From 1c8c3cf0b5239388e712508a85821f4718f4d889 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Mon, 19 May 2014 11:04:39 +0100 Subject: 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 Acked-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/include/asm/io.h | 6 ++++++ arch/arm/mm/ioremap.c | 9 ++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) 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 -- cgit v1.2.3