Patchwork [1/3] efi/x86: turn EFI runtime semaphore into a global lock

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Submitter Hedi Berriche
Date Jan. 9, 2019, 10:45 a.m.
Message ID <20190109104541.25733-2-hedi.berriche@hpe.com>
Download mbox | patch
Permalink /patch/695665/
State New
Headers show

Comments

Hedi Berriche - Jan. 9, 2019, 10:45 a.m.
Make efi_runtime_lock semaphore global so that it can be used by EFI
runtime callers that may be defined outside efi/runtime-wrappers.c.

The immediate motivation is to piggy-back it to serialise UV platform BIOS
calls.

No functional changes.

Signed-off-by: Hedi Berriche <hedi.berriche@hpe.com>
Reviewed-by: Russ Anderson <rja@hpe.com>
Reviewed-by: Mike Travis <mike.travis@hpe.com>
Reviewed-by: Dimitri Sivanich <sivanich@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
---
 drivers/firmware/efi/runtime-wrappers.c |   60 ++++++++++++++++----------------
 include/linux/efi.h                     |    3 +
 2 files changed, 33 insertions(+), 30 deletions(-)
Thomas Gleixner - Jan. 15, 2019, 6:55 p.m.
On Wed, 9 Jan 2019, Hedi Berriche wrote:

> Make efi_runtime_lock semaphore global so that it can be used by EFI
> runtime callers that may be defined outside efi/runtime-wrappers.c.

The changelog should mention why the lock is renamed. I have no strong
opinion, but to apply that I need an Ack from Ard.

Thanks,

	tglx
Hedi Berriche - Jan. 15, 2019, 7:35 p.m.
On Tue, Jan 15, 2019 at 18:55 Thomas Gleixner wrote:
>On Wed, 9 Jan 2019, Hedi Berriche wrote:
>
>> Make efi_runtime_lock semaphore global so that it can be used by EFI
>> runtime callers that may be defined outside efi/runtime-wrappers.c.
>
>The changelog should mention why the lock is renamed.

OK; will add to V2 that it was renamed so that it doesn't clash with the
efi_runtime_lock spinlock defined by CONFIG_EFI_MIXED.

>I have no strong opinion, but to apply that I need an Ack from Ard.

OK; thanks for the feedback.

Cheers,
Hedi.
Ard Biesheuvel - Jan. 26, 2019, 2:03 p.m.
Hello Hedi,

On Wed, 9 Jan 2019 at 11:46, Hedi Berriche <hedi.berriche@hpe.com> wrote:
>
> Make efi_runtime_lock semaphore global so that it can be used by EFI
> runtime callers that may be defined outside efi/runtime-wrappers.c.
>
> The immediate motivation is to piggy-back it to serialise UV platform BIOS
> calls.
>
> No functional changes.
>
> Signed-off-by: Hedi Berriche <hedi.berriche@hpe.com>
> Reviewed-by: Russ Anderson <rja@hpe.com>
> Reviewed-by: Mike Travis <mike.travis@hpe.com>
> Reviewed-by: Dimitri Sivanich <sivanich@hpe.com>
> Reviewed-by: Steve Wahl <steve.wahl@hpe.com>

Please drop these reviewed-bys. They may be given on the mailing list,
but having a whole list of R-bs from your co-workers on a first
posting of a series doesn't make a lot of sense.


> ---
>  drivers/firmware/efi/runtime-wrappers.c |   60 ++++++++++++++++----------------
>  include/linux/efi.h                     |    3 +
>  2 files changed, 33 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
> index 8903b9ccfc2b..ec60d6227925 100644
> --- a/drivers/firmware/efi/runtime-wrappers.c
> +++ b/drivers/firmware/efi/runtime-wrappers.c
> @@ -53,7 +53,7 @@ struct efi_runtime_work efi_rts_work;
>   * @rts_arg<1-5>:      efi_runtime_service() function arguments
>   *
>   * Accesses to efi_runtime_services() are serialized by a binary
> - * semaphore (efi_runtime_lock) and caller waits until the work is
> + * semaphore (efi_runtime_sem) and caller waits until the work is
>   * finished, hence _only_ one work is queued at a time and the caller
>   * thread waits for completion.
>   */
> @@ -144,7 +144,7 @@ void efi_call_virt_check_flags(unsigned long flags, const char *call)
>   * none of the remaining functions are actually ever called at runtime.
>   * So let's just use a single lock to serialize all Runtime Services calls.
>   */
> -static DEFINE_SEMAPHORE(efi_runtime_lock);
> +DEFINE_SEMAPHORE(efi_runtime_sem);

Please don't rename the lock unless there is a good reason for doing so.

Your commit log does not even mention that the lock is renamed, so I
am going to assume there is no good reason for it.

