[1/1] efi: rtc: Enable SET/GET WAKEUP services as optional

  The current implementation of rtc-efi is expecting all the 4
time services GET{SET}_TIME{WAKEUP} must be supported by UEFI
firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform
specific implementations can choose to enable selective time
services based on the RTC device capabilities.

This patch does the following changes to provide GET/SET RTC
services on platforms that do not support the WAKEUP feature.

1) Relax time services cap check when creating a platform device.
2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services.
3) Conditional alarm entries in '/proc/driver/rtc'.

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
---
 drivers/rtc/rtc-efi.c | 48 ++++++++++++++++++++++++-------------------
 include/linux/efi.h   |  3 ++-
 2 files changed, 29 insertions(+), 22 deletions(-)
  

On Tue, 27 Dec 2022 at 05:09, Shanker Donthineni <sdonthineni@nvidia.com> wrote:
>
> The current implementation of rtc-efi is expecting all the 4
> time services GET{SET}_TIME{WAKEUP} must be supported by UEFI
> firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform
> specific implementations can choose to enable selective time
> services based on the RTC device capabilities.
>
> This patch does the following changes to provide GET/SET RTC
> services on platforms that do not support the WAKEUP feature.
>
> 1) Relax time services cap check when creating a platform device.
> 2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services.
> 3) Conditional alarm entries in '/proc/driver/rtc'.
>
> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>

Queued as a fix in efi/urgent, thanks.


> ---
>  drivers/rtc/rtc-efi.c | 48 ++++++++++++++++++++++++-------------------
>  include/linux/efi.h   |  3 ++-
>  2 files changed, 29 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c
> index e991cccdb6e9c..1e8bc6cc1e12d 100644
> --- a/drivers/rtc/rtc-efi.c
> +++ b/drivers/rtc/rtc-efi.c
> @@ -188,9 +188,10 @@ static int efi_set_time(struct device *dev, struct rtc_time *tm)
>
>  static int efi_procfs(struct device *dev, struct seq_file *seq)
>  {
> -       efi_time_t      eft, alm;
> -       efi_time_cap_t  cap;
> -       efi_bool_t      enabled, pending;
> +       efi_time_t        eft, alm;
> +       efi_time_cap_t    cap;
> +       efi_bool_t        enabled, pending;
> +       struct rtc_device *rtc = dev_get_drvdata(dev);
>
>         memset(&eft, 0, sizeof(eft));
>         memset(&alm, 0, sizeof(alm));
> @@ -213,23 +214,25 @@ static int efi_procfs(struct device *dev, struct seq_file *seq)
>                 /* XXX fixme: convert to string? */
>                 seq_printf(seq, "Timezone\t: %u\n", eft.timezone);
>
> -       seq_printf(seq,
> -                  "Alarm Time\t: %u:%u:%u.%09u\n"
> -                  "Alarm Date\t: %u-%u-%u\n"
> -                  "Alarm Daylight\t: %u\n"
> -                  "Enabled\t\t: %s\n"
> -                  "Pending\t\t: %s\n",
> -                  alm.hour, alm.minute, alm.second, alm.nanosecond,
> -                  alm.year, alm.month, alm.day,
> -                  alm.daylight,
> -                  enabled == 1 ? "yes" : "no",
> -                  pending == 1 ? "yes" : "no");
> -
> -       if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
> -               seq_puts(seq, "Timezone\t: unspecified\n");
> -       else
> -               /* XXX fixme: convert to string? */
> -               seq_printf(seq, "Timezone\t: %u\n", alm.timezone);
> +       if (test_bit(RTC_FEATURE_ALARM, rtc->features)) {
> +               seq_printf(seq,
> +                          "Alarm Time\t: %u:%u:%u.%09u\n"
> +                          "Alarm Date\t: %u-%u-%u\n"
> +                          "Alarm Daylight\t: %u\n"
> +                          "Enabled\t\t: %s\n"
> +                          "Pending\t\t: %s\n",
> +                          alm.hour, alm.minute, alm.second, alm.nanosecond,
> +                          alm.year, alm.month, alm.day,
> +                          alm.daylight,
> +                          enabled == 1 ? "yes" : "no",
> +                          pending == 1 ? "yes" : "no");
> +
> +               if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
> +                       seq_puts(seq, "Timezone\t: unspecified\n");
> +               else
> +                       /* XXX fixme: convert to string? */
> +                       seq_printf(seq, "Timezone\t: %u\n", alm.timezone);
> +       }
>
>         /*
>          * now prints the capabilities
> @@ -269,7 +272,10 @@ static int __init efi_rtc_probe(struct platform_device *dev)
>
>         rtc->ops = &efi_rtc_ops;
>         clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
> -       set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);
> +       if (efi_rt_services_supported(EFI_RT_SUPPORTED_WAKEUP_SERVICES))
> +               set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);
> +       else
> +               clear_bit(RTC_FEATURE_ALARM, rtc->features);
>
>         device_init_wakeup(&dev->dev, true);
>
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 4b27519143f56..98598bd1d2fa5 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -668,7 +668,8 @@ extern struct efi {
>
>  #define EFI_RT_SUPPORTED_ALL                                   0x3fff
>
> -#define EFI_RT_SUPPORTED_TIME_SERVICES                         0x000f
> +#define EFI_RT_SUPPORTED_TIME_SERVICES                         0x0003
> +#define EFI_RT_SUPPORTED_WAKEUP_SERVICES                       0x000c
>  #define EFI_RT_SUPPORTED_VARIABLE_SERVICES                     0x0070
>
>  extern struct mm_struct efi_mm;
> --
> 2.25.1
>
  

On 02/01/2023 11:47:11+0100, Ard Biesheuvel wrote:
> On Tue, 27 Dec 2022 at 05:09, Shanker Donthineni <sdonthineni@nvidia.com> wrote:
> >
> > The current implementation of rtc-efi is expecting all the 4
> > time services GET{SET}_TIME{WAKEUP} must be supported by UEFI
> > firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform
> > specific implementations can choose to enable selective time
> > services based on the RTC device capabilities.
> >
> > This patch does the following changes to provide GET/SET RTC
> > services on platforms that do not support the WAKEUP feature.
> >
> > 1) Relax time services cap check when creating a platform device.
> > 2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services.
> > 3) Conditional alarm entries in '/proc/driver/rtc'.
> >
> > Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
> 
> Queued as a fix in efi/urgent, thanks.

This rather seems like an rtc heavy patch and the subject line is
misleading. This should be rtc: efi:
Also, I'm pretty sure this doesn't qualify as an urgent fix.

> 
> 
> > ---
> >  drivers/rtc/rtc-efi.c | 48 ++++++++++++++++++++++++-------------------
> >  include/linux/efi.h   |  3 ++-
> >  2 files changed, 29 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c
> > index e991cccdb6e9c..1e8bc6cc1e12d 100644
> > --- a/drivers/rtc/rtc-efi.c
> > +++ b/drivers/rtc/rtc-efi.c
> > @@ -188,9 +188,10 @@ static int efi_set_time(struct device *dev, struct rtc_time *tm)
> >
> >  static int efi_procfs(struct device *dev, struct seq_file *seq)
> >  {
> > -       efi_time_t      eft, alm;
> > -       efi_time_cap_t  cap;
> > -       efi_bool_t      enabled, pending;
> > +       efi_time_t        eft, alm;
> > +       efi_time_cap_t    cap;
> > +       efi_bool_t        enabled, pending;
> > +       struct rtc_device *rtc = dev_get_drvdata(dev);
> >
> >         memset(&eft, 0, sizeof(eft));
> >         memset(&alm, 0, sizeof(alm));
> > @@ -213,23 +214,25 @@ static int efi_procfs(struct device *dev, struct seq_file *seq)
> >                 /* XXX fixme: convert to string? */
> >                 seq_printf(seq, "Timezone\t: %u\n", eft.timezone);
> >
> > -       seq_printf(seq,
> > -                  "Alarm Time\t: %u:%u:%u.%09u\n"
> > -                  "Alarm Date\t: %u-%u-%u\n"
> > -                  "Alarm Daylight\t: %u\n"
> > -                  "Enabled\t\t: %s\n"
> > -                  "Pending\t\t: %s\n",
> > -                  alm.hour, alm.minute, alm.second, alm.nanosecond,
> > -                  alm.year, alm.month, alm.day,
> > -                  alm.daylight,
> > -                  enabled == 1 ? "yes" : "no",
> > -                  pending == 1 ? "yes" : "no");
> > -
> > -       if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
> > -               seq_puts(seq, "Timezone\t: unspecified\n");
> > -       else
> > -               /* XXX fixme: convert to string? */
> > -               seq_printf(seq, "Timezone\t: %u\n", alm.timezone);
> > +       if (test_bit(RTC_FEATURE_ALARM, rtc->features)) {
> > +               seq_printf(seq,
> > +                          "Alarm Time\t: %u:%u:%u.%09u\n"
> > +                          "Alarm Date\t: %u-%u-%u\n"
> > +                          "Alarm Daylight\t: %u\n"
> > +                          "Enabled\t\t: %s\n"
> > +                          "Pending\t\t: %s\n",
> > +                          alm.hour, alm.minute, alm.second, alm.nanosecond,
> > +                          alm.year, alm.month, alm.day,
> > +                          alm.daylight,
> > +                          enabled == 1 ? "yes" : "no",
> > +                          pending == 1 ? "yes" : "no");
> > +
> > +               if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
> > +                       seq_puts(seq, "Timezone\t: unspecified\n");
> > +               else
> > +                       /* XXX fixme: convert to string? */
> > +                       seq_printf(seq, "Timezone\t: %u\n", alm.timezone);
> > +       }
> >
> >         /*
> >          * now prints the capabilities
> > @@ -269,7 +272,10 @@ static int __init efi_rtc_probe(struct platform_device *dev)
> >
> >         rtc->ops = &efi_rtc_ops;
> >         clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
> > -       set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);
> > +       if (efi_rt_services_supported(EFI_RT_SUPPORTED_WAKEUP_SERVICES))
> > +               set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);
> > +       else
> > +               clear_bit(RTC_FEATURE_ALARM, rtc->features);
> >
> >         device_init_wakeup(&dev->dev, true);
> >
> > diff --git a/include/linux/efi.h b/include/linux/efi.h
> > index 4b27519143f56..98598bd1d2fa5 100644
> > --- a/include/linux/efi.h
> > +++ b/include/linux/efi.h
> > @@ -668,7 +668,8 @@ extern struct efi {
> >
> >  #define EFI_RT_SUPPORTED_ALL                                   0x3fff
> >
> > -#define EFI_RT_SUPPORTED_TIME_SERVICES                         0x000f
> > +#define EFI_RT_SUPPORTED_TIME_SERVICES                         0x0003
> > +#define EFI_RT_SUPPORTED_WAKEUP_SERVICES                       0x000c
> >  #define EFI_RT_SUPPORTED_VARIABLE_SERVICES                     0x0070
> >
> >  extern struct mm_struct efi_mm;
> > --
> > 2.25.1
> >
  

