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      1 /*	$NetBSD: intel_region_lmem.c,v 1.2 2021/12/18 23:45:28 riastradh Exp $	*/
      2 
      3 // SPDX-License-Identifier: MIT
      4 /*
      5  * Copyright  2019 Intel Corporation
      6  */
      7 
      8 #include <sys/cdefs.h>
      9 __KERNEL_RCSID(0, "$NetBSD: intel_region_lmem.c,v 1.2 2021/12/18 23:45:28 riastradh Exp $");
     10 
     11 #include "i915_drv.h"
     12 #include "intel_memory_region.h"
     13 #include "gem/i915_gem_lmem.h"
     14 #include "gem/i915_gem_region.h"
     15 #include "intel_region_lmem.h"
     16 
     17 static int init_fake_lmem_bar(struct intel_memory_region *mem)
     18 {
     19 	struct drm_i915_private *i915 = mem->i915;
     20 	struct i915_ggtt *ggtt = &i915->ggtt;
     21 	unsigned long n;
     22 	int ret;
     23 
     24 	/* We want to 1:1 map the mappable aperture to our reserved region */
     25 
     26 	mem->fake_mappable.start = 0;
     27 	mem->fake_mappable.size = resource_size(&mem->region);
     28 	mem->fake_mappable.color = I915_COLOR_UNEVICTABLE;
     29 
     30 	ret = drm_mm_reserve_node(&ggtt->vm.mm, &mem->fake_mappable);
     31 	if (ret)
     32 		return ret;
     33 
     34 	mem->remap_addr = dma_map_resource(&i915->drm.pdev->dev,
     35 					   mem->region.start,
     36 					   mem->fake_mappable.size,
     37 					   PCI_DMA_BIDIRECTIONAL,
     38 					   DMA_ATTR_FORCE_CONTIGUOUS);
     39 	if (dma_mapping_error(&i915->drm.pdev->dev, mem->remap_addr)) {
     40 		drm_mm_remove_node(&mem->fake_mappable);
     41 		return -EINVAL;
     42 	}
     43 
     44 	for (n = 0; n < mem->fake_mappable.size >> PAGE_SHIFT; ++n) {
     45 		ggtt->vm.insert_page(&ggtt->vm,
     46 				     mem->remap_addr + (n << PAGE_SHIFT),
     47 				     n << PAGE_SHIFT,
     48 				     I915_CACHE_NONE, 0);
     49 	}
     50 
     51 	mem->region = (struct resource)DEFINE_RES_MEM(mem->remap_addr,
     52 						      mem->fake_mappable.size);
     53 
     54 	return 0;
     55 }
     56 
     57 static void release_fake_lmem_bar(struct intel_memory_region *mem)
     58 {
     59 	if (!drm_mm_node_allocated(&mem->fake_mappable))
     60 		return;
     61 
     62 	drm_mm_remove_node(&mem->fake_mappable);
     63 
     64 	dma_unmap_resource(&mem->i915->drm.pdev->dev,
     65 			   mem->remap_addr,
     66 			   mem->fake_mappable.size,
     67 			   PCI_DMA_BIDIRECTIONAL,
     68 			   DMA_ATTR_FORCE_CONTIGUOUS);
     69 }
     70 
     71 static void
     72 region_lmem_release(struct intel_memory_region *mem)
     73 {
     74 	release_fake_lmem_bar(mem);
     75 	io_mapping_fini(&mem->iomap);
     76 	intel_memory_region_release_buddy(mem);
     77 }
     78 
     79 static int
     80 region_lmem_init(struct intel_memory_region *mem)
     81 {
     82 	int ret;
     83 
     84 	if (i915_modparams.fake_lmem_start) {
     85 		ret = init_fake_lmem_bar(mem);
     86 		GEM_BUG_ON(ret);
     87 	}
     88 
     89 	if (!io_mapping_init_wc(&mem->iomap,
     90 				mem->io_start,
     91 				resource_size(&mem->region)))
     92 		return -EIO;
     93 
     94 	ret = intel_memory_region_init_buddy(mem);
     95 	if (ret)
     96 		io_mapping_fini(&mem->iomap);
     97 
     98 	intel_memory_region_set_name(mem, "local");
     99 
    100 	return ret;
    101 }
    102 
    103 const struct intel_memory_region_ops intel_region_lmem_ops = {
    104 	.init = region_lmem_init,
    105 	.release = region_lmem_release,
    106 	.create_object = __i915_gem_lmem_object_create,
    107 };
    108 
    109 struct intel_memory_region *
    110 intel_setup_fake_lmem(struct drm_i915_private *i915)
    111 {
    112 	struct pci_dev *pdev = i915->drm.pdev;
    113 	struct intel_memory_region *mem;
    114 	resource_size_t mappable_end;
    115 	resource_size_t io_start;
    116 	resource_size_t start;
    117 
    118 	GEM_BUG_ON(i915_ggtt_has_aperture(&i915->ggtt));
    119 	GEM_BUG_ON(!i915_modparams.fake_lmem_start);
    120 
    121 	/* Your mappable aperture belongs to me now! */
    122 	mappable_end = pci_resource_len(pdev, 2);
    123 	io_start = pci_resource_start(pdev, 2),
    124 	start = i915_modparams.fake_lmem_start;
    125 
    126 	mem = intel_memory_region_create(i915,
    127 					 start,
    128 					 mappable_end,
    129 					 PAGE_SIZE,
    130 					 io_start,
    131 					 &intel_region_lmem_ops);
    132 	if (!IS_ERR(mem)) {
    133 		drm_info(&i915->drm, "Intel graphics fake LMEM: %pR\n",
    134 			 &mem->region);
    135 		drm_info(&i915->drm,
    136 			 "Intel graphics fake LMEM IO start: %llx\n",
    137 			(u64)mem->io_start);
    138 		drm_info(&i915->drm, "Intel graphics fake LMEM size: %llx\n",
    139 			 (u64)resource_size(&mem->region));
    140 	}
    141 
    142 	return mem;
    143 }
    144