cregit-Linux how code gets into the kernel

Release 4.7 arch/frv/mb93090-mb00/pci-dma-nommu.c

/* pci-dma-nommu.c: Dynamic DMA mapping support for the FRV
 *
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Woodhouse (dwmw2@infradead.org)
 *
 * 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/types.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/dma-mapping.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <asm/io.h>

#if 1

#define DMA_SRAM_START	dma_coherent_mem_start

#define DMA_SRAM_END	dma_coherent_mem_end
#else // Use video RAM on Matrox

#define DMA_SRAM_START	0xe8900000

#define DMA_SRAM_END	0xe8a00000
#endif


struct dma_alloc_record {
	
struct list_head	list;
	
unsigned long		ofs;
	
unsigned long		len;
};

static DEFINE_SPINLOCK(dma_alloc_lock);
static LIST_HEAD(dma_alloc_list);


static void *frv_dma_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs *attrs) { struct dma_alloc_record *new; struct list_head *this = &dma_alloc_list; unsigned long flags; unsigned long start = DMA_SRAM_START; unsigned long end; if (!DMA_SRAM_START) { printk("%s called without any DMA area reserved!\n", __func__); return NULL; } new = kmalloc(sizeof (*new), GFP_ATOMIC); if (!new) return NULL; /* Round up to a reasonable alignment */ new->len = (size + 31) & ~31; spin_lock_irqsave(&dma_alloc_lock, flags); list_for_each (this, &dma_alloc_list) { struct dma_alloc_record *this_r = list_entry(this, struct dma_alloc_record, list); end = this_r->ofs; if (end - start >= size) goto gotone; start = this_r->ofs + this_r->len; } /* Reached end of list. */ end = DMA_SRAM_END; this = &dma_alloc_list; if (end - start >= size) { gotone: new->ofs = start; list_add_tail(&new->list, this); spin_unlock_irqrestore(&dma_alloc_lock, flags); *dma_handle = start; return (void *)start; } kfree(new); spin_unlock_irqrestore(&dma_alloc_lock, flags); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
david howellsdavid howells23096.64%133.33%
christoph hellwigchristoph hellwig72.94%133.33%
al viroal viro10.42%133.33%
Total238100.00%3100.00%


static void frv_dma_free(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle, struct dma_attrs *attrs) { struct dma_alloc_record *rec; unsigned long flags; spin_lock_irqsave(&dma_alloc_lock, flags); list_for_each_entry(rec, &dma_alloc_list, list) { if (rec->ofs == dma_handle) { list_del(&rec->list); kfree(rec); spin_unlock_irqrestore(&dma_alloc_lock, flags); return; } } spin_unlock_irqrestore(&dma_alloc_lock, flags); BUG(); }

Contributors

PersonTokensPropCommitsCommitProp
david howellsdavid howells8992.71%150.00%
christoph hellwigchristoph hellwig77.29%150.00%
Total96100.00%2100.00%


static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction, struct dma_attrs *attrs) { int i; struct scatterlist *sg; for_each_sg(sglist, sg, nents, i) { frv_cache_wback_inv(sg_dma_address(sg), sg_dma_address(sg) + sg_dma_len(sg)); } BUG_ON(direction == DMA_NONE); return nents; }

Contributors

PersonTokensPropCommitsCommitProp
david howellsdavid howells4863.16%125.00%
akinobu mitaakinobu mita1823.68%125.00%
christoph hellwigchristoph hellwig79.21%125.00%
stoyan gaydarovstoyan gaydarov33.95%125.00%
Total76100.00%4100.00%


static dma_addr_t frv_dma_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction direction, struct dma_attrs *attrs) { BUG_ON(direction == DMA_NONE); flush_dcache_page(page); return (dma_addr_t) page_to_phys(page) + offset; }

Contributors

PersonTokensPropCommitsCommitProp
david howellsdavid howells4887.27%150.00%
christoph hellwigchristoph hellwig712.73%150.00%
Total55100.00%2100.00%


static void frv_dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction) { flush_write_buffers(); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig24100.00%1100.00%
Total24100.00%1100.00%


static void frv_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, enum dma_data_direction direction) { flush_write_buffers(); }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig26100.00%1100.00%
Total26100.00%1100.00%


static int frv_dma_supported(struct device *dev, u64 mask) { /* * we fall back to GFP_DMA when the mask isn't all 1s, * so we can't guarantee allocations that must be * within a tighter range than GFP_DMA.. */ if (mask < 0x00ffffff) return 0; return 1; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig27100.00%1100.00%
Total27100.00%1100.00%

struct dma_map_ops frv_dma_ops = { .alloc = frv_dma_alloc, .free = frv_dma_free, .map_page = frv_dma_map_page, .map_sg = frv_dma_map_sg, .sync_single_for_device = frv_dma_sync_single_for_device, .sync_sg_for_device = frv_dma_sync_sg_for_device, .dma_supported = frv_dma_supported, }; EXPORT_SYMBOL(frv_dma_ops);

Overall Contributors

PersonTokensPropCommitsCommitProp
david howellsdavid howells48973.76%333.33%
christoph hellwigchristoph hellwig14722.17%111.11%
akinobu mitaakinobu mita182.71%111.11%
thomas gleixnerthomas gleixner40.60%111.11%
stoyan gaydarovstoyan gaydarov30.45%111.11%
david woodhousedavid woodhouse10.15%111.11%
al viroal viro10.15%111.11%
Total663100.00%9100.00%
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