context.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2016-2019 HabanaLabs, Ltd.
* All Rights Reserved.
*/
#include "habanalabs.h"
#include <linux/slab.h>
static void hl_ctx_fini(struct hl_ctx *ctx)
{
struct hl_device *hdev = ctx->hdev;
int i;
/*
* If we arrived here, there are no jobs waiting for this context
* on its queues so we can safely remove it.
* This is because for each CS, we increment the ref count and for
* every CS that was finished we decrement it and we won't arrive
* to this function unless the ref count is 0
*/
for (i = 0 ; i < HL_MAX_PENDING_CS ; i++)
dma_fence_put(ctx->cs_pending[i]);
if (ctx->asid != HL_KERNEL_ASID_ID) {
/* The engines are stopped as there is no executing CS, but the
* Coresight might be still working by accessing addresses
* related to the stopped engines. Hence stop it explicitly.
* Stop only if this is the compute context, as there can be
* only one compute context
*/
if ((hdev->in_debug) && (hdev->compute_ctx == ctx))
hl_device_set_debug_mode(hdev, false);
hl_vm_ctx_fini(ctx);
hl_asid_free(hdev, ctx->asid);
} else {
hl_mmu_ctx_fini(ctx);
}
}
void hl_ctx_do_release(struct kref *ref)
{
struct hl_ctx *ctx;
ctx = container_of(ref, struct hl_ctx, refcount);
hl_ctx_fini(ctx);
if (ctx->hpriv)
hl_hpriv_put(ctx->hpriv);
kfree(ctx);
}
int hl_ctx_create(struct hl_device *hdev, struct hl_fpriv *hpriv)
{
struct hl_ctx_mgr *mgr = &hpriv->ctx_mgr;
struct hl_ctx *ctx;
int rc;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx) {
rc = -ENOMEM;
goto out_err;
}
mutex_lock(&mgr->ctx_lock);
rc = idr_alloc(&mgr->ctx_handles, ctx, 1, 0, GFP_KERNEL);
mutex_unlock(&mgr->ctx_lock);
if (rc < 0) {
dev_err(hdev->dev, "Failed to allocate IDR for a new CTX\n");
goto free_ctx;
}
ctx->handle = rc;
rc = hl_ctx_init(hdev, ctx, false);
if (rc)
goto remove_from_idr;
hl_hpriv_get(hpriv);
ctx->hpriv = hpriv;
/* TODO: remove for multiple contexts per process */
hpriv->ctx = ctx;
/* TODO: remove the following line for multiple process support */
hdev->compute_ctx = ctx;
return 0;
remove_from_idr:
mutex_lock(&mgr->ctx_lock);
idr_remove(&mgr->ctx_handles, ctx->handle);
mutex_unlock(&mgr->ctx_lock);
free_ctx:
kfree(ctx);
out_err:
return rc;
}
void hl_ctx_free(struct hl_device *hdev, struct hl_ctx *ctx)
{
if (kref_put(&ctx->refcount, hl_ctx_do_release) == 1)
return;
dev_warn(hdev->dev,
"Context %d closed or terminated but its CS are executing\n",
ctx->asid);
}
int hl_ctx_init(struct hl_device *hdev, struct hl_ctx *ctx, bool is_kernel_ctx)
{
int rc = 0;
ctx->hdev = hdev;
kref_init(&ctx->refcount);
ctx->cs_sequence = 1;
spin_lock_init(&ctx->cs_lock);
atomic_set(&ctx->thread_ctx_switch_token, 1);
ctx->thread_ctx_switch_wait_token = 0;
if (is_kernel_ctx) {
ctx->asid = HL_KERNEL_ASID_ID; /* Kernel driver gets ASID 0 */
rc = hl_mmu_ctx_init(ctx);
if (rc) {
dev_err(hdev->dev, "Failed to init mmu ctx module\n");
goto mem_ctx_err;
}
} else {
ctx->asid = hl_asid_alloc(hdev);
if (!ctx->asid) {
dev_err(hdev->dev, "No free ASID, failed to create context\n");
return -ENOMEM;
}
rc = hl_vm_ctx_init(ctx);
if (rc) {
dev_err(hdev->dev, "Failed to init mem ctx module\n");
rc = -ENOMEM;
goto mem_ctx_err;
}
}
return 0;
mem_ctx_err:
if (ctx->asid != HL_KERNEL_ASID_ID)
hl_asid_free(hdev, ctx->asid);
return rc;
}
void hl_ctx_get(struct hl_device *hdev, struct hl_ctx *ctx)
{
kref_get(&ctx->refcount);
}
int hl_ctx_put(struct hl_ctx *ctx)
{
return kref_put(&ctx->refcount, hl_ctx_do_release);
}
struct dma_fence *hl_ctx_get_fence(struct hl_ctx *ctx, u64 seq)
{
struct hl_device *hdev = ctx->hdev;
struct dma_fence *fence;
spin_lock(&ctx->cs_lock);
if (seq >= ctx->cs_sequence) {
dev_notice(hdev->dev,
"Can't wait on seq %llu because current CS is at seq %llu\n",
seq, ctx->cs_sequence);
spin_unlock(&ctx->cs_lock);
return ERR_PTR(-EINVAL);
}
if (seq + HL_MAX_PENDING_CS < ctx->cs_sequence) {
dev_dbg(hdev->dev,
"Can't wait on seq %llu because current CS is at seq %llu (Fence is gone)\n",
seq, ctx->cs_sequence);
spin_unlock(&ctx->cs_lock);
return NULL;
}
fence = dma_fence_get(
ctx->cs_pending[seq & (HL_MAX_PENDING_CS - 1)]);
spin_unlock(&ctx->cs_lock);
return fence;
}
/*
* hl_ctx_mgr_init - initialize the context manager
*
* @mgr: pointer to context manager structure
*
* This manager is an object inside the hpriv object of the user process.
* The function is called when a user process opens the FD.
*/
void hl_ctx_mgr_init(struct hl_ctx_mgr *mgr)
{
mutex_init(&mgr->ctx_lock);
idr_init(&mgr->ctx_handles);
}
/*
* hl_ctx_mgr_fini - finalize the context manager
*
* @hdev: pointer to device structure
* @mgr: pointer to context manager structure
*
* This function goes over all the contexts in the manager and frees them.
* It is called when a process closes the FD.
*/
void hl_ctx_mgr_fini(struct hl_device *hdev, struct hl_ctx_mgr *mgr)
{
struct hl_ctx *ctx;
struct idr *idp;
u32 id;
idp = &mgr->ctx_handles;
idr_for_each_entry(idp, ctx, id)
hl_ctx_free(hdev, ctx);
idr_destroy(&mgr->ctx_handles);
mutex_destroy(&mgr->ctx_lock);
}