Hi again, On Fri, 15 Jul 2005 13:09:33 +1000 Stephen Rothwell <[EMAIL PROTECTED]> wrote: > > We (Anton Blanchard and others) have been trying to figure out the best > (or any) way to allow for IOMMU bypass when setting up DMA mappings on > particular devices. Our current idea is to hang a structure of pointers > to DMA mapping operations off the struct device and inherit it from the > device's parent. This would allow for per-bus (rather than per-bus_type) > mapping operations and also allow a driver to override the bus's > operations for a particular device. > > Does this make sense? Comments (hopefully consructive) please. > > Is there a better/simpler/more sensible way to do this?
Just to give you all something concrete to attack^Wcomment on, here is a preliminary patch with the generic work and PPC64 converted. It actually helps ppc64 more than some others because we already have two different "busses": pci and vio. This has been built on both pSeries and iSeries ppc64 but not tested, yet. -- Cheers, Stephen Rothwell [EMAIL PROTECTED] http://www.canb.auug.org.au/~sfr/ diff -ruN linus/arch/ppc64/kernel/Makefile linus-dma_bypass.3/arch/ppc64/kernel/Makefile --- linus/arch/ppc64/kernel/Makefile 2005-06-27 16:08:00.000000000 +1000 +++ linus-dma_bypass.3/arch/ppc64/kernel/Makefile 2005-06-27 17:41:10.000000000 +1000 @@ -5,7 +5,7 @@ EXTRA_CFLAGS += -mno-minimal-toc extra-y := head.o vmlinux.lds -obj-y := setup.o entry.o traps.o irq.o idle.o dma.o \ +obj-y := setup.o entry.o traps.o irq.o idle.o \ time.o process.o signal.o syscalls.o misc.o ptrace.o \ align.o semaphore.o bitops.o pacaData.o \ udbg.o binfmt_elf32.o sys_ppc32.o ioctl32.o \ diff -ruN linus/arch/ppc64/kernel/bpa_iommu.c linus-dma_bypass.3/arch/ppc64/kernel/bpa_iommu.c --- linus/arch/ppc64/kernel/bpa_iommu.c 2005-06-27 16:08:00.000000000 +1000 +++ linus-dma_bypass.3/arch/ppc64/kernel/bpa_iommu.c 2005-07-19 14:25:11.000000000 +1000 @@ -359,6 +359,11 @@ return mask < 0x100000000ull; } +static int bpa_direct_set_dma_mask(struct device *dev, u64 mask) +{ + return pci_set_dma_mask(to_pci_dev(dev), mask); +} + void bpa_init_iommu(void) { bpa_map_iommu(); @@ -374,4 +379,5 @@ pci_dma_ops.map_sg = bpa_map_sg; pci_dma_ops.unmap_sg = bpa_unmap_sg; pci_dma_ops.dma_supported = bpa_dma_supported; + pci_dma_ops.set_dma_mask = bpa_set_dma_mask; } diff -ruN linus/arch/ppc64/kernel/dma.c linus-dma_bypass.3/arch/ppc64/kernel/dma.c --- linus/arch/ppc64/kernel/dma.c 2005-06-27 16:08:00.000000000 +1000 +++ linus-dma_bypass.3/arch/ppc64/kernel/dma.c 1970-01-01 10:00:00.000000000 +1000 @@ -1,151 +0,0 @@ -/* - * Copyright (C) 2004 IBM Corporation - * - * Implements the generic device dma API for ppc64. Handles - * the pci and vio busses - */ - -#include <linux/device.h> -#include <linux/dma-mapping.h> -/* Include the busses we support */ -#include <linux/pci.h> -#include <asm/vio.h> -#include <asm/scatterlist.h> -#include <asm/bug.h> - -static struct dma_mapping_ops *get_dma_ops(struct device *dev) -{ -#ifdef CONFIG_PCI - if (dev->bus == &pci_bus_type) - return &pci_dma_ops; -#endif -#ifdef CONFIG_IBMVIO - if (dev->bus == &vio_bus_type) - return &vio_dma_ops; -#endif - return NULL; -} - -int dma_supported(struct device *dev, u64 mask) -{ - struct dma_mapping_ops *dma_ops = get_dma_ops(dev); - - if (dma_ops) - return dma_ops->dma_supported(dev, mask); - BUG(); - return 0; -} -EXPORT_SYMBOL(dma_supported); - -int dma_set_mask(struct device *dev, u64 dma_mask) -{ -#ifdef CONFIG_PCI - if (dev->bus == &pci_bus_type) - return pci_set_dma_mask(to_pci_dev(dev), dma_mask); -#endif -#ifdef CONFIG_IBMVIO - if (dev->bus == &vio_bus_type) - return -EIO; -#endif /* CONFIG_IBMVIO */ - BUG(); - return 0; -} -EXPORT_SYMBOL(dma_set_mask); - -void *dma_alloc_coherent(struct device *dev, size_t size, - dma_addr_t *dma_handle, unsigned int __nocast flag) -{ - struct dma_mapping_ops *dma_ops = get_dma_ops(dev); - - if (dma_ops) - return dma_ops->alloc_coherent(dev, size, dma_handle, flag); - BUG(); - return NULL; -} -EXPORT_SYMBOL(dma_alloc_coherent); - -void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, - dma_addr_t dma_handle) -{ - struct dma_mapping_ops *dma_ops = get_dma_ops(dev); - - if (dma_ops) - dma_ops->free_coherent(dev, size, cpu_addr, dma_handle); - else - BUG(); -} -EXPORT_SYMBOL(dma_free_coherent); - -dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, size_t size, - enum dma_data_direction direction) -{ - struct dma_mapping_ops *dma_ops = get_dma_ops(dev); - - if (dma_ops) - return dma_ops->map_single(dev, cpu_addr, size, direction); - BUG(); - return (dma_addr_t)0; -} -EXPORT_SYMBOL(dma_map_single); - -void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size, - enum dma_data_direction direction) -{ - struct dma_mapping_ops *dma_ops = get_dma_ops(dev); - - if (dma_ops) - dma_ops->unmap_single(dev, dma_addr, size, direction); - else - BUG(); -} -EXPORT_SYMBOL(dma_unmap_single); - -dma_addr_t dma_map_page(struct device *dev, struct page *page, - unsigned long offset, size_t size, - enum dma_data_direction direction) -{ - struct dma_mapping_ops *dma_ops = get_dma_ops(dev); - - if (dma_ops) - return dma_ops->map_single(dev, - (page_address(page) + offset), size, direction); - BUG(); - return (dma_addr_t)0; -} -EXPORT_SYMBOL(dma_map_page); - -void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size, - enum dma_data_direction direction) -{ - struct dma_mapping_ops *dma_ops = get_dma_ops(dev); - - if (dma_ops) - dma_ops->unmap_single(dev, dma_address, size, direction); - else - BUG(); -} -EXPORT_SYMBOL(dma_unmap_page); - -int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, - enum dma_data_direction direction) -{ - struct dma_mapping_ops *dma_ops = get_dma_ops(dev); - - if (dma_ops) - return dma_ops->map_sg(dev, sg, nents, direction); - BUG(); - return 0; -} -EXPORT_SYMBOL(dma_map_sg); - -void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries, - enum dma_data_direction direction) -{ - struct dma_mapping_ops *dma_ops = get_dma_ops(dev); - - if (dma_ops) - dma_ops->unmap_sg(dev, sg, nhwentries, direction); - else - BUG(); -} -EXPORT_SYMBOL(dma_unmap_sg); diff -ruN linus/arch/ppc64/kernel/pci.c linus-dma_bypass.3/arch/ppc64/kernel/pci.c --- linus/arch/ppc64/kernel/pci.c 2005-06-29 11:08:36.000000000 +1000 +++ linus-dma_bypass.3/arch/ppc64/kernel/pci.c 2005-07-19 15:28:32.000000000 +1000 @@ -71,9 +71,6 @@ LIST_HEAD(hose_list); -struct dma_mapping_ops pci_dma_ops; -EXPORT_SYMBOL(pci_dma_ops); - int global_phb_number; /* Global phb counter */ /* Cached ISA bridge dev. */ diff -ruN linus/arch/ppc64/kernel/pci_direct_iommu.c linus-dma_bypass.3/arch/ppc64/kernel/pci_direct_iommu.c --- linus/arch/ppc64/kernel/pci_direct_iommu.c 2005-06-27 16:08:00.000000000 +1000 +++ linus-dma_bypass.3/arch/ppc64/kernel/pci_direct_iommu.c 2005-07-19 15:35:04.000000000 +1000 @@ -83,6 +83,11 @@ return mask < 0x100000000ull; } +static int pci_direct_set_dma_mask(struct device *dev, u64 mask) +{ + return pci_set_dma_mask(to_pci_dev(dev), mask); +} + void __init pci_direct_iommu_init(void) { pci_dma_ops.alloc_coherent = pci_direct_alloc_coherent; @@ -92,4 +97,5 @@ pci_dma_ops.map_sg = pci_direct_map_sg; pci_dma_ops.unmap_sg = pci_direct_unmap_sg; pci_dma_ops.dma_supported = pci_direct_dma_supported; + pci_dma_ops.set_dma_mask = pci_direct_set_dma_mask; } diff -ruN linus/arch/ppc64/kernel/pci_iommu.c linus-dma_bypass.3/arch/ppc64/kernel/pci_iommu.c --- linus/arch/ppc64/kernel/pci_iommu.c 2005-06-27 16:08:00.000000000 +1000 +++ linus-dma_bypass.3/arch/ppc64/kernel/pci_iommu.c 2005-07-19 15:35:26.000000000 +1000 @@ -127,6 +127,11 @@ return 1; } +static int pci_iommu_set_dma_mask(struct device *dev, u64 mask) +{ + return pci_set_dma_mask(to_pci_dev(dev), mask); +} + void pci_iommu_init(void) { pci_dma_ops.alloc_coherent = pci_iommu_alloc_coherent; @@ -136,4 +141,5 @@ pci_dma_ops.map_sg = pci_iommu_map_sg; pci_dma_ops.unmap_sg = pci_iommu_unmap_sg; pci_dma_ops.dma_supported = pci_iommu_dma_supported; + pci_dma_ops.set_dma_mask = pci_iommu_set_dma_mask; } diff -ruN linus/arch/ppc64/kernel/vio.c linus-dma_bypass.3/arch/ppc64/kernel/vio.c --- linus/arch/ppc64/kernel/vio.c 2005-06-27 16:08:00.000000000 +1000 +++ linus-dma_bypass.3/arch/ppc64/kernel/vio.c 2005-07-19 15:45:05.000000000 +1000 @@ -45,6 +45,8 @@ static struct iommu_table veth_iommu_table; static struct iommu_table vio_iommu_table; #endif +static struct bus_type vio_bus_type; +static struct dma_mapping_ops vio_dma_mapping_ops; static struct vio_dev vio_bus_device = { /* fake "parent" device */ .name = vio_bus_device.dev.bus_id, .type = "", @@ -53,6 +55,7 @@ #endif .dev.bus_id = "vio", .dev.bus = &vio_bus_type, + .dev.dma_mapping_ops = &vio_dma_mapping_ops, }; #ifdef CONFIG_PPC_ISERIES @@ -600,7 +603,12 @@ return 1; } -struct dma_mapping_ops vio_dma_ops = { +static int vio_set_dma_mask(struct device *dev, u64 mask) +{ + return -EIO; +} + +static struct dma_mapping_ops vio_dma_mapping_ops = { .alloc_coherent = vio_alloc_coherent, .free_coherent = vio_free_coherent, .map_single = vio_map_single, @@ -608,6 +616,7 @@ .map_sg = vio_map_sg, .unmap_sg = vio_unmap_sg, .dma_supported = vio_dma_supported, + .set_dma_mask = vio_set_dma_mask, }; static int vio_bus_match(struct device *dev, struct device_driver *drv) @@ -629,7 +638,7 @@ return 0; } -struct bus_type vio_bus_type = { +static struct bus_type vio_bus_type = { .name = "vio", .match = vio_bus_match, }; diff -ruN linus/drivers/base/core.c linus-dma_bypass.3/drivers/base/core.c --- linus/drivers/base/core.c 2005-07-01 09:58:50.000000000 +1000 +++ linus-dma_bypass.3/drivers/base/core.c 2005-07-19 15:18:22.000000000 +1000 @@ -251,6 +251,9 @@ if (parent) klist_add_tail(&parent->klist_children, &dev->knode_parent); + if (parent && (dev->dma_mapping_ops == NULL)) + dev->dma_mapping_ops = parent->dma_mapping_ops; + /* notify platform of device entry */ if (platform_notify) platform_notify(dev); diff -ruN linus/drivers/pci/probe.c linus-dma_bypass.3/drivers/pci/probe.c --- linus/drivers/pci/probe.c 2005-07-06 21:18:22.000000000 +1000 +++ linus-dma_bypass.3/drivers/pci/probe.c 2005-07-19 15:43:37.000000000 +1000 @@ -9,6 +9,7 @@ #include <linux/slab.h> #include <linux/module.h> #include <linux/cpumask.h> +#include <linux/dma-mapping.h> #include "pci.h" #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ @@ -22,6 +23,8 @@ LIST_HEAD(pci_devices); +struct dma_mapping_ops pci_dma_ops; + #ifdef HAVE_PCI_LEGACY /** * pci_create_legacy_files - create legacy I/O port and memory files @@ -915,6 +918,8 @@ dev->parent = parent; dev->release = pci_release_bus_bridge_dev; sprintf(dev->bus_id, "pci%04x:%02x", pci_domain_nr(b), bus); + if (parent == NULL) + dev->dma_mapping_ops = &pci_dma_ops; error = device_register(dev); if (error) goto dev_reg_err; diff -ruN linus/include/asm-ppc64/dma-mapping.h linus-dma_bypass.3/include/asm-ppc64/dma-mapping.h --- linus/include/asm-ppc64/dma-mapping.h 2005-06-27 16:08:08.000000000 +1000 +++ linus-dma_bypass.3/include/asm-ppc64/dma-mapping.h 2005-07-19 13:47:08.000000000 +1000 @@ -16,25 +16,72 @@ #define DMA_ERROR_CODE (~(dma_addr_t)0x0) -extern int dma_supported(struct device *dev, u64 mask); -extern int dma_set_mask(struct device *dev, u64 dma_mask); -extern void *dma_alloc_coherent(struct device *dev, size_t size, - dma_addr_t *dma_handle, unsigned int __nocast flag); -extern void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, - dma_addr_t