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-rw-r--r--drivers/gpu/drm/i915/i915_mm.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
new file mode 100644
index 000000000..7998bc74a
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_mm.c
@@ -0,0 +1,154 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/mm.h>
+#include <linux/io-mapping.h>
+
+
+#include "i915_drv.h"
+#include "i915_mm.h"
+
+struct remap_pfn {
+ struct mm_struct *mm;
+ unsigned long pfn;
+ pgprot_t prot;
+
+ struct sgt_iter sgt;
+ resource_size_t iobase;
+};
+
+#define use_dma(io) ((io) != -1)
+
+static inline unsigned long sgt_pfn(const struct remap_pfn *r)
+{
+ if (use_dma(r->iobase))
+ return (r->sgt.dma + r->sgt.curr + r->iobase) >> PAGE_SHIFT;
+ else
+ return r->sgt.pfn + (r->sgt.curr >> PAGE_SHIFT);
+}
+
+static int remap_sg(pte_t *pte, unsigned long addr, void *data)
+{
+ struct remap_pfn *r = data;
+
+ if (GEM_WARN_ON(!r->sgt.sgp))
+ return -EINVAL;
+
+ /* Special PTE are not associated with any struct page */
+ set_pte_at(r->mm, addr, pte,
+ pte_mkspecial(pfn_pte(sgt_pfn(r), r->prot)));
+ r->pfn++; /* track insertions in case we need to unwind later */
+
+ r->sgt.curr += PAGE_SIZE;
+ if (r->sgt.curr >= r->sgt.max)
+ r->sgt = __sgt_iter(__sg_next(r->sgt.sgp), use_dma(r->iobase));
+
+ return 0;
+}
+
+#define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)
+
+#if IS_ENABLED(CONFIG_X86)
+static int remap_pfn(pte_t *pte, unsigned long addr, void *data)
+{
+ struct remap_pfn *r = data;
+
+ /* Special PTE are not associated with any struct page */
+ set_pte_at(r->mm, addr, pte, pte_mkspecial(pfn_pte(r->pfn, r->prot)));
+ r->pfn++;
+
+ return 0;
+}
+
+/**
+ * remap_io_mapping - remap an IO mapping to userspace
+ * @vma: user vma to map to
+ * @addr: target user address to start at
+ * @pfn: physical address of kernel memory
+ * @size: size of map area
+ * @iomap: the source io_mapping
+ *
+ * Note: this is only safe if the mm semaphore is held when called.
+ */
+int remap_io_mapping(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long pfn, unsigned long size,
+ struct io_mapping *iomap)
+{
+ struct remap_pfn r;
+ int err;
+
+ GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
+
+ /* We rely on prevalidation of the io-mapping to skip track_pfn(). */
+ r.mm = vma->vm_mm;
+ r.pfn = pfn;
+ r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) |
+ (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK));
+
+ err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r);
+ if (unlikely(err)) {
+ zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
+ return err;
+ }
+
+ return 0;
+}
+#endif
+
+/**
+ * remap_io_sg - remap an IO mapping to userspace
+ * @vma: user vma to map to
+ * @addr: target user address to start at
+ * @size: size of map area
+ * @sgl: Start sg entry
+ * @iobase: Use stored dma address offset by this address or pfn if -1
+ *
+ * Note: this is only safe if the mm semaphore is held when called.
+ */
+int remap_io_sg(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long size,
+ struct scatterlist *sgl, resource_size_t iobase)
+{
+ struct remap_pfn r = {
+ .mm = vma->vm_mm,
+ .prot = vma->vm_page_prot,
+ .sgt = __sgt_iter(sgl, use_dma(iobase)),
+ .iobase = iobase,
+ };
+ int err;
+
+ /* We rely on prevalidation of the io-mapping to skip track_pfn(). */
+ GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
+
+ if (!use_dma(iobase))
+ flush_cache_range(vma, addr, size);
+
+ err = apply_to_page_range(r.mm, addr, size, remap_sg, &r);
+ if (unlikely(err)) {
+ zap_vma_ptes(vma, addr, r.pfn << PAGE_SHIFT);
+ return err;
+ }
+
+ return 0;
+}