Hi Alexandre Belloni,

On 1/2/23 16:21, Alexandre Belloni wrote:
> On 02/01/2023 11:47:11+0100, Ard Biesheuvel wrote:
>> On Tue, 27 Dec 2022 at 05:09, Shanker Donthineni<sdonthineni@nvidia.com>  wrote:
>>> The current implementation of rtc-efi is expecting all the 4
>>> time services GET{SET}_TIME{WAKEUP} must be supported by UEFI
>>> firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform
>>> specific implementations can choose to enable selective time
>>> services based on the RTC device capabilities.
>>>
>>> This patch does the following changes to provide GET/SET RTC
>>> services on platforms that do not support the WAKEUP feature.
>>>
>>> 1) Relax time services cap check when creating a platform device.
>>> 2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services.
>>> 3) Conditional alarm entries in '/proc/driver/rtc'.
>>>
>>> Signed-off-by: Shanker Donthineni<sdonthineni@nvidia.com>
>> Queued as a fix in efi/urgent, thanks.
> This rather seems like an rtc heavy patch and the subject line is
> misleading. This should be rtc: efi:
> Also, I'm pretty sure this doesn't qualify as an urgent fix.
> 

Thanks, I'll post v2 patch with your suggested subject.
  

On Mon, 2 Jan 2023 at 23:21, Alexandre Belloni
<alexandre.belloni@bootlin.com> wrote:
>
> On 02/01/2023 11:47:11+0100, Ard Biesheuvel wrote:
> > On Tue, 27 Dec 2022 at 05:09, Shanker Donthineni <sdonthineni@nvidia.com> wrote:
> > >
> > > The current implementation of rtc-efi is expecting all the 4
> > > time services GET{SET}_TIME{WAKEUP} must be supported by UEFI
> > > firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform
> > > specific implementations can choose to enable selective time
> > > services based on the RTC device capabilities.
> > >
> > > This patch does the following changes to provide GET/SET RTC
> > > services on platforms that do not support the WAKEUP feature.
> > >
> > > 1) Relax time services cap check when creating a platform device.
> > > 2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services.
> > > 3) Conditional alarm entries in '/proc/driver/rtc'.
> > >
> > > Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
> >
> > Queued as a fix in efi/urgent, thanks.
>
> This rather seems like an rtc heavy patch and the subject line is
> misleading. This should be rtc: efi:
> Also, I'm pretty sure this doesn't qualify as an urgent fix.
>

I'm happy to drop it from my tree, but please add a cc:stable so it
gets backported to v6.1 at least. Otherwise, EFI compliant systems
that implement get/set_time but not get/set_wakeup_time have no RTC at
all on any LTS kernel until a year from now, and this was never the
intent when we introduced the EFI_RT_PROPERTIES_TABLE.
  

