* [U-Boot] [PATCH] efi_loader: add back optional efi_handler::open()
@ 2017-07-25 12:21 Rob Clark
2017-07-25 16:39 ` Heinrich Schuchardt
0 siblings, 1 reply; 5+ messages in thread
From: Rob Clark @ 2017-07-25 12:21 UTC (permalink / raw)
To: u-boot
In some cases it is useful to defer creation of the protocol interface
object. So add back an optional ->open() hook that is used if
protcol_interface is NULL.
I've slightly simplified the fxn ptr signature to remove unneeded args,
and so compiler will complain if patches that used the "old way" are,
and which do not need this extra complexity, are rebased.
Signed-off-by: Rob Clark <robdclark@gmail.com>
---
v2: also handle this properly in locate_protocol as agraf pointed out
Note that I might be misunderstanding what the EFI application expects
when looking up device-path on a file handle.. if this is only expected
to be the device path up to the partition object (and not including the
file-path part of the path), then maybe ->open() isn't *as* important
as I thought it would be. OTOH I think it would be cleaner to use for
loaded_image_info_obj and bootefi_device_obj.. currently I have to
patch in the real boot device-path in efi_set_bootdev(), which is
messy and fragile.
I don't fully understand Heinrich's concerns, especially since the
EFI_OPEN_PROTOCOL_INFORMATION_ENTRY stuff looks like it only cares
about already opened protocols, which should already have their open()
called. (And either way, since open() is optional maybe it is enough
to just not use it for any efiobj's where it would be problematic?)
So tl;dr, if this is really going to be a problem for some things that
Heinrich has got in the pipeline, maybe (pending clarification of a
file handle's device-path) we can get by without this. But if it is
not a problem, then it certainly seems useful in a few places.
include/efi_loader.h | 9 ++++++++-
lib/efi_loader/efi_boottime.c | 30 ++++++++++++++++++++++++------
2 files changed, 32 insertions(+), 7 deletions(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 48eeb4cdd8..a9888afb04 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -41,10 +41,17 @@ extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop;
/*
* When the UEFI payload wants to open a protocol on an object to get its
* interface (usually a struct with callback functions), this struct maps the
- * protocol GUID to the respective protocol interface */
+ * protocol GUID to the respective protocol interface.
+ *
+ * The optional ->open() fxn can be used for cases where the protocol
+ * interface is constructed on-demand, and is called if protocol_interface
+ * is NULL.
+ */
struct efi_handler {
const efi_guid_t *guid;
void *protocol_interface;
+ efi_status_t (EFIAPI *open)(void *handle, const efi_guid_t *protocol,
+ void **protocol_interface);
};
/*
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 7d45c18ff7..80d9024a53 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -903,6 +903,23 @@ out:
return EFI_EXIT(r);
}
+static efi_status_t open_protocol(struct efi_object *efiobj,
+ struct efi_handler *handler,
+ void **protocol_interface)
+{
+ efi_status_t ret = EFI_SUCCESS;
+
+ if (!handler->protocol_interface) {
+ ret = handler->open(efiobj->handle,
+ handler->guid,
+ &handler->protocol_interface);
+ }
+ *protocol_interface =
+ handler->protocol_interface;
+
+ return ret;
+}
+
static efi_status_t EFIAPI efi_locate_protocol(efi_guid_t *protocol,
void *registration,
void **protocol_interface)
@@ -925,9 +942,10 @@ static efi_status_t EFIAPI efi_locate_protocol(efi_guid_t *protocol,
if (!handler->guid)
continue;
if (!guidcmp(handler->guid, protocol)) {
- *protocol_interface =
- handler->protocol_interface;
- return EFI_EXIT(EFI_SUCCESS);
+ efi_status_t ret;
+ ret = open_protocol(efiobj, handler,
+ protocol_interface);
+ return EFI_EXIT(ret);
}
}
}
@@ -1061,12 +1079,12 @@ static efi_status_t EFIAPI efi_open_protocol(
if (!hprotocol)
continue;
if (!guidcmp(hprotocol, protocol)) {
+ r = EFI_SUCCESS;
if (attributes !=
EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
- *protocol_interface =
- handler->protocol_interface;
+ r = open_protocol(efiobj, handler,
+ protocol_interface);
}
- r = EFI_SUCCESS;
goto out;
}
}
--
2.13.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [U-Boot] [PATCH] efi_loader: add back optional efi_handler::open()
2017-07-25 12:21 [U-Boot] [PATCH] efi_loader: add back optional efi_handler::open() Rob Clark
@ 2017-07-25 16:39 ` Heinrich Schuchardt
2017-07-25 17:20 ` Rob Clark
0 siblings, 1 reply; 5+ messages in thread
From: Heinrich Schuchardt @ 2017-07-25 16:39 UTC (permalink / raw)
To: u-boot
On 07/25/2017 02:21 PM, Rob Clark wrote:
> In some cases it is useful to defer creation of the protocol interface
> object. So add back an optional ->open() hook that is used if
> protcol_interface is NULL.
