diff mbox series

[RFC,12/32] powerpc: Provide dummy versions of plpar_hcall functions when !CONFIG_PPC_PSERIES

Message ID 1537524123-9578-13-git-send-email-paulus@ozlabs.org (mailing list archive)
State New, archived
Headers show
Series KVM: PPC: Book3S HV: Nested HV virtualization | expand

Commit Message

Paul Mackerras Sept. 21, 2018, 10:01 a.m. UTC
This will reduce the number of instances where we require ifdefs in
code which needs to call a hypercall on a pseries platform or do
something different on a powernv platform.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
---
 arch/powerpc/include/asm/hvcall.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

Comments

David Gibson Sept. 26, 2018, 3:30 a.m. UTC | #1
On Fri, Sep 21, 2018 at 08:01:43PM +1000, Paul Mackerras wrote:
> This will reduce the number of instances where we require ifdefs in
> code which needs to call a hypercall on a pseries platform or do
> something different on a powernv platform.
> 
> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Wouldn't it make more sense for these to BUG_ON() or at least
WARN_ON() before returning H_FUNCTION, since calling a hypercall on a
non pseries platform is definitely a kernel bug?

> ---
>  arch/powerpc/include/asm/hvcall.h | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
> index a0b17f9..cc9fe87 100644
> --- a/arch/powerpc/include/asm/hvcall.h
> +++ b/arch/powerpc/include/asm/hvcall.h
> @@ -362,6 +362,7 @@
>  #ifndef __ASSEMBLY__
>  #include <linux/types.h>
>  
> +#ifdef CONFIG_PPC_PSERIES
>  /**
>   * plpar_hcall_norets: - Make a pseries hypervisor call with no return arguments
>   * @opcode: The hypervisor call to make.
> @@ -411,6 +412,27 @@ long plpar_hcall_raw(unsigned long opcode, unsigned long *retbuf, ...);
>  long plpar_hcall9(unsigned long opcode, unsigned long *retbuf, ...);
>  long plpar_hcall9_raw(unsigned long opcode, unsigned long *retbuf, ...);
>  
> +#else /* CONFIG_PPC_PSERIES */
> +static inline long plpar_hcall_norets(unsigned long opcode, ...)
> +{ return H_FUNCTION; }
> +
> +#define PLPAR_HCALL_BUFSIZE 4
> +static inline long plpar_hcall(unsigned long opcode, unsigned long *retbuf, ...)
> +{ return H_FUNCTION; }
> +
> +static inline long plpar_hcall_raw(unsigned long opcode,
> +				   unsigned long *retbuf, ...)
> +{ return H_FUNCTION; }
> +
> +#define PLPAR_HCALL9_BUFSIZE 9
> +static inline long plpar_hcall9(unsigned long opcode,
> +				unsigned long *retbuf, ...)
> +{ return H_FUNCTION; }
> +static inline long plpar_hcall9_raw(unsigned long opcode,
> +				    unsigned long *retbuf, ...)
> +{ return H_FUNCTION; }
> +#endif /* CONFIG_PPC_PSERIES */
> +
>  struct hvcall_mpp_data {
>  	unsigned long entitled_mem;
>  	unsigned long mapped_mem;
Paul Mackerras Sept. 26, 2018, 11:21 a.m. UTC | #2
On Wed, Sep 26, 2018 at 01:30:40PM +1000, David Gibson wrote:
> On Fri, Sep 21, 2018 at 08:01:43PM +1000, Paul Mackerras wrote:
> > This will reduce the number of instances where we require ifdefs in
> > code which needs to call a hypercall on a pseries platform or do
> > something different on a powernv platform.
> > 
> > Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
> 
> Wouldn't it make more sense for these to BUG_ON() or at least
> WARN_ON() before returning H_FUNCTION, since calling a hypercall on a
> non pseries platform is definitely a kernel bug?

Not BUG_ON, since at this level we have no indication that the kernel
can't continue executing without whatever it was that it expected the
hcall to do.  I could come at a WARN_ON (or WARN_ON_ONCE) -- I'll talk
to mpe and see what he thinks.

Paul.
diff mbox series

Patch

diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index a0b17f9..cc9fe87 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -362,6 +362,7 @@ 
 #ifndef __ASSEMBLY__
 #include <linux/types.h>
 
+#ifdef CONFIG_PPC_PSERIES
 /**
  * plpar_hcall_norets: - Make a pseries hypervisor call with no return arguments
  * @opcode: The hypervisor call to make.
@@ -411,6 +412,27 @@  long plpar_hcall_raw(unsigned long opcode, unsigned long *retbuf, ...);
 long plpar_hcall9(unsigned long opcode, unsigned long *retbuf, ...);
 long plpar_hcall9_raw(unsigned long opcode, unsigned long *retbuf, ...);
 
+#else /* CONFIG_PPC_PSERIES */
+static inline long plpar_hcall_norets(unsigned long opcode, ...)
+{ return H_FUNCTION; }
+
+#define PLPAR_HCALL_BUFSIZE 4
+static inline long plpar_hcall(unsigned long opcode, unsigned long *retbuf, ...)
+{ return H_FUNCTION; }
+
+static inline long plpar_hcall_raw(unsigned long opcode,
+				   unsigned long *retbuf, ...)
+{ return H_FUNCTION; }
+
+#define PLPAR_HCALL9_BUFSIZE 9
+static inline long plpar_hcall9(unsigned long opcode,
+				unsigned long *retbuf, ...)
+{ return H_FUNCTION; }
+static inline long plpar_hcall9_raw(unsigned long opcode,
+				    unsigned long *retbuf, ...)
+{ return H_FUNCTION; }
+#endif /* CONFIG_PPC_PSERIES */
+
 struct hvcall_mpp_data {
 	unsigned long entitled_mem;
 	unsigned long mapped_mem;