// SPDX-License-Identifier: GPL-2.0-only/* * Copyright (c) 2021, NVIDIA Corporation. */ #include <linux/device.h>#include <linux/host1x_context_bus.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 devs, 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; 	devs = 0; 	for (i = 0; i < err / 4; i++) {		u32 length; 		of_property_read_u32_index(node, "iommu-map", i * 4 + 3, &length);		devs += length;	} 	cdl->len = devs;	cdl->devs = kzalloc_objs(*cdl->devs, cdl->len);	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; 		ctx->dev.dma_parms = &ctx->dma_parms;		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);