diff mbox series

[v2,1/2] ACPI: PRM: Add PRM handler direct call support

Message ID 20240506174721.72018-2-john.allen@amd.com
State Superseded
Headers show
Series PRM handler direct call interface | expand

Commit Message

John Allen May 6, 2024, 5:47 p.m. UTC 
Platform Runtime Mechanism (PRM) handlers can be invoked from either the
AML interpreter or directly by an OS driver. Implement the direct call
method.

Export the symbol as this will be used by modules such as the AMD
Address Translation Library and likely others in the future.

Signed-off-by: John Allen <john.allen@amd.com>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
---
v2:
  - Align statements setting fields in context buffer on '='
---
 drivers/acpi/prmt.c  | 24 ++++++++++++++++++++++++
 include/linux/prmt.h |  5 +++++
 2 files changed, 29 insertions(+)

Comments

Rafael J. Wysocki June 26, 2024, 7:21 p.m. UTC | #1 
On Mon, May 6, 2024 at 7:48 PM John Allen <john.allen@amd.com> wrote:
>
> Platform Runtime Mechanism (PRM) handlers can be invoked from either the
> AML interpreter or directly by an OS driver. Implement the direct call
> method.
>
> Export the symbol as this will be used by modules such as the AMD
> Address Translation Library and likely others in the future.
>
> Signed-off-by: John Allen <john.allen@amd.com>
> Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
> ---
> v2:
>   - Align statements setting fields in context buffer on '='

I would actually prefer spaces around the "=" there, but anyway

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
>  drivers/acpi/prmt.c  | 24 ++++++++++++++++++++++++
>  include/linux/prmt.h |  5 +++++
>  2 files changed, 29 insertions(+)
>
> diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
> index c78453c74ef5..1cfaa5957ac4 100644
> --- a/drivers/acpi/prmt.c
> +++ b/drivers/acpi/prmt.c
> @@ -214,6 +214,30 @@ static struct prm_handler_info *find_prm_handler(const guid_t *guid)
>  #define UPDATE_LOCK_ALREADY_HELD       4
>  #define UPDATE_UNLOCK_WITHOUT_LOCK     5
>
> +int acpi_call_prm_handler(guid_t handler_guid, void *param_buffer)
> +{
> +       struct prm_handler_info *handler = find_prm_handler(&handler_guid);
> +       struct prm_module_info *module = find_prm_module(&handler_guid);
> +       struct prm_context_buffer context;
> +       efi_status_t status;
> +
> +       if (!module || !handler)
> +               return -ENODEV;
> +
> +       memset(&context, 0, sizeof(context));
> +       ACPI_COPY_NAMESEG(context.signature, "PRMC");
> +       context.identifier         = handler->guid;
> +       context.static_data_buffer = handler->static_data_buffer_addr;
> +       context.mmio_ranges        = module->mmio_info;
> +
> +       status = efi_call_acpi_prm_handler(handler->handler_addr,
> +                                          (u64)param_buffer,
> +                                          &context);
> +
> +       return efi_status_to_err(status);
> +}
> +EXPORT_SYMBOL_GPL(acpi_call_prm_handler);
> +
>  /*
>   * This is the PlatformRtMechanism opregion space handler.
>   * @function: indicates the read/write. In fact as the PlatformRtMechanism
> diff --git a/include/linux/prmt.h b/include/linux/prmt.h
> index 24da8364b919..9c094294403f 100644
> --- a/include/linux/prmt.h
> +++ b/include/linux/prmt.h
> @@ -2,6 +2,11 @@
>
>  #ifdef CONFIG_ACPI_PRMT
>  void init_prmt(void);
> +int acpi_call_prm_handler(guid_t handler_guid, void *param_buffer);
>  #else
>  static inline void init_prmt(void) { }
> +static inline int acpi_call_prm_handler(guid_t handler_guid, void *param_buffer)
> +{
> +       return -EOPNOTSUPP;
> +}
>  #endif
> --
> 2.34.1
>
Borislav Petkov June 27, 2024, 8:08 a.m. UTC | #2 
On Mon, May 06, 2024 at 05:47:20PM +0000, John Allen wrote:
> Platform Runtime Mechanism (PRM) handlers can be invoked from either the
> AML interpreter or directly by an OS driver. Implement the direct call
> method.
> 
> Export the symbol as this will be used by modules such as the AMD
> Address Translation Library and likely others in the future.
> 
> Signed-off-by: John Allen <john.allen@amd.com>
> Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
> ---
> v2:
>   - Align statements setting fields in context buffer on '='
> ---
>  drivers/acpi/prmt.c  | 24 ++++++++++++++++++++++++
>  include/linux/prmt.h |  5 +++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
> index c78453c74ef5..1cfaa5957ac4 100644
> --- a/drivers/acpi/prmt.c
> +++ b/drivers/acpi/prmt.c
> @@ -214,6 +214,30 @@ static struct prm_handler_info *find_prm_handler(const guid_t *guid)
>  #define UPDATE_LOCK_ALREADY_HELD 	4
>  #define UPDATE_UNLOCK_WITHOUT_LOCK 	5
>  
> +int acpi_call_prm_handler(guid_t handler_guid, void *param_buffer)
> +{
> +	struct prm_handler_info *handler = find_prm_handler(&handler_guid);
> +	struct prm_module_info *module = find_prm_module(&handler_guid);
> +	struct prm_context_buffer context;
> +	efi_status_t status;
> +
> +	if (!module || !handler)
> +		return -ENODEV;
> +
> +	memset(&context, 0, sizeof(context));
> +	ACPI_COPY_NAMESEG(context.signature, "PRMC");
> +	context.identifier         = handler->guid;
> +	context.static_data_buffer = handler->static_data_buffer_addr;
> +	context.mmio_ranges        = module->mmio_info;
> +
> +	status = efi_call_acpi_prm_handler(handler->handler_addr,
> +					   (u64)param_buffer,
> +					   &context);
> +
> +	return efi_status_to_err(status);
> +}