>
> I've slightly simplified the fxn ptr signature to remove unneeded args,
> and so compiler will complain if patches that used the "old way" are,
> and which do not need this extra complexity, are rebased.
>
> Signed-off-by: Rob Clark <robdclark@gmail.com>
> ---
> v2: also handle this properly in locate_protocol as agraf pointed out
>
> Note that I might be misunderstanding what the EFI application expects
> when looking up device-path on a file handle.. if this is only expected
> to be the device path up to the partition object (and not including the
> file-path part of the path), then maybe ->open() isn't *as* important
> as I thought it would be. OTOH I think it would be cleaner to use for
> loaded_image_info_obj and bootefi_device_obj.. currently I have to
> patch in the real boot device-path in efi_set_bootdev(), which is
> messy and fragile.
>
> I don't fully understand Heinrich's concerns, especially since the
> EFI_OPEN_PROTOCOL_INFORMATION_ENTRY stuff looks like it only cares
> about already opened protocols, which should already have their open()
> called. (And either way, since open() is optional maybe it is enough
> to just not use it for any efiobj's where it would be problematic?)
>
> So tl;dr, if this is really going to be a problem for some things that
> Heinrich has got in the pipeline, maybe (pending clarification of a
> file handle's device-path) we can get by without this. But if it is
> not a problem, then it certainly seems useful in a few places.
>
> include/efi_loader.h | 9 ++++++++-
> lib/efi_loader/efi_boottime.c | 30 ++++++++++++++++++++++++------
> 2 files changed, 32 insertions(+), 7 deletions(-)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 48eeb4cdd8..a9888afb04 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -41,10 +41,17 @@ extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop;
> /*
> * When the UEFI payload wants to open a protocol on an object to get its
> * interface (usually a struct with callback functions), this struct maps the
> - * protocol GUID to the respective protocol interface */
> + * protocol GUID to the respective protocol interface.
> + *
> + * The optional ->open() fxn can be used for cases where the protocol
> + * interface is constructed on-demand, and is called if protocol_interface
> + * is NULL.
> + */
> struct efi_handler {
> const efi_guid_t *guid;
> void *protocol_interface;
> + efi_status_t (EFIAPI *open)(void *handle, const efi_guid_t *protocol,
> + void **protocol_interface);
> };
>
> /*
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 7d45c18ff7..80d9024a53 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -903,6 +903,23 @@ out:
> return EFI_EXIT(r);
> }
>
> +static efi_status_t open_protocol(struct efi_object *efiobj,
> + struct efi_handler *handler,
> + void **protocol_interface)
> +{
> + efi_status_t ret = EFI_SUCCESS;
> +
> + if (!handler->protocol_interface) {
> + ret = handler->open(efiobj->handle,
> + handler->guid,
> + &handler->protocol_interface);
> + }
> + *protocol_interface =
> + handler->protocol_interface;
> +
> + return ret;
> +}
> +
> static efi_status_t EFIAPI efi_locate_protocol(efi_guid_t *protocol,
> void *registration,
> void **protocol_interface)
> @@ -925,9 +942,10 @@ static efi_status_t EFIAPI efi_locate_protocol(efi_guid_t *protocol,
> if (!handler->guid)
> continue;
> if (!guidcmp(handler->guid, protocol)) {
> - *protocol_interface =
> - handler->protocol_interface;
> - return EFI_EXIT(EFI_SUCCESS);
> + efi_status_t ret;
> + ret = open_protocol(efiobj, handler,
> + protocol_interface);
NAK
With your design a driver could decide that on the first call of
open_protocol it exposes a protocol and on the second it does not.
