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* [PATCH v2 4/9] PM / Domains: Drop unused parameter in genpd_allocate_dev_data()
From: Ulf Hansson @ 2018-05-29 10:04 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529100421.31022-1-ulf.hansson@linaro.org>

The in-parameter struct generic_pm_domain *genpd to
genpd_allocate_dev_data() is unused, so let's drop it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/base/power/domain.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index c89b0ad068b7..7ebf7993273a 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1316,7 +1316,6 @@ EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron);
 #endif /* CONFIG_PM_SLEEP */
 
 static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
-					struct generic_pm_domain *genpd,
 					struct gpd_timing_data *td)
 {
 	struct generic_pm_domain_data *gpd_data;
@@ -1385,7 +1384,7 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
 		return -EINVAL;
 
-	gpd_data = genpd_alloc_dev_data(dev, genpd, td);
+	gpd_data = genpd_alloc_dev_data(dev, td);
 	if (IS_ERR(gpd_data))
 		return PTR_ERR(gpd_data);
 
-- 
2.17.0

^ permalink raw reply related

* [PATCH v2 3/9] PM / Domains: Drop genpd as in-param for pm_genpd_remove_device()
From: Ulf Hansson @ 2018-05-29 10:04 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529100421.31022-1-ulf.hansson@linaro.org>

There is no need to pass a genpd struct to pm_genpd_remove_device(), as we
already have the information about the PM domain (genpd) through the device
structure.

Additionally, we don't allow to remove a PM domain from a device, other
than the one it may have assigned to it, so really it does not make sense
to have a separate in-param for it.

For these reason, drop it and update the current only call to
pm_genpd_remove_device() from amdgpu_acp.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian K?nig <christian.koenig@amd.com>
Cc: David (ChunMing) Zhou <David1.Zhou@amd.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/base/power/domain.c             | 8 ++++----
 drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c | 2 +-
 include/linux/pm_domain.h               | 5 ++---
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 469edb401811..c89b0ad068b7 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1475,13 +1475,13 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
 
 /**
  * pm_genpd_remove_device - Remove a device from an I/O PM domain.
- * @genpd: PM domain to remove the device from.
  * @dev: Device to be removed.
  */
-int pm_genpd_remove_device(struct generic_pm_domain *genpd,
-			   struct device *dev)
+int pm_genpd_remove_device(struct device *dev)
 {
-	if (!genpd || genpd != genpd_lookup_dev(dev))
+	struct generic_pm_domain *genpd = genpd_lookup_dev(dev);
+
+	if (!genpd)
 		return -EINVAL;
 
 	return genpd_remove_device(genpd, dev);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
index a29362f9ef41..12558044acd4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
@@ -513,7 +513,7 @@ static int acp_hw_fini(void *handle)
 	if (adev->acp.acp_genpd) {
 		for (i = 0; i < ACP_DEVS ; i++) {
 			dev = get_mfd_cell_dev(adev->acp.acp_cell[i].name, i);
-			ret = pm_genpd_remove_device(&adev->acp.acp_genpd->gpd, dev);
+			ret = pm_genpd_remove_device(dev);
 			/* If removal fails, dont giveup and try rest */
 			if (ret)
 				dev_err(dev, "remove dev from genpd failed\n");
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 79888fb4a81f..42e0d649e653 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -144,7 +144,7 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
 }
 
 int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev);
-int pm_genpd_remove_device(struct generic_pm_domain *genpd, struct device *dev);
+int pm_genpd_remove_device(struct device *dev);
 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 			   struct generic_pm_domain *new_subdomain);
 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
@@ -167,8 +167,7 @@ static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
 {
 	return -ENOSYS;
 }
-static inline int pm_genpd_remove_device(struct generic_pm_domain *genpd,
-					 struct device *dev)
+static inline int pm_genpd_remove_device(struct device *dev)
 {
 	return -ENOSYS;
 }
-- 
2.17.0

^ permalink raw reply related

* [PATCH v2 2/9] PM / Domains: Drop __pm_genpd_add_device()
From: Ulf Hansson @ 2018-05-29 10:04 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529100421.31022-1-ulf.hansson@linaro.org>

There are still a few non-DT existing users of genpd, however neither of
them uses __pm_genpd_add_device(), hence let's drop it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/base/power/domain.c | 10 ++++------
 include/linux/pm_domain.h   | 14 +++-----------
 2 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 71a1cc79fbaa..469edb401811 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1414,23 +1414,21 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 }
 
 /**
- * __pm_genpd_add_device - Add a device to an I/O PM domain.
+ * pm_genpd_add_device - Add a device to an I/O PM domain.
  * @genpd: PM domain to add the device to.
  * @dev: Device to be added.
- * @td: Set of PM QoS timing parameters to attach to the device.
  */
-int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
-			  struct gpd_timing_data *td)
+int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
 {
 	int ret;
 
 	mutex_lock(&gpd_list_lock);
-	ret = genpd_add_device(genpd, dev, td);
+	ret = genpd_add_device(genpd, dev, NULL);
 	mutex_unlock(&gpd_list_lock);
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(__pm_genpd_add_device);
+EXPORT_SYMBOL_GPL(pm_genpd_add_device);
 
 static int genpd_remove_device(struct generic_pm_domain *genpd,
 			       struct device *dev)
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index c847e9a3033d..79888fb4a81f 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -143,8 +143,7 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
 	return to_gpd_data(dev->power.subsys_data->domain_data);
 }
 
-int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
-			  struct gpd_timing_data *td);
+int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev);
 int pm_genpd_remove_device(struct generic_pm_domain *genpd, struct device *dev);
 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 			   struct generic_pm_domain *new_subdomain);
@@ -163,9 +162,8 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
 {
 	return ERR_PTR(-ENOSYS);
 }
-static inline int __pm_genpd_add_device(struct generic_pm_domain *genpd,
-					struct device *dev,
-					struct gpd_timing_data *td)
+static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
+				      struct device *dev)
 {
 	return -ENOSYS;
 }
@@ -204,12 +202,6 @@ static inline int dev_pm_genpd_set_performance_state(struct device *dev,
 #define pm_domain_always_on_gov		(*(struct dev_power_governor *)(NULL))
 #endif
 
-static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
-				      struct device *dev)
-{
-	return __pm_genpd_add_device(genpd, dev, NULL);
-}
-
 #ifdef CONFIG_PM_GENERIC_DOMAINS_SLEEP
 void pm_genpd_syscore_poweroff(struct device *dev);
 void pm_genpd_syscore_poweron(struct device *dev);
-- 
2.17.0

^ permalink raw reply related

* [PATCH v2 1/9] PM / Domains: Drop extern declarations of functions in pm_domain.h
From: Ulf Hansson @ 2018-05-29 10:04 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529100421.31022-1-ulf.hansson@linaro.org>

Using "extern" to declare a function in a public header file is somewhat
pointless, but also doesn't hurt. However, to make all the function
declarations in pm_domain.h to be consistent, let's drop the use of
"extern".

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 include/linux/pm_domain.h | 51 ++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 28 deletions(-)

diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 4e5764083fd8..c847e9a3033d 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -143,21 +143,17 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
 	return to_gpd_data(dev->power.subsys_data->domain_data);
 }
 
-extern int __pm_genpd_add_device(struct generic_pm_domain *genpd,
-				 struct device *dev,
-				 struct gpd_timing_data *td);
-
-extern int pm_genpd_remove_device(struct generic_pm_domain *genpd,
-				  struct device *dev);
-extern int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
-				  struct generic_pm_domain *new_subdomain);
-extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
-				     struct generic_pm_domain *target);
-extern int pm_genpd_init(struct generic_pm_domain *genpd,
-			 struct dev_power_governor *gov, bool is_off);
-extern int pm_genpd_remove(struct generic_pm_domain *genpd);
-extern int dev_pm_genpd_set_performance_state(struct device *dev,
-					      unsigned int state);
+int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
+			  struct gpd_timing_data *td);
+int pm_genpd_remove_device(struct generic_pm_domain *genpd, struct device *dev);
+int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
+			   struct generic_pm_domain *new_subdomain);
+int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
+			      struct generic_pm_domain *target);
+int pm_genpd_init(struct generic_pm_domain *genpd,
+		  struct dev_power_governor *gov, bool is_off);
+int pm_genpd_remove(struct generic_pm_domain *genpd);
+int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state);
 
 extern struct dev_power_governor simple_qos_governor;
 extern struct dev_power_governor pm_domain_always_on_gov;
@@ -215,8 +211,8 @@ static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
 }
 