>
>  /*
>   * Calls the appropriate efi_runtime_service() with the appropriate
> @@ -233,10 +233,10 @@ static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
>  {
>         efi_status_t status;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(GET_TIME, tm, tc, NULL, NULL, NULL);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -244,10 +244,10 @@ static efi_status_t virt_efi_set_time(efi_time_t *tm)
>  {
>         efi_status_t status;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(SET_TIME, tm, NULL, NULL, NULL, NULL);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -257,11 +257,11 @@ static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
>  {
>         efi_status_t status;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(GET_WAKEUP_TIME, enabled, pending, tm, NULL,
>                                 NULL);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -269,11 +269,11 @@ static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
>  {
>         efi_status_t status;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(SET_WAKEUP_TIME, &enabled, tm, NULL, NULL,
>                                 NULL);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -285,11 +285,11 @@ static efi_status_t virt_efi_get_variable(efi_char16_t *name,
>  {
>         efi_status_t status;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(GET_VARIABLE, name, vendor, attr, data_size,
>                                 data);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -299,11 +299,11 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
>  {
>         efi_status_t status;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(GET_NEXT_VARIABLE, name_size, name, vendor,
>                                 NULL, NULL);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -315,11 +315,11 @@ static efi_status_t virt_efi_set_variable(efi_char16_t *name,
>  {
>         efi_status_t status;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(SET_VARIABLE, name, vendor, &attr, &data_size,
>                                 data);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -330,12 +330,12 @@ virt_efi_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
>  {
>         efi_status_t status;
>
> -       if (down_trylock(&efi_runtime_lock))
> +       if (down_trylock(&efi_runtime_sem))
>                 return EFI_NOT_READY;
>
>         status = efi_call_virt(set_variable, name, vendor, attr, data_size,
>                                data);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -350,11 +350,11 @@ static efi_status_t virt_efi_query_variable_info(u32 attr,
>         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
>                 return EFI_UNSUPPORTED;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(QUERY_VARIABLE_INFO, &attr, storage_space,
>                                 remaining_space, max_variable_size, NULL);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -369,12 +369,12 @@ virt_efi_query_variable_info_nonblocking(u32 attr,
>         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
>                 return EFI_UNSUPPORTED;
>
> -       if (down_trylock(&efi_runtime_lock))
> +       if (down_trylock(&efi_runtime_sem))
>                 return EFI_NOT_READY;
>
>         status = efi_call_virt(query_variable_info, attr, storage_space,
>                                remaining_space, max_variable_size);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -382,11 +382,11 @@ static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
>  {
>         efi_status_t status;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(GET_NEXT_HIGH_MONO_COUNT, count, NULL, NULL,
>                                 NULL, NULL);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -395,14 +395,14 @@ static void virt_efi_reset_system(int reset_type,
>                                   unsigned long data_size,
>                                   efi_char16_t *data)
>  {
> -       if (down_interruptible(&efi_runtime_lock)) {
> +       if (down_interruptible(&efi_runtime_sem)) {
>                 pr_warn("failed to invoke the reset_system() runtime service:\n"
>                         "could not get exclusive access to the firmware\n");
>                 return;
>         }
>         efi_rts_work.efi_rts_id = RESET_SYSTEM;
>         __efi_call_virt(reset_system, reset_type, status, data_size, data);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>  }
>
>  static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
> @@ -414,11 +414,11 @@ static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
>         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
>                 return EFI_UNSUPPORTED;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(UPDATE_CAPSULE, capsules, &count, &sg_list,
>                                 NULL, NULL);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> @@ -432,11 +432,11 @@ static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
>         if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
>                 return EFI_UNSUPPORTED;
>
> -       if (down_interruptible(&efi_runtime_lock))
> +       if (down_interruptible(&efi_runtime_sem))
>                 return EFI_ABORTED;
>         status = efi_queue_work(QUERY_CAPSULE_CAPS, capsules, &count,
>                                 max_size, reset_type, NULL);
> -       up(&efi_runtime_lock);
> +       up(&efi_runtime_sem);
>         return status;
>  }
>
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 45ff763fba76..930cd20842b8 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -1745,6 +1745,9 @@ extern struct efi_runtime_work efi_rts_work;
>  /* Workqueue to queue EFI Runtime Services */
>  extern struct workqueue_struct *efi_rts_wq;
>
> +/* EFI runtime semaphore */
> +extern struct semaphore efi_runtime_sem;
> +
>  struct linux_efi_memreserve {
>         int             size;                   // allocated size of the array
>         atomic_t        count;                  // number of entries used

