This patch includes the basic infrastructure to use swiotlb bounce buffering on 32-bit powerpc. It is not yet enabled on any platforms.
Signed-off-by: Becky Bruce <bec...@kernel.crashing.org> --- arch/powerpc/Kconfig | 2 +- arch/powerpc/include/asm/dma-mapping.h | 11 ++ arch/powerpc/include/asm/swiotlb.h | 24 +++++ arch/powerpc/kernel/Makefile | 1 + arch/powerpc/kernel/dma-swiotlb.c | 161 ++++++++++++++++++++++++++++++++ arch/powerpc/kernel/dma.c | 2 +- arch/powerpc/kernel/setup_32.c | 4 + 7 files changed, 203 insertions(+), 2 deletions(-) create mode 100644 arch/powerpc/include/asm/swiotlb.h create mode 100644 arch/powerpc/kernel/dma-swiotlb.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 5b50e1a..197f6a3 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -294,7 +294,7 @@ config IOMMU_HELPER config PPC_NEED_DMA_SYNC_OPS def_bool y - depends on NOT_COHERENT_CACHE + depends on (NOT_COHERENT_CACHE || SWIOTLB) config HOTPLUG_CPU bool "Support for enabling/disabling CPUs" diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h index c69f2b5..71bbc17 100644 --- a/arch/powerpc/include/asm/dma-mapping.h +++ b/arch/powerpc/include/asm/dma-mapping.h @@ -15,9 +15,18 @@ #include <linux/scatterlist.h> #include <linux/dma-attrs.h> #include <asm/io.h> +#include <asm/swiotlb.h> #define DMA_ERROR_CODE (~(dma_addr_t)0x0) +/* Some dma direct funcs must be visible for use in other dma_ops */ +extern void *dma_direct_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t flag); +extern void dma_direct_free_coherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_handle); + +extern unsigned long get_dma_direct_offset(struct device *dev); + #ifdef CONFIG_NOT_COHERENT_CACHE /* * DMA-consistent mapping functions for PowerPCs that don't support @@ -76,6 +85,8 @@ struct dma_mapping_ops { dma_addr_t dma_address, size_t size, enum dma_data_direction direction, struct dma_attrs *attrs); + int (*addr_needs_map)(struct device *dev, dma_addr_t addr, + size_t size); #ifdef CONFIG_PPC_NEED_DMA_SYNC_OPS void (*sync_single_range_for_cpu)(struct device *hwdev, dma_addr_t dma_handle, unsigned long offset, diff --git a/arch/powerpc/include/asm/swiotlb.h b/arch/powerpc/include/asm/swiotlb.h new file mode 100644 index 0000000..6440fdf --- /dev/null +++ b/arch/powerpc/include/asm/swiotlb.h @@ -0,0 +1,24 @@ +/* + * Copyright (C) 2009 Becky Bruce, Freescale Semiconductor + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + */ + +#ifndef __ASM_SWIOTLB_H +#define __ASM_SWIOTLB_H + +#include <linux/swiotlb.h> + +extern struct dma_mapping_ops swiotlb_dma_ops; +extern struct dma_mapping_ops swiotlb_pci_dma_ops; + +int swiotlb_arch_address_needs_mapping(struct device *, dma_addr_t, + size_t size); + +static inline void dma_mark_clean(void *addr, size_t size) {} + +#endif /* __ASM_SWIOTLB_H */ diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 71901fb..34c0a95 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -82,6 +82,7 @@ obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_PPC_UDBG_16550) += legacy_serial.o udbg_16550.o obj-$(CONFIG_STACKTRACE) += stacktrace.o +obj-$(CONFIG_SWIOTLB) += dma-swiotlb.o pci64-$(CONFIG_PPC64) += pci_dn.o isa-bridge.o obj-$(CONFIG_PCI) += pci_$(CONFIG_WORD_SIZE).o $(pci64-y) \ diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c new file mode 100644 index 0000000..29a68e6 --- /dev/null +++ b/arch/powerpc/kernel/dma-swiotlb.c @@ -0,0 +1,161 @@ +/* + * Contains routines needed to support swiotlb for ppc. + * + * Copyright (C) 2009 Becky Bruce, Freescale Semiconductor + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + */ + +#include <linux/dma-mapping.h> +#include <linux/pfn.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/pci.h> + +#include <asm/machdep.h> +#include <asm/swiotlb.h> +#include <asm/dma.h> +#include <asm/abs_addr.h> + +int swiotlb __read_mostly; + +void *swiotlb_bus_to_virt(struct device *hwdev, dma_addr_t addr) +{ + unsigned long pfn = PFN_DOWN(swiotlb_bus_to_phys(hwdev, addr)); + void *pageaddr = page_address(pfn_to_page(pfn)); + + if (pageaddr != NULL) + return pageaddr + (addr % PAGE_SIZE); + return NULL; +} + +dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr) +{ + return paddr + get_dma_direct_offset(hwdev); +} + +phys_addr_t swiotlb_bus_to_phys(struct device *hwdev, dma_addr_t baddr) + +{ + return baddr - get_dma_direct_offset(hwdev); +} + +/* + * Determine if an address needs bounce buffering via swiotlb. + * Going forward I expect the swiotlb code to generalize on using + * a dma_ops->addr_needs_map, and this function will move from here to the + * generic swiotlb code. + */ +int +swiotlb_arch_address_needs_mapping(struct device *hwdev, dma_addr_t addr, + size_t size) +{ + struct dma_mapping_ops *dma_ops = get_dma_ops(hwdev); + + BUG_ON(!dma_ops); + return dma_ops->addr_needs_map(hwdev, addr, size); +} + +/* + * Determine if an address is reachable by a pci device, or if we must bounce. + */ +static int +swiotlb_pci_addr_needs_map(struct device *hwdev, dma_addr_t addr, size_t size) +{ + u64 mask = dma_get_mask(hwdev); + dma_addr_t max; + struct pci_controller *hose; + struct pci_dev *pdev = to_pci_dev(hwdev); + + hose = pci_bus_to_host(pdev->bus); + max = hose->dma_window_base_cur + hose->dma_window_size; + + /* check that we're within mapped pci window space */ + if ((addr + size > max) | (addr < hose->dma_window_base_cur)) + return 1; + + return !is_buffer_dma_capable(mask, addr, size); +} + +static int +swiotlb_addr_needs_map(struct device *hwdev, dma_addr_t addr, size_t size) +{ + return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size); +} + + +/* + * At the moment, all platforms that use this code only require + * swiotlb to be used if we're operating on HIGHMEM. Since + * we don't ever call anything other than map_sg, unmap_sg, + * map_page, and unmap_page on highmem, use normal dma_ops + * for everything else. + */ +struct dma_mapping_ops swiotlb_dma_ops = { + .alloc_coherent = dma_direct_alloc_coherent, + .free_coherent = dma_direct_free_coherent, + .map_sg = swiotlb_map_sg_attrs, + .unmap_sg = swiotlb_unmap_sg_attrs, + .dma_supported = swiotlb_dma_supported, + .map_page = swiotlb_map_page, + .unmap_page = swiotlb_unmap_page, + .addr_needs_map = swiotlb_addr_needs_map, + .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu, + .sync_single_range_for_device = swiotlb_sync_single_range_for_device, + .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = swiotlb_sync_sg_for_device +}; + +struct dma_mapping_ops swiotlb_pci_dma_ops = { + .alloc_coherent = dma_direct_alloc_coherent, + .free_coherent = dma_direct_free_coherent, + .map_sg = swiotlb_map_sg_attrs, + .unmap_sg = swiotlb_unmap_sg_attrs, + .dma_supported = swiotlb_dma_supported, + .map_page = swiotlb_map_page, + .unmap_page = swiotlb_unmap_page, + .addr_needs_map = swiotlb_pci_addr_needs_map, + .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu, + .sync_single_range_for_device = swiotlb_sync_single_range_for_device, + .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = swiotlb_sync_sg_for_device +}; + +static int ppc_swiotlb_bus_notify(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + + /* We are only intereted in device addition */ + if (action != BUS_NOTIFY_ADD_DEVICE) + return 0; + + if (dma_get_mask(dev) < DMA_BIT_MASK(36)) + set_dma_ops(dev, &swiotlb_dma_ops); + + return NOTIFY_DONE; +} + +static struct notifier_block ppc_swiotlb_plat_bus_notifier = { + .notifier_call = ppc_swiotlb_bus_notify, + .priority = 0, +}; + +static struct notifier_block ppc_swiotlb_of_bus_notifier = { + .notifier_call = ppc_swiotlb_bus_notify, + .priority = 0, +}; + +static int __init setup_bus_notifier(void) +{ + bus_register_notifier(&platform_bus_type, + &ppc_swiotlb_plat_bus_notifier); + bus_register_notifier(&of_platform_bus_type, + &ppc_swiotlb_of_bus_notifier); + + return 0; +} diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index 53c7788..62d80c4 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -19,7 +19,7 @@ * default the offset is PCI_DRAM_OFFSET. */ -static unsigned long get_dma_direct_offset(struct device *dev) +unsigned long get_dma_direct_offset(struct device *dev) { if (dev) return (unsigned long)dev->archdata.dma_data; diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index 9e1ca74..f038b13 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -332,6 +332,10 @@ void __init setup_arch(char **cmdline_p) ppc_md.setup_arch(); if ( ppc_md.progress ) ppc_md.progress("arch: exit", 0x3eab); + /* Allow iotlb to do it's setup */ +#ifdef CONFIG_SWIOTLB + swiotlb_init(); +#endif paging_init(); /* Initialize the MMU context management stuff */ -- 1.6.0.6 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev