linux-stable/drivers/misc/ocxl/afu_irq.c
Alastair D'Silva 0601466146 ocxl: move event_fd handling to frontend
Event_fd is only used in the driver frontend, so it does not
need to exist in the backend code. Relocate it to the frontend
and provide an opaque mechanism for consumers instead.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:55:02 +10:00

209 lines
4.4 KiB
C

// SPDX-License-Identifier: GPL-2.0+
// Copyright 2017 IBM Corp.
#include <linux/interrupt.h>
#include <asm/pnv-ocxl.h>
#include "ocxl_internal.h"
#include "trace.h"
struct afu_irq {
int id;
int hw_irq;
unsigned int virq;
char *name;
u64 trigger_page;
irqreturn_t (*handler)(void *private);
void (*free_private)(void *private);
void *private;
};
int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset)
{
return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT;
}
u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id)
{
return ctx->afu->irq_base_offset + (irq_id << PAGE_SHIFT);
}
int ocxl_irq_set_handler(struct ocxl_context *ctx, int irq_id,
irqreturn_t (*handler)(void *private),
void (*free_private)(void *private),
void *private)
{
struct afu_irq *irq;
int rc;
mutex_lock(&ctx->irq_lock);
irq = idr_find(&ctx->irq_idr, irq_id);
if (!irq) {
rc = -EINVAL;
goto unlock;
}
irq->handler = handler;
irq->private = private;
irq->free_private = free_private;
rc = 0;
// Fall through to unlock
unlock:
mutex_unlock(&ctx->irq_lock);
return rc;
}
EXPORT_SYMBOL_GPL(ocxl_irq_set_handler);
static irqreturn_t afu_irq_handler(int virq, void *data)
{
struct afu_irq *irq = (struct afu_irq *) data;
trace_ocxl_afu_irq_receive(virq);
if (irq->handler)
return irq->handler(irq->private);
return IRQ_HANDLED; // Just drop it on the ground
}
static int setup_afu_irq(struct ocxl_context *ctx, struct afu_irq *irq)
{
int rc;
irq->virq = irq_create_mapping(NULL, irq->hw_irq);
if (!irq->virq) {
pr_err("irq_create_mapping failed\n");
return -ENOMEM;
}
pr_debug("hw_irq %d mapped to virq %u\n", irq->hw_irq, irq->virq);
irq->name = kasprintf(GFP_KERNEL, "ocxl-afu-%u", irq->virq);
if (!irq->name) {
irq_dispose_mapping(irq->virq);
return -ENOMEM;
}
rc = request_irq(irq->virq, afu_irq_handler, 0, irq->name, irq);
if (rc) {
kfree(irq->name);
irq->name = NULL;
irq_dispose_mapping(irq->virq);
pr_err("request_irq failed: %d\n", rc);
return rc;
}
return 0;
}
static void release_afu_irq(struct afu_irq *irq)
{
free_irq(irq->virq, irq);
irq_dispose_mapping(irq->virq);
kfree(irq->name);
}
int ocxl_afu_irq_alloc(struct ocxl_context *ctx, int *irq_id)
{
struct afu_irq *irq;
int rc;
irq = kzalloc(sizeof(struct afu_irq), GFP_KERNEL);
if (!irq)
return -ENOMEM;
/*
* We limit the number of afu irqs per context and per link to
* avoid a single process or user depleting the pool of IPIs
*/
mutex_lock(&ctx->irq_lock);
irq->id = idr_alloc(&ctx->irq_idr, irq, 0, MAX_IRQ_PER_CONTEXT,
GFP_KERNEL);
if (irq->id < 0) {
rc = -ENOSPC;
goto err_unlock;
}
rc = ocxl_link_irq_alloc(ctx->afu->fn->link, &irq->hw_irq,
&irq->trigger_page);
if (rc)
goto err_idr;
rc = setup_afu_irq(ctx, irq);
if (rc)
goto err_alloc;
trace_ocxl_afu_irq_alloc(ctx->pasid, irq->id, irq->virq, irq->hw_irq);
mutex_unlock(&ctx->irq_lock);
*irq_id = irq->id;
return 0;
err_alloc:
ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
err_idr:
idr_remove(&ctx->irq_idr, irq->id);
err_unlock:
mutex_unlock(&ctx->irq_lock);
kfree(irq);
return rc;
}
EXPORT_SYMBOL_GPL(ocxl_afu_irq_alloc);
static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx)
{
trace_ocxl_afu_irq_free(ctx->pasid, irq->id);
if (ctx->mapping)
unmap_mapping_range(ctx->mapping,
ocxl_irq_id_to_offset(ctx, irq->id),
1 << PAGE_SHIFT, 1);
release_afu_irq(irq);
if (irq->free_private)
irq->free_private(irq->private);
ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq);
kfree(irq);
}
int ocxl_afu_irq_free(struct ocxl_context *ctx, int irq_id)
{
struct afu_irq *irq;
mutex_lock(&ctx->irq_lock);
irq = idr_find(&ctx->irq_idr, irq_id);
if (!irq) {
mutex_unlock(&ctx->irq_lock);
return -EINVAL;
}
idr_remove(&ctx->irq_idr, irq->id);
afu_irq_free(irq, ctx);
mutex_unlock(&ctx->irq_lock);
return 0;
}
EXPORT_SYMBOL_GPL(ocxl_afu_irq_free);
void ocxl_afu_irq_free_all(struct ocxl_context *ctx)
{
struct afu_irq *irq;
int id;
mutex_lock(&ctx->irq_lock);
idr_for_each_entry(&ctx->irq_idr, irq, id)
afu_irq_free(irq, ctx);
mutex_unlock(&ctx->irq_lock);
}
u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, int irq_id)
{
struct afu_irq *irq;
u64 addr = 0;
mutex_lock(&ctx->irq_lock);
irq = idr_find(&ctx->irq_idr, irq_id);
if (irq)
addr = irq->trigger_page;
mutex_unlock(&ctx->irq_lock);
return addr;
}
EXPORT_SYMBOL_GPL(ocxl_afu_irq_get_addr);