gpu/host1x/context.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (c) 2021, NVIDIA Corporation.
0004  */
0005
0006 #include <linux/device.h>
0007 #include <linux/kref.h>
0008 #include <linux/of.h>
0009 #include <linux/of_platform.h>
0010 #include <linux/pid.h>
0011 #include <linux/slab.h>
0012
0013 #include "context.h"
0014 #include "dev.h"
0015
0016 int host1x_memory_context_list_init(struct host1x *host1x)
0017 {
0018     struct host1x_memory_context_list *cdl = &host1x->context_list;
0019     struct device_node *node = host1x->dev->of_node;
0020     struct host1x_memory_context *ctx;
0021     unsigned int i;
0022     int err;
0023
0024     cdl->devs = NULL;
0025     cdl->len = 0;
0026     mutex_init(&cdl->lock);
0027
0028     err = of_property_count_u32_elems(node, "iommu-map");
0029     if (err < 0)
0030         return 0;
0031
0032     cdl->devs = kcalloc(err, sizeof(*cdl->devs), GFP_KERNEL);
0033     if (!cdl->devs)
0034         return -ENOMEM;
0035     cdl->len = err / 4;
0036
0037     for (i = 0; i < cdl->len; i++) {
0038         struct iommu_fwspec *fwspec;
0039
0040         ctx = &cdl->devs[i];
0041
0042         ctx->host = host1x;
0043
0044         device_initialize(&ctx->dev);
0045
0046         /*
0047          * Due to an issue with T194 NVENC, only 38 bits can be used.
0048          * Anyway, 256GiB of IOVA ought to be enough for anyone.
0049          */
0050         ctx->dma_mask = DMA_BIT_MASK(38);
0051         ctx->dev.dma_mask = &ctx->dma_mask;
0052         ctx->dev.coherent_dma_mask = ctx->dma_mask;
0053         dev_set_name(&ctx->dev, "host1x-ctx.%d", i);
0054         ctx->dev.bus = &host1x_context_device_bus_type;
0055         ctx->dev.parent = host1x->dev;
0056
0057         dma_set_max_seg_size(&ctx->dev, UINT_MAX);
0058
0059         err = device_add(&ctx->dev);
0060         if (err) {
0061             dev_err(host1x->dev, "could not add context device %d: %d\n", i, err);
0062             goto del_devices;
0063         }
0064
0065         err = of_dma_configure_id(&ctx->dev, node, true, &i);
0066         if (err) {
0067             dev_err(host1x->dev, "IOMMU configuration failed for context device %d: %d\n",
0068                 i, err);
0069             device_del(&ctx->dev);
0070             goto del_devices;
0071         }
0072
0073         fwspec = dev_iommu_fwspec_get(&ctx->dev);
0074         if (!fwspec || !device_iommu_mapped(&ctx->dev)) {
0075             dev_err(host1x->dev, "Context device %d has no IOMMU!\n", i);
0076             device_del(&ctx->dev);
0077             goto del_devices;
0078         }
0079
0080         ctx->stream_id = fwspec->ids[0] & 0xffff;
0081     }
0082
0083     return 0;
0084
0085 del_devices:
0086     while (i--)
0087         device_del(&cdl->devs[i].dev);
0088
0089     kfree(cdl->devs);
0090     cdl->len = 0;
0091
0092     return err;
0093 }
0094
0095 void host1x_memory_context_list_free(struct host1x_memory_context_list *cdl)
0096 {
0097     unsigned int i;
0098
0099     for (i = 0; i < cdl->len; i++)
0100         device_del(&cdl->devs[i].dev);
0101
0102     kfree(cdl->devs);
0103     cdl->len = 0;
0104 }
0105
0106 struct host1x_memory_context *host1x_memory_context_alloc(struct host1x *host1x,
0107                               struct pid *pid)
0108 {
0109     struct host1x_memory_context_list *cdl = &host1x->context_list;
0110     struct host1x_memory_context *free = NULL;
0111     int i;
0112
0113     if (!cdl->len)
0114         return ERR_PTR(-EOPNOTSUPP);
0115
0116     mutex_lock(&cdl->lock);
0117
0118     for (i = 0; i < cdl->len; i++) {
0119         struct host1x_memory_context *cd = &cdl->devs[i];
0120
0121         if (cd->owner == pid) {
0122             refcount_inc(&cd->ref);
0123             mutex_unlock(&cdl->lock);
0124             return cd;
0125         } else if (!cd->owner && !free) {
0126             free = cd;
0127         }
0128     }
0129
0130     if (!free) {
0131         mutex_unlock(&cdl->lock);
0132         return ERR_PTR(-EBUSY);
0133     }
0134
0135     refcount_set(&free->ref, 1);
0136     free->owner = get_pid(pid);
0137
0138     mutex_unlock(&cdl->lock);
0139
0140     return free;
0141 }
0142 EXPORT_SYMBOL_GPL(host1x_memory_context_alloc);
0143
0144 void host1x_memory_context_get(struct host1x_memory_context *cd)
0145 {
0146     refcount_inc(&cd->ref);
0147 }
0148 EXPORT_SYMBOL_GPL(host1x_memory_context_get);
0149
0150 void host1x_memory_context_put(struct host1x_memory_context *cd)
0151 {
0152     struct host1x_memory_context_list *cdl = &cd->host->context_list;
0153
0154     if (refcount_dec_and_mutex_lock(&cd->ref, &cdl->lock)) {
0155         put_pid(cd->owner);
0156         cd->owner = NULL;
0157         mutex_unlock(&cdl->lock);
0158     }
0159 }
0160 EXPORT_SYMBOL_GPL(host1x_memory_context_put);