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linux/drivers/misc/ocxl/afu_irq.c

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// SPDX-License-Identifier: GPL-2.0+
// Copyright 2017 IBM Corp.
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <asm/pnv-ocxl.h>
#include <asm/xive.h>
#include "ocxl_internal.h"
#include "trace.h"
struct afu_irq {
int id;
int hw_irq;
unsigned int virq;
char *name;
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 = 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);
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 xive_irq_data *xd;
struct afu_irq *irq;
u64 addr = 0;
mutex_lock(&ctx->irq_lock);
irq = idr_find(&ctx->irq_idr, irq_id);
if (irq) {
xd = irq_get_handler_data(irq->virq);
addr = xd ? xd->trig_page : 0;
}
mutex_unlock(&ctx->irq_lock);
return addr;
}
EXPORT_SYMBOL_GPL(ocxl_afu_irq_get_addr);