 #ifdef CONFIG_PM_GENERIC_DOMAINS_SLEEP
-extern void pm_genpd_syscore_poweroff(struct device *dev);
-extern void pm_genpd_syscore_poweron(struct device *dev);
+void pm_genpd_syscore_poweroff(struct device *dev);
+void pm_genpd_syscore_poweron(struct device *dev);
 #else
 static inline void pm_genpd_syscore_poweroff(struct device *dev) {}
 static inline void pm_genpd_syscore_poweron(struct device *dev) {}
@@ -240,14 +236,13 @@ int of_genpd_add_provider_simple(struct device_node *np,
 int of_genpd_add_provider_onecell(struct device_node *np,
 				  struct genpd_onecell_data *data);
 void of_genpd_del_provider(struct device_node *np);
-extern int of_genpd_add_device(struct of_phandle_args *args,
-			       struct device *dev);
-extern int of_genpd_add_subdomain(struct of_phandle_args *parent,
-				  struct of_phandle_args *new_subdomain);
-extern struct generic_pm_domain *of_genpd_remove_last(struct device_node *np);
-extern int of_genpd_parse_idle_states(struct device_node *dn,
-			struct genpd_power_state **states, int *n);
-extern unsigned int of_genpd_opp_to_performance_state(struct device *dev,
+int of_genpd_add_device(struct of_phandle_args *args, struct device *dev);
+int of_genpd_add_subdomain(struct of_phandle_args *parent,
+			   struct of_phandle_args *new_subdomain);
+struct generic_pm_domain *of_genpd_remove_last(struct device_node *np);
+int of_genpd_parse_idle_states(struct device_node *dn,
+			       struct genpd_power_state **states, int *n);
+unsigned int of_genpd_opp_to_performance_state(struct device *dev,
 				struct device_node *opp_node);
 
 int genpd_dev_pm_attach(struct device *dev);
@@ -304,9 +299,9 @@ struct generic_pm_domain *of_genpd_remove_last(struct device_node *np)
 #endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
 
 #ifdef CONFIG_PM
-extern int dev_pm_domain_attach(struct device *dev, bool power_on);
-extern void dev_pm_domain_detach(struct device *dev, bool power_off);
-extern void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd);
+int dev_pm_domain_attach(struct device *dev, bool power_on);
+void dev_pm_domain_detach(struct device *dev, bool power_off);
+void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd);
 #else
 static inline int dev_pm_domain_attach(struct device *dev, bool power_on)
 {
-- 
2.17.0

^ permalink raw reply related

* [PATCH v2 0/9] PM / Domains: Add support for multi PM domains per device
From: Ulf Hansson @ 2018-05-29 10:04 UTC (permalink / raw)
  To: linux-arm-kernel

Changes in v2:
	- Addressed comments from Geert around DT doc.
	- Addressed comments from Jon around clarification of how to use this
	and changes to returned error codes.
	- Fixed build error in case CONFIG_PM was unset.

There are devices that are partitioned across multiple PM domains. Currently
these can't be supported well by the available PM infrastructures we have in
the kernel. This series is an attempt to address this.

The interesting parts happens from patch 5 an onwards, including a minor DT
update to the existing power-domain bindings, the 4 earlier are just trivial
clean-ups of some related code in genpd, which I happened to stumble over.

Some additional background:

One existing case where devices are partitioned across multiple PM domains, is
the Nvida Tegra 124/210 X-USB subsystem. A while ago Jon Hunter (Nvidia) sent a
series, trying to address these issues, however this is a new approach, while
it re-uses the same concepts from DT point of view.

The Tegra 124/210 X-USB subsystem contains of a host controller and a device
controller. Each controller have its own independent PM domain, but are being
partitioned across another shared PM domain for the USB super-speed logic.

Currently to make the drivers work, either the related PM domains needs to stay
powered on always or the PM domain topology needs to be in-correctly modelled
through sub-domains. In both cases PM domains may be powered on while they
don't need to be, so in the end this means - wasting power -.

As stated above, this series intends to address these problem from a PM
infrastructure point of view. More details are available in each changelog.

It should be noted that this series has been tested on HW, however only by using
a home-cooked test PM domain driver for genpd and together with a test driver.
This allowed me to play with PM domain (genpd), runtime PM and device links.

Any further deployment for real use cases are greatly appreciated. I am happy to
to help, if needed!

Kind regards
Ulf Hansson


Ulf Hansson (9):
  PM / Domains: Drop extern declarations of functions in pm_domain.h
  PM / Domains: Drop __pm_genpd_add_device()
  PM / Domains: Drop genpd as in-param for pm_genpd_remove_device()
  PM / Domains: Drop unused parameter in genpd_allocate_dev_data()
  PM / Domains: dt: Allow power-domain property to be a list of
    specifiers
  PM / Domains: Don't attach devices in genpd with multi PM domains
  PM / Domains: Split genpd_dev_pm_attach()
  PM / Domains: Add support for multi PM domains per device to genpd
  PM / Domains: Add dev_pm_domain_attach_by_id() to manage multi PM
    domains

 .../bindings/power/power_domain.txt           |  19 ++-
 drivers/base/power/common.c                   |  39 ++++-
 drivers/base/power/domain.c                   | 155 ++++++++++++++----
 drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c       |   2 +-
 include/linux/pm_domain.h                     |  79 ++++-----
 5 files changed, 216 insertions(+), 78 deletions(-)

-- 
2.17.0

^ permalink raw reply

* [PATCH v2 07/40] iommu: Add a page fault handler
From: Jean-Philippe Brucker @ 2018-05-29 10:00 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180525173544.05638510@jacob-builder>

On 26/05/18 01:35, Jacob Pan wrote:
>>>> Not exactly, it's the IOMMU driver that makes sure all LPIG in its
>>>> queues are submitted by the above flush call. In more details the
>>>> flow is:
>>>>
>>>> * Either device driver calls unbind()/sva_device_shutdown(), or the
>>>> process exits.
>>>> * If the device driver called, then it already told the device to
>>>> stop using the PASID. Otherwise we use the mm_exit() callback to
>>>> tell the device driver to stop using the PASID.
> Sorry I still need more clarification. For the PASID termination
> initiated by vfio unbind, I don't see device driver given a chance to
> stop PASID. Seems just call __iommu_sva_unbind_device() which already
> assume device stopped issuing DMA with the PASID.
> So it is the vfio unbind caller responsible for doing driver callback
> to stop DMA on a given PASID?

Yes, but I don't know how to implement this. Since PCI doesn't formalize
the PASID stop mechanism and the device doesn't have a kernel driver,
VFIO would need help from the userspace driver for stopping PASID
(notify the userspace driver when an other process exits).


>>>> * In either case, when receiving a stop request from the driver,
>>>> the device sends the LPIGs to the IOMMU queue.
>>>> * Then, the flush call above ensures that the IOMMU reports the
>>>> LPIG with iommu_report_device_fault.
>>>> * While submitting all LPIGs for this PASID to the work queue,
>>>> ipof_queue_fault also picked up all partial faults, so the partial
>>>> list is clean.
>>>>
>>>> Maybe I should improve this comment?
>>>>  
>>> thanks for explaining. LPIG submission is done by device
>>> asynchronously w.r.t. driver stopping/decommission PASID.  
>>
>> Hmm, it should really be synchronous, otherwise there is no way to
>> know when the PASID can be decommissioned. We need a guarantee such
>> as the one in 6.20.1 of the PCIe spec, "Managing PASID TLP Prefix
>> Usage":
>>
>> "When the stop request mechanism indicates completion, the Function
>> has:
>> * Completed all Non-Posted Requests associated with this PASID.
>> * Flushed to the host all Posted Requests addressing host memory in
>> all TCs that were used by the PASID."
>>
>> That's in combination with "The function shall [...] finish
>> transmitting any multi-page Page Request Messages for this PASID
>> (i.e. send the Page Request Message with the L bit Set)." from the
>> ATS spec.
>>
> I am not contesting on the device side, what I meant was from the
> host IOMMU driver perspective, LPIG is received via IOMMU host queue,
> therefore asynchronous. Not sure about ARM, but on VT-d LPIG submission
> could meet queue full condition. So per VT-d spec, iommu will generate a
> successful auto response to the device. At this point, assume we
> already stopped the given PASID on the device, there might not be
> another LPIG sent for the device. Therefore, you could have a partial
> list. I think we can just drop the requests in the partial list for
> that PASID until the PASID gets re-allocated.

Indeed, I'll add this in next version. For a complete solution to the
queue-full condition (which seems to behave the same way on ARM) I was
thinking the IOMMU driver should also have a method for removing all
partial faults when detecting a queue overflow. Since it doesn't know
which PRGs did receive an auto-response, all it can do is remove all
partial faults, for all devices using this queue. But freeing the stuck
partial faults in flush() and remove_device() should be good enough

Thanks,
Jean

^ permalink raw reply

* [PATCH v10 0/2] Initial Allwinner V3s CSI Support
From: Maxime Ripard @ 2018-05-29  9:57 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180517090224.u3ygdzjr77im2mmp@flea>

On Thu, May 17, 2018 at 11:02:24AM +0200, Maxime Ripard wrote:
> On Fri, May 04, 2018 at 02:44:08PM +0800, Yong Deng wrote:
> > This patchset add initial support for Allwinner V3s CSI.
> > 
> > Allwinner V3s SoC features two CSI module. CSI0 is used for MIPI CSI-2
> > interface and CSI1 is used for parallel interface. This is not
> > documented in datasheet but by test and guess.
> > 
> > This patchset implement a v4l2 framework driver and add a binding 
> > documentation for it. 
> > 
> > Currently, the driver only support the parallel interface. And has been
> > tested with a BT1120 signal which generating from FPGA. The following
> > fetures are not support with this patchset:
> >   - ISP 
> >   - MIPI-CSI2
> >   - Master clock for camera sensor
> >   - Power regulator for the front end IC
> 
> I tested it on my H3 with a parallel camera, and it still works. Thanks!
> 
> Hans, Sakari, any chance this might land in 4.18?

Ping?

Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

^ permalink raw reply

* [PATCH v4 3/6] mfd: at91-usart: added mfd driver for usart
From: Alexandre Belloni @ 2018-05-29  9:32 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <CAHp75VeeiFhShuMOVzuy2FjxrkfsxxzhyfAnwQNOoeaRwZ103Q@mail.gmail.com>

On 28/05/2018 11:00:49+0300, Andy Shevchenko wrote:
> On Fri, May 25, 2018 at 8:19 PM, Radu Pirea <radu.pirea@microchip.com> wrote:
> > This mfd driver is just a wrapper over atmel_serial driver and
> > spi-at91-usart driver. Selection of one of the drivers is based on a
> > property from device tree. If the property is not specified, the default
> > driver is atmel_serial.
> 
> > +       depends on OF
> 
> What makes this driver OF specific?
> 
> > +       err = of_property_read_u32(np, "atmel,usart-mode", &opmode);
> 
> Check unified device property API.
> 

We don't care, this makes the driver OF specific and this is the correct
thing to do.


-- 
Alexandre Belloni, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

^ permalink raw reply

* [PATCH 1/4] ARM: dts: Restructure Vexpress motherboard includes
From: Sudeep Holla @ 2018-05-29  9:25 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180528122658.3241-2-linus.walleij@linaro.org>

Hi Linus,

On 28/05/18 13:26, Linus Walleij wrote:
> It is a bit unorthodox to just include a file in the middle
> of a another DTS file, it breaks the pattern from other device
> trees and also makes it really hard to reference things
> across the files with phandles.
> 
> Restructure the include for the Versatile Express motherboards
> to happen at the top of the file, reference the target nodes
> directly, and indent the motherboard .dtsi files to reflect
> their actual depth in the hiearchy.
> 
> This is a purely syntactic change that result in the same
> DTB files from the DTS/DTSI files.
Is it different from v1/earlier version you had posted ?
I have already sent this to ARM SoC and it should be in -next by now.
I will add the remaining 3 patches for v4.19 once you confirm
that I can drop this patch as it's already queued.

-- 
Regards,
Sudeep

^ permalink raw reply

* [PATCH 1/3] arm64:add missing CONFIG_STRICT_KERNEL_RWX for mark_rodata_ro
From: Will Deacon @ 2018-05-29  9:21 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180528033353.54725-1-nixiaoming@huawei.com>


On Mon, May 28, 2018 at 11:33:53AM +0800, nixiaoming wrote:
> Signed-off-by: nixiaoming <nixiaoming@huawei.com>

Please can you write a commit message explaining what this fixes and also
give me a pointer to patches 2 and 3 from this series?

Will

> ---
>  arch/arm64/mm/mmu.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index 2dbb2c9..849f326 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -491,6 +491,7 @@ static void __init map_mem(pgd_t *pgdp)
>  #endif
>  }
>  
> +#ifdef CONFIG_STRICT_KERNEL_RWX
>  void mark_rodata_ro(void)
>  {
>  	unsigned long section_size;
> @@ -505,6 +506,7 @@ void mark_rodata_ro(void)
>  
>  	debug_checkwx();
>  }
> +#endif
>  
>  static void __init map_kernel_segment(pgd_t *pgdp, void *va_start, void *va_end,
>  				      pgprot_t prot, struct vm_struct *vma,
> -- 
> 2.10.1
> 

^ permalink raw reply

* [PATCH v4 6/6] tty/serial: atmel: changed the driver to work under at91-usart mfd
From: Radu Pirea @ 2018-05-29  9:15 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <e1445467-2df0-4593-852d-939e6795f318@sorico.fr>



On 05/28/2018 01:08 PM, Richard Genoud wrote:
> On 25/05/2018 19:19, Radu Pirea wrote:
>> This patch modifies the place where resources and device tree properties
>> are searched.
>>
>> Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
>> ---
>>   drivers/tty/serial/Kconfig        |  1 +
>>   drivers/tty/serial/atmel_serial.c | 40 +++++++++++++++++--------------
>>   2 files changed, 23 insertions(+), 18 deletions(-)
> the stdout-path property of the chosen node is still broken in this verion.
> if :
> stdout-path = "serial0:115200n8";
> is set in the DTS, the console output should go on serial0 (aka dbgu)
> cf Documentation/devicetree/bindings/chosen.txt
> 
> With this patch applied, this is not the case anymore.
> Adding console=ttyS0,115200 in the chosen node is not the solution here.
> 

I fixed the issue few minutes ago :)

I hope DMA setup is ok now.

> 
> regards,
> Richard.
> 

^ permalink raw reply

* [PATCH v2 10/11] arm64: dts: r8a77965-salvator-x: Enable DU external clocks and HDMI
From: Geert Uytterhoeven @ 2018-05-29  9:12 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <3a36b5e7-56ab-c680-e575-7a8394e5799a@ideasonboard.com>

Hi Kieran,

On Tue, May 29, 2018 at 11:08 AM, Kieran Bingham
<kieran.bingham+renesas@ideasonboard.com> wrote:
> On 28/05/18 10:06, Geert Uytterhoeven wrote:
>> On Fri, Apr 27, 2018 at 6:57 PM, Kieran Bingham
>> <kieran.bingham+renesas@ideasonboard.com> wrote:
>>> The DU1 external dot clock is provided by the fixed frequency clock
>>> generator X21, while the DU0 and DU3 clocks are provided by the
>>> programmable Versaclock5 clock generator.
>>>
>>> Enable the clocks, and the HDMI encoder for the M3-N Salvator-X board
>>> and hook it up to the HDMI connector.
>>>
>>> Based on patches from Takeshi Kihara <takeshi.kihara.df@renesas.com>
>>>
>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>>>
>>> ---
>>> v2:
>>>  - Remove LVDS clocks from DU node
>>>  - Merge DU Clocks and HDMI enablement
>>> ---
>>>  .../boot/dts/renesas/r8a77965-salvator-x.dts  | 28 +++++++++++++++++++
>>>  1 file changed, 28 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/renesas/r8a77965-salvator-x.dts b/arch/arm64/boot/dts/renesas/r8a77965-salvator-x.dts
>>> index 75d890d91df9..340a3c72b65a 100644
>>> --- a/arch/arm64/boot/dts/renesas/r8a77965-salvator-x.dts
>>> +++ b/arch/arm64/boot/dts/renesas/r8a77965-salvator-x.dts
>>> @@ -19,3 +19,31 @@
>>>                 reg = <0x0 0x48000000 0x0 0x78000000>;
>>>         };
>>>  };
>>> +
>>> +&du {
>>> +       clocks = <&cpg CPG_MOD 724>,
>>> +                <&cpg CPG_MOD 723>,
>>> +                <&cpg CPG_MOD 721>,
>>> +                <&versaclock5 1>,
>>> +                <&x21_clk>,
>>> +                <&versaclock5 2>;
>>> +       clock-names = "du.0", "du.1", "du.3",
>>> +                     "dclkin.0", "dclkin.1", "dclkin.3";
>>> +};
>>> +
>>> +&hdmi0 {
>>> +       status = "okay";
>>> +
>>> +       ports {
>>> +               port at 1 {
>>> +                       reg = <1>;
>>> +                       rcar_dw_hdmi0_out: endpoint {
>>> +                               remote-endpoint = <&hdmi0_con>;
>>> +                       };
>>> +               };
>>> +       };
>>> +};
>>> +
>>> +&hdmi0_con {
>>> +       remote-endpoint = <&rcar_dw_hdmi0_out>;
>>> +};
>>
>> I think the hdmi0 and hdmi0_con parts can be moved to salvator-common.dtsi.
>> Can we do that now (with stubs?), or does this have to wait until r8a77965 has
>> received HDMI sound support?
>
> I don't know about the sound integration I'm afraid, but common HDMI connections
> would certainly be a benefit I believe.
>
> Is this something you're looking to tackle? Or would you like
> me/Morimoto-san/media team to look at it?

Feel free to give it a try.

Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply

* [PATCH v4 15/15] ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1
From: Russell King @ 2018-05-29  9:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

Report support for SMCCC_ARCH_WORKAROUND_1 to KVM guests for affected
CPUs.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/include/asm/kvm_host.h | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 248b930563e5..11f91744ffb0 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -21,6 +21,7 @@
 
 #include <linux/types.h>
 #include <linux/kvm_types.h>
+#include <asm/cputype.h>
 #include <asm/kvm.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmio.h>
@@ -311,8 +312,17 @@ static inline void kvm_arm_vhe_guest_exit(void) {}
 
 static inline bool kvm_arm_harden_branch_predictor(void)
 {
-	/* No way to detect it yet, pretend it is not there. */
-	return false;
+	switch(read_cpuid_part()) {
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+	case ARM_CPU_PART_BRAHMA_B15:
+	case ARM_CPU_PART_CORTEX_A12:
+	case ARM_CPU_PART_CORTEX_A15:
+	case ARM_CPU_PART_CORTEX_A17:
+		return true;
+#endif
+	default:
+		return false;
+	}
 }
 
 #endif /* __ARM_KVM_HOST_H__ */
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 14/15] ARM: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
From: Russell King @ 2018-05-29  9:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible.
So let's intercept it as early as we can by testing for the
function call number as soon as we've identified a HVC call
coming from the guest.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/kvm/hyp/hyp-entry.S | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index 918a05dd2d63..aa3f9a9837ac 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -16,6 +16,7 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
+#include <linux/arm-smccc.h>
 #include <linux/linkage.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
@@ -202,7 +203,7 @@ ENDPROC(__hyp_do_panic)
 	lsr     r2, r2, #16
 	and     r2, r2, #0xff
 	cmp     r2, #0
-	bne	guest_trap		@ Guest called HVC
+	bne	guest_hvc_trap		@ Guest called HVC
 