Or LocateHandleBuffer return an object meant to support a protocol and
then opening is refused.
The UEFI standard assumes that the supported protocols can be reliably
be determined once and for all.
If anything, please, use an init function of type:
void init(efi_guid guid);
Simply pass the protocol guid to the init function of the handler.
How many ms and kiB do you think you will save when starting grub with
deferred initialization?
Best regards
Heinrich
> + return EFI_EXIT(ret);
> }
> }
> }
> @@ -1061,12 +1079,12 @@ static efi_status_t EFIAPI efi_open_protocol(
> if (!hprotocol)
> continue;
> if (!guidcmp(hprotocol, protocol)) {
> + r = EFI_SUCCESS;
> if (attributes !=
> EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
> - *protocol_interface =
> - handler->protocol_interface;
> + r = open_protocol(efiobj, handler,
> + protocol_interface);
> }
> - r = EFI_SUCCESS;
> goto out;
> }
> }
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [U-Boot] [PATCH] efi_loader: add back optional efi_handler::open()
2017-07-25 16:39 ` Heinrich Schuchardt
@ 2017-07-25 17:20 ` Rob Clark
0 siblings, 0 replies; 5+ messages in thread
From: Rob Clark @ 2017-07-25 17:20 UTC (permalink / raw)
To: u-boot
On Tue, Jul 25, 2017 at 12:39 PM, Heinrich Schuchardt
<xypron.glpk@gmx.de> wrote:
> On 07/25/2017 02:21 PM, Rob Clark wrote:
>> In some cases it is useful to defer creation of the protocol interface
>> object. So add back an optional ->open() hook that is used if
>> protcol_interface is NULL.
>>
>> I've slightly simplified the fxn ptr signature to remove unneeded args,
>> and so compiler will complain if patches that used the "old way" are,
>> and which do not need this extra complexity, are rebased.
>>
>> Signed-off-by: Rob Clark <robdclark@gmail.com>
>> ---
>> v2: also handle this properly in locate_protocol as agraf pointed out
>>
>> Note that I might be misunderstanding what the EFI application expects
>> when looking up device-path on a file handle.. if this is only expected
>> to be the device path up to the partition object (and not including the
>> file-path part of the path), then maybe ->open() isn't *as* important
>> as I thought it would be. OTOH I think it would be cleaner to use for
>> loaded_image_info_obj and bootefi_device_obj.. currently I have to
>> patch in the real boot device-path in efi_set_bootdev(), which is
>> messy and fragile.
>>
>> I don't fully understand Heinrich's concerns, especially since the
>> EFI_OPEN_PROTOCOL_INFORMATION_ENTRY stuff looks like it only cares
>> about already opened protocols, which should already have their open()
>> called. (And either way, since open() is optional maybe it is enough
>> to just not use it for any efiobj's where it would be problematic?)
>>
>> So tl;dr, if this is really going to be a problem for some things that
>> Heinrich has got in the pipeline, maybe (pending clarification of a
>> file handle's device-path) we can get by without this. But if it is
>> not a problem, then it certainly seems useful in a few places.
>>
>> include/efi_loader.h | 9 ++++++++-
>> lib/efi_loader/efi_boottime.c | 30 ++++++++++++++++++++++++------
>> 2 files changed, 32 insertions(+), 7 deletions(-)
>>
>> diff --git a/include/efi_loader.h b/include/efi_loader.h
>> index 48eeb4cdd8..a9888afb04 100644
>> --- a/include/efi_loader.h
>> +++ b/include/efi_loader.h
>> @@ -41,10 +41,17 @@ extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop;
>> /*
>> * When the UEFI payload wants to open a protocol on an object to get its
>> * interface (usually a struct with callback functions), this struct maps the
>> - * protocol GUID to the respective protocol interface */
>> + * protocol GUID to the respective protocol interface.
