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From:   Thomas Gleixner <tglx@linutronix.de>
To:     "Michael Kelley (LINUX)" <mikelley@microsoft.com>,
        LKML <linux-kernel@vger.kernel.org>
Cc:     "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        Andy Lutomirski <luto@kernel.org>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>
Subject: RE: [PATCH] clocksource/drivers/hyper-v: Include asm/hyperv-tlfs.h
 not asm/mshyperv.h
In-Reply-To: <87fsemtut0.ffs@tglx>
References: <87zgcwt2qg.ffs@tglx>
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 <87wn7ztc89.ffs@tglx> <87sfinta8q.ffs@tglx> <87leoft9w1.ffs@tglx>
 <87fsemtut0.ffs@tglx>
Date:   Wed, 16 Nov 2022 21:52:26 +0100
Message-ID: <8735aipqph.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Michael!

On Sun, Nov 13 2022 at 22:21, Thomas Gleixner wrote:
> Subject: clocksource/drivers/hyper-v: Include asm/hyperv-tlfs.h not asm/mshyperv.h
> From: Thomas Gleixner <tglx@linutronix.de>
> Date: Sat, 12 Nov 2022 19:08:15 +0100
>
> clocksource/hyperv_timer.h is included into the VDSO build. It includes
> asm/mshyperv.h which in turn includes the world and some more. This worked
> so far by chance, but any subtle change in the include chain results in a
> build breakage because VDSO builds are building user space libraries.
>
> Include asm/hyperv-tlfs.h instead which contains everything what the VDSO
> build needs and move the hv_get_raw_timer() define into the header file.
>
> Fixup drivers/hv/vmbus_drv.c which relies on the indirect include of
> asm/mshyperv.h.

Any comments on this latest version?

> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>  arch/x86/include/asm/hyperv_timer.h |    9 +++++++++
>  arch/x86/include/asm/mshyperv.h     |    2 --
>  drivers/hv/vmbus_drv.c              |    1 +
>  include/clocksource/hyperv_timer.h  |    4 +++-
>  4 files changed, 13 insertions(+), 3 deletions(-)
>
> --- /dev/null
> +++ b/arch/x86/include/asm/hyperv_timer.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_X86_HYPERV_TIMER_H
> +#define _ASM_X86_HYPERV_TIMER_H
> +
> +#include <asm/msr.h>
> +
> +#define hv_get_raw_timer() rdtsc_ordered()
> +
> +#endif
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -19,8 +19,6 @@ typedef int (*hyperv_fill_flush_list_fun
>  		struct hv_guest_mapping_flush_list *flush,
>  		void *data);
>  
> -#define hv_get_raw_timer() rdtsc_ordered()
> -
>  void hyperv_vector_handler(struct pt_regs *regs);
>  
>  #if IS_ENABLED(CONFIG_HYPERV)
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -37,6 +37,7 @@
>  #include <linux/dma-map-ops.h>
>  #include <linux/pci.h>
>  #include <clocksource/hyperv_timer.h>
> +#include <asm/mshyperv.h>
>  #include "hyperv_vmbus.h"
>  
>  struct vmbus_dynid {
> --- a/include/clocksource/hyperv_timer.h
> +++ b/include/clocksource/hyperv_timer.h
> @@ -15,13 +15,15 @@
>  
>  #include <linux/clocksource.h>
>  #include <linux/math64.h>
> -#include <asm/mshyperv.h>
> +#include <asm/hyperv-tlfs.h>
>  
>  #define HV_MAX_MAX_DELTA_TICKS 0xffffffff
>  #define HV_MIN_DELTA_TICKS 1
>  
>  #ifdef CONFIG_HYPERV_TIMER
>  
> +#include <asm/hyperv_timer.h>
> +
>  /* Routines called by the VMbus driver */
>  extern int hv_stimer_alloc(bool have_percpu_irqs);
>  extern int hv_stimer_cleanup(unsigned int cpu);