 	/*
 	 * Getting here means host called HVC, we shift parameters and branch
@@ -253,6 +254,20 @@ THUMB(	orr	lr, #1)
 	pop	{r2, lr}
 	eret
 
+guest_hvc_trap:
+	movw	r2, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+	movt	r2, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+	ldr	r0, [sp]		@ Guest's r0
+	teq	r0, r2
+	bne	guest_trap
+	add	sp, sp, #12
+	@ Returns:
+	@ r0 = 0
+	@ r1 = HSR value (perfectly predictable)
+	@ r2 = ARM_SMCCC_ARCH_WORKAROUND_1
+	mov	r0, #0
+	eret
+
 guest_trap:
 	load_vcpu r0			@ Load VCPU pointer to r0
 
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 13/15] ARM: spectre-v2: KVM: invalidate icache on guest exit for Brahma B15
From: Russell King @ 2018-05-29  9:10 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

Include Brahma B15 in the Spectre v2 KVM workarounds.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/include/asm/kvm_mmu.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 48edb1f4ced4..fea770f78144 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -306,6 +306,7 @@ static inline void *kvm_get_hyp_vector(void)
 		return kvm_ksym_ref(__kvm_hyp_vector_bp_inv);
 	}
 
+	case ARM_CPU_PART_BRAHMA_B15:
 	case ARM_CPU_PART_CORTEX_A15:
 	{
 		extern char __kvm_hyp_vector_ic_inv[];
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 12/15] ARM: KVM: invalidate icache on guest exit for Cortex-A15
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

From: Marc Zyngier <marc.zyngier@arm.com>

In order to avoid aliasing attacks against the branch predictor
on Cortex-A15, let's invalidate the BTB on guest exit, which can
only be done by invalidating the icache (with ACTLR[0] being set).

We use the same hack as for A12/A17 to perform the vector decoding.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/include/asm/kvm_mmu.h |  5 +++++
 arch/arm/kvm/hyp/hyp-entry.S   | 24 ++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index d08ce9c41df4..48edb1f4ced4 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -306,6 +306,11 @@ static inline void *kvm_get_hyp_vector(void)
 		return kvm_ksym_ref(__kvm_hyp_vector_bp_inv);
 	}
 
+	case ARM_CPU_PART_CORTEX_A15:
+	{
+		extern char __kvm_hyp_vector_ic_inv[];
+		return kvm_ksym_ref(__kvm_hyp_vector_ic_inv);
+	}
 #endif
 	default:
 	{
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index e789f52a5129..918a05dd2d63 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -73,6 +73,28 @@
 
 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
 	.align 5
+__kvm_hyp_vector_ic_inv:
+	.global __kvm_hyp_vector_ic_inv
+
+	/*
+	 * We encode the exception entry in the bottom 3 bits of
+	 * SP, and we have to guarantee to be 8 bytes aligned.
+	 */
+	W(add)	sp, sp, #1	/* Reset 	  7 */
+	W(add)	sp, sp, #1	/* Undef	  6 */
+	W(add)	sp, sp, #1	/* Syscall	  5 */
+	W(add)	sp, sp, #1	/* Prefetch abort 4 */
+	W(add)	sp, sp, #1	/* Data abort	  3 */
+	W(add)	sp, sp, #1	/* HVC		  2 */
+	W(add)	sp, sp, #1	/* IRQ		  1 */
+	W(nop)			/* FIQ		  0 */
+
+	mcr	p15, 0, r0, c7, c5, 0	/* ICIALLU */
+	isb
+
+	b	decode_vectors
+
+	.align 5
 __kvm_hyp_vector_bp_inv:
 	.global __kvm_hyp_vector_bp_inv
 
@@ -92,6 +114,8 @@
 	mcr	p15, 0, r0, c7, c5, 6	/* BPIALL */
 	isb
 
+decode_vectors:
+
 #ifdef CONFIG_THUMB2_KERNEL
 	/*
 	 * Yet another silly hack: Use VPIDR as a temp register.
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 11/15] ARM: KVM: invalidate BTB on guest exit for Cortex-A12/A17
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

From: Marc Zyngier <marc.zyngier@arm.com>

In order to avoid aliasing attacks against the branch predictor,
let's invalidate the BTB on guest exit. This is made complicated
by the fact that we cannot take a branch before invalidating the
BTB.

We only apply this to A12 and A17, which are the only two ARM
cores on which this useful.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/include/asm/kvm_asm.h |  2 --
 arch/arm/include/asm/kvm_mmu.h | 17 +++++++++-
 arch/arm/kvm/hyp/hyp-entry.S   | 71 ++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 85 insertions(+), 5 deletions(-)

diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 36dd2962a42d..df24ed48977d 100644
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -61,8 +61,6 @@ struct kvm_vcpu;
 extern char __kvm_hyp_init[];
 extern char __kvm_hyp_init_end[];
 
-extern char __kvm_hyp_vector[];
-
 extern void __kvm_flush_vm_context(void);
 extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
 extern void __kvm_tlb_flush_vmid(struct kvm *kvm);
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index de1b919404e4..d08ce9c41df4 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -297,7 +297,22 @@ static inline unsigned int kvm_get_vmid_bits(void)
 
 static inline void *kvm_get_hyp_vector(void)
 {
-	return kvm_ksym_ref(__kvm_hyp_vector);
+	switch(read_cpuid_part()) {
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+	case ARM_CPU_PART_CORTEX_A12:
+	case ARM_CPU_PART_CORTEX_A17:
+	{
+		extern char __kvm_hyp_vector_bp_inv[];
+		return kvm_ksym_ref(__kvm_hyp_vector_bp_inv);
+	}
+
+#endif
+	default:
+	{
+		extern char __kvm_hyp_vector[];
+		return kvm_ksym_ref(__kvm_hyp_vector);
+	}
+	}
 }
 
 static inline int kvm_map_vectors(void)
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index 95a2faefc070..e789f52a5129 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -71,6 +71,66 @@
 	W(b)	hyp_irq
 	W(b)	hyp_fiq
 
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+	.align 5
+__kvm_hyp_vector_bp_inv:
+	.global __kvm_hyp_vector_bp_inv
+
+	/*
+	 * We encode the exception entry in the bottom 3 bits of
+	 * SP, and we have to guarantee to be 8 bytes aligned.
+	 */
+	W(add)	sp, sp, #1	/* Reset 	  7 */
+	W(add)	sp, sp, #1	/* Undef	  6 */
+	W(add)	sp, sp, #1	/* Syscall	  5 */
+	W(add)	sp, sp, #1	/* Prefetch abort 4 */
+	W(add)	sp, sp, #1	/* Data abort	  3 */
+	W(add)	sp, sp, #1	/* HVC		  2 */
+	W(add)	sp, sp, #1	/* IRQ		  1 */
+	W(nop)			/* FIQ		  0 */
+
+	mcr	p15, 0, r0, c7, c5, 6	/* BPIALL */
+	isb
+
+#ifdef CONFIG_THUMB2_KERNEL
+	/*
+	 * Yet another silly hack: Use VPIDR as a temp register.
+	 * Thumb2 is really a pain, as SP cannot be used with most
+	 * of the bitwise instructions. The vect_br macro ensures
+	 * things gets cleaned-up.
+	 */
+	mcr	p15, 4, r0, c0, c0, 0	/* VPIDR */
+	mov	r0, sp
+	and	r0, r0, #7
+	sub	sp, sp, r0
+	push	{r1, r2}
+	mov	r1, r0
+	mrc	p15, 4, r0, c0, c0, 0	/* VPIDR */
+	mrc	p15, 0, r2, c0, c0, 0	/* MIDR  */
+	mcr	p15, 4, r2, c0, c0, 0	/* VPIDR */
+#endif
+
+.macro vect_br val, targ
+ARM(	eor	sp, sp, #\val	)
+ARM(	tst	sp, #7		)
+ARM(	eorne	sp, sp, #\val	)
+
+THUMB(	cmp	r1, #\val	)
+THUMB(	popeq	{r1, r2}	)
+
+	beq	\targ
+.endm
+
+	vect_br	0, hyp_fiq
+	vect_br	1, hyp_irq
+	vect_br	2, hyp_hvc
+	vect_br	3, hyp_dabt
+	vect_br	4, hyp_pabt
+	vect_br	5, hyp_svc
+	vect_br	6, hyp_undef
+	vect_br	7, hyp_reset
+#endif
+
 .macro invalid_vector label, cause
 	.align
 \label:	mov	r0, #\cause
@@ -149,7 +209,14 @@ ENDPROC(__hyp_do_panic)
 	bx	ip
 
 1:
-	push	{lr}
+	/*
+	 * Pushing r2 here is just a way of keeping the stack aligned to
+	 * 8 bytes on any path that can trigger a HYP exception. Here,
+	 * we may well be about to jump into the guest, and the guest
+	 * exit would otherwise be badly decoded by our fancy
+	 * "decode-exception-without-a-branch" code...
+	 */
+	push	{r2, lr}
 
 	mov	lr, r0
 	mov	r0, r1
@@ -159,7 +226,7 @@ ENDPROC(__hyp_do_panic)
 THUMB(	orr	lr, #1)
 	blx	lr			@ Call the HYP function
 
-	pop	{lr}
+	pop	{r2, lr}
 	eret
 
 guest_trap:
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 10/15] ARM: spectre-v2: warn about incorrect context switching functions
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

Warn at error level if the context switching function is not what we
are expecting.  This can happen with big.Little systems, which we
currently do not support.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mm/proc-v7-bugs.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index 62fa822abd3d..7370530d4169 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -12,6 +12,8 @@
 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
 DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
 