>> + *
>> + * The optional ->open() fxn can be used for cases where the protocol
>> + * interface is constructed on-demand, and is called if protocol_interface
>> + * is NULL.
>> + */
>> struct efi_handler {
>> const efi_guid_t *guid;
>> void *protocol_interface;
>> + efi_status_t (EFIAPI *open)(void *handle, const efi_guid_t *protocol,
>> + void **protocol_interface);
>> };
>>
>> /*
>> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
>> index 7d45c18ff7..80d9024a53 100644
>> --- a/lib/efi_loader/efi_boottime.c
>> +++ b/lib/efi_loader/efi_boottime.c
>> @@ -903,6 +903,23 @@ out:
>> return EFI_EXIT(r);
>> }
>>
>> +static efi_status_t open_protocol(struct efi_object *efiobj,
>> + struct efi_handler *handler,
>> + void **protocol_interface)
>> +{
>> + efi_status_t ret = EFI_SUCCESS;
>> +
>> + if (!handler->protocol_interface) {
>> + ret = handler->open(efiobj->handle,
>> + handler->guid,
>> + &handler->protocol_interface);
>> + }
>> + *protocol_interface =
>> + handler->protocol_interface;
>> +
>> + return ret;
>> +}
>> +
>> static efi_status_t EFIAPI efi_locate_protocol(efi_guid_t *protocol,
>> void *registration,
>> void **protocol_interface)
>> @@ -925,9 +942,10 @@ static efi_status_t EFIAPI efi_locate_protocol(efi_guid_t *protocol,
>> if (!handler->guid)
>> continue;
>> if (!guidcmp(handler->guid, protocol)) {
>> - *protocol_interface =
>> - handler->protocol_interface;
>> - return EFI_EXIT(EFI_SUCCESS);
>> + efi_status_t ret;
>> + ret = open_protocol(efiobj, handler,
>> + protocol_interface);
>
> NAK
>
> With your design a driver could decide that on the first call of
> open_protocol it exposes a protocol and on the second it does not.
Not true, please read the patch again. ->open() is only called the first time.
> Or LocateHandleBuffer return an object meant to support a protocol and
> then opening is refused.
>
> The UEFI standard assumes that the supported protocols can be reliably
> be determined once and for all.
>
> If anything, please, use an init function of type:
> void init(efi_guid guid);
> Simply pass the protocol guid to the init function of the handler.
>
> How many ms and kiB do you think you will save when starting grub with
> deferred initialization?
I did confirm that the device-path for an file object should include
the file path. So this also avoids needing to construct a device path
on each file open, which will most likely never be accessed.
BR,
-R
> Best regards
>
> Heinrich
>
>
>> + return EFI_EXIT(ret);
>> }
>> }
>> }
>> @@ -1061,12 +1079,12 @@ static efi_status_t EFIAPI efi_open_protocol(
>> if (!hprotocol)
>> continue;
>> if (!guidcmp(hprotocol, protocol)) {
>> + r = EFI_SUCCESS;
>> if (attributes !=
>> EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
>> - *protocol_interface =
>> - handler->protocol_interface;
>> + r = open_protocol(efiobj, handler,
>> + protocol_interface);
>> }
>> - r = EFI_SUCCESS;
>> goto out;
>> }
>> }
>>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [U-Boot] [PATCH] efi_loader: add back optional efi_handler::open()
2017-07-24 14:38 Rob Clark
@ 2017-07-25 8:52 ` Alexander Graf
0 siblings, 0 replies; 5+ messages in thread
From: Alexander Graf @ 2017-07-25 8:52 UTC (permalink / raw)
To: u-boot
On 24.07.17 16:38, Rob Clark wrote:
> In some cases it is useful to defer creation of the protocol interface
> object. So add back an optional ->open() hook that is used if
> protcol_interface is NULL.
>
> I've slightly simplified the fxn ptr signature to remove unneeded args,
> and so compiler will complain if patches that used the "old way" are,
> and which do not need this extra complexity, are rebased.
