Messages in this thread Patch in this message | | | Date | Thu, 9 Apr 2009 15:25:00 -0500 (CDT) | From | Kumar Gala <> | Subject | Re: [PATCH 4/7] swiotlb: Allow arch override of address_needs_mapping |
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Here's the WIP patch for the PPC changes to give some sense of what we need out of swiotlb for PPC.
- k
--- arch/powerpc/include/asm/dma-mapping.h | 18 ++++ arch/powerpc/include/asm/scatterlist.h | 6 +- arch/powerpc/include/asm/swiotlb.h | 15 +++ arch/powerpc/kernel/Makefile | 1 + arch/powerpc/kernel/dma-swiotlb.c | 154 ++++++++++++++++++++++++++++ arch/powerpc/kernel/dma.c | 2 +- arch/powerpc/kernel/pci-common.c | 2 + arch/powerpc/kernel/setup_32.c | 4 + 10 files changed, 211 insertions(+), 7 deletions(-) create mode 100644 arch/powerpc/include/asm/swiotlb.h create mode 100644 arch/powerpc/kernel/dma-swiotlb.c
diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h index c69f2b5..db6edfe 100644 --- a/arch/powerpc/include/asm/dma-mapping.h +++ b/arch/powerpc/include/asm/dma-mapping.h @@ -16,8 +16,18 @@ #include <linux/dma-attrs.h> #include <asm/io.h>
+#ifdef CONFIG_SWIOTLB +#include <asm/swiotlb.h> +#endif + #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); + #ifdef CONFIG_NOT_COHERENT_CACHE /* * DMA-consistent mapping functions for PowerPCs that don't support @@ -112,11 +122,19 @@ static inline struct dma_mapping_ops *get_dma_ops(struct device *dev) if (unlikely(dev == NULL)) return NULL;
+ /* BGILL - temp code to look for problems */ + if(dev->archdata.dma_ops == NULL) + printk(KERN_EMERG "dev %s has null dma_ops\n", dev->bus->name); + return dev->archdata.dma_ops; }
static inline void set_dma_ops(struct device *dev, struct dma_mapping_ops *ops) { + printk(KERN_EMERG "Setting dma_ops to %s\n", + (ops == &dma_direct_ops) ? "dma_direct_ops" : + ((ops == &swiotlb_dma_ops) ? "swiotlb_dma_ops" : "unknown")); + dev->archdata.dma_ops = ops; }
diff --git a/arch/powerpc/include/asm/scatterlist.h b/arch/powerpc/include/asm/scatterlist.h index fcf7d55..912bf59 100644 --- a/arch/powerpc/include/asm/scatterlist.h +++ b/arch/powerpc/include/asm/scatterlist.h @@ -21,7 +21,7 @@ struct scatterlist { unsigned int offset; unsigned int length;
- /* For TCE support */ + /* For TCE or SWIOTLB support */ dma_addr_t dma_address; u32 dma_length; }; @@ -34,11 +34,7 @@ struct scatterlist { * is 0. */ #define sg_dma_address(sg) ((sg)->dma_address) -#ifdef __powerpc64__ #define sg_dma_len(sg) ((sg)->dma_length) -#else -#define sg_dma_len(sg) ((sg)->length) -#endif
#ifdef __powerpc64__ #define ISA_DMA_THRESHOLD (~0UL) diff --git a/arch/powerpc/include/asm/swiotlb.h b/arch/powerpc/include/asm/swiotlb.h new file mode 100644 index 0000000..cbfce6c --- /dev/null +++ b/arch/powerpc/include/asm/swiotlb.h @@ -0,0 +1,15 @@ +#ifndef __ASM_SWIOTLB_H +#define __ASM_SWIOTLB_H + +#include <linux/swiotlb.h> + +extern int swiotlb_force; +extern int swiotlb; +extern struct dma_mapping_ops swiotlb_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..639f3bc --- /dev/null +++ b/arch/powerpc/kernel/dma-swiotlb.c @@ -0,0 +1,154 @@ +/* + * Copyright (C) 2009 Becky Bruce, Freescale Semiconductor + * + * swiotlb dma ops and functions required by the swiotlb code. + */ + +#include <linux/dma-mapping.h> +#include <linux/pfn.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> + +#include <asm/machdep.h> +#include <asm/swiotlb.h> +#include <asm/dma.h> +#include <asm/abs_addr.h> + +int swiotlb __read_mostly; + +unsigned long get_dma_direct_offset(struct device *dev); + +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; +} + +#if 0 /* BGILL - don't need */ +/* This can only be called on pages with a kernel mapping */ +dma_addr_t swiotlb_virt_to_bus(struct device *hwdev, void *addr) +{ + return swiotlb_phys_to_bus(hwdev, virt_to_abs((unsigned long)addr)); +} +#endif + +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)); +} + +/* + * Eventually, we should really be looking at some per-device + * quantity stored in archdata, and not a global value, since this is + * only needed for devices like PCI that use part of their 32 bit address + * space for something other than mapping memory. + * + * For now, require swiotlb mapping above MAX_32B_DIRECT_DMA_ADDR for devs + * that are not 64-bit capable. This should be determined using the PCI mem + * allocations in the devtree. -beckyb + */ +#define MAX_32B_DIRECT_DMA_ADDR 0x80000000 + +/* determine if an address needs bounce buffering via swiotlb. */ +int +swiotlb_arch_address_needs_mapping(struct device *hwdev, dma_addr_t addr, + size_t size) +{ + dma_addr_t mask = DMA_BIT_MASK(32); + + /* Max dma_address we can access without bounce buffering */ + dma_addr_t max = swiotlb_phys_to_bus(hwdev, MAX_32B_DIRECT_DMA_ADDR); + + /* BGILL - can we get rid of this? */ + if (hwdev && hwdev->dma_mask) + mask = *hwdev->dma_mask; + + if ((mask <= DMA_BIT_MASK(36)) && (addr + size > max)) + return 1; + + return !is_buffer_dma_capable(mask, 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 = { +#if 0 + .alloc_coherent = dma_direct_alloc_coherent, + .free_coherent = dma_direct_free_coherent, +#else + .alloc_coherent = swiotlb_alloc_coherent, + .free_coherent = swiotlb_free_coherent, +#endif + .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, + .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 0 /* BGILL - should look like this; use other form for debug */ + if(dma_get_mask(dev) < DMA_BIT_MASK(36)) + set_dma_ops(dev, &swiotlb_dma_ops); +#else + if(!dev->dma_mask) { + printk(KERN_EMERG "ERROR: no dma_mask set for dev\n"); + set_dma_ops(dev, &swiotlb_dma_ops); + } + else if(*dev->dma_mask < DMA_BIT_MASK(36)) { + set_dma_ops(dev, &swiotlb_dma_ops); + } + else + printk(KERN_EMERG "ERROR; fall thru with direct_ops\n"); +#endif + + 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; +} + +machine_arch_initcall(mpc86xx_hpcn, setup_bus_notifier); + 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 */
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