+extern void cpu_v7_iciallu_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+extern void cpu_v7_bpiall_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
 extern void cpu_v7_smc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
 extern void cpu_v7_hvc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
 
@@ -52,6 +54,8 @@ static void cpu_v7_spectre_init(void)
 	case ARM_CPU_PART_CORTEX_A17:
 	case ARM_CPU_PART_CORTEX_A73:
 	case ARM_CPU_PART_CORTEX_A75:
+		if (processor.switch_mm != cpu_v7_bpiall_switch_mm)
+			goto bl_error;
 		per_cpu(harden_branch_predictor_fn, cpu) =
 			harden_branch_predictor_bpiall;
 		spectre_v2_method = "BPIALL";
@@ -59,6 +63,8 @@ static void cpu_v7_spectre_init(void)
 
 	case ARM_CPU_PART_CORTEX_A15:
 	case ARM_CPU_PART_BRAHMA_B15:
+		if (processor.switch_mm != cpu_v7_iciallu_switch_mm)
+			goto bl_error;
 		per_cpu(harden_branch_predictor_fn, cpu) =
 			harden_branch_predictor_iciallu;
 		spectre_v2_method = "ICIALLU";
@@ -84,6 +90,8 @@ static void cpu_v7_spectre_init(void)
 					  ARM_SMCCC_ARCH_WORKAROUND_1, &res);
 			if ((int)res.a0 != 0)
 				break;
+			if (processor.switch_mm != cpu_v7_hvc_switch_mm && cpu)
+				goto bl_error;
 			per_cpu(harden_branch_predictor_fn, cpu) =
 				call_hvc_arch_workaround_1;
 			processor.switch_mm = cpu_v7_hvc_switch_mm;
@@ -95,6 +103,8 @@ static void cpu_v7_spectre_init(void)
 					  ARM_SMCCC_ARCH_WORKAROUND_1, &res);
 			if ((int)res.a0 != 0)
 				break;
+			if (processor.switch_mm != cpu_v7_smc_switch_mm && cpu)
+				goto bl_error;
 			per_cpu(harden_branch_predictor_fn, cpu) =
 				call_smc_arch_workaround_1;
 			processor.switch_mm = cpu_v7_smc_switch_mm;
@@ -111,6 +121,11 @@ static void cpu_v7_spectre_init(void)
 	if (spectre_v2_method)
 		pr_info("CPU%u: Spectre v2: using %s workaround\n",
 			smp_processor_id(), spectre_v2_method);
+	return;
+
+bl_error:
+	pr_err("CPU%u: Spectre v2: incorrect context switching function, system vulnerable\n",
+		cpu);
 }
 #else
 static void cpu_v7_spectre_init(void)
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 09/15] ARM: spectre-v2: add firmware based hardening
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

Add firmware based hardening for cores that require more complex
handling in firmware.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mm/proc-v7-bugs.c | 64 +++++++++++++++++++++++++++++++++++++++++++++-
 arch/arm/mm/proc-v7.S      | 21 +++++++++++++++
 2 files changed, 84 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index 0b48270b7318..62fa822abd3d 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -1,14 +1,20 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/arm-smccc.h>
 #include <linux/kernel.h>
+#include <linux/psci.h>
 #include <linux/smp.h>
 
 #include <asm/cp15.h>
 #include <asm/cputype.h>
+#include <asm/proc-fns.h>
 #include <asm/system_misc.h>
 
 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
 DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
 
+extern void cpu_v7_smc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+extern void cpu_v7_hvc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+
 static void harden_branch_predictor_bpiall(void)
 {
 	write_sysreg(0, BPIALL);
@@ -19,15 +25,27 @@ static void harden_branch_predictor_iciallu(void)
 	write_sysreg(0, ICIALLU);
 }
 
+static void __maybe_unused call_smc_arch_workaround_1(void)
+{
+	arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
+}
+
+static void __maybe_unused call_hvc_arch_workaround_1(void)
+{
+	arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
+}
+
 static void cpu_v7_spectre_init(void)
 {
 	const char *spectre_v2_method = NULL;
 	int cpu = smp_processor_id();
+	u32 cpuid;
 
 	if (per_cpu(harden_branch_predictor_fn, cpu))
 		return;
 
-	switch (read_cpuid_part()) {
+	cpuid = read_cpuid_part();
+	switch (cpuid) {
 	case ARM_CPU_PART_CORTEX_A8:
 	case ARM_CPU_PART_CORTEX_A9:
 	case ARM_CPU_PART_CORTEX_A12:
@@ -45,7 +63,51 @@ static void cpu_v7_spectre_init(void)
 			harden_branch_predictor_iciallu;
 		spectre_v2_method = "ICIALLU";
 		break;
+
+#ifdef CONFIG_ARM_PSCI
+	default:
+		/* Other ARM CPUs require no workaround */
+		if (cpuid >> 24 == ARM_CPU_IMP_ARM)
+			break;
+		/* fallthrough */
+		/* Cortex A57/A72 require firmware workaround */
+	case ARM_CPU_PART_CORTEX_A57:
+	case ARM_CPU_PART_CORTEX_A72: {
+		struct arm_smccc_res res;
+
+		if (psci_ops.smccc_version == SMCCC_VERSION_1_0)
+			break;
+
+		switch (psci_ops.conduit) {
+		case PSCI_CONDUIT_HVC:
+			arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+					  ARM_SMCCC_ARCH_WORKAROUND_1, &res);
+			if ((int)res.a0 != 0)
+				break;
+			per_cpu(harden_branch_predictor_fn, cpu) =
+				call_hvc_arch_workaround_1;
+			processor.switch_mm = cpu_v7_hvc_switch_mm;
+			spectre_v2_method = "hypervisor";
+			break;
+
+		case PSCI_CONDUIT_SMC:
+			arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+					  ARM_SMCCC_ARCH_WORKAROUND_1, &res);
+			if ((int)res.a0 != 0)
+				break;
+			per_cpu(harden_branch_predictor_fn, cpu) =
+				call_smc_arch_workaround_1;
+			processor.switch_mm = cpu_v7_smc_switch_mm;
+			spectre_v2_method = "firmware";
+			break;
+
+		default:
+			break;
+		}
 	}
+#endif
+	}
+
 	if (spectre_v2_method)
 		pr_info("CPU%u: Spectre v2: using %s workaround\n",
 			smp_processor_id(), spectre_v2_method);
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 79510011e7eb..b78d59a1cc05 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -9,6 +9,7 @@
  *
  *  This is the "shell" of the ARMv7 processor support.
  */
+#include <linux/arm-smccc.h>
 #include <linux/init.h>
 #include <linux/linkage.h>
 #include <asm/assembler.h>
@@ -93,6 +94,26 @@ ENTRY(cpu_v7_dcache_clean_area)
 	ret	lr
 ENDPROC(cpu_v7_dcache_clean_area)
 
+#ifdef CONFIG_ARM_PSCI
+	.arch_extension sec
+ENTRY(cpu_v7_smc_switch_mm)
+	stmfd	sp!, {r0 - r3}
+	movw	r0, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+	movt	r0, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+	smc	#0
+	ldmfd	sp!, {r0 - r3}
+	b	cpu_v7_switch_mm
+ENDPROC(cpu_v7_smc_switch_mm)
+	.arch_extension virt
+ENTRY(cpu_v7_hvc_switch_mm)
+	stmfd	sp!, {r0 - r3}
+	movw	r0, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+	movt	r0, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+	hvc	#0
+	ldmfd	sp!, {r0 - r3}
+	b	cpu_v7_switch_mm
+ENDPROC(cpu_v7_smc_switch_mm)
+#endif
 ENTRY(cpu_v7_iciallu_switch_mm)
 	mov	r3, #0
 	mcr	p15, 0, r3, c7, c5, 0		@ ICIALLU
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 08/15] ARM: spectre-v2: harden user aborts in kernel space
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

In order to prevent aliasing attacks on the branch predictor,
invalidate the BTB or instruction cache on CPUs that are known to be
affected when taking an abort on a address that is outside of a user
task limit:

Cortex A8, A9, A12, A17, A73, A75: flush BTB.
Cortex A15, Brahma B15: invalidate icache.

If the IBE bit is not set, then there is little point to enabling the
workaround.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/include/asm/cp15.h        |  3 ++
 arch/arm/include/asm/system_misc.h | 15 ++++++++
 arch/arm/mm/fault.c                |  3 ++
 arch/arm/mm/proc-v7-bugs.c         | 78 ++++++++++++++++++++++++++++++++++----
 arch/arm/mm/proc-v7.S              |  8 ++--
 5 files changed, 97 insertions(+), 10 deletions(-)

diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h
index 4c9fa72b59f5..07e27f212dc7 100644
--- a/arch/arm/include/asm/cp15.h
+++ b/arch/arm/include/asm/cp15.h
@@ -65,6 +65,9 @@
 #define __write_sysreg(v, r, w, c, t)	asm volatile(w " " c : : "r" ((t)(v)))
 #define write_sysreg(v, ...)		__write_sysreg(v, __VA_ARGS__)
 
+#define BPIALL				__ACCESS_CP15(c7, 0, c5, 6)
+#define ICIALLU				__ACCESS_CP15(c7, 0, c5, 0)
+
 extern unsigned long cr_alignment;	/* defined in entry-armv.S */
 
 static inline unsigned long get_cr(void)
diff --git a/arch/arm/include/asm/system_misc.h b/arch/arm/include/asm/system_misc.h
index 78f6db114faf..8e76db83c498 100644
--- a/arch/arm/include/asm/system_misc.h
+++ b/arch/arm/include/asm/system_misc.h
@@ -8,6 +8,7 @@
 #include <linux/linkage.h>
 #include <linux/irqflags.h>
 #include <linux/reboot.h>
+#include <linux/percpu.h>
 
 extern void cpu_init(void);
 
@@ -15,6 +16,20 @@ void soft_restart(unsigned long);
 extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
 extern void (*arm_pm_idle)(void);
 
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+typedef void (*harden_branch_predictor_fn_t)(void);
+DECLARE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+static inline void harden_branch_predictor(void)
+{
+	harden_branch_predictor_fn_t fn = per_cpu(harden_branch_predictor_fn,
+						  smp_processor_id());
+	if (fn)
+		fn();
+}
+#else
+#define harden_branch_predictor() do { } while (0)
+#endif
+
 #define UDBG_UNDEFINED	(1 << 0)
 #define UDBG_SYSCALL	(1 << 1)
 #define UDBG_BADABORT	(1 << 2)
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index b75eada23d0a..3b1ba003c4f9 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -163,6 +163,9 @@ __do_user_fault(struct task_struct *tsk, unsigned long addr,
 {
 	struct siginfo si;
 
+	if (addr > TASK_SIZE)
+		harden_branch_predictor();
+
 #ifdef CONFIG_DEBUG_USER
 	if (((user_debug & UDBG_SEGV) && (sig == SIGSEGV)) ||
 	    ((user_debug & UDBG_BUS)  && (sig == SIGBUS))) {
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index cd368f1e6748..0b48270b7318 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -2,31 +2,95 @@
 #include <linux/kernel.h>
 #include <linux/smp.h>
 
-static __maybe_unused void cpu_v7_check_auxcr_set(u32 mask, const char *msg)
+#include <asm/cp15.h>
+#include <asm/cputype.h>
+#include <asm/system_misc.h>
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+
+static void harden_branch_predictor_bpiall(void)
+{
+	write_sysreg(0, BPIALL);
+}
+
+static void harden_branch_predictor_iciallu(void)
+{
+	write_sysreg(0, ICIALLU);
+}
+
+static void cpu_v7_spectre_init(void)
+{
+	const char *spectre_v2_method = NULL;
+	int cpu = smp_processor_id();
+
+	if (per_cpu(harden_branch_predictor_fn, cpu))
+		return;
+
+	switch (read_cpuid_part()) {
+	case ARM_CPU_PART_CORTEX_A8:
+	case ARM_CPU_PART_CORTEX_A9:
+	case ARM_CPU_PART_CORTEX_A12:
+	case ARM_CPU_PART_CORTEX_A17:
+	case ARM_CPU_PART_CORTEX_A73:
+	case ARM_CPU_PART_CORTEX_A75:
+		per_cpu(harden_branch_predictor_fn, cpu) =
+			harden_branch_predictor_bpiall;
+		spectre_v2_method = "BPIALL";
+		break;
+
+	case ARM_CPU_PART_CORTEX_A15:
+	case ARM_CPU_PART_BRAHMA_B15:
+		per_cpu(harden_branch_predictor_fn, cpu) =
+			harden_branch_predictor_iciallu;
+		spectre_v2_method = "ICIALLU";
+		break;
+	}
+	if (spectre_v2_method)
+		pr_info("CPU%u: Spectre v2: using %s workaround\n",
+			smp_processor_id(), spectre_v2_method);
+}
+#else
+static void cpu_v7_spectre_init(void)
+{
+}
+#endif
+
+static __maybe_unused bool cpu_v7_check_auxcr_set(u32 mask, const char *msg)
 {
 	u32 aux_cr;
 
 	asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (aux_cr));
 
-	if ((aux_cr & mask) != mask)
+	if ((aux_cr & mask) != mask) {
 		pr_err("CPU%u: %s", smp_processor_id(), msg);
+		return false;
+	}
+	return true;
 }
 
 static DEFINE_PER_CPU(bool, spectre_checked);
 
-static void check_spectre_auxcr(u32 bit)
+static bool check_spectre_auxcr(u32 bit)
 {
-	if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR) &&
-	    !__this_cpu_xchg(spectre_checked, true))
+	return IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR) &&
+		!__this_cpu_xchg(spectre_checked, true) &&
 		cpu_v7_check_auxcr_set(bit, "Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable\n");
 }
 
 void cpu_v7_ca8_ibe(void)
 {
-	check_spectre_auxcr(BIT(6));
+	if (check_spectre_auxcr(BIT(6)))
+		cpu_v7_spectre_init();
 }
 
 void cpu_v7_ca15_ibe(void)
 {
-	check_spectre_auxcr(BIT(0));
+	if (check_spectre_auxcr(BIT(0)))
+		cpu_v7_spectre_init();
+}
+
+void cpu_v7_bugs_init(void)
+{
+	cpu_v7_spectre_init();
 }
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index fa9214036fb3..79510011e7eb 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -532,8 +532,10 @@ ENDPROC(__v7_setup)
 
 	__INITDATA
 
+	.weak cpu_v7_bugs_init
+
 	@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
-	define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+	define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_bugs_init
 
 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
 	@ generic v7 bpiall on context switch
@@ -548,7 +550,7 @@ ENDPROC(__v7_setup)
 	globl_equ	cpu_v7_bpiall_do_suspend,	cpu_v7_do_suspend
 	globl_equ	cpu_v7_bpiall_do_resume,	cpu_v7_do_resume
 #endif
-	define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+	define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_bugs_init
 
 #define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_bpiall_processor_functions
 #else
@@ -584,7 +586,7 @@ ENDPROC(__v7_setup)
 	globl_equ	cpu_ca9mp_switch_mm,	cpu_v7_switch_mm
 #endif
 	globl_equ	cpu_ca9mp_set_pte_ext,	cpu_v7_set_pte_ext
-	define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+	define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_bugs_init
 #endif
 
 	@ Cortex-A15 - needs iciallu switch_mm for hardening
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 07/15] ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bit
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

When the branch predictor hardening is enabled, firmware must have set
the IBE bit in the auxiliary control register.  If this bit has not
been set, the Spectre workarounds will not be functional.

Add validation that this bit is set, and print a warning at alert level
if this is not the case.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mm/Makefile       |  2 +-
 arch/arm/mm/proc-v7-bugs.c | 32 ++++++++++++++++++++++++++++++++
 arch/arm/mm/proc-v7.S      |  4 ++--
 3 files changed, 35 insertions(+), 3 deletions(-)
 create mode 100644 arch/arm/mm/proc-v7-bugs.c

diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 9dbb84923e12..a0c40610210c 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -97,7 +97,7 @@ obj-$(CONFIG_CPU_MOHAWK)	+= proc-mohawk.o
 obj-$(CONFIG_CPU_FEROCEON)	+= proc-feroceon.o
 obj-$(CONFIG_CPU_V6)		+= proc-v6.o
 obj-$(CONFIG_CPU_V6K)		+= proc-v6.o
-obj-$(CONFIG_CPU_V7)		+= proc-v7.o
+obj-$(CONFIG_CPU_V7)		+= proc-v7.o proc-v7-bugs.o
 obj-$(CONFIG_CPU_V7M)		+= proc-v7m.o
 
 AFLAGS_proc-v6.o	:=-Wa,-march=armv6
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
new file mode 100644
index 000000000000..cd368f1e6748
--- /dev/null
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/smp.h>
+
+static __maybe_unused void cpu_v7_check_auxcr_set(u32 mask, const char *msg)
+{
+	u32 aux_cr;
+
+	asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (aux_cr));
+
+	if ((aux_cr & mask) != mask)
+		pr_err("CPU%u: %s", smp_processor_id(), msg);
+}
+
+static DEFINE_PER_CPU(bool, spectre_checked);
+
+static void check_spectre_auxcr(u32 bit)
+{
+	if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR) &&
+	    !__this_cpu_xchg(spectre_checked, true))
+		cpu_v7_check_auxcr_set(bit, "Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable\n");
+}
+
+void cpu_v7_ca8_ibe(void)
+{
+	check_spectre_auxcr(BIT(6));
+}
+
+void cpu_v7_ca15_ibe(void)
+{
+	check_spectre_auxcr(BIT(0));
+}
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index a2d433d59848..fa9214036fb3 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -569,7 +569,7 @@ ENDPROC(__v7_setup)
 	globl_equ	cpu_ca8_do_suspend,	cpu_v7_do_suspend
 	globl_equ	cpu_ca8_do_resume,	cpu_v7_do_resume
 #endif
-	define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+	define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca8_ibe
 
 	@ Cortex-A9 - needs more registers preserved across suspend/resume
 	@ and bpiall switch_mm for hardening
@@ -602,7 +602,7 @@ ENDPROC(__v7_setup)
 	globl_equ	cpu_ca15_suspend_size,	cpu_v7_suspend_size
 	globl_equ	cpu_ca15_do_suspend,	cpu_v7_do_suspend
 	globl_equ	cpu_ca15_do_resume,	cpu_v7_do_resume
-	define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+	define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca15_ibe
 #ifdef CONFIG_CPU_PJ4B
 	define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
 #endif
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 06/15] ARM: spectre-v2: harden branch predictor on context switches
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

Harden the branch predictor against Spectre v2 attacks on context
switches for ARMv7 and later CPUs.  We do this by:

Cortex A9, A12, A17, A73, A75: invalidating the BTB.
Cortex A15, Brahma B15: invalidating the instruction cache.

