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* [PATCH v3 1/2] lib: devres: add a helper function for ioremap_uc
@ 2019-10-10  3:03 Tuowen Zhao
  2019-10-10  3:03 ` [PATCH v3 2/2] mfd: intel-lpss: use devm_ioremap_uc for MMIO Tuowen Zhao
  2019-10-10 12:06 ` [PATCH v3 1/2] lib: devres: add a helper function for ioremap_uc Luis Chamberlain
  0 siblings, 2 replies; 5+ messages in thread
From: Tuowen Zhao @ 2019-10-10  3:03 UTC (permalink / raw)
  To: lee.jones, linux-kernel
  Cc: andriy.shevchenko, mika.westerberg, acelan.kao, bhelgaas,
	kai.heng.feng, mcgrof, Tuowen Zhao

Implement a resource managed strongly uncachable ioremap function.

Tested-by: AceLan Kao <acelan.kao@canonical.com>
Signed-off-by: Tuowen Zhao <ztuowen@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
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


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH v3 2/2] mfd: intel-lpss: use devm_ioremap_uc for MMIO
  2019-10-10  3:03 [PATCH v3 1/2] lib: devres: add a helper function for ioremap_uc Tuowen Zhao
@ 2019-10-10  3:03 ` Tuowen Zhao
  2019-10-10 12:08   ` Luis Chamberlain
  2019-10-10 12:06 ` [PATCH v3 1/2] lib: devres: add a helper function for ioremap_uc Luis Chamberlain
  1 sibling, 1 reply; 5+ messages in thread
From: Tuowen Zhao @ 2019-10-10  3:03 UTC (permalink / raw)
  To: lee.jones, linux-kernel
  Cc: andriy.shevchenko, mika.westerberg, acelan.kao, bhelgaas,
	kai.heng.feng, mcgrof, Tuowen Zhao

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 <acelan.kao@canonical.com>
Signed-off-by: Tuowen Zhao <ztuowen@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 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


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH v3 1/2] lib: devres: add a helper function for ioremap_uc
  2019-10-10  3:03 [PATCH v3 1/2] lib: devres: add a helper function for ioremap_uc Tuowen Zhao
  2019-10-10  3:03 ` [PATCH v3 2/2] mfd: intel-lpss: use devm_ioremap_uc for MMIO Tuowen Zhao
@ 2019-10-10 12:06 ` Luis Chamberlain
  1 sibling, 0 replies; 5+ messages in thread
From: Luis Chamberlain @ 2019-10-10 12:06 UTC (permalink / raw)
  To: Tuowen Zhao
  Cc: lee.jones, linux-kernel, andriy.shevchenko, mika.westerberg,
	acelan.kao, bhelgaas, kai.heng.feng

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 <acelan.kao@canonical.com>
> Signed-off-by: Tuowen Zhao <ztuowen@gmail.com>
> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Acked-by: Luis Chamberlain <mcgrof@kernel.org>

  Luis

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v3 2/2] mfd: intel-lpss: use devm_ioremap_uc for MMIO
  2019-10-10  3:03 ` [PATCH v3 2/2] mfd: intel-lpss: use devm_ioremap_uc for MMIO Tuowen Zhao
@ 2019-10-10 12:08   ` Luis Chamberlain
  2019-10-14  7:06     ` Lee Jones
  0 siblings, 1 reply; 5+ messages in thread
From: Luis Chamberlain @ 2019-10-10 12:08 UTC (permalink / raw)
  To: Tuowen Zhao
  Cc: lee.jones, linux-kernel, andriy.shevchenko, mika.westerberg,
	acelan.kao, bhelgaas, kai.heng.feng

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 <acelan.kao@canonical.com>
> Signed-off-by: Tuowen Zhao <ztuowen@gmail.com>
> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

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

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v3 2/2] mfd: intel-lpss: use devm_ioremap_uc for MMIO
  2019-10-10 12:08   ` Luis Chamberlain
@ 2019-10-14  7:06     ` Lee Jones
  0 siblings, 0 replies; 5+ messages in thread
From: Lee Jones @ 2019-10-14  7:06 UTC (permalink / raw)
  To: Luis Chamberlain
  Cc: Tuowen Zhao, linux-kernel, andriy.shevchenko, mika.westerberg,
	acelan.kao, bhelgaas, kai.heng.feng

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 <acelan.kao@canonical.com>
> > Signed-off-by: Tuowen Zhao <ztuowen@gmail.com>
> > Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> > Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> 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 <lee.jones@linaro.org>

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2019-10-14  7:06 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-10  3:03 [PATCH v3 1/2] lib: devres: add a helper function for ioremap_uc Tuowen Zhao
2019-10-10  3:03 ` [PATCH v3 2/2] mfd: intel-lpss: use devm_ioremap_uc for MMIO Tuowen Zhao
2019-10-10 12:08   ` Luis Chamberlain
2019-10-14  7:06     ` Lee Jones
2019-10-10 12:06 ` [PATCH v3 1/2] lib: devres: add a helper function for ioremap_uc Luis Chamberlain

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