Hi Markos,
On 09/07/15 10:40, Markos Chandras wrote:
> From: Paul Burton <paul.burton@xxxxxxxxxx>
>
> Provide a function to trivially return the version of the CM present in
> the system, or 0 if no CM is present. The mips_cm_revision() will be
> used later on to determine the CM register width, so it must not use
> the regular CM accessors to read the revision register since that will
> lead to build failures due to recursive inlines.
>
> Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
> Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx>
> ---
> arch/mips/include/asm/mips-cm.h | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
> index edc7ee95269e..29ff74a629f6 100644
> --- a/arch/mips/include/asm/mips-cm.h
> +++ b/arch/mips/include/asm/mips-cm.h
> @@ -189,6 +189,13 @@ BUILD_CM_Cx_R_(tcid_8_priority, 0x80)
> #define CM_GCR_REV_MINOR_SHF 0
> #define CM_GCR_REV_MINOR_MSK (_ULCAST_(0xff) << 0)
>
> +#define CM_ENCODE_REV(major, minor) \
> + ((major << CM_GCR_REV_MAJOR_SHF) | \
> + ((minor) << CM_GCR_REV_MINOR_SHF))
> +
> +#define CM_REV_CM2 CM_ENCODE_REV(6, 0)
> +#define CM_REV_CM3 CM_ENCODE_REV(8, 0)
> +
> /* GCR_ERROR_CAUSE register fields */
> #define CM_GCR_ERROR_CAUSE_ERRTYPE_SHF 27
> #define CM_GCR_ERROR_CAUSE_ERRTYPE_MSK (_ULCAST_(0x1f) << 27)
> @@ -324,4 +331,26 @@ static inline int mips_cm_l2sync(void)
> return 0;
> }
>
> +/**
> + * mips_cm_revision - return CM revision
don't forget brackets: "mips_cm_revision()"
> + *
> + * Returns the revision of the CM, from GCR_REV, or 0 if no CM is present.
> + * The return value should be checked against the CM_REV_* macros.
Use "Return: bla bla bla." so it lands in a nice return section.
see Documentation/kernel-doc-nano-HOWTO.txt for an example.
Cheers
James
> + */
> +static inline int mips_cm_revision(void)
> +{
> + static int mips_cm_revision_nr = -1;
> +
> + /* No need to read that register over and over */
> + if (mips_cm_revision_nr >= 0)
> + return mips_cm_revision_nr;
> +
> + if (!mips_cm_present())
> + return 0;
> +
> + mips_cm_revision_nr = read_gcr_rev();
> +
> + return mips_cm_revision_nr;
> +}
> +
> #endif /* __MIPS_ASM_MIPS_CM_H__ */
>
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