diff options
Diffstat (limited to 'drivers/gpu/host1x/context.c')
| -rw-r--r-- | drivers/gpu/host1x/context.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/drivers/gpu/host1x/context.c b/drivers/gpu/host1x/context.c new file mode 100644 index 000000000..93c0c532f --- /dev/null +++ b/drivers/gpu/host1x/context.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2021, NVIDIA Corporation. + */ + +#include <linux/device.h> +#include <linux/kref.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/pid.h> +#include <linux/slab.h> + +#include "context.h" +#include "dev.h" + +static void host1x_memory_context_release(struct device *dev) +{ + /* context device is freed in host1x_memory_context_list_free() */ +} + +int host1x_memory_context_list_init(struct host1x *host1x) +{ + struct host1x_memory_context_list *cdl = &host1x->context_list; + struct device_node *node = host1x->dev->of_node; + struct host1x_memory_context *ctx; + unsigned int i; + int err; + + cdl->devs = NULL; + cdl->len = 0; + mutex_init(&cdl->lock); + + err = of_property_count_u32_elems(node, "iommu-map"); + if (err < 0) + return 0; + + cdl->len = err / 4; + cdl->devs = kcalloc(cdl->len, sizeof(*cdl->devs), GFP_KERNEL); + if (!cdl->devs) + return -ENOMEM; + + for (i = 0; i < cdl->len; i++) { + struct iommu_fwspec *fwspec; + + ctx = &cdl->devs[i]; + + ctx->host = host1x; + + device_initialize(&ctx->dev); + + /* + * Due to an issue with T194 NVENC, only 38 bits can be used. + * Anyway, 256GiB of IOVA ought to be enough for anyone. + */ + ctx->dma_mask = DMA_BIT_MASK(38); + ctx->dev.dma_mask = &ctx->dma_mask; + ctx->dev.coherent_dma_mask = ctx->dma_mask; + dev_set_name(&ctx->dev, "host1x-ctx.%d", i); + ctx->dev.bus = &host1x_context_device_bus_type; + ctx->dev.parent = host1x->dev; + ctx->dev.release = host1x_memory_context_release; + + dma_set_max_seg_size(&ctx->dev, UINT_MAX); + + err = device_add(&ctx->dev); + if (err) { + dev_err(host1x->dev, "could not add context device %d: %d\n", i, err); + put_device(&ctx->dev); + goto unreg_devices; + } + + err = of_dma_configure_id(&ctx->dev, node, true, &i); + if (err) { + dev_err(host1x->dev, "IOMMU configuration failed for context device %d: %d\n", + i, err); + device_unregister(&ctx->dev); + goto unreg_devices; + } + + fwspec = dev_iommu_fwspec_get(&ctx->dev); + if (!fwspec || !device_iommu_mapped(&ctx->dev)) { + dev_err(host1x->dev, "Context device %d has no IOMMU!\n", i); + device_unregister(&ctx->dev); + goto unreg_devices; + } + + ctx->stream_id = fwspec->ids[0] & 0xffff; + } + + return 0; + +unreg_devices: + while (i--) + device_unregister(&cdl->devs[i].dev); + + kfree(cdl->devs); + cdl->devs = NULL; + cdl->len = 0; + + return err; +} + +void host1x_memory_context_list_free(struct host1x_memory_context_list *cdl) +{ + unsigned int i; + + for (i = 0; i < cdl->len; i++) + device_unregister(&cdl->devs[i].dev); + + kfree(cdl->devs); + cdl->len = 0; +} + +struct host1x_memory_context *host1x_memory_context_alloc(struct host1x *host1x, + struct pid *pid) +{ + struct host1x_memory_context_list *cdl = &host1x->context_list; + struct host1x_memory_context *free = NULL; + int i; + + if (!cdl->len) + return ERR_PTR(-EOPNOTSUPP); + + mutex_lock(&cdl->lock); + + for (i = 0; i < cdl->len; i++) { + struct host1x_memory_context *cd = &cdl->devs[i]; + + if (cd->owner == pid) { + refcount_inc(&cd->ref); + mutex_unlock(&cdl->lock); + return cd; + } else if (!cd->owner && !free) { + free = cd; + } + } + + if (!free) { + mutex_unlock(&cdl->lock); + return ERR_PTR(-EBUSY); + } + + refcount_set(&free->ref, 1); + free->owner = get_pid(pid); + + mutex_unlock(&cdl->lock); + + return free; +} +EXPORT_SYMBOL_GPL(host1x_memory_context_alloc); + +void host1x_memory_context_get(struct host1x_memory_context *cd) +{ + refcount_inc(&cd->ref); +} +EXPORT_SYMBOL_GPL(host1x_memory_context_get); + +void host1x_memory_context_put(struct host1x_memory_context *cd) +{ + struct host1x_memory_context_list *cdl = &cd->host->context_list; + + if (refcount_dec_and_mutex_lock(&cd->ref, &cdl->lock)) { + put_pid(cd->owner); + cd->owner = NULL; + mutex_unlock(&cdl->lock); + } +} +EXPORT_SYMBOL_GPL(host1x_memory_context_put); |