Implement a resource managed strongly uncachable ioremap function.
Tested-by: AceLan Kao <[email protected]>
Signed-off-by: Tuowen Zhao <[email protected]>
Acked-by: Mika Westerberg <[email protected]>
Acked-by: Andy Shevchenko <[email protected]>
---
Changes from previous version:
* Split the patch in 2
* Use GPL export for devm_ioremap_uc
* Add entry to devres doc
.../driver-api/driver-model/devres.rst | 1 +
include/linux/io.h | 2 ++
lib/devres.c | 19 +++++++++++++++++++
3 files changed, 22 insertions(+)
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index a100bef54952..92628fdc2f11 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -314,6 +314,7 @@ IOMAP
devm_ioport_unmap()
devm_ioremap()
devm_ioremap_nocache()
+ devm_ioremap_uc()
devm_ioremap_wc()
devm_ioremap_resource() : checks resource, requests memory region, ioremaps
devm_iounmap()
diff --git a/include/linux/io.h b/include/linux/io.h
index accac822336a..a59834bc0a11 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -64,6 +64,8 @@ static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
resource_size_t size);
+void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
+ resource_size_t size);
void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
resource_size_t size);
void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
diff --git a/lib/devres.c b/lib/devres.c
index 6a0e9bd6524a..17624d35e82d 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -9,6 +9,7 @@
enum devm_ioremap_type {
DEVM_IOREMAP = 0,
DEVM_IOREMAP_NC,
+ DEVM_IOREMAP_UC,
DEVM_IOREMAP_WC,
};
@@ -39,6 +40,9 @@ static void __iomem *__devm_ioremap(struct device *dev, resource_size_t offset,
case DEVM_IOREMAP_NC:
addr = ioremap_nocache(offset, size);
break;
+ case DEVM_IOREMAP_UC:
+ addr = ioremap_uc(offset, size);
+ break;
case DEVM_IOREMAP_WC:
addr = ioremap_wc(offset, size);
break;
@@ -68,6 +72,21 @@ void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
}
EXPORT_SYMBOL(devm_ioremap);
+/**
+ * devm_ioremap_uc - Managed ioremap_uc()
+ * @dev: Generic device to remap IO address for
+ * @offset: Resource address to map
+ * @size: Size of map
+ *
+ * Managed ioremap_uc(). Map is automatically unmapped on driver detach.
+ */
+void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
+ resource_size_t size)
+{
+ return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_UC);
+}
+EXPORT_SYMBOL_GPL(devm_ioremap_uc);
+
/**
* devm_ioremap_nocache - Managed ioremap_nocache()
* @dev: Generic device to remap IO address for
--
2.23.0
Some BIOS erroneously specifies write-combining BAR for intel-lpss-pci
in MTRR. This will cause the system to hang during boot. If possible,
this bug could be corrected with a firmware update.
This patch use devm_ioremap_uc to overwrite/ignore the MTRR settings
by forcing the use of strongly uncachable pages for intel-lpss.
The BIOS bug is present on Dell XPS 13 7390 2-in-1:
[ 0.001734] 5 base 4000000000 mask 6000000000 write-combining
4000000000-7fffffffff : PCI Bus 0000:00
4000000000-400fffffff : 0000:00:02.0 (i915)
4010000000-4010000fff : 0000:00:15.0 (intel-lpss-pci)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203485
Tested-by: AceLan Kao <[email protected]>
Signed-off-by: Tuowen Zhao <[email protected]>
Acked-by: Mika Westerberg <[email protected]>
Acked-by: Andy Shevchenko <[email protected]>
---
drivers/mfd/intel-lpss.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
index bfe4ff337581..b0f0781a6b9c 100644
--- a/drivers/mfd/intel-lpss.c
+++ b/drivers/mfd/intel-lpss.c
@@ -384,7 +384,7 @@ int intel_lpss_probe(struct device *dev,
if (!lpss)
return -ENOMEM;
- lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
+ lpss->priv = devm_ioremap_uc(dev, info->mem->start + LPSS_PRIV_OFFSET,
LPSS_PRIV_SIZE);
if (!lpss->priv)
return -ENOMEM;
--
2.23.0
On Wed, Oct 09, 2019 at 09:03:34PM -0600, Tuowen Zhao wrote:
> Implement a resource managed strongly uncachable ioremap function.
>
> Tested-by: AceLan Kao <[email protected]>
> Signed-off-by: Tuowen Zhao <[email protected]>
> Acked-by: Mika Westerberg <[email protected]>
> Acked-by: Andy Shevchenko <[email protected]>
Acked-by: Luis Chamberlain <[email protected]>
Luis
On Wed, Oct 09, 2019 at 09:03:35PM -0600, Tuowen Zhao wrote:
> Some BIOS erroneously specifies write-combining BAR for intel-lpss-pci
> in MTRR. This will cause the system to hang during boot. If possible,
> this bug could be corrected with a firmware update.
>
> This patch use devm_ioremap_uc to overwrite/ignore the MTRR settings
> by forcing the use of strongly uncachable pages for intel-lpss.
>
> The BIOS bug is present on Dell XPS 13 7390 2-in-1:
>
> [ 0.001734] 5 base 4000000000 mask 6000000000 write-combining
>
> 4000000000-7fffffffff : PCI Bus 0000:00
> 4000000000-400fffffff : 0000:00:02.0 (i915)
> 4010000000-4010000fff : 0000:00:15.0 (intel-lpss-pci)
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=203485
> Tested-by: AceLan Kao <[email protected]>
> Signed-off-by: Tuowen Zhao <[email protected]>
> Acked-by: Mika Westerberg <[email protected]>
> Acked-by: Andy Shevchenko <[email protected]>
I think you'll want to Cc stable for this, as well as the last patch.
LTS kernels with the ioremap_uc will be able to leverage the fix.
Luis
On Thu, 10 Oct 2019, Luis Chamberlain wrote:
> On Wed, Oct 09, 2019 at 09:03:35PM -0600, Tuowen Zhao wrote:
> > Some BIOS erroneously specifies write-combining BAR for intel-lpss-pci
> > in MTRR. This will cause the system to hang during boot. If possible,
> > this bug could be corrected with a firmware update.
> >
> > This patch use devm_ioremap_uc to overwrite/ignore the MTRR settings
> > by forcing the use of strongly uncachable pages for intel-lpss.
> >
> > The BIOS bug is present on Dell XPS 13 7390 2-in-1:
> >
> > [ 0.001734] 5 base 4000000000 mask 6000000000 write-combining
> >
> > 4000000000-7fffffffff : PCI Bus 0000:00
> > 4000000000-400fffffff : 0000:00:02.0 (i915)
> > 4010000000-4010000fff : 0000:00:15.0 (intel-lpss-pci)
> >
> > Link: https://bugzilla.kernel.org/show_bug.cgi?id=203485
> > Tested-by: AceLan Kao <[email protected]>
> > Signed-off-by: Tuowen Zhao <[email protected]>
> > Acked-by: Mika Westerberg <[email protected]>
> > Acked-by: Andy Shevchenko <[email protected]>
>
> I think you'll want to Cc stable for this, as well as the last patch.
> LTS kernels with the ioremap_uc will be able to leverage the fix.
When you re-submit adding Stable, you can apply my:
For my own reference:
Acked-for-MFD-by: Lee Jones <[email protected]>
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog