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| author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2014-05-19 11:04:39 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2014-06-01 01:15:04 +0100 |
| commit | 1c8c3cf0b5239388e712508a85821f4718f4d889 (patch) | |
| tree | 8454ad999882d20118d1af924c0cf6d2d42c97bd /arch | |
| parent | 437b680a222098f67ecb1690f8eb91f550bfaac8 (diff) | |
| download | linux-1c8c3cf0b5239388e712508a85821f4718f4d889.tar.gz linux-1c8c3cf0b5239388e712508a85821f4718f4d889.tar.bz2 linux-1c8c3cf0b5239388e712508a85821f4718f4d889.zip | |
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')
| -rw-r--r-- | arch/arm/include/asm/io.h | 6 | ||||
| -rw-r--r-- | arch/arm/mm/ioremap.c | 9 |
2 files changed, 14 insertions, 1 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); +#else +static inline void pci_ioremap_set_mem_type(int mem_type) {} +#endif + extern int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr); /* diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c index f9c32ba73544..d1e5ad7ab3bc 100644 --- a/arch/arm/mm/ioremap.c +++ b/arch/arm/mm/ioremap.c @@ -438,6 +438,13 @@ void __arm_iounmap(volatile void __iomem *io_addr) EXPORT_SYMBOL(__arm_iounmap); #ifdef CONFIG_PCI +static int pci_ioremap_mem_type = MT_DEVICE; + +void pci_ioremap_set_mem_type(int mem_type) +{ + pci_ioremap_mem_type = mem_type; +} + int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr) { BUG_ON(offset + SZ_64K > IO_SPACE_LIMIT); @@ -445,7 +452,7 @@ int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr) return ioremap_page_range(PCI_IO_VIRT_BASE + offset, PCI_IO_VIRT_BASE + offset + SZ_64K, phys_addr, - __pgprot(get_mem_type(MT_DEVICE)->prot_pte)); + __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte)); } EXPORT_SYMBOL_GPL(pci_ioremap_io); #endif |