35b69a420b
Add support for platforms where pit_shutdown() doesn't work because of a quirk in the PIT emulation. On these platforms setting the counter register to zero causes the PIT to start running again, negating the shutdown. Provide a global variable that controls whether the counter register is zero'ed, which platform specific code can override. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org> Cc: "devel@linuxdriverproject.org" <devel@linuxdriverproject.org> Cc: "daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org> Cc: "virtualization@lists.linux-foundation.org" <virtualization@lists.linux-foundation.org> Cc: "jgross@suse.com" <jgross@suse.com> Cc: "akataria@vmware.com" <akataria@vmware.com> Cc: "olaf@aepfle.de" <olaf@aepfle.de> Cc: "apw@canonical.com" <apw@canonical.com> Cc: vkuznets <vkuznets@redhat.com> Cc: "jasowang@redhat.com" <jasowang@redhat.com> Cc: "marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com> Cc: KY Srinivasan <kys@microsoft.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1541303219-11142-2-git-send-email-mikelley@microsoft.com
31 lines
809 B
C
31 lines
809 B
C
/*
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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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* Machine specific IO port address definition for generic.
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* Written by Osamu Tomita <tomita@cinet.co.jp>
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*/
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#ifndef __LINUX_I8253_H
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#define __LINUX_I8253_H
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#include <linux/param.h>
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#include <linux/spinlock.h>
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#include <linux/timex.h>
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/* i8253A PIT registers */
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#define PIT_MODE 0x43
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#define PIT_CH0 0x40
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#define PIT_CH2 0x42
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#define PIT_LATCH ((PIT_TICK_RATE + HZ/2) / HZ)
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extern raw_spinlock_t i8253_lock;
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extern bool i8253_clear_counter_on_shutdown;
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extern struct clock_event_device i8253_clockevent;
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extern void clockevent_i8253_init(bool oneshot);
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extern void setup_pit_timer(void);
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#endif /* __LINUX_I8253_H */
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