Patch

diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
index 8903b9ccfc2b..ec60d6227925 100644
--- a/drivers/firmware/efi/runtime-wrappers.c
+++ b/drivers/firmware/efi/runtime-wrappers.c
@@ -53,7 +53,7 @@  struct efi_runtime_work efi_rts_work;
  * @rts_arg<1-5>:	efi_runtime_service() function arguments
  *
  * Accesses to efi_runtime_services() are serialized by a binary
- * semaphore (efi_runtime_lock) and caller waits until the work is
+ * semaphore (efi_runtime_sem) and caller waits until the work is
  * finished, hence _only_ one work is queued at a time and the caller
  * thread waits for completion.
  */
@@ -144,7 +144,7 @@  void efi_call_virt_check_flags(unsigned long flags, const char *call)
  * none of the remaining functions are actually ever called at runtime.
  * So let's just use a single lock to serialize all Runtime Services calls.
  */
-static DEFINE_SEMAPHORE(efi_runtime_lock);
+DEFINE_SEMAPHORE(efi_runtime_sem);
 
 /*
  * Calls the appropriate efi_runtime_service() with the appropriate
@@ -233,10 +233,10 @@  static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 {
 	efi_status_t status;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(GET_TIME, tm, tc, NULL, NULL, NULL);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -244,10 +244,10 @@  static efi_status_t virt_efi_set_time(efi_time_t *tm)
 {
 	efi_status_t status;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(SET_TIME, tm, NULL, NULL, NULL, NULL);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -257,11 +257,11 @@  static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
 {
 	efi_status_t status;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(GET_WAKEUP_TIME, enabled, pending, tm, NULL,
 				NULL);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -269,11 +269,11 @@  static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
 {
 	efi_status_t status;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(SET_WAKEUP_TIME, &enabled, tm, NULL, NULL,
 				NULL);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -285,11 +285,11 @@  static efi_status_t virt_efi_get_variable(efi_char16_t *name,
 {
 	efi_status_t status;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(GET_VARIABLE, name, vendor, attr, data_size,
 				data);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -299,11 +299,11 @@  static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
 {
 	efi_status_t status;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(GET_NEXT_VARIABLE, name_size, name, vendor,
 				NULL, NULL);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -315,11 +315,11 @@  static efi_status_t virt_efi_set_variable(efi_char16_t *name,
 {
 	efi_status_t status;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(SET_VARIABLE, name, vendor, &attr, &data_size,
 				data);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -330,12 +330,12 @@  virt_efi_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
 {
 	efi_status_t status;
 
-	if (down_trylock(&efi_runtime_lock))
+	if (down_trylock(&efi_runtime_sem))
 		return EFI_NOT_READY;
 
 	status = efi_call_virt(set_variable, name, vendor, attr, data_size,
 			       data);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -350,11 +350,11 @@  static efi_status_t virt_efi_query_variable_info(u32 attr,
 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 		return EFI_UNSUPPORTED;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(QUERY_VARIABLE_INFO, &attr, storage_space,
 				remaining_space, max_variable_size, NULL);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -369,12 +369,12 @@  virt_efi_query_variable_info_nonblocking(u32 attr,
 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 		return EFI_UNSUPPORTED;
 
-	if (down_trylock(&efi_runtime_lock))
+	if (down_trylock(&efi_runtime_sem))
 		return EFI_NOT_READY;
 
 	status = efi_call_virt(query_variable_info, attr, storage_space,
 			       remaining_space, max_variable_size);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -382,11 +382,11 @@  static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
 {
 	efi_status_t status;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(GET_NEXT_HIGH_MONO_COUNT, count, NULL, NULL,
 				NULL, NULL);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -395,14 +395,14 @@  static void virt_efi_reset_system(int reset_type,
 				  unsigned long data_size,
 				  efi_char16_t *data)
 {
-	if (down_interruptible(&efi_runtime_lock)) {
+	if (down_interruptible(&efi_runtime_sem)) {
 		pr_warn("failed to invoke the reset_system() runtime service:\n"
 			"could not get exclusive access to the firmware\n");
 		return;
 	}
 	efi_rts_work.efi_rts_id = RESET_SYSTEM;
 	__efi_call_virt(reset_system, reset_type, status, data_size, data);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 }
 
 static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
@@ -414,11 +414,11 @@  static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 		return EFI_UNSUPPORTED;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(UPDATE_CAPSULE, capsules, &count, &sg_list,
 				NULL, NULL);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
@@ -432,11 +432,11 @@  static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
 		return EFI_UNSUPPORTED;
 
-	if (down_interruptible(&efi_runtime_lock))
+	if (down_interruptible(&efi_runtime_sem))
 		return EFI_ABORTED;
 	status = efi_queue_work(QUERY_CAPSULE_CAPS, capsules, &count,
 				max_size, reset_type, NULL);
-	up(&efi_runtime_lock);
+	up(&efi_runtime_sem);
 	return status;
 }
 
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 45ff763fba76..930cd20842b8 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1745,6 +1745,9 @@  extern struct efi_runtime_work efi_rts_work;
 /* Workqueue to queue EFI Runtime Services */
 extern struct workqueue_struct *efi_rts_wq;
 
+/* EFI runtime semaphore */
+extern struct semaphore efi_runtime_sem;
+
 struct linux_efi_memreserve {
 	int		size;			// allocated size of the array
 	atomic_t	count;			// number of entries used