| Message ID | 20230515093446.73123-8-ajones@ventanamicro.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v5,1/7] lib: sbi: Introduce register_extensions extension callback | expand |
On Mon, May 15, 2023 at 3:05 PM Andrew Jones <ajones@ventanamicro.com> wrote: > > With the introduction of the register_extensions callback the > range members (extid_start and extid_end) may now change and it > has become a bit subtle as to when a probe function should be > implemented. Document all the members and their relationship to > the register_extensions callback. > > Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Looks good to me. Reviewed-by: Anup Patel <anup@brainfault.org> Thanks, Anup > --- > include/sbi/sbi_ecall.h | 35 +++++++++++++++++++++++++++++++++++ > 1 file changed, 35 insertions(+) > > diff --git a/include/sbi/sbi_ecall.h b/include/sbi/sbi_ecall.h > index fac26429cf5d..3cb25ae80fb0 100644 > --- a/include/sbi/sbi_ecall.h > +++ b/include/sbi/sbi_ecall.h > @@ -21,11 +21,46 @@ struct sbi_trap_regs; > struct sbi_trap_info; > > struct sbi_ecall_extension { > + /* head is used by the extension list */ > struct sbi_dlist head; > + /* > + * extid_start and extid_end specify the range for this extension. > + * As the initial range may be wider than the valid runtime range, > + * the register_extensions callback is responsible for narrowing > + * the range before other callbacks may be invoked. > + */ > unsigned long extid_start; > unsigned long extid_end; > + /* > + * register_extensions > + * > + * Calls sbi_ecall_register_extension() one or more times to > + * register extension ID range(s) which should be handled by this > + * extension. More than one sbi_ecall_extension struct and > + * sbi_ecall_register_extension() call is necessary when the supported > + * extension ID ranges have gaps. Additionally, extension availability > + * must be checked before registering, which means, when this callback > + * returns, only valid extension IDs from the initial range, which are > + * also available, have been registered. > + */ > int (* register_extensions)(void); > + /* > + * probe > + * > + * Implements the Base extension's probe function for the extension. As > + * the register_extensions callback ensures that no other extension > + * callbacks will be invoked when the extension is not available, then > + * probe can never fail. However, an extension may choose to set out_val > + * to a nonzero value other than one. In those cases, it should implement > + * this callback. > + */ > int (* probe)(unsigned long extid, unsigned long *out_val); > + /* > + * handle > + * > + * This is the extension handler. register_extensions ensures it is > + * never invoked with an invalid or unavailable extension ID. > + */ > int (* handle)(unsigned long extid, unsigned long funcid, > const struct sbi_trap_regs *regs, > unsigned long *out_val, > -- > 2.40.0 >
diff --git a/include/sbi/sbi_ecall.h b/include/sbi/sbi_ecall.h index fac26429cf5d..3cb25ae80fb0 100644 --- a/include/sbi/sbi_ecall.h +++ b/include/sbi/sbi_ecall.h @@ -21,11 +21,46 @@ struct sbi_trap_regs; struct sbi_trap_info; struct sbi_ecall_extension { + /* head is used by the extension list */ struct sbi_dlist head; + /* + * extid_start and extid_end specify the range for this extension. + * As the initial range may be wider than the valid runtime range, + * the register_extensions callback is responsible for narrowing + * the range before other callbacks may be invoked. + */ unsigned long extid_start; unsigned long extid_end; + /* + * register_extensions + * + * Calls sbi_ecall_register_extension() one or more times to + * register extension ID range(s) which should be handled by this + * extension. More than one sbi_ecall_extension struct and + * sbi_ecall_register_extension() call is necessary when the supported + * extension ID ranges have gaps. Additionally, extension availability + * must be checked before registering, which means, when this callback + * returns, only valid extension IDs from the initial range, which are + * also available, have been registered. + */ int (* register_extensions)(void); + /* + * probe + * + * Implements the Base extension's probe function for the extension. As + * the register_extensions callback ensures that no other extension + * callbacks will be invoked when the extension is not available, then + * probe can never fail. However, an extension may choose to set out_val + * to a nonzero value other than one. In those cases, it should implement + * this callback. + */ int (* probe)(unsigned long extid, unsigned long *out_val); + /* + * handle + * + * This is the extension handler. register_extensions ensures it is + * never invoked with an invalid or unavailable extension ID. + */ int (* handle)(unsigned long extid, unsigned long funcid, const struct sbi_trap_regs *regs, unsigned long *out_val,
With the introduction of the register_extensions callback the range members (extid_start and extid_end) may now change and it has become a bit subtle as to when a probe function should be implemented. Document all the members and their relationship to the register_extensions callback. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> --- include/sbi/sbi_ecall.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)