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Diffstat (limited to 'drivers/gpu/host1x/context.c')
-rw-r--r--drivers/gpu/host1x/context.c168
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);