+ linux-efi as Rafael wanted to make sure the environment is created properly
for the EFI runtime services call...
Ard Biesheuvel July 2, 2024, 2:54 p.m. UTC | #3 
On Thu, 27 Jun 2024 at 10:08, Borislav Petkov <bp@alien8.de> wrote:
>
> On Mon, May 06, 2024 at 05:47:20PM +0000, John Allen wrote:
> > Platform Runtime Mechanism (PRM) handlers can be invoked from either the
> > AML interpreter or directly by an OS driver. Implement the direct call
> > method.
> >
> > Export the symbol as this will be used by modules such as the AMD
> > Address Translation Library and likely others in the future.
> >
> > Signed-off-by: John Allen <john.allen@amd.com>
> > Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
> > ---
> > v2:
> >   - Align statements setting fields in context buffer on '='
> > ---
> >  drivers/acpi/prmt.c  | 24 ++++++++++++++++++++++++
> >  include/linux/prmt.h |  5 +++++
> >  2 files changed, 29 insertions(+)
> >
> > diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
> > index c78453c74ef5..1cfaa5957ac4 100644
> > --- a/drivers/acpi/prmt.c
> > +++ b/drivers/acpi/prmt.c
> > @@ -214,6 +214,30 @@ static struct prm_handler_info *find_prm_handler(const guid_t *guid)
> >  #define UPDATE_LOCK_ALREADY_HELD     4
> >  #define UPDATE_UNLOCK_WITHOUT_LOCK   5
> >
> > +int acpi_call_prm_handler(guid_t handler_guid, void *param_buffer)
> > +{
> > +     struct prm_handler_info *handler = find_prm_handler(&handler_guid);
> > +     struct prm_module_info *module = find_prm_module(&handler_guid);
> > +     struct prm_context_buffer context;
> > +     efi_status_t status;
> > +
> > +     if (!module || !handler)
> > +             return -ENODEV;
> > +
> > +     memset(&context, 0, sizeof(context));
> > +     ACPI_COPY_NAMESEG(context.signature, "PRMC");
> > +     context.identifier         = handler->guid;
> > +     context.static_data_buffer = handler->static_data_buffer_addr;
> > +     context.mmio_ranges        = module->mmio_info;
> > +
> > +     status = efi_call_acpi_prm_handler(handler->handler_addr,
> > +                                        (u64)param_buffer,
> > +                                        &context);
> > +
> > +     return efi_status_to_err(status);
> > +}
>
> + linux-efi as Rafael wanted to make sure the environment is created properly
> for the EFI runtime services call...
>

This looks fine to me.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
diff mbox series

Patch

diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
index c78453c74ef5..1cfaa5957ac4 100644
--- a/drivers/acpi/prmt.c
+++ b/drivers/acpi/prmt.c
@@ -214,6 +214,30 @@  static struct prm_handler_info *find_prm_handler(const guid_t *guid)
 #define UPDATE_LOCK_ALREADY_HELD 	4
 #define UPDATE_UNLOCK_WITHOUT_LOCK 	5
 
+int acpi_call_prm_handler(guid_t handler_guid, void *param_buffer)
+{
+	struct prm_handler_info *handler = find_prm_handler(&handler_guid);
+	struct prm_module_info *module = find_prm_module(&handler_guid);
+	struct prm_context_buffer context;
+	efi_status_t status;
+
+	if (!module || !handler)
+		return -ENODEV;
+
+	memset(&context, 0, sizeof(context));
+	ACPI_COPY_NAMESEG(context.signature, "PRMC");
+	context.identifier         = handler->guid;
+	context.static_data_buffer = handler->static_data_buffer_addr;
+	context.mmio_ranges        = module->mmio_info;
+
+	status = efi_call_acpi_prm_handler(handler->handler_addr,
+					   (u64)param_buffer,
+					   &context);
+
+	return efi_status_to_err(status);
+}
+EXPORT_SYMBOL_GPL(acpi_call_prm_handler);
+
 /*
  * This is the PlatformRtMechanism opregion space handler.
  * @function: indicates the read/write. In fact as the PlatformRtMechanism
diff --git a/include/linux/prmt.h b/include/linux/prmt.h
index 24da8364b919..9c094294403f 100644
--- a/include/linux/prmt.h
+++ b/include/linux/prmt.h
@@ -2,6 +2,11 @@ 
 
 #ifdef CONFIG_ACPI_PRMT
 void init_prmt(void);
+int acpi_call_prm_handler(guid_t handler_guid, void *param_buffer);
 #else
 static inline void init_prmt(void) { }
+static inline int acpi_call_prm_handler(guid_t handler_guid, void *param_buffer)
+{
+	return -EOPNOTSUPP;
+}
 #endif