path: root/arch/arm/include
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authorThomas Petazzoni <thomas.petazzoni@free-electrons.com>2014-05-19 11:04:39 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-06-01 01:15:04 +0100
commit1c8c3cf0b5239388e712508a85821f4718f4d889 (patch)
tree8454ad999882d20118d1af924c0cf6d2d42c97bd /arch/arm/include
parent437b680a222098f67ecb1690f8eb91f550bfaac8 (diff)
ARM: 8060/1: mm: allow sub-architectures to override PCI I/O memory type
Due to a design incompatibility between the PCIe Marvell controller and the Cortex-A9, stressing PCIe devices with a lot of traffic quickly causes a deadlock. One part of the workaround for this is to have all PCIe regions mapped as strongly-ordered (MT_UNCACHED) instead of the default MT_DEVICE. While the arch_ioremap_caller() mechanism allows sub-architecture code to override ioremap(), used to map PCIe memory regions, there isn't such a mechanism to override the behavior of pci_ioremap_io(). This commit adds the arch_pci_ioremap_mem_type variable, initialized to MT_DEVICE by default, and that sub-architecture code can override. We have chosen to expose a single variable rather than offering the possibility of overriding the entire pci_ioremap_io(), because implementing pci_ioremap_io() requires calling functions (get_mem_type()) that are private to the arch/arm/mm/ code. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include')
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 8aa4cca74501..3d23418cbddd 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -179,6 +179,12 @@ static inline void __iomem *__typesafe_io(unsigned long addr)
/* PCI fixed i/o mapping */
#define PCI_IO_VIRT_BASE 0xfee00000
+#if defined(CONFIG_PCI)
+void pci_ioremap_set_mem_type(int mem_type);
+static inline void pci_ioremap_set_mem_type(int mem_type) {}
extern int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr);