[PATCH v2] lib: sbi: Ensure SBI extension is available

[Andrew Jones <ajones@ventanamicro.com>]

On Thu, Apr 27, 2023 at 11:41:38AM +0200, Andrew Jones wrote:
> Ensure attempts to invoke SBI extension functions fail with
> SBI_ERR_NOT_SUPPORTED when the extension's probe function has
> reported that the extension is not available. By adding a new status
> member to the extension, which has three states (uninitialized,
> available, unavailable), we can ensure that the probe functions of
> single ID extensions, i.e.  extid_start == extid_end, are only
> invoked once, lazily, upon first use. Extensions that have multiple
> IDs cannot use a single status field to avoid making probe calls, as
> probe functions are extension ID specific. It's expected that these
> multi-ID extension probe functions implement their own optimizations
> in order to ensure extension lookups are fast.
> 
> Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
> ---
>  include/sbi/sbi_ecall.h | 14 ++++++++++++++
>  lib/sbi/sbi_ecall.c     | 26 ++++++++++++++++++++++----
>  2 files changed, 36 insertions(+), 4 deletions(-)
>

self-nack. Sent a v3 based on feedback I got on v1.

Thanks,
drew