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path: root/drivers/xen/mcelog.c
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2012-07-19xen/mce: add .poll method for mcelog device driverLiu, Jinsong1-0/+18
If a driver leaves its poll method NULL, the device is assumed to be both readable and writable without blocking. This patch add .poll method to xen mcelog device driver, so that when mcelog use system calls like ppoll or select, it would be blocked when no data available, and avoid spinning at CPU. Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-07-19xen/mce: schedule a workqueue to avoid sleep in atomic contextLiu, Jinsong1-7/+11
copy_to_user might sleep and print a stack trace if it is executed in an atomic spinlock context. Like this: (XEN) CMCI: send CMCI to DOM0 through virq BUG: sleeping function called from invalid context at /home/konradinux/kernel.h:199 in_atomic(): 1, irqs_disabled(): 0, pid: 4581, name: mcelog Pid: 4581, comm: mcelog Tainted: G O 3.5.0-rc1upstream-00003-g149000b-dirty #1 [<ffffffff8109ad9a>] __might_sleep+0xda/0x100 [<ffffffff81329b0b>] xen_mce_chrdev_read+0xab/0x140 [<ffffffff81148945>] vfs_read+0xc5/0x190 [<ffffffff81148b0c>] sys_read+0x4c/0x90 [<ffffffff815bd039>] system_call_fastpath+0x16 This patch schedule a workqueue for IRQ handler to poll the data, and use mutex instead of spinlock, so copy_to_user sleep in atomic context would not occur. Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Suggested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-07-19xen/mce: Add mcelog support for Xen platformLiu, Jinsong1-0/+392
When MCA error occurs, it would be handled by Xen hypervisor first, and then the error information would be sent to initial domain for logging. This patch gets error information from Xen hypervisor and convert Xen format error into Linux format mcelog. This logic is basically self-contained, not touching other kernel components. By using tools like mcelog tool users could read specific error information, like what they did under native Linux. To test follow directions outlined in Documentation/acpi/apei/einj.txt Acked-and-tested-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Ke, Liping <liping.ke@intel.com> Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>