Cortex A57 and Cortex A72 are not addressed in this patch.

Cortex R7 and Cortex R8 are also not addressed as we do not enforce
memory protection on these cores.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mm/Kconfig          |  19 +++++++
 arch/arm/mm/proc-v7-2level.S |   6 ---
 arch/arm/mm/proc-v7.S        | 125 +++++++++++++++++++++++++++++++++----------
 3 files changed, 115 insertions(+), 35 deletions(-)

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 6f3ef86b4cb7..9357ff52c221 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -830,6 +830,25 @@ config CPU_BPREDICT_DISABLE
 config CPU_SPECTRE
 	bool
 
+config HARDEN_BRANCH_PREDICTOR
+	bool "Harden the branch predictor against aliasing attacks" if EXPERT
+	depends on CPU_SPECTRE
+	default y
+	help
+	   Speculation attacks against some high-performance processors rely
+	   on being able to manipulate the branch predictor for a victim
+	   context by executing aliasing branches in the attacker context.
+	   Such attacks can be partially mitigated against by clearing
+	   internal branch predictor state and limiting the prediction
+	   logic in some situations.
+
+	   This config option will take CPU-specific actions to harden
+	   the branch predictor against aliasing attacks and may rely on
+	   specific instruction sequences or control bits being set by
+	   the system firmware.
+
+	   If unsure, say Y.
+
 config TLS_REG_EMUL
 	bool
 	select NEED_KUSER_HELPERS
diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
index c6141a5435c3..f8d45ad2a515 100644
--- a/arch/arm/mm/proc-v7-2level.S
+++ b/arch/arm/mm/proc-v7-2level.S
@@ -41,11 +41,6 @@
  *	even on Cortex-A8 revisions not affected by 430973.
  *	If IBE is not set, the flush BTAC/BTB won't do anything.
  */
-ENTRY(cpu_ca8_switch_mm)
-#ifdef CONFIG_MMU
-	mov	r2, #0
-	mcr	p15, 0, r2, c7, c5, 6		@ flush BTAC/BTB
-#endif
 ENTRY(cpu_v7_switch_mm)
 #ifdef CONFIG_MMU
 	mmid	r1, r1				@ get mm->context.id
@@ -66,7 +61,6 @@ ENTRY(cpu_v7_switch_mm)
 #endif
 	bx	lr
 ENDPROC(cpu_v7_switch_mm)
-ENDPROC(cpu_ca8_switch_mm)
 
 /*
  *	cpu_v7_set_pte_ext(ptep, pte)
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index d55d493f9a1e..a2d433d59848 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -93,6 +93,17 @@ ENTRY(cpu_v7_dcache_clean_area)
 	ret	lr
 ENDPROC(cpu_v7_dcache_clean_area)
 
+ENTRY(cpu_v7_iciallu_switch_mm)
+	mov	r3, #0
+	mcr	p15, 0, r3, c7, c5, 0		@ ICIALLU
+	b	cpu_v7_switch_mm
+ENDPROC(cpu_v7_iciallu_switch_mm)
+ENTRY(cpu_v7_bpiall_switch_mm)
+	mov	r3, #0
+	mcr	p15, 0, r3, c7, c5, 6		@ flush BTAC/BTB
+	b	cpu_v7_switch_mm
+ENDPROC(cpu_v7_bpiall_switch_mm)
+
 	string	cpu_v7_name, "ARMv7 Processor"
 	.align
 
@@ -158,31 +169,6 @@ ENTRY(cpu_v7_do_resume)
 ENDPROC(cpu_v7_do_resume)
 #endif
 
-/*
- * Cortex-A8
- */
-	globl_equ	cpu_ca8_proc_init,	cpu_v7_proc_init
-	globl_equ	cpu_ca8_proc_fin,	cpu_v7_proc_fin
-	globl_equ	cpu_ca8_reset,		cpu_v7_reset
-	globl_equ	cpu_ca8_do_idle,	cpu_v7_do_idle
-	globl_equ	cpu_ca8_dcache_clean_area, cpu_v7_dcache_clean_area
-	globl_equ	cpu_ca8_set_pte_ext,	cpu_v7_set_pte_ext
-	globl_equ	cpu_ca8_suspend_size,	cpu_v7_suspend_size
-#ifdef CONFIG_ARM_CPU_SUSPEND
-	globl_equ	cpu_ca8_do_suspend,	cpu_v7_do_suspend
-	globl_equ	cpu_ca8_do_resume,	cpu_v7_do_resume
-#endif
-
-/*
- * Cortex-A9 processor functions
- */
-	globl_equ	cpu_ca9mp_proc_init,	cpu_v7_proc_init
-	globl_equ	cpu_ca9mp_proc_fin,	cpu_v7_proc_fin
-	globl_equ	cpu_ca9mp_reset,	cpu_v7_reset
-	globl_equ	cpu_ca9mp_do_idle,	cpu_v7_do_idle
-	globl_equ	cpu_ca9mp_dcache_clean_area, cpu_v7_dcache_clean_area
-	globl_equ	cpu_ca9mp_switch_mm,	cpu_v7_switch_mm
-	globl_equ	cpu_ca9mp_set_pte_ext,	cpu_v7_set_pte_ext
 .globl	cpu_ca9mp_suspend_size
 .equ	cpu_ca9mp_suspend_size, cpu_v7_suspend_size + 4 * 2
 #ifdef CONFIG_ARM_CPU_SUSPEND
@@ -548,10 +534,75 @@ ENDPROC(__v7_setup)
 
 	@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
 	define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+	@ generic v7 bpiall on context switch
+	globl_equ	cpu_v7_bpiall_proc_init,	cpu_v7_proc_init
+	globl_equ	cpu_v7_bpiall_proc_fin,		cpu_v7_proc_fin
+	globl_equ	cpu_v7_bpiall_reset,		cpu_v7_reset
+	globl_equ	cpu_v7_bpiall_do_idle,		cpu_v7_do_idle
+	globl_equ	cpu_v7_bpiall_dcache_clean_area, cpu_v7_dcache_clean_area
+	globl_equ	cpu_v7_bpiall_set_pte_ext,	cpu_v7_set_pte_ext
+	globl_equ	cpu_v7_bpiall_suspend_size,	cpu_v7_suspend_size
+#ifdef CONFIG_ARM_CPU_SUSPEND
+	globl_equ	cpu_v7_bpiall_do_suspend,	cpu_v7_do_suspend
+	globl_equ	cpu_v7_bpiall_do_resume,	cpu_v7_do_resume
+#endif
+	define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+
+#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_bpiall_processor_functions
+#else
+#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_processor_functions
+#endif
+
 #ifndef CONFIG_ARM_LPAE
+	@ Cortex-A8 - always needs bpiall switch_mm implementation
+	globl_equ	cpu_ca8_proc_init,	cpu_v7_proc_init
+	globl_equ	cpu_ca8_proc_fin,	cpu_v7_proc_fin
+	globl_equ	cpu_ca8_reset,		cpu_v7_reset
+	globl_equ	cpu_ca8_do_idle,	cpu_v7_do_idle
+	globl_equ	cpu_ca8_dcache_clean_area, cpu_v7_dcache_clean_area
+	globl_equ	cpu_ca8_set_pte_ext,	cpu_v7_set_pte_ext
+	globl_equ	cpu_ca8_switch_mm,	cpu_v7_bpiall_switch_mm
+	globl_equ	cpu_ca8_suspend_size,	cpu_v7_suspend_size
+#ifdef CONFIG_ARM_CPU_SUSPEND
+	globl_equ	cpu_ca8_do_suspend,	cpu_v7_do_suspend
+	globl_equ	cpu_ca8_do_resume,	cpu_v7_do_resume
+#endif
 	define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
+
+	@ Cortex-A9 - needs more registers preserved across suspend/resume
+	@ and bpiall switch_mm for hardening
+	globl_equ	cpu_ca9mp_proc_init,	cpu_v7_proc_init
+	globl_equ	cpu_ca9mp_proc_fin,	cpu_v7_proc_fin
+	globl_equ	cpu_ca9mp_reset,	cpu_v7_reset
+	globl_equ	cpu_ca9mp_do_idle,	cpu_v7_do_idle
+	globl_equ	cpu_ca9mp_dcache_clean_area, cpu_v7_dcache_clean_area
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+	globl_equ	cpu_ca9mp_switch_mm,	cpu_v7_bpiall_switch_mm
+#else
+	globl_equ	cpu_ca9mp_switch_mm,	cpu_v7_switch_mm
+#endif
+	globl_equ	cpu_ca9mp_set_pte_ext,	cpu_v7_set_pte_ext
 	define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
 #endif
+
+	@ Cortex-A15 - needs iciallu switch_mm for hardening
+	globl_equ	cpu_ca15_proc_init,	cpu_v7_proc_init
+	globl_equ	cpu_ca15_proc_fin,	cpu_v7_proc_fin
+	globl_equ	cpu_ca15_reset,		cpu_v7_reset
+	globl_equ	cpu_ca15_do_idle,	cpu_v7_do_idle
+	globl_equ	cpu_ca15_dcache_clean_area, cpu_v7_dcache_clean_area
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+	globl_equ	cpu_ca15_switch_mm,	cpu_v7_iciallu_switch_mm
+#else
+	globl_equ	cpu_ca15_switch_mm,	cpu_v7_switch_mm
+#endif
+	globl_equ	cpu_ca15_set_pte_ext,	cpu_v7_set_pte_ext
+	globl_equ	cpu_ca15_suspend_size,	cpu_v7_suspend_size
+	globl_equ	cpu_ca15_do_suspend,	cpu_v7_do_suspend
+	globl_equ	cpu_ca15_do_resume,	cpu_v7_do_resume
+	define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
 #ifdef CONFIG_CPU_PJ4B
 	define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
 #endif
@@ -658,7 +709,7 @@ ENDPROC(__v7_setup)
 __v7_ca12mp_proc_info:
 	.long	0x410fc0d0
 	.long	0xff0ffff0
-	__v7_proc __v7_ca12mp_proc_info, __v7_ca12mp_setup
+	__v7_proc __v7_ca12mp_proc_info, __v7_ca12mp_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
 	.size	__v7_ca12mp_proc_info, . - __v7_ca12mp_proc_info
 
