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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2021, NVIDIA Corporation.4 */5 6#include <linux/device.h>7#include <linux/kref.h>8#include <linux/of.h>9#include <linux/of_device.h>10#include <linux/pid.h>11#include <linux/slab.h>12 13#include "context.h"14#include "dev.h"15 16static void host1x_memory_context_release(struct device *dev)17{18 /* context device is freed in host1x_memory_context_list_free() */19}20 21int host1x_memory_context_list_init(struct host1x *host1x)22{23 struct host1x_memory_context_list *cdl = &host1x->context_list;24 struct device_node *node = host1x->dev->of_node;25 struct host1x_memory_context *ctx;26 unsigned int i;27 int err;28 29 cdl->devs = NULL;30 cdl->len = 0;31 mutex_init(&cdl->lock);32 33 err = of_property_count_u32_elems(node, "iommu-map");34 if (err < 0)35 return 0;36 37 cdl->len = err / 4;38 cdl->devs = kcalloc(cdl->len, sizeof(*cdl->devs), GFP_KERNEL);39 if (!cdl->devs)40 return -ENOMEM;41 42 for (i = 0; i < cdl->len; i++) {43 ctx = &cdl->devs[i];44 45 ctx->host = host1x;46 47 device_initialize(&ctx->dev);48 49 /*50 * Due to an issue with T194 NVENC, only 38 bits can be used.51 * Anyway, 256GiB of IOVA ought to be enough for anyone.52 */53 ctx->dma_mask = DMA_BIT_MASK(38);54 ctx->dev.dma_mask = &ctx->dma_mask;55 ctx->dev.coherent_dma_mask = ctx->dma_mask;56 dev_set_name(&ctx->dev, "host1x-ctx.%d", i);57 ctx->dev.bus = &host1x_context_device_bus_type;58 ctx->dev.parent = host1x->dev;59 ctx->dev.release = host1x_memory_context_release;60 61 ctx->dev.dma_parms = &ctx->dma_parms;62 dma_set_max_seg_size(&ctx->dev, UINT_MAX);63 64 err = device_add(&ctx->dev);65 if (err) {66 dev_err(host1x->dev, "could not add context device %d: %d\n", i, err);67 put_device(&ctx->dev);68 goto unreg_devices;69 }70 71 err = of_dma_configure_id(&ctx->dev, node, true, &i);72 if (err) {73 dev_err(host1x->dev, "IOMMU configuration failed for context device %d: %d\n",74 i, err);75 device_unregister(&ctx->dev);76 goto unreg_devices;77 }78 79 if (!tegra_dev_iommu_get_stream_id(&ctx->dev, &ctx->stream_id) ||80 !device_iommu_mapped(&ctx->dev)) {81 dev_err(host1x->dev, "Context device %d has no IOMMU!\n", i);82 device_unregister(&ctx->dev);83 84 /*85 * This means that if IOMMU is disabled but context devices86 * are defined in the device tree, Host1x will fail to probe.87 * That's probably OK in this time and age.88 */89 err = -EINVAL;90 91 goto unreg_devices;92 }93 }94 95 return 0;96 97unreg_devices:98 while (i--)99 device_unregister(&cdl->devs[i].dev);100 101 kfree(cdl->devs);102 cdl->devs = NULL;103 cdl->len = 0;104 105 return err;106}107 108void host1x_memory_context_list_free(struct host1x_memory_context_list *cdl)109{110 unsigned int i;111 112 for (i = 0; i < cdl->len; i++)113 device_unregister(&cdl->devs[i].dev);114 115 kfree(cdl->devs);116 cdl->len = 0;117}118 119struct host1x_memory_context *host1x_memory_context_alloc(struct host1x *host1x,120 struct device *dev,121 struct pid *pid)122{123 struct host1x_memory_context_list *cdl = &host1x->context_list;124 struct host1x_memory_context *free = NULL;125 int i;126 127 if (!cdl->len)128 return ERR_PTR(-EOPNOTSUPP);129 130 mutex_lock(&cdl->lock);131 132 for (i = 0; i < cdl->len; i++) {133 struct host1x_memory_context *cd = &cdl->devs[i];134 135 if (cd->dev.iommu->iommu_dev != dev->iommu->iommu_dev)136 continue;137 138 if (cd->owner == pid) {139 refcount_inc(&cd->ref);140 mutex_unlock(&cdl->lock);141 return cd;142 } else if (!cd->owner && !free) {143 free = cd;144 }145 }146 147 if (!free) {148 mutex_unlock(&cdl->lock);149 return ERR_PTR(-EBUSY);150 }151 152 refcount_set(&free->ref, 1);153 free->owner = get_pid(pid);154 155 mutex_unlock(&cdl->lock);156 157 return free;158}159EXPORT_SYMBOL_GPL(host1x_memory_context_alloc);160 161void host1x_memory_context_get(struct host1x_memory_context *cd)162{163 refcount_inc(&cd->ref);164}165EXPORT_SYMBOL_GPL(host1x_memory_context_get);166 167void host1x_memory_context_put(struct host1x_memory_context *cd)168{169 struct host1x_memory_context_list *cdl = &cd->host->context_list;170 171 if (refcount_dec_and_mutex_lock(&cd->ref, &cdl->lock)) {172 put_pid(cd->owner);173 cd->owner = NULL;174 mutex_unlock(&cdl->lock);175 }176}177EXPORT_SYMBOL_GPL(host1x_memory_context_put);178