>
> Signed-off-by: Rob Clark <robdclark@gmail.com>
> ---
> include/efi_loader.h | 9 ++++++++-
> lib/efi_loader/efi_boottime.c | 7 +++++++
> 2 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 90411cdbab..3da0477fdc 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -41,10 +41,17 @@ extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop;
> /*
> * When the UEFI payload wants to open a protocol on an object to get its
> * interface (usually a struct with callback functions), this struct maps the
> - * protocol GUID to the respective protocol interface */
> + * protocol GUID to the respective protocol interface.
> + *
> + * The optional ->open() fxn can be used for cases where the protocol
> + * interface is constructed on-demand, and is called if protocol_interface
> + * is NULL.
> + */
> struct efi_handler {
> const efi_guid_t *guid;
> void *protocol_interface;
> + efi_status_t (EFIAPI *open)(void *handle, efi_guid_t *protocol,
> + void **protocol_interface);
> };
>
> /*
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 7d45c18ff7..21f41866d0 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -1063,6 +1063,13 @@ static efi_status_t EFIAPI efi_open_protocol(
> if (!guidcmp(hprotocol, protocol)) {
> if (attributes !=
> EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
> + if (!handler->protocol_interface) {
> + r = handler->open(efiobj->handle,
> + protocol,
> + &handler->protocol_interface);
With this patch you basically allow deferred setting of
handler->protocol_interface. I think that's a reasonable thing to do,
but we have to be careful not to break UEFI assumptions.
For example efi_locate_protocol reads handler->protocol_interface, so
that needs adjustment I suppose.
Alex
^ permalink raw reply [flat|nested] 5+ messages in thread
* [U-Boot] [PATCH] efi_loader: add back optional efi_handler::open()
@ 2017-07-24 14:38 Rob Clark
2017-07-25 8:52 ` Alexander Graf
0 siblings, 1 reply; 5+ messages in thread
From: Rob Clark @ 2017-07-24 14:38 UTC (permalink / raw)
To: u-boot
In some cases it is useful to defer creation of the protocol interface
object. So add back an optional ->open() hook that is used if
protcol_interface is NULL.
I've slightly simplified the fxn ptr signature to remove unneeded args,
and so compiler will complain if patches that used the "old way" are,
and which do not need this extra complexity, are rebased.
Signed-off-by: Rob Clark <robdclark@gmail.com>
---
include/efi_loader.h | 9 ++++++++-
lib/efi_loader/efi_boottime.c | 7 +++++++
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 90411cdbab..3da0477fdc 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -41,10 +41,17 @@ extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop;
/*
* When the UEFI payload wants to open a protocol on an object to get its
* interface (usually a struct with callback functions), this struct maps the
- * protocol GUID to the respective protocol interface */
+ * protocol GUID to the respective protocol interface.
+ *
+ * The optional ->open() fxn can be used for cases where the protocol
+ * interface is constructed on-demand, and is called if protocol_interface
+ * is NULL.
+ */
struct efi_handler {
const efi_guid_t *guid;
void *protocol_interface;
+ efi_status_t (EFIAPI *open)(void *handle, efi_guid_t *protocol,
+ void **protocol_interface);
};
/*
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 7d45c18ff7..21f41866d0 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -1063,6 +1063,13 @@ static efi_status_t EFIAPI efi_open_protocol(
if (!guidcmp(hprotocol, protocol)) {
if (attributes !=
EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
+ if (!handler->protocol_interface) {
+ r = handler->open(efiobj->handle,
+ protocol,
+ &handler->protocol_interface);
+ if (r != EFI_SUCCESS)
+ goto out;
+ }
*protocol_interface =
handler->protocol_interface;
}
--
2.13.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
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2017-07-25 12:21 [U-Boot] [PATCH] efi_loader: add back optional efi_handler::open() Rob Clark
2017-07-25 16:39 ` Heinrich Schuchardt
2017-07-25 17:20 ` Rob Clark
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2017-07-24 14:38 Rob Clark
2017-07-25 8:52 ` Alexander Graf
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