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36d46a5907
It's cumbersome and error-prone to keep adding fixed IRQ numbers, and for proper device wakeup support for the virtio/vhost-user support we need to have different IRQs for each device. Even if in theory two IRQs (with and without wake) might be sufficient, it's much easier to reason about it when we have dynamic number assignment. It also makes it easier to add new devices that may dynamically exist or depending on the configuration, etc. Add support for this, up to 64 IRQs (the same limit as epoll FDs we have right now). Since it's not easy to port all the existing places to dynamic allocation (some data is statically initialized) keep the low numbers are reserved for the existing hard-coded IRQ numbers. Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
75 lines
1.5 KiB
C
75 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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*/
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#include <linux/slab.h>
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#include <linux/completion.h>
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#include <linux/irqreturn.h>
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#include <asm/irq.h>
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#include <irq_kern.h>
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#include <os.h>
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struct xterm_wait {
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struct completion ready;
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int fd;
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int pid;
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int new_fd;
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};
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static irqreturn_t xterm_interrupt(int irq, void *data)
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{
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struct xterm_wait *xterm = data;
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int fd;
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fd = os_rcv_fd(xterm->fd, &xterm->pid);
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if (fd == -EAGAIN)
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return IRQ_NONE;
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xterm->new_fd = fd;
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complete(&xterm->ready);
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return IRQ_HANDLED;
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}
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int xterm_fd(int socket, int *pid_out)
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{
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struct xterm_wait *data;
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int err, ret;
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data = kmalloc(sizeof(*data), GFP_KERNEL);
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if (data == NULL) {
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printk(KERN_ERR "xterm_fd : failed to allocate xterm_wait\n");
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return -ENOMEM;
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}
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/* This is a locked semaphore... */
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*data = ((struct xterm_wait) { .fd = socket,
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.pid = -1,
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.new_fd = -1 });
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init_completion(&data->ready);
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err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt,
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IRQF_SHARED, "xterm", data);
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if (err < 0) {
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printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, "
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"err = %d\n", err);
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ret = err;
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goto out;
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}
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/* ... so here we wait for an xterm interrupt.
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*
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* XXX Note, if the xterm doesn't work for some reason (eg. DISPLAY
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* isn't set) this will hang... */
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wait_for_completion(&data->ready);
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um_free_irq(XTERM_IRQ, data);
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ret = data->new_fd;
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*pid_out = data->pid;
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out:
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kfree(data);
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return ret;
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}
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