1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2021, NVIDIA Corporation. 4 */ 5 6 #include <linux/device.h> 7 #include <linux/host1x_context_bus.h> 8 #include <linux/kref.h> 9 #include <linux/of.h> 10 #include <linux/of_device.h> 11 #include <linux/pid.h> 12 #include <linux/slab.h> 13 14 #include "context.h" 15 #include "dev.h" 16 17 static void host1x_memory_context_release(struct device *dev) 18 { 19 /* context device is freed in host1x_memory_context_list_free() */ 20 } 21 22 int host1x_memory_context_list_init(struct host1x *host1x) 23 { 24 struct host1x_memory_context_list *cdl = &host1x->context_list; 25 struct device_node *node = host1x->dev->of_node; 26 struct host1x_memory_context *ctx; 27 unsigned int i; 28 int err; 29 30 cdl->devs = NULL; 31 cdl->len = 0; 32 mutex_init(&cdl->lock); 33 34 err = of_property_count_u32_elems(node, "iommu-map"); 35 if (err < 0) 36 return 0; 37 38 cdl->len = err / 4; 39 cdl->devs = kzalloc_objs(*cdl->devs, cdl->len); 40 if (!cdl->devs) 41 return -ENOMEM; 42 43 for (i = 0; i < cdl->len; i++) { 44 ctx = &cdl->devs[i]; 45 46 ctx->host = host1x; 47 48 device_initialize(&ctx->dev); 49 50 /* 51 * Due to an issue with T194 NVENC, only 38 bits can be used. 52 * Anyway, 256GiB of IOVA ought to be enough for anyone. 53 */ 54 ctx->dma_mask = DMA_BIT_MASK(38); 55 ctx->dev.dma_mask = &ctx->dma_mask; 56 ctx->dev.coherent_dma_mask = ctx->dma_mask; 57 dev_set_name(&ctx->dev, "host1x-ctx.%d", i); 58 ctx->dev.bus = &host1x_context_device_bus_type; 59 ctx->dev.parent = host1x->dev; 60 ctx->dev.release = host1x_memory_context_release; 61 62 ctx->dev.dma_parms = &ctx->dma_parms; 63 dma_set_max_seg_size(&ctx->dev, UINT_MAX); 64 65 err = device_add(&ctx->dev); 66 if (err) { 67 dev_err(host1x->dev, "could not add context device %d: %d\n", i, err); 68 put_device(&ctx->dev); 69 goto unreg_devices; 70 } 71 72 err = of_dma_configure_id(&ctx->dev, node, true, &i); 73 if (err) { 74 dev_err(host1x->dev, "IOMMU configuration failed for context device %d: %d\n", 75 i, err); 76 device_unregister(&ctx->dev); 77 goto unreg_devices; 78 } 79 80 if (!tegra_dev_iommu_get_stream_id(&ctx->dev, &ctx->stream_id) || 81 !device_iommu_mapped(&ctx->dev)) { 82 dev_err(host1x->dev, "Context device %d has no IOMMU!\n", i); 83 device_unregister(&ctx->dev); 84 85 /* 86 * This means that if IOMMU is disabled but context devices 87 * are defined in the device tree, Host1x will fail to probe. 88 * That's probably OK in this time and age. 89 */ 90 err = -EINVAL; 91 92 goto unreg_devices; 93 } 94 } 95 96 return 0; 97 98 unreg_devices: 99 while (i--) 100 device_unregister(&cdl->devs[i].dev); 101 102 kfree(cdl->devs); 103 cdl->devs = NULL; 104 cdl->len = 0; 105 106 return err; 107 } 108 109 void host1x_memory_context_list_free(struct host1x_memory_context_list *cdl) 110 { 111 unsigned int i; 112 113 for (i = 0; i < cdl->len; i++) 114 device_unregister(&cdl->devs[i].dev); 115 116 kfree(cdl->devs); 117 cdl->len = 0; 118 } 119 120 struct host1x_memory_context *host1x_memory_context_alloc(struct host1x *host1x, 121 struct device *dev, 122 struct pid *pid) 123 { 124 struct host1x_memory_context_list *cdl = &host1x->context_list; 125 struct host1x_memory_context *free = NULL; 126 int i; 127 128 if (!cdl->len) 129 return ERR_PTR(-EOPNOTSUPP); 130 131 mutex_lock(&cdl->lock); 132 133 for (i = 0; i < cdl->len; i++) { 134 struct host1x_memory_context *cd = &cdl->devs[i]; 135 136 if (cd->dev.iommu->iommu_dev != dev->iommu->iommu_dev) 137 continue; 138 139 if (cd->owner == pid) { 140 refcount_inc(&cd->ref); 141 mutex_unlock(&cdl->lock); 142 return cd; 143 } else if (!cd->owner && !free) { 144 free = cd; 145 } 146 } 147 148 if (!free) { 149 mutex_unlock(&cdl->lock); 150 return ERR_PTR(-EBUSY); 151 } 152 153 refcount_set(&free->ref, 1); 154 free->owner = get_pid(pid); 155 156 mutex_unlock(&cdl->lock); 157 158 return free; 159 } 160 EXPORT_SYMBOL_GPL(host1x_memory_context_alloc); 161 162 void host1x_memory_context_get(struct host1x_memory_context *cd) 163 { 164 refcount_inc(&cd->ref); 165 } 166 EXPORT_SYMBOL_GPL(host1x_memory_context_get); 167 168 void host1x_memory_context_put(struct host1x_memory_context *cd) 169 { 170 struct host1x_memory_context_list *cdl = &cd->host->context_list; 171 172 if (refcount_dec_and_mutex_lock(&cd->ref, &cdl->lock)) { 173 put_pid(cd->owner); 174 cd->owner = NULL; 175 mutex_unlock(&cdl->lock); 176 } 177 } 178 EXPORT_SYMBOL_GPL(host1x_memory_context_put); 179