From 7d63fb3af87aa67aa7d24466e792f9d7c57d8e79 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 10 Jul 2018 16:22:22 -0700 Subject: swiotlb: clean up reporting This removes needless use of '%p', and refactors the printk calls to use pr_*() helpers instead. Signed-off-by: Kees Cook Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Christoph Hellwig --- kernel/dma/swiotlb.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 904541055792..4f8a6dbf0b60 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -17,6 +17,8 @@ * 08/12/11 beckyb Add highmem support */ +#define pr_fmt(fmt) "software IO TLB: " fmt + #include #include #include @@ -162,20 +164,16 @@ static bool no_iotlb_memory; void swiotlb_print_info(void) { unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT; - unsigned char *vstart, *vend; if (no_iotlb_memory) { - pr_warn("software IO TLB: No low mem\n"); + pr_warn("No low mem\n"); return; } - vstart = phys_to_virt(io_tlb_start); - vend = phys_to_virt(io_tlb_end); - - printk(KERN_INFO "software IO TLB [mem %#010llx-%#010llx] (%luMB) mapped at [%p-%p]\n", + pr_info("mapped [mem %#010llx-%#010llx] (%luMB)\n", (unsigned long long)io_tlb_start, (unsigned long long)io_tlb_end, - bytes >> 20, vstart, vend - 1); + bytes >> 20); } /* @@ -275,7 +273,7 @@ swiotlb_init(int verbose) if (io_tlb_start) memblock_free_early(io_tlb_start, PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT)); - pr_warn("Cannot allocate SWIOTLB buffer"); + pr_warn("Cannot allocate buffer"); no_iotlb_memory = true; } @@ -317,8 +315,8 @@ swiotlb_late_init_with_default_size(size_t default_size) return -ENOMEM; } if (order != get_order(bytes)) { - printk(KERN_WARNING "Warning: only able to allocate %ld MB " - "for software IO TLB\n", (PAGE_SIZE << order) >> 20); + pr_warn("only able to allocate %ld MB\n", + (PAGE_SIZE << order) >> 20); io_tlb_nslabs = SLABS_PER_PAGE << order; } rc = swiotlb_late_init_with_tbl(vstart, io_tlb_nslabs); -- cgit v1.2.3-71-gd317 From f07d141fe9430cdf9f8a65a87c4136bd83b8ab2e Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Mon, 23 Jul 2018 23:16:07 +0100 Subject: dma-mapping: Generalise dma_32bit_limit flag Whilst the notion of an upstream DMA restriction is most commonly seen in PCI host bridges saddled with a 32-bit native interface, a more general version of the same issue can exist on complex SoCs where a bus or point-to-point interconnect link from a device's DMA master interface to another component along the path to memory (often an IOMMU) may carry fewer address bits than the interfaces at both ends nominally support. In order to properly deal with this, the first step is to expand the dma_32bit_limit flag into an arbitrary mask. To minimise the impact on existing code, we'll make sure to only consider this new mask valid if set. That makes sense anyway, since a mask of zero would represent DMA not being wired up at all, and that would be better handled by not providing valid ops in the first place. Signed-off-by: Robin Murphy Acked-by: Ard Biesheuvel Signed-off-by: Christoph Hellwig --- arch/x86/kernel/pci-dma.c | 2 +- include/linux/device.h | 6 +++--- kernel/dma/direct.c | 6 +++--- 3 files changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index ab5d9dd668d2..80f9fe8d27d0 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -175,7 +175,7 @@ rootfs_initcall(pci_iommu_init); static int via_no_dac_cb(struct pci_dev *pdev, void *data) { - pdev->dev.dma_32bit_limit = true; + pdev->dev.bus_dma_mask = DMA_BIT_MASK(32); return 0; } diff --git a/include/linux/device.h b/include/linux/device.h index 055a69dbcd18..6d3b000be57e 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -886,6 +886,8 @@ struct dev_links_info { * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all * hardware supports 64-bit addresses for consistent allocations * such descriptors. + * @bus_dma_mask: Mask of an upstream bridge or bus which imposes a smaller DMA + * limit than the device itself supports. * @dma_pfn_offset: offset of DMA memory range relatively of RAM * @dma_parms: A low level driver may set these to teach IOMMU code about * segment limitations. @@ -912,8 +914,6 @@ struct dev_links_info { * @offline: Set after successful invocation of bus type's .offline(). * @of_node_reused: Set if the device-tree node is shared with an ancestor * device. - * @dma_32bit_limit: bridge limited to 32bit DMA even if the device itself - * indicates support for a higher limit in the dma_mask field. * * At the lowest level, every device in a Linux system is represented by an * instance of struct device. The device structure contains the information @@ -967,6 +967,7 @@ struct device { not all hardware supports 64 bit addresses for consistent allocations such descriptors. */ + u64 bus_dma_mask; /* upstream dma_mask constraint */ unsigned long dma_pfn_offset; struct device_dma_parameters *dma_parms; @@ -1002,7 +1003,6 @@ struct device { bool offline_disabled:1; bool offline:1; bool of_node_reused:1; - bool dma_32bit_limit:1; }; static inline struct device *kobj_to_dev(struct kobject *kobj) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 8be8106270c2..c2860c5a9e96 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -180,10 +180,10 @@ int dma_direct_supported(struct device *dev, u64 mask) return 0; #endif /* - * Various PCI/PCIe bridges have broken support for > 32bit DMA even - * if the device itself might support it. + * Upstream PCI/PCIe bridges or SoC interconnects may not carry + * as many DMA address bits as the device itself supports. */ - if (dev->dma_32bit_limit && mask > DMA_BIT_MASK(32)) + if (dev->bus_dma_mask && mask > dev->bus_dma_mask) return 0; return 1; } -- cgit v1.2.3-71-gd317