> -----Original Message----- > From: Greg KH [mailto:gre...@linuxfoundation.org] > Sent: Thursday, January 19, 2017 10:52 AM > To: KY Srinivasan <k...@microsoft.com> > Cc: o...@aepfle.de; jasow...@redhat.com; linux-ker...@vger.kernel.org; > a...@canonical.com; de...@linuxdriverproject.org; > leann.ogasaw...@canonical.com > Subject: Re: [PATCH V2 05/18] Drivers: hv: vmbus: Consolidate all Hyper-V > specific clocksource code > > On Thu, Jan 19, 2017 at 04:49:35PM +0000, KY Srinivasan wrote: > > > > > > > -----Original Message----- > > > From: Greg KH [mailto:gre...@linuxfoundation.org] > > > Sent: Thursday, January 19, 2017 4:59 AM > > > To: KY Srinivasan <k...@microsoft.com> > > > Cc: linux-ker...@vger.kernel.org; de...@linuxdriverproject.org; > > > o...@aepfle.de; a...@canonical.com; vkuzn...@redhat.com; > > > jasow...@redhat.com; leann.ogasaw...@canonical.com > > > Subject: Re: [PATCH V2 05/18] Drivers: hv: vmbus: Consolidate all Hyper-V > > > specific clocksource code > > > > > > On Wed, Jan 18, 2017 at 04:45:04PM -0700, k...@exchange.microsoft.com > > > wrote: > > > > From: K. Y. Srinivasan <k...@microsoft.com> > > > > > > > > As part of the effort to separate out architecture specific code, > > > > consolidate all Hyper-V specific clocksource code to an architecture > > > > specific code. > > > > > > > > Signed-off-by: K. Y. Srinivasan <k...@microsoft.com> > > > > --- > > > > arch/x86/hyperv/hv_init.c | 104 > > > +++++++++++++++++++++++++++++++++++++++ > > > > arch/x86/include/asm/mshyperv.h | 12 +++++ > > > > arch/x86/kernel/cpu/mshyperv.c | 23 --------- > > > > drivers/hv/hv.c | 95 > > > > ----------------------------------- > > > > drivers/hv/hyperv_vmbus.h | 8 --- > > > > 5 files changed, 116 insertions(+), 126 deletions(-) > > > > > > > > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c > > > > index b5c8e04..691dfaf 100644 > > > > --- a/arch/x86/hyperv/hv_init.c > > > > +++ b/arch/x86/hyperv/hv_init.c > > > > @@ -24,6 +24,79 @@ > > > > #include <linux/version.h> > > > > #include <linux/vmalloc.h> > > > > #include <linux/mm.h> > > > > +#include <linux/clockchips.h> > > > > + > > > > + > > > > +#ifdef CONFIG_X86_64 > > > > + > > > > +static struct ms_hyperv_tsc_page *tsc_pg; > > > > + > > > > +static u64 read_hv_clock_tsc(struct clocksource *arg) > > > > +{ > > > > + u64 current_tick; > > > > + > > > > + if (tsc_pg->tsc_sequence != 0) { > > > > + /* > > > > + * Use the tsc page to compute the value. > > > > + */ > > > > + > > > > + while (1) { > > > > + u64 tmp; > > > > + u32 sequence = tsc_pg->tsc_sequence; > > > > + u64 cur_tsc; > > > > + u64 scale = tsc_pg->tsc_scale; > > > > + s64 offset = tsc_pg->tsc_offset; > > > > + > > > > + rdtscll(cur_tsc); > > > > + /* current_tick = ((cur_tsc *scale) >> 64) + > > > > offset */ > > > > + asm("mulq %3" > > > > + : "=d" (current_tick), "=a" (tmp) > > > > + : "a" (cur_tsc), "r" (scale)); > > > > + > > > > + current_tick += offset; > > > > + if (tsc_pg->tsc_sequence == sequence) > > > > + return current_tick; > > > > + > > > > + if (tsc_pg->tsc_sequence != 0) > > > > + continue; > > > > + /* > > > > + * Fallback using MSR method. > > > > + */ > > > > + break; > > > > + } > > > > + } > > > > + rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick); > > > > + return current_tick; > > > > +} > > > > + > > > > +static struct clocksource hyperv_cs_tsc = { > > > > + .name = "hyperv_clocksource_tsc_page", > > > > + .rating = 400, > > > > + .read = read_hv_clock_tsc, > > > > + .mask = CLOCKSOURCE_MASK(64), > > > > + .flags = CLOCK_SOURCE_IS_CONTINUOUS, > > > > +}; > > > > +#endif > > > > + > > > > +static u64 read_hv_clock_msr(struct clocksource *arg) > > > > +{ > > > > + u64 current_tick; > > > > + /* > > > > + * Read the partition counter to get the current tick count. > > > > This count > > > > + * is set to 0 when the partition is created and is incremented > > > > in > > > > + * 100 nanosecond units. > > > > + */ > > > > + rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick); > > > > + return current_tick; > > > > +} > > > > + > > > > +static struct clocksource hyperv_cs_msr = { > > > > + .name = "hyperv_clocksource_msr", > > > > + .rating = 400, > > > > + .read = read_hv_clock_msr, > > > > + .mask = CLOCKSOURCE_MASK(64), > > > > + .flags = CLOCK_SOURCE_IS_CONTINUOUS, > > > > +}; > > > > > > > > static void *hypercall_pg; > > > > /* > > > > @@ -31,6 +104,7 @@ > > > > * hypervisor has been detected. > > > > * > > > > * 1. Setup the hypercall page. > > > > + * 2. Register Hyper-V specific clocksource. > > > > */ > > > > void hyperv_init(void) > > > > { > > > > @@ -58,6 +132,36 @@ void hyperv_init(void) > > > > hypercall_msr.enable = 1; > > > > hypercall_msr.guest_physical_address = > > > vmalloc_to_pfn(hypercall_pg); > > > > wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); > > > > + > > > > + /* > > > > + * Register Hyper-V specific clocksource. > > > > + */ > > > > +#ifdef CONFIG_X86_64 > > > > + if (ms_hyperv.features & > > > HV_X64_MSR_REFERENCE_TSC_AVAILABLE) { > > > > + union hv_x64_msr_hypercall_contents tsc_msr; > > > > + > > > > + tsc_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, > > > PAGE_KERNEL); > > > > + if (!tsc_pg) > > > > + clocksource_register_hz(&hyperv_cs_msr, > > > NSEC_PER_SEC/100); > > > > + return; > > > > > > There's a reason you always test-build your patches and pay attention to > > > the warnings! > > > > > > How did this pass your tests? > > > > > > I've stopped applying patches here. > > > > Greg, > > > > Thank you for spotting the issue; I will fix the problem and resend. > > Again, I have to ask, how did this past testing?
The patches were developed on one machine and testing was done on a different machine. While the bug was fixed on the test machine I forgot to pick up the fix prior to posting the patches. Regards, K. Y _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
