Hi Ankitprasad, just a quick heads-up, Rafael asked that the function name acpi_dev_present() be changed, so there's now a commit queued for Linux 4.7 to rename it to acpi_dev_found(): https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=c68ae33e7fb4 It will therefore unfortunately be necessary that you respin this patch with the new function name once the above-linked commit has landed in Linus' tree (which I expect will happen early in the merge window, sometime in mid-May). My apologies for the inconvenience! Lukas On Wed, Apr 20, 2016 at 04:47:37PM +0530, ankitprasad.r.sharma@xxxxxxxxx wrote: > From: Ankitprasad Sharma <ankitprasad.r.sharma@xxxxxxxxx> > > The BIOS RapidStartTechnology may corrupt the stolen memory across S3 > suspend due to unalarmed hibernation, in which case we will not be able > to preserve the User data stored in the stolen region. Hence this patch > tries to identify presence of the RST device on the ACPI bus, and > disables use of stolen memory (for persistent data) if found. > > v2: Updated comment, updated/corrected new functions private to driver > (Chris/Tvrtko) > > v3: Disabling stolen by default, wait till required acpi changes to > detect device presence are pulled in (Ankit) > > v4: Enabled stolen by default as required acpi changes are merged > (Ankit) > > v5: renamed variable, is IS_ENABLED() in place of #ifdef, use char* > instead of structures (Lukas) > > Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sharma@xxxxxxxxx> > Cc: Lukas Wunner <lukas@xxxxxxxxx> > Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_drv.h | 11 +++++++++++ > drivers/gpu/drm/i915/i915_gem.c | 8 ++++++++ > drivers/gpu/drm/i915/i915_gem_stolen.c | 12 ++++++++++++ > drivers/gpu/drm/i915/intel_acpi.c | 7 +++++++ > 4 files changed, 38 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index c7fe863..37f9de8 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -1326,6 +1326,16 @@ struct i915_gem_mm { > */ > bool busy; > > + /** > + * Stolen will be lost upon hibernate (as the memory is unpowered). > + * Across resume, we expect stolen to be intact - however, it may > + * also be utililised by third parties (e.g. Intel RapidStart > + * Technology) and if so we have to assume that any data stored in > + * stolen across resume is lost and we set this flag to indicate that > + * the stolen memory is volatile. > + */ > + bool volatile_stolen; > + > /* the indicator for dispatch video commands on two BSD rings */ > unsigned int bsd_ring_dispatch_index; > > @@ -3559,6 +3569,7 @@ static inline int intel_opregion_get_panel_type(struct drm_device *dev) > #endif > > /* intel_acpi.c */ > +bool intel_detect_acpi_rst(void); > #ifdef CONFIG_ACPI > extern void intel_register_dsm_handler(void); > extern void intel_unregister_dsm_handler(void); > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index 48959cf..45fd049 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -391,8 +391,16 @@ static struct drm_i915_gem_object * > i915_gem_alloc_object_stolen(struct drm_device *dev, size_t size) > { > struct drm_i915_gem_object *obj; > + struct drm_i915_private *dev_priv = dev->dev_private; > int ret; > > + if (dev_priv->mm.volatile_stolen) { > + /* Stolen may be overwritten by external parties > + * so unsuitable for persistent user data. > + */ > + return ERR_PTR(-ENODEV); > + } > + > mutex_lock(&dev->struct_mutex); > obj = i915_gem_object_create_stolen(dev, size); > if (IS_ERR(obj)) > diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c > index d9756ee..ef28af6 100644 > --- a/drivers/gpu/drm/i915/i915_gem_stolen.c > +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c > @@ -490,6 +490,18 @@ int i915_gem_init_stolen(struct drm_device *dev) > */ > drm_mm_init(&dev_priv->mm.stolen, 0, ggtt->stolen_usable_size); > > + /* If the stolen region can be modified behind our backs upon suspend, > + * then we cannot use it to store nonvolatile contents (i.e user data) > + * as it will be corrupted upon resume. > + */ > + dev_priv->mm.volatile_stolen = false; > + if (IS_ENABLED(CONFIG_SUSPEND)) { > + /* BIOSes using RapidStart Technology have been reported > + * to overwrite stolen across S3, not just S4. > + */ > + dev_priv->mm.volatile_stolen = intel_detect_acpi_rst(); > + } > + > return 0; > } > > diff --git a/drivers/gpu/drm/i915/intel_acpi.c b/drivers/gpu/drm/i915/intel_acpi.c > index eb638a1..05fd67f 100644 > --- a/drivers/gpu/drm/i915/intel_acpi.c > +++ b/drivers/gpu/drm/i915/intel_acpi.c > @@ -23,6 +23,8 @@ static const u8 intel_dsm_guid[] = { > 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c > }; > > +static const char *irst_id = "INT3392"; > + > static char *intel_dsm_port_name(u8 id) > { > switch (id) { > @@ -162,3 +164,8 @@ void intel_register_dsm_handler(void) > void intel_unregister_dsm_handler(void) > { > } > + > +bool intel_detect_acpi_rst(void) > +{ > + return acpi_dev_present(irst_id); > +} > -- > 1.9.1 > _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