Hi Ard Biesheuvel,

On 1/3/23 03:18, Ard Biesheuvel wrote:
> External email: Use caution opening links or attachments
> 
> 
> On Mon, 2 Jan 2023 at 23:21, Alexandre Belloni
> <alexandre.belloni@bootlin.com> wrote:
>>
>> On 02/01/2023 11:47:11+0100, Ard Biesheuvel wrote:
>>> On Tue, 27 Dec 2022 at 05:09, Shanker Donthineni <sdonthineni@nvidia.com> wrote:
>>>>
>>>> The current implementation of rtc-efi is expecting all the 4
>>>> time services GET{SET}_TIME{WAKEUP} must be supported by UEFI
>>>> firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform
>>>> specific implementations can choose to enable selective time
>>>> services based on the RTC device capabilities.
>>>>
>>>> This patch does the following changes to provide GET/SET RTC
>>>> services on platforms that do not support the WAKEUP feature.
>>>>
>>>> 1) Relax time services cap check when creating a platform device.
>>>> 2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services.
>>>> 3) Conditional alarm entries in '/proc/driver/rtc'.
>>>>
>>>> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
>>>
>>> Queued as a fix in efi/urgent, thanks.
>>
>> This rather seems like an rtc heavy patch and the subject line is
>> misleading. This should be rtc: efi:
>> Also, I'm pretty sure this doesn't qualify as an urgent fix.
>>
> 
> I'm happy to drop it from my tree, but please add a cc:stable so it
> gets backported to v6.1 at least. Otherwise, EFI compliant systems
> that implement get/set_time but not get/set_wakeup_time have no RTC at
> all on any LTS kernel until a year from now, and this was never the
> intent when we introduced the EFI_RT_PROPERTIES_TABLE.

Thanks for considering the fix for stable releases, I'll post v3 patch
with tag 'CC: <stable@vger.kernel.org> # v6.0+'
  

On Tue, 3 Jan 2023 at 17:37, Shanker Donthineni <sdonthineni@nvidia.com> wrote:
>
> Hi Ard Biesheuvel,
>
> On 1/3/23 03:18, Ard Biesheuvel wrote:
> > External email: Use caution opening links or attachments
> >
> >
> > On Mon, 2 Jan 2023 at 23:21, Alexandre Belloni
> > <alexandre.belloni@bootlin.com> wrote:
> >>
> >> On 02/01/2023 11:47:11+0100, Ard Biesheuvel wrote:
> >>> On Tue, 27 Dec 2022 at 05:09, Shanker Donthineni <sdonthineni@nvidia.com> wrote:
> >>>>
> >>>> The current implementation of rtc-efi is expecting all the 4
> >>>> time services GET{SET}_TIME{WAKEUP} must be supported by UEFI
> >>>> firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform
> >>>> specific implementations can choose to enable selective time
> >>>> services based on the RTC device capabilities.
> >>>>
> >>>> This patch does the following changes to provide GET/SET RTC
> >>>> services on platforms that do not support the WAKEUP feature.
> >>>>
> >>>> 1) Relax time services cap check when creating a platform device.
> >>>> 2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services.
> >>>> 3) Conditional alarm entries in '/proc/driver/rtc'.
> >>>>
> >>>> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
> >>>
> >>> Queued as a fix in efi/urgent, thanks.
> >>
> >> This rather seems like an rtc heavy patch and the subject line is
> >> misleading. This should be rtc: efi:
> >> Also, I'm pretty sure this doesn't qualify as an urgent fix.
> >>
> >
> > I'm happy to drop it from my tree, but please add a cc:stable so it
> > gets backported to v6.1 at least. Otherwise, EFI compliant systems
> > that implement get/set_time but not get/set_wakeup_time have no RTC at
> > all on any LTS kernel until a year from now, and this was never the
> > intent when we introduced the EFI_RT_PROPERTIES_TABLE.
>
> Thanks for considering the fix for stable releases, I'll post v3 patch
> with tag 'CC: <stable@vger.kernel.org> # v6.0+'

No please don't resend the patch