dma_handle); -extern dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, - size_t size, enum dma_data_direction direction); -extern void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, - size_t size, enum dma_data_direction direction); -extern dma_addr_t dma_map_page(struct device *dev, struct page *page, +static inline struct dma_mapping_ops *__get_dma_ops(struct device *dev) +{ + BUG_ON(dev->dma_mapping_ops == NULL); + return dev->dma_mapping_ops; +} + +static inline int dma_supported(struct device *dev, u64 mask) +{ + return dev->dma_mapping_ops && + __get_dma_ops(dev)->dma_supported(dev, mask); +} + +static inline int dma_set_mask(struct device *dev, u64 dma_mask) +{ + return __get_dma_ops(dev)->set_dma_mask(dev, dma_mask); +} + +static inline void *dma_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, unsigned int __nocast flag) +{ + return __get_dma_ops(dev)->alloc_coherent(dev, size, dma_handle, flag); +} + +static inline void dma_free_coherent(struct device *dev, size_t size, + void *cpu_addr, dma_addr_t dma_handle) +{ + __get_dma_ops(dev)->free_coherent(dev, size, cpu_addr, dma_handle); +} + +static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, + size_t size, enum dma_data_direction direction) +{ + return __get_dma_ops(dev)->map_single(dev, cpu_addr, size, direction); +} + +static inline void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, + size_t size, enum dma_data_direction direction) +{ + __get_dma_ops(dev)->unmap_single(dev, dma_addr, size, direction); +} + +static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, - enum dma_data_direction direction); -extern void dma_unmap_page(struct device *dev, dma_addr_t dma_address, - size_t size, enum dma_data_direction direction); -extern int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, - enum dma_data_direction direction); -extern void dma_unmap_sg(struct device *dev, struct scatterlist *sg, - int nhwentries, enum dma_data_direction direction); + enum dma_data_direction direction) +{ + return __get_dma_ops(dev)->map_single(dev, + (page_address(page) + offset), size, direction); +} + +static inline void dma_unmap_page(struct device *dev, dma_addr_t dma_address, + size_t size, enum dma_data_direction direction) +{ + __get_dma_ops(dev)->unmap_single(dev, dma_address, size, direction); +} + +static inline int dma_map_sg(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction direction) +{ + return __get_dma_ops(dev)->map_sg(dev, sg, nents, direction); +} + +static inline void dma_unmap_sg(struct device *dev, struct scatterlist *sg, + int nhwentries, enum dma_data_direction direction) +{ + __get_dma_ops(dev)->unmap_sg(dev, sg, nhwentries, direction); +} static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, @@ -113,24 +160,4 @@ /* nothing to do */ } -/* - * DMA operations are abstracted for G5 vs. i/pSeries, PCI vs. VIO - */ -struct dma_mapping_ops { - void * (*alloc_coherent)(struct device *dev, size_t size, - dma_addr_t *dma_handle, unsigned int __nocast flag); - void (*free_coherent)(struct device *dev, size_t size, - void *vaddr, dma_addr_t dma_handle); - dma_addr_t (*map_single)(struct device *dev, void *ptr, - size_t size, enum dma_data_direction direction); - void (*unmap_single)(struct device *dev, dma_addr_t dma_addr, - size_t size, enum dma_data_direction direction); - int (*map_sg)(struct device *dev, struct scatterlist *sg, - int nents, enum dma_data_direction direction); - void (*unmap_sg)(struct device *dev, struct scatterlist *sg, - int nents, enum dma_data_direction direction); - int (*dma_supported)(struct device *dev, u64 mask); - int (*dac_dma_supported)(struct device *dev, u64 mask); -}; - #endif /* _ASM_DMA_MAPPING_H */ diff -ruN linus/include/asm-ppc64/pci.h linus-dma_bypass.3/include/asm-ppc64/pci.h --- linus/include/asm-ppc64/pci.h 2005-07-13 11:38:01.000000000 +1000 +++ linus-dma_bypass.3/include/asm-ppc64/pci.h 2005-07-19 15:55:23.000000000 +1000 @@ -66,15 +66,15 @@ extern unsigned int pcibios_assign_all_busses(void); -extern struct dma_mapping_ops pci_dma_ops; - /* For DAC DMA, we currently don't support it by default, but * we let the platform override this */ static inline int pci_dac_dma_supported(struct pci_dev *hwdev,u64 mask) { +#if 0 if (pci_dma_ops.dac_dma_supported) return pci_dma_ops.dac_dma_supported(&hwdev->dev, mask); +#endif return 0; } diff -ruN linus/include/asm-ppc64/vio.h linus-dma_bypass.3/include/asm-ppc64/vio.h --- linus/include/asm-ppc64/vio.h 2005-06-27 16:08:08.000000000 +1000 +++ linus-dma_bypass.3/include/asm-ppc64/vio.h 2005-06-27 17:40:50.000000000 +1000 @@ -57,10 +57,6 @@ int vio_enable_interrupts(struct vio_dev *dev); int vio_disable_interrupts(struct vio_dev *dev); -extern struct dma_mapping_ops vio_dma_ops; - -extern struct bus_type vio_bus_type; - struct vio_device_id { char *type; char *compat; diff -ruN linus/include/linux/device.h linus-dma_bypass.3/include/linux/device.h --- linus/include/linux/device.h 2005-07-13 11:38:01.000000000 +1000 +++ linus-dma_bypass.3/include/linux/device.h 2005-07-19 13:44:49.000000000 +1000 @@ -45,6 +45,7 @@ struct device_driver; struct class; struct class_device; +struct dma_mapping_ops; struct bus_type { const char * name; @@ -301,6 +302,7 @@ struct dma_coherent_mem *dma_mem; /* internal for coherent mem override */ + struct dma_mapping_ops *dma_mapping_ops; void (*release)(struct device * dev); }; diff -ruN linus/include/linux/dma-mapping.h linus-dma_bypass.3/include/linux/dma-mapping.h --- linus/include/linux/dma-mapping.h 2005-06-27 16:08:11.000000000 +1000 +++ linus-dma_bypass.3/include/linux/dma-mapping.h 2005-07-19 15:54:50.000000000 +1000 @@ -21,6 +21,28 @@ #define DMA_30BIT_MASK 0x000000003fffffffULL #define DMA_29BIT_MASK 0x000000001fffffffULL +struct scatterlist; + +/* + * DMA operations may be defined per bus or per device. + */ +struct dma_mapping_ops { + void * (*alloc_coherent)(struct device *dev, size_t size, + dma_addr_t *dma_handle, unsigned int __nocast flag); + void (*free_coherent)(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_handle); + dma_addr_t (*map_single)(struct device *dev, void *ptr, + size_t size, enum dma_data_direction direction); + void (*unmap_single)(struct device *dev, dma_addr_t dma_addr, + size_t size, enum dma_data_direction direction); + int (*map_sg)(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction direction); + void (*unmap_sg)(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction direction); + int (*dma_supported)(struct device *dev, u64 mask); + int (*set_dma_mask)(struct device *dev, u64 mask); +}; + #include <asm/dma-mapping.h> /* Backwards compat, remove in 2.7.x */ diff -ruN linus/include/linux/pci.h linus-dma_bypass.3/include/linux/pci.h --- linus/include/linux/pci.h 2005-07-06 21:18:22.000000000 +1000 +++ linus-dma_bypass.3/include/linux/pci.h 2005-07-19 15:42:03.000000000 +1000 @@ -18,6 +18,7 @@ #define LINUX_PCI_H #include <linux/mod_devicetable.h> +#include <linux/dma-mapping.h> /* * Under PCI, each device has 256 bytes of configuration address space, @@ -722,6 +723,12 @@ extern struct list_head pci_root_buses; /* list of all known PCI buses */ extern struct list_head pci_devices; /* list of all devices */ +/* + * These DMA mapping ops will be applied to all discovered + * pci busses and inherited, by default, by all pci devices. + */ +extern struct dma_mapping_ops pci_dma_ops; + void pcibios_fixup_bus(struct pci_bus *); int pcibios_enable_device(struct pci_dev *, int mask); char *pcibios_setup (char *str); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
