew Morton
<[email protected]> wrote:
> On Thu, 10 Sep 2009 20:30:54 -0500 Dimitri Sivanich <[email protected]> wrote:
>
>> This driver memory maps the UV Hub RTC.
>>
>> ...
>>
>> +/**
>> + * uv_mmtimer_ioctl - ioctl interface for /dev/uv_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 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.
>
> Are these % thingies part of kerneldoc?
>
>> + */
>> +static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? unsigned long arg)
>> +{
>> + ? ? int ret = 0;
>> +
>> + ? ? switch (cmd) {
>> + ? ? case MMTIMER_GETOFFSET: /* offset of the counter */
>> + ? ? ? ? ? ? /*
>> + ? ? ? ? ? ? ?* UV RTC register is on it's own page
>
> "its" ;)
>
>> + ? ? ? ? ? ? ?*/
>> + ? ? ? ? ? ? if (PAGE_SIZE <= (1 << 16))
>> + ? ? ? ? ? ? ? ? ? ? ret = ((UV_LOCAL_MMR_BASE | UVH_RTC) & (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,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? &uv_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 = hweight64(UVH_RTC_REAL_TIME_CLOCK_MASK);
>> + ? ? ? ? ? ? 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,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? (unsigned long *)uv_local_mmr_address(UVH_RTC),
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? sizeof(unsigned long)))
>> + ? ? ? ? ? ? ? ? ? ? ret = -EFAULT;
>> + ? ? ? ? ? ? break;
>> + ? ? default:
>> + ? ? ? ? ? ? ret = -ENOTTY;
>> + ? ? ? ? ? ? break;
>> + ? ? }
>> + ? ? return ret;
>> +}
>> +
>> +/**
>> + * uv_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 uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
>> +{
>> + ? ? unsigned long uv_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);
>> +
>> + ? ? uv_mmtimer_addr = UV_LOCAL_MMR_BASE | UVH_RTC;
>> + ? ? uv_mmtimer_addr &= ~(PAGE_SIZE - 1);
>> + ? ? uv_mmtimer_addr &= 0xfffffffffffffffUL;
>> +
>> + ? ? if (remap_pfn_range(vma, vma->vm_start, uv_mmtimer_addr >> PAGE_SHIFT,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? PAGE_SIZE, vma->vm_page_prot)) {
>> + ? ? ? ? ? ? printk(KERN_ERR "remap_pfn_range failed in uv_mmtimer_mmap\n");
>> + ? ? ? ? ? ? return -EAGAIN;
>> + ? ? }
>> +
>> + ? ? return 0;
>> +}
>
> Methinks we should be setting vma->vm_flags's VM_IO here and perhaps
> also VM_RESERVED.
remap_pfn_range already does it. :)
--
Kind regards,
Minchan Kim
On Thu, Sep 10, 2009 at 10:52:42PM -0700, Andrew Morton wrote:
> On Thu, 10 Sep 2009 20:30:54 -0500 Dimitri Sivanich <[email protected]> wrote:
> > + * 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 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.
>
> Are these % thingies part of kerneldoc?
I assume you're referring to Documentation/ioctl/ioctl-number.txt? Added.
> > + * UV RTC register is on it's own page
> "its" ;)
Fixed ;)
> > +
> > + if (remap_pfn_range(vma, vma->vm_start, uv_mmtimer_addr >> PAGE_SHIFT,
> > + PAGE_SIZE, vma->vm_page_prot)) {
> > + printk(KERN_ERR "remap_pfn_range failed in uv_mmtimer_mmap\n");
> > + return -EAGAIN;
> > + }
> > +
> > + return 0;
> > +}
>
> Methinks we should be setting vma->vm_flags's VM_IO here and perhaps
> also VM_RESERVED.
As Minchan Kim mentioned, these are already added by remap_pfn_range.
> > +static int __init uv_mmtimer_init(void)
> > +{
> > + if (!is_uv_system())
> > + return 0;
>
> This will leave the module loaded but inactive. Would it make more
> sense to return an error code in this case so that a) the user
> discovers that he wasted his time and b) the module will get booted out
> again?
>
Done.
Here's the updated patch.
----------------------------------------------------------------------------
This driver memory maps the UV Hub RTC.
Signed-off-by: Dimitri Sivanich <[email protected]>
---
Documentation/ioctl/ioctl-number.txt | 1
drivers/char/Kconfig | 8 +
drivers/char/Makefile | 1
drivers/char/uv_mmtimer.c | 216 +++++++++++++++++++++++++++++++
4 files changed, 226 insertions(+)
Index: linux/drivers/char/Kconfig
===================================================================
--- linux.orig/drivers/char/Kconfig 2009-09-11 08:30:38.000000000 -0500
+++ linux/drivers/char/Kconfig 2009-09-11 08:30:40.000000000 -0500
@@ -1087,6 +1087,14 @@ config MMTIMER
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
+ default m
+ help
+ The uv_mmtimer device allows direct userspace access to the
+ UV system timer.
+
source "drivers/char/tpm/Kconfig"
config TELCLOCK
Index: linux/drivers/char/Makefile
===================================================================
--- linux.orig/drivers/char/Makefile 2009-09-11 08:30:38.000000000 -0500
+++ linux/drivers/char/Makefile 2009-09-11 08:30:40.000000000 -0500
@@ -58,6 +58,7 @@ 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_VIOTAPE) += viotape.o
obj-$(CONFIG_HVCS) += hvcs.o
obj-$(CONFIG_IBM_BSR) += bsr.o
Index: linux/drivers/char/uv_mmtimer.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux/drivers/char/uv_mmtimer.c 2009-09-11 08:39:48.000000000 -0500
@@ -0,0 +1,216 @@
+/*
+ * Timer device implementation for SGI UV platform.
