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![Christoph Hellwig](/assets/img/avatar_default.png)
Half of the file just contains platform device memory setup code which is required for all builds, and half contains helpers for dma coherent allocation, which is only needed if CONFIG_DMA_NONCOHERENT is enabled. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
68 lines
1.6 KiB
C
68 lines
1.6 KiB
C
/*
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* Copyright (C) 2004 - 2007 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/dma-mapping.h>
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#include <linux/io.h>
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static int __init memchunk_setup(char *str)
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{
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return 1; /* accept anything that begins with "memchunk." */
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}
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__setup("memchunk.", memchunk_setup);
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static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
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{
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char *p = boot_command_line;
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int k = strlen(name);
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while ((p = strstr(p, "memchunk."))) {
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p += 9; /* strlen("memchunk.") */
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if (!strncmp(name, p, k) && p[k] == '=') {
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p += k + 1;
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*sizep = memparse(p, NULL);
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pr_info("%s: forcing memory chunk size to 0x%08lx\n",
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name, *sizep);
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break;
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}
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}
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}
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int __init platform_resource_setup_memory(struct platform_device *pdev,
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char *name, unsigned long memsize)
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{
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struct resource *r;
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dma_addr_t dma_handle;
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void *buf;
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r = pdev->resource + pdev->num_resources - 1;
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if (r->flags) {
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pr_warning("%s: unable to find empty space for resource\n",
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name);
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return -EINVAL;
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}
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memchunk_cmdline_override(name, &memsize);
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if (!memsize)
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return 0;
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buf = dma_alloc_coherent(&pdev->dev, memsize, &dma_handle, GFP_KERNEL);
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if (!buf) {
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pr_warning("%s: unable to allocate memory\n", name);
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return -ENOMEM;
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}
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memset(buf, 0, memsize);
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r->flags = IORESOURCE_MEM;
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r->start = dma_handle;
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r->end = r->start + memsize - 1;
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r->name = name;
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return 0;
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}
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