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 devs, 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 devs = 0; 39 40 for (i = 0; i < err / 4; i++) { 41 u32 length; 42 43 of_property_read_u32_index(node, "iommu-map", i * 4 + 3, &length); 44 devs += length; 45 } 46 47 cdl->len = devs; 48 cdl->devs = kzalloc_objs(*cdl->devs, cdl->len); 49 if (!cdl->devs) 50 return -ENOMEM; 51 52 for (i = 0; i < cdl->len; i++) { 53 ctx = &cdl->devs[i]; 54 55 ctx->host = host1x; 56 57 device_initialize(&ctx->dev); 58 59 /* 60 * Due to an issue with T194 NVENC, only 38 bits can be used. 61 * Anyway, 256GiB of IOVA ought to be enough for anyone. 62 */ 63 ctx->dma_mask = DMA_BIT_MASK(38); 64 ctx->dev.dma_mask = &ctx->dma_mask; 65 ctx->dev.coherent_dma_mask = ctx->dma_mask; 66 dev_set_name(&ctx->dev, "host1x-ctx.%d", i); 67 ctx->dev.bus = &host1x_context_device_bus_type; 68 ctx->dev.parent = host1x->dev; 69 ctx->dev.release = host1x_memory_context_release; 70 71 ctx->dev.dma_parms = &ctx->dma_parms; 72 dma_set_max_seg_size(&ctx->dev, UINT_MAX); 73 74 err = device_add(&ctx->dev); 75 if (err) { 76 dev_err(host1x->dev, "could not add context device %d: %d\n", i, err); 77 put_device(&ctx->dev); 78 goto unreg_devices; 79 } 80 81 err = of_dma_configure_id(&ctx->dev, node, true, &i); 82 if (err) { 83 dev_err(host1x->dev, "IOMMU configuration failed for context device %d: %d\n", 84 i, err); 85 device_unregister(&ctx->dev); 86 goto unreg_devices; 87 } 88 89 if (!tegra_dev_iommu_get_stream_id(&ctx->dev, &ctx->stream_id) || 90 !device_iommu_mapped(&ctx->dev)) { 91 dev_err(host1x->dev, "Context device %d has no IOMMU!\n", i); 92 device_unregister(&ctx->dev); 93 94 /* 95 * This means that if IOMMU is disabled but context devices 96 * are defined in the device tree, Host1x will fail to probe. 97 * That's probably OK in this time and age. 98 */ 99 err = -EINVAL; 100 101 goto unreg_devices; 102 } 103 } 104 105 return 0; 106 107 unreg_devices: 108 while (i--) 109 device_unregister(&cdl->devs[i].dev); 110 111 kfree(cdl->devs); 112 cdl->devs = NULL; 113 cdl->len = 0; 114 115 return err; 116 } 117 118 void host1x_memory_context_list_free(struct host1x_memory_context_list *cdl) 119 { 120 unsigned int i; 121 122 for (i = 0; i < cdl->len; i++) 123 device_unregister(&cdl->devs[i].dev); 124 125 kfree(cdl->devs); 126 cdl->len = 0; 127 } 128 129 struct host1x_memory_context *host1x_memory_context_alloc(struct host1x *host1x, 130 struct device *dev, 131 struct pid *pid) 132 { 133 struct host1x_memory_context_list *cdl = &host1x->context_list; 134 struct host1x_memory_context *free = NULL; 135 int i; 136 137 if (!cdl->len) 138 return ERR_PTR(-EOPNOTSUPP); 139 140 mutex_lock(&cdl->lock); 141 142 for (i = 0; i < cdl->len; i++) { 143 struct host1x_memory_context *cd = &cdl->devs[i]; 144 145 if (cd->dev.iommu->iommu_dev != dev->iommu->iommu_dev) 146 continue; 147 148 if (cd->owner == pid) { 149 refcount_inc(&cd->ref); 150 mutex_unlock(&cdl->lock); 151 return cd; 152 } else if (!cd->owner && !free) { 153 free = cd; 154 } 155 } 156 157 if (!free) { 158 mutex_unlock(&cdl->lock); 159 return ERR_PTR(-EBUSY); 160 } 161 162 refcount_set(&free->ref, 1); 163 free->owner = get_pid(pid); 164 165 mutex_unlock(&cdl->lock); 166 167 return free; 168 } 169 EXPORT_SYMBOL_GPL(host1x_memory_context_alloc); 170 171 void host1x_memory_context_get(struct host1x_memory_context *cd) 172 { 173 refcount_inc(&cd->ref); 174 } 175 EXPORT_SYMBOL_GPL(host1x_memory_context_get); 176 177 void host1x_memory_context_put(struct host1x_memory_context *cd) 178 { 179 struct host1x_memory_context_list *cdl = &cd->host->context_list; 180 181 if (refcount_dec_and_mutex_lock(&cd->ref, &cdl->lock)) { 182 put_pid(cd->owner); 183 cd->owner = NULL; 184 mutex_unlock(&cdl->lock); 185 } 186 } 187 EXPORT_SYMBOL_GPL(host1x_memory_context_put); 188