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// 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_device.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++) {
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;
}
if (!tegra_dev_iommu_get_stream_id(&ctx->dev, &ctx->stream_id) ||
!device_iommu_mapped(&ctx->dev)) {
dev_err(host1x->dev, "Context device %d has no IOMMU!\n", i);
device_unregister(&ctx->dev);
/*
* This means that if IOMMU is disabled but context devices
* are defined in the device tree, Host1x will fail to probe.
* That's probably OK in this time and age.
*/
err = -EINVAL;
goto unreg_devices;
}
}
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 device *dev,
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->dev.iommu->iommu_dev != dev->iommu->iommu_dev)
continue;
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);
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