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	We don't really want to use VM_IO for our GGTT mmaps (it implies that the mmap contains memory mapped registers, which we do not expose) yet I overzealously added it to an assert just because that's how we always had setup the vma. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com> Reviewed-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190807094128.9993-1-chris@chris-wilson.co.uk
		
			
				
	
	
		
			82 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright © 2014 Intel Corporation
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 *
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 * Permission is hereby granted, free of charge, to any person obtaining a
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 * copy of this software and associated documentation files (the "Software"),
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 * to deal in the Software without restriction, including without limitation
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 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
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 * and/or sell copies of the Software, and to permit persons to whom the
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 * Software is furnished to do so, subject to the following conditions:
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 *
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 * The above copyright notice and this permission notice (including the next
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 * paragraph) shall be included in all copies or substantial portions of the
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 * Software.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
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 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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 * IN THE SOFTWARE.
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 *
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 */
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#include <linux/mm.h>
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#include <linux/io-mapping.h>
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#include <asm/pgtable.h>
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#include "i915_drv.h"
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struct remap_pfn {
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	struct mm_struct *mm;
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	unsigned long pfn;
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	pgprot_t prot;
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};
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static int remap_pfn(pte_t *pte, unsigned long addr, void *data)
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{
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	struct remap_pfn *r = data;
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	/* Special PTE are not associated with any struct page */
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	set_pte_at(r->mm, addr, pte, pte_mkspecial(pfn_pte(r->pfn, r->prot)));
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	r->pfn++;
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	return 0;
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}
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/**
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 * remap_io_mapping - remap an IO mapping to userspace
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 * @vma: user vma to map to
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 * @addr: target user address to start at
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 * @pfn: physical address of kernel memory
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 * @size: size of map area
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 * @iomap: the source io_mapping
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 *
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 *  Note: this is only safe if the mm semaphore is held when called.
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 */
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int remap_io_mapping(struct vm_area_struct *vma,
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		     unsigned long addr, unsigned long pfn, unsigned long size,
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		     struct io_mapping *iomap)
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{
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	struct remap_pfn r;
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	int err;
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#define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)
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	GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
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	/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
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	r.mm = vma->vm_mm;
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	r.pfn = pfn;
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	r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) |
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			  (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK));
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	err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r);
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	if (unlikely(err)) {
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		zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
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		return err;
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	}
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	return 0;
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}
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