 	/*
@@ -668,7 +719,7 @@ ENDPROC(__v7_setup)
 __v7_ca15mp_proc_info:
 	.long	0x410fc0f0
 	.long	0xff0ffff0
-	__v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup
+	__v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup, proc_fns = ca15_processor_functions
 	.size	__v7_ca15mp_proc_info, . - __v7_ca15mp_proc_info
 
 	/*
@@ -678,7 +729,7 @@ ENDPROC(__v7_setup)
 __v7_b15mp_proc_info:
 	.long	0x420f00f0
 	.long	0xff0ffff0
-	__v7_proc __v7_b15mp_proc_info, __v7_b15mp_setup, cache_fns = b15_cache_fns
+	__v7_proc __v7_b15mp_proc_info, __v7_b15mp_setup, proc_fns = ca15_processor_functions, cache_fns = b15_cache_fns
 	.size	__v7_b15mp_proc_info, . - __v7_b15mp_proc_info
 
 	/*
@@ -688,9 +739,25 @@ ENDPROC(__v7_setup)
 __v7_ca17mp_proc_info:
 	.long	0x410fc0e0
 	.long	0xff0ffff0
-	__v7_proc __v7_ca17mp_proc_info, __v7_ca17mp_setup
+	__v7_proc __v7_ca17mp_proc_info, __v7_ca17mp_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
 	.size	__v7_ca17mp_proc_info, . - __v7_ca17mp_proc_info
 
+	/* ARM Ltd. Cortex A73 processor */
+	.type	__v7_ca73_proc_info, #object
+__v7_ca73_proc_info:
+	.long	0x410fd090
+	.long	0xff0ffff0
+	__v7_proc __v7_ca73_proc_info, __v7_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
+	.size	__v7_ca73_proc_info, . - __v7_ca73_proc_info
+
+	/* ARM Ltd. Cortex A75 processor */
+	.type	__v7_ca75_proc_info, #object
+__v7_ca75_proc_info:
+	.long	0x410fd0a0
+	.long	0xff0ffff0
+	__v7_proc __v7_ca75_proc_info, __v7_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS
+	.size	__v7_ca75_proc_info, . - __v7_ca75_proc_info
+
 	/*
 	 * Qualcomm Inc. Krait processors.
 	 */
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 05/15] ARM: spectre: add Kconfig symbol for CPUs vulnerable to Spectre
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

Add a Kconfig symbol for CPUs which are vulnerable to the Spectre
attacks.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mm/Kconfig | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 7f14acf67caf..6f3ef86b4cb7 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -415,6 +415,7 @@ config CPU_V7
 	select CPU_CP15_MPU if !MMU
 	select CPU_HAS_ASID if MMU
 	select CPU_PABRT_V7
+	select CPU_SPECTRE if MMU
 	select CPU_THUMB_CAPABLE
 	select CPU_TLB_V7 if MMU
 
@@ -826,6 +827,9 @@ config CPU_BPREDICT_DISABLE
 	help
 	  Say Y here to disable branch prediction.  If unsure, say N.
 
+config CPU_SPECTRE
+	bool
+
 config TLS_REG_EMUL
 	bool
 	select NEED_KUSER_HELPERS
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 04/15] ARM: bugs: add support for per-processor bug checking
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

Add support for per-processor bug checking - each processor function
descriptor gains a function pointer for this check, which must not be
an __init function.  If non-NULL, this will be called whenever a CPU
enters the kernel via which ever path (boot CPU, secondary CPU startup,
CPU resuming, etc.)

This allows processor specific bug checks to validate that workaround
bits are properly enabled by firmware via all entry paths to the kernel.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/include/asm/proc-fns.h | 4 ++++
 arch/arm/kernel/bugs.c          | 4 ++++
 arch/arm/mm/proc-macros.S       | 3 ++-
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/proc-fns.h b/arch/arm/include/asm/proc-fns.h
index f2e1af45bd6f..e25f4392e1b2 100644
--- a/arch/arm/include/asm/proc-fns.h
+++ b/arch/arm/include/asm/proc-fns.h
@@ -37,6 +37,10 @@ extern struct processor {
 	 */
 	void (*_proc_init)(void);
 	/*
+	 * Check for processor bugs
+	 */
+	void (*check_bugs)(void);
+	/*
 	 * Disable any processor specifics
 	 */
 	void (*_proc_fin)(void);
diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
index 16e7ba2a9cc4..7be511310191 100644
--- a/arch/arm/kernel/bugs.c
+++ b/arch/arm/kernel/bugs.c
@@ -5,6 +5,10 @@
 
 void check_other_bugs(void)
 {
+#ifdef MULTI_CPU
+	if (processor.check_bugs)
+		processor.check_bugs();
+#endif
 }
 
 void __init check_bugs(void)
diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index f10e31d0730a..81d0efb055c6 100644
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -273,13 +273,14 @@
 	mcr	p15, 0, ip, c7, c10, 4		@ data write barrier
 	.endm
 
-.macro define_processor_functions name:req, dabort:req, pabort:req, nommu=0, suspend=0
+.macro define_processor_functions name:req, dabort:req, pabort:req, nommu=0, suspend=0, bugs=0
 	.type	\name\()_processor_functions, #object
 	.align 2
 ENTRY(\name\()_processor_functions)
 	.word	\dabort
 	.word	\pabort
 	.word	cpu_\name\()_proc_init
+	.word	\bugs
 	.word	cpu_\name\()_proc_fin
 	.word	cpu_\name\()_reset
 	.word	cpu_\name\()_do_idle
-- 
2.7.4

^ permalink raw reply related

* [PATCH v4 03/15] ARM: bugs: hook processor bug checking into SMP and suspend paths
From: Russell King @ 2018-05-29  9:09 UTC (permalink / raw)
  To: linux-arm-kernel
In-Reply-To: <20180529090756.GG17671@n2100.armlinux.org.uk>

Check for CPU bugs when secondary processors are being brought online,
and also when CPUs are resuming from a low power mode.  This gives an
opportunity to check that processor specific bug workarounds are
correctly enabled for all paths that a CPU re-enters the kernel.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/include/asm/bugs.h | 2 ++
 arch/arm/kernel/bugs.c      | 5 +++++
 arch/arm/kernel/smp.c       | 4 ++++
 arch/arm/kernel/suspend.c   | 2 ++
 4 files changed, 13 insertions(+)

diff --git a/arch/arm/include/asm/bugs.h b/arch/arm/include/asm/bugs.h
index ed122d294f3f..73a99c72a930 100644
--- a/arch/arm/include/asm/bugs.h
+++ b/arch/arm/include/asm/bugs.h
@@ -14,8 +14,10 @@ extern void check_writebuffer_bugs(void);
 
 #ifdef CONFIG_MMU
 extern void check_bugs(void);
+extern void check_other_bugs(void);
 #else
 #define check_bugs() do { } while (0)
+#define check_other_bugs() do { } while (0)
 #endif
 
 #endif
diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
index 88024028bb70..16e7ba2a9cc4 100644
--- a/arch/arm/kernel/bugs.c
+++ b/arch/arm/kernel/bugs.c
@@ -3,7 +3,12 @@
 #include <asm/bugs.h>
 #include <asm/proc-fns.h>
 
+void check_other_bugs(void)
+{
+}
+
 void __init check_bugs(void)
 {
 	check_writebuffer_bugs();
+	check_other_bugs();
 }
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 2da087926ebe..5ad0b67b9e33 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -31,6 +31,7 @@
 #include <linux/irq_work.h>
 
 #include <linux/atomic.h>
+#include <asm/bugs.h>
 #include <asm/smp.h>
 #include <asm/cacheflush.h>
 #include <asm/cpu.h>
@@ -405,6 +406,9 @@ asmlinkage void secondary_start_kernel(void)
 	 * before we continue - which happens after __cpu_up returns.
 	 */
 	set_cpu_online(cpu, true);
+
+	check_other_bugs();
+
 	complete(&cpu_running);
 
 	local_irq_enable();
diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c
index a40ebb7c0896..d08099269e35 100644
--- a/arch/arm/kernel/suspend.c
+++ b/arch/arm/kernel/suspend.c
@@ -3,6 +3,7 @@
 #include <linux/slab.h>
 #include <linux/mm_types.h>
 
+#include <asm/bugs.h>
 #include <asm/cacheflush.h>
 #include <asm/idmap.h>
 #include <asm/pgalloc.h>
@@ -36,6 +37,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
 		cpu_switch_mm(mm->pgd, mm);
 		local_flush_bp_all();
 		local_flush_tlb_all();
+		check_other_bugs();
 	}
 
 	return ret;
-- 
2.7.4

^ permalink raw reply related


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