[PATCH] powerpc: Fix compile issue with force DAWR

[Christophe Leroy]

Le 08/05/2019 à 03:30, Michael Neuling a écrit :
> If you compile with KVM but without CONFIG_HAVE_HW_BREAKPOINT you fail
> at linking with:
>    arch/powerpc/kvm/book3s_hv_rmhandlers.o:(.text+0x708): undefined reference to `dawr_force_enable'
> 
> This was caused by this recent patch:
>     commit c1fe190c06723322f2dfac31d3b982c581e434ef
>     Author: Michael Neuling <mikey at neuling.org>
>     powerpc: Add force enable of DAWR on P9 option

I think you should use the standard commit format, checkpatch will tell you.

> 
> This builds dawr_force_enable in always via a new file.

Do we really need a new file just for that ?
As far as I understand, it is always compiled in, so can't we use 
another file like traps.o or setup-common.o or somewhere else ?

Or just put an ifdef in arch/powerpc/kvm/book3s_hv_rmhandlers.S ?
Because your fix will put dawr_force_enable on every build even the ones 
who don't need it at all.

Christophe

> 
> Signed-off-by: Michael Neuling <mikey at neuling.org> > ---
>   arch/powerpc/kernel/Makefile        |  2 +-
>   arch/powerpc/kernel/dawr.c          | 11 +++++++++++
>   arch/powerpc/kernel/hw_breakpoint.c |  3 ---
>   3 files changed, 12 insertions(+), 4 deletions(-)
>   create mode 100644 arch/powerpc/kernel/dawr.c
> 
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> index 0ea6c4aa3a..48a20ef5be 100644
> --- a/arch/powerpc/kernel/Makefile
> +++ b/arch/powerpc/kernel/Makefile
> @@ -49,7 +49,7 @@ obj-y				:= cputable.o ptrace.o syscalls.o \
>   				   signal.o sysfs.o cacheinfo.o time.o \
>   				   prom.o traps.o setup-common.o \
>   				   udbg.o misc.o io.o misc_$(BITS).o \
> -				   of_platform.o prom_parse.o
> +				   of_platform.o prom_parse.o dawr.o
>   obj-$(CONFIG_PPC64)		+= setup_64.o sys_ppc32.o \
>   				   signal_64.o ptrace32.o \
>   				   paca.o nvram_64.o firmware.o
> diff --git a/arch/powerpc/kernel/dawr.c b/arch/powerpc/kernel/dawr.c
> new file mode 100644
> index 0000000000..ca343efd23
> --- /dev/null
> +++ b/arch/powerpc/kernel/dawr.c
> @@ -0,0 +1,11 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +//
> +// DAWR global variables
> +//
> +// Copyright 2019, Michael Neuling, IBM Corporation.
> +
> +#include <linux/types.h>
> +#include <linux/export.h>
> +
> +bool dawr_force_enable;
> +EXPORT_SYMBOL_GPL(dawr_force_enable);
> diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
> index da307dd93e..78a17454f4 100644
> --- a/arch/powerpc/kernel/hw_breakpoint.c
> +++ b/arch/powerpc/kernel/hw_breakpoint.c
> @@ -381,9 +381,6 @@ void hw_breakpoint_pmu_read(struct perf_event *bp)
>   	/* TODO */
>   }
>   
> -bool dawr_force_enable;
> -EXPORT_SYMBOL_GPL(dawr_force_enable);
> -
>   static ssize_t dawr_write_file_bool(struct file *file,
>   				    const char __user *user_buf,
>   				    size_t count, loff_t *ppos)
>