From a93a121a96531b99d6feb8db96417b49e1bb28e8 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Sat, 27 May 2017 19:17:43 +0530 Subject: ARM: dma-mapping: Don't tear down third-party mappings arch_setup_dma_ops() is used in device probe code paths to create an IOMMU mapping and attach it to the device. The function assumes that the device is attached to a device-specific IOMMU instance (or at least a device-specific TLB in a shared IOMMU instance) and thus creates a separate mapping for every device. On several systems (Renesas R-Car Gen2 being one of them), that assumption is not true, and IOMMU mappings must be shared between multiple devices. In those cases the IOMMU driver knows better than the generic ARM dma-mapping layer and attaches mapping to devices manually with arm_iommu_attach_device(), which sets the DMA ops for the device. The arch_setup_dma_ops() function takes this into account and bails out immediately if the device already has DMA ops assigned. However, the corresponding arch_teardown_dma_ops() function, called from driver unbind code paths (including probe deferral), will tear the mapping down regardless of who created it. When the device is reprobed arch_setup_dma_ops() will be called again but won't perform any operation as the DMA ops will still be set. We need to reset the DMA ops in arch_teardown_dma_ops() to fix this. However, we can't do so unconditionally, as then a new mapping would be created by arch_setup_dma_ops() when the device is reprobed, regardless of whether the device needs to share a mapping or not. We must thus keep track of whether arch_setup_dma_ops() created the mapping, and only in that case tear it down in arch_teardown_dma_ops(). Keep track of that information in the dev_archdata structure. As the structure is embedded in all instances of struct device let's not grow it, but turn the existing dma_coherent bool field into a bitfield that can be used for other purposes. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Reviewed-by: Robin Murphy Signed-off-by: Laurent Pinchart Signed-off-by: Joerg Roedel --- arch/arm/include/asm/device.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm/include/asm') diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h index 36ec9c8f6e16..3234fe9bba6e 100644 --- a/arch/arm/include/asm/device.h +++ b/arch/arm/include/asm/device.h @@ -19,7 +19,8 @@ struct dev_archdata { #ifdef CONFIG_XEN const struct dma_map_ops *dev_dma_ops; #endif - bool dma_coherent; + unsigned int dma_coherent:1; + unsigned int dma_ops_setup:1; }; struct omap_device; -- cgit v1.2.3 From 7ef4783e19a84fe1e8b58f4c27b858dfdcaef207 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Wed, 24 May 2017 10:30:18 +0100 Subject: ARM: 8676/1: NOMMU: provide pgprot_device() macro NOMMU build leads to the following error: CC drivers/pci/mmap.o drivers/pci/mmap.c: In function 'pci_mmap_resource_range': drivers/pci/mmap.c:60:3: error: implicit declaration of function 'pgprot_device' [-Werror=implicit-function-declaration] vma->vm_page_prot = pgprot_device(vma->vm_page_prot); ^ cc1: some warnings being treated as errors scripts/Makefile.build:302: recipe for target 'drivers/pci/mmap.o' failed make[2]: *** [drivers/pci/mmap.o] Error 1 scripts/Makefile.build:561: recipe for target 'drivers/pci' failed make[1]: *** [drivers/pci] Error 2 Makefile:1016: recipe for target 'drivers' failed make: *** [drivers] Error 2 Fix it with support of pgprot_device() macro for NOMMU. Fixes: 00d2904ffeac ("ARM/PCI: Use generic pci_mmap_resource_range()") Signed-off-by: Vladimir Murzin Signed-off-by: Russell King --- arch/arm/include/asm/pgtable-nommu.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/include/asm') diff --git a/arch/arm/include/asm/pgtable-nommu.h b/arch/arm/include/asm/pgtable-nommu.h index 302240c19a5a..a0d726a47c8a 100644 --- a/arch/arm/include/asm/pgtable-nommu.h +++ b/arch/arm/include/asm/pgtable-nommu.h @@ -66,6 +66,7 @@ typedef pte_t *pte_addr_t; #define pgprot_noncached(prot) (prot) #define pgprot_writecombine(prot) (prot) #define pgprot_dmacoherent(prot) (prot) +#define pgprot_device(prot) (prot) /* -- cgit v1.2.3