+ *
+ * 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) 2009 Silicon Graphics, Inc. All rights reserved.
+ *
+ */
+
+#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/smp_lock.h>
+
+#include <asm/genapic.h>
+#include <asm/uv/uv_hub.h>
+#include <asm/uv/bios.h>
+#include <asm/uv/uv.h>
+
+MODULE_AUTHOR("Dimitri Sivanich <[email protected]>");
+MODULE_DESCRIPTION("SGI UV Memory Mapped RTC Timer");
+MODULE_LICENSE("GPL");
+
+/* name of the device, usually in /dev */
+#define UV_MMTIMER_NAME "mmtimer"
+#define UV_MMTIMER_DESC "SGI UV Memory Mapped RTC Timer"
+#define UV_MMTIMER_VERSION "1.0"
+
+static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg);
+static int uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
+
+/*
+ * Period in femtoseconds (10^-15 s)
+ */
+static unsigned long uv_mmtimer_femtoperiod;
+
+static const struct file_operations uv_mmtimer_fops = {
+ .owner = THIS_MODULE,
+ .mmap = uv_mmtimer_mmap,
+ .unlocked_ioctl = uv_mmtimer_ioctl,
+};
+
+/**
+ * uv_mmtimer_ioctl - ioctl interface for /dev/uv_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 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 uv_mmtimer_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int ret = 0;
+
+ switch (cmd) {
+ case MMTIMER_GETOFFSET: /* offset of the counter */
+ /*
+ * UV RTC register is on its own page
+ */
+ if (PAGE_SIZE <= (1 << 16))
+ ret = ((UV_LOCAL_MMR_BASE | UVH_RTC) & (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,
+ &uv_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 = hweight64(UVH_RTC_REAL_TIME_CLOCK_MASK);
+ 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,
+ (unsigned long *)uv_local_mmr_address(UVH_RTC),
+ sizeof(unsigned long)))
+ ret = -EFAULT;
+ break;
+ default:
+ ret = -ENOTTY;
+ break;
+ }
+ return ret;
+}
+
+/**
+ * uv_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 uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ unsigned long uv_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);
+
+ uv_mmtimer_addr = UV_LOCAL_MMR_BASE | UVH_RTC;
+ uv_mmtimer_addr &= ~(PAGE_SIZE - 1);
+ uv_mmtimer_addr &= 0xfffffffffffffffUL;
+
+ if (remap_pfn_range(vma, vma->vm_start, uv_mmtimer_addr >> PAGE_SHIFT,
+ PAGE_SIZE, vma->vm_page_prot)) {
+ printk(KERN_ERR "remap_pfn_range failed in uv_mmtimer_mmap\n");
+ return -EAGAIN;
+ }
+
+ return 0;
+}
+
+static struct miscdevice uv_mmtimer_miscdev = {
+ MISC_DYNAMIC_MINOR,
+ UV_MMTIMER_NAME,
+ &uv_mmtimer_fops
+};
+
+
+/**
+ * uv_mmtimer_init - device initialization routine
+ *
+ * Does initial setup for the uv_mmtimer device.
+ */
+static int __init uv_mmtimer_init(void)
+{
+ if (!is_uv_system()) {
+ printk(KERN_ERR "%s: Hardware unsupported\n", UV_MMTIMER_NAME);
+ return -1;
+ }
+
+ /*
+ * Sanity check the cycles/sec variable
+ */
+ if (sn_rtc_cycles_per_second < 100000) {
+ printk(KERN_ERR "%s: unable to determine clock frequency\n",
+ UV_MMTIMER_NAME);
+ return -1;
+ }
+
+ uv_mmtimer_femtoperiod = ((unsigned long)1E15 +
+ sn_rtc_cycles_per_second / 2) /
+ sn_rtc_cycles_per_second;
+
+ if (misc_register(&uv_mmtimer_miscdev)) {
+ printk(KERN_ERR "%s: failed to register device\n",
+ UV_MMTIMER_NAME);
+ return -1;
+ }
+
+ printk(KERN_INFO "%s: v%s, %ld MHz\n", UV_MMTIMER_DESC,
+ UV_MMTIMER_VERSION,
+ sn_rtc_cycles_per_second/(unsigned long)1E6);
+
+ return 0;
+}
+
+module_init(uv_mmtimer_init);
Index: linux/Documentation/ioctl/ioctl-number.txt
===================================================================
--- linux.orig/Documentation/ioctl/ioctl-number.txt 2009-09-10 09:50:31.000000000 -0500
+++ linux/Documentation/ioctl/ioctl-number.txt 2009-09-11 08:34:32.000000000 -0500
@@ -135,6 +135,7 @@ Code Seq# Include File Comments
<http://mikonos.dia.unisa.it/tcfs>
'l' 40-7F linux/udf_fs_i.h in development:
<http://sourceforge.net/projects/linux-udf/>
+'m' 00-09 linux/mmtimer.h
'm' all linux/mtio.h conflict!
'm' all linux/soundcard.h conflict!
'm' all linux/synclink.h conflict!