From 9e250ff4f015c9497d372373470ba49b6ae0ae30 Mon Sep 17 00:00:00 2001 From: Tuowen Zhao Date: Wed, 16 Oct 2019 15:06:27 -0600 Subject: [PATCH 1/4] sparc64: implement ioremap_uc On sparc64, the whole physical IO address space is accessible using physically addressed loads and stores. *_uc does nothing like the others. Cc: Reported-by: kbuild test robot Signed-off-by: Tuowen Zhao Acked-by: David S. Miller --- arch/sparc/include/asm/io_64.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/sparc/include/asm/io_64.h b/arch/sparc/include/asm/io_64.h index 688911051b446..f4afa301954a2 100644 --- a/arch/sparc/include/asm/io_64.h +++ b/arch/sparc/include/asm/io_64.h @@ -407,6 +407,7 @@ static inline void __iomem *ioremap(unsigned long offset, unsigned long size) } #define ioremap_nocache(X,Y) ioremap((X),(Y)) +#define ioremap_uc(X,Y) ioremap((X),(Y)) #define ioremap_wc(X,Y) ioremap((X),(Y)) #define ioremap_wt(X,Y) ioremap((X),(Y)) From 127f1a729b43f5497bad435e8c1664a7c1bb881e Mon Sep 17 00:00:00 2001 From: Tuowen Zhao Date: Wed, 16 Oct 2019 15:06:28 -0600 Subject: [PATCH 2/4] lib: devres: add a helper function for ioremap_uc Implement a resource managed strongly uncachable ioremap function. Cc: Tested-by: AceLan Kao Signed-off-by: Tuowen Zhao Acked-by: Mika Westerberg Acked-by: Andy Shevchenko Acked-by: Luis Chamberlain Acked-for-MFD-by: Lee Jones --- include/linux/io.h | 2 ++ lib/devres.c | 19 +++++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/include/linux/io.h b/include/linux/io.h index accac822336aa..a59834bc0a114 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 6a0e9bd6524ae..17624d35e82d4 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 From 6f1806d2a519dac69073279b51ef1c6755b2689f Mon Sep 17 00:00:00 2001 From: Tuowen Zhao Date: Wed, 16 Oct 2019 15:06:29 -0600 Subject: [PATCH 3/4] mfd: intel-lpss: use devm_ioremap_uc for MMIO 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 Cc: Tested-by: AceLan Kao Signed-off-by: Tuowen Zhao Acked-by: Mika Westerberg Acked-by: Andy Shevchenko Acked-for-MFD-by: Lee Jones Tested-by: Roman Gilg --- 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 277f48f1cc1c8..06106c9320bb1 100644 --- a/drivers/mfd/intel-lpss.c +++ b/drivers/mfd/intel-lpss.c @@ -395,7 +395,7 @@ 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; From aceca893b4adf400c1b8573e8585293c799953d1 Mon Sep 17 00:00:00 2001 From: Tuowen Zhao Date: Wed, 16 Oct 2019 15:06:30 -0600 Subject: [PATCH 4/4] docs: driver-model: add devm_ioremap_uc Signed-off-by: Tuowen Zhao Acked-by: Luis Chamberlain --- Documentation/driver-api/driver-model/devres.rst | 1 + 1 file changed, 1 insertion(+) diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst index a100bef549528..92628fdc2f11c 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()