mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-06 06:26:40 +07:00
e4a7431240
Since 05a812ac47
(xen/events/fifo:
correctly align bitops), ready is an unsigned long instead of uint32_t
and the BM() macro is no longer required.
Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
451 lines
11 KiB
C
451 lines
11 KiB
C
/*
|
|
* Xen event channels (FIFO-based ABI)
|
|
*
|
|
* Copyright (C) 2013 Citrix Systems R&D ltd.
|
|
*
|
|
* This source code is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation; either version 2 of the
|
|
* License, or (at your option) any later version.
|
|
*
|
|
* Or, when distributed separately from the Linux kernel or
|
|
* incorporated into other software packages, subject to the following
|
|
* license:
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this source file (the "Software"), to deal in the Software without
|
|
* restriction, including without limitation the rights to use, copy, modify,
|
|
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
|
|
* and to permit persons to whom the Software is furnished to do so, subject to
|
|
* the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
|
|
* IN THE SOFTWARE.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/linkage.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/module.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/cpu.h>
|
|
|
|
#include <asm/sync_bitops.h>
|
|
#include <asm/xen/hypercall.h>
|
|
#include <asm/xen/hypervisor.h>
|
|
#include <asm/xen/page.h>
|
|
|
|
#include <xen/xen.h>
|
|
#include <xen/xen-ops.h>
|
|
#include <xen/events.h>
|
|
#include <xen/interface/xen.h>
|
|
#include <xen/interface/event_channel.h>
|
|
|
|
#include "events_internal.h"
|
|
|
|
#define EVENT_WORDS_PER_PAGE (PAGE_SIZE / sizeof(event_word_t))
|
|
#define MAX_EVENT_ARRAY_PAGES (EVTCHN_FIFO_NR_CHANNELS / EVENT_WORDS_PER_PAGE)
|
|
|
|
struct evtchn_fifo_queue {
|
|
uint32_t head[EVTCHN_FIFO_MAX_QUEUES];
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct evtchn_fifo_control_block *, cpu_control_block);
|
|
static DEFINE_PER_CPU(struct evtchn_fifo_queue, cpu_queue);
|
|
static event_word_t *event_array[MAX_EVENT_ARRAY_PAGES] __read_mostly;
|
|
static unsigned event_array_pages __read_mostly;
|
|
|
|
/*
|
|
* sync_set_bit() and friends must be unsigned long aligned.
|
|
*/
|
|
#if BITS_PER_LONG > 32
|
|
|
|
#define BM(w) (unsigned long *)((unsigned long)w & ~0x7UL)
|
|
#define EVTCHN_FIFO_BIT(b, w) \
|
|
(((unsigned long)w & 0x4UL) ? (EVTCHN_FIFO_ ##b + 32) : EVTCHN_FIFO_ ##b)
|
|
|
|
#else
|
|
|
|
#define BM(w) ((unsigned long *)(w))
|
|
#define EVTCHN_FIFO_BIT(b, w) EVTCHN_FIFO_ ##b
|
|
|
|
#endif
|
|
|
|
static inline event_word_t *event_word_from_port(unsigned port)
|
|
{
|
|
unsigned i = port / EVENT_WORDS_PER_PAGE;
|
|
|
|
return event_array[i] + port % EVENT_WORDS_PER_PAGE;
|
|
}
|
|
|
|
static unsigned evtchn_fifo_max_channels(void)
|
|
{
|
|
return EVTCHN_FIFO_NR_CHANNELS;
|
|
}
|
|
|
|
static unsigned evtchn_fifo_nr_channels(void)
|
|
{
|
|
return event_array_pages * EVENT_WORDS_PER_PAGE;
|
|
}
|
|
|
|
static int init_control_block(int cpu,
|
|
struct evtchn_fifo_control_block *control_block)
|
|
{
|
|
struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu);
|
|
struct evtchn_init_control init_control;
|
|
unsigned int i;
|
|
|
|
/* Reset the control block and the local HEADs. */
|
|
clear_page(control_block);
|
|
for (i = 0; i < EVTCHN_FIFO_MAX_QUEUES; i++)
|
|
q->head[i] = 0;
|
|
|
|
init_control.control_gfn = virt_to_mfn(control_block);
|
|
init_control.offset = 0;
|
|
init_control.vcpu = cpu;
|
|
|
|
return HYPERVISOR_event_channel_op(EVTCHNOP_init_control, &init_control);
|
|
}
|
|
|
|
static void free_unused_array_pages(void)
|
|
{
|
|
unsigned i;
|
|
|
|
for (i = event_array_pages; i < MAX_EVENT_ARRAY_PAGES; i++) {
|
|
if (!event_array[i])
|
|
break;
|
|
free_page((unsigned long)event_array[i]);
|
|
event_array[i] = NULL;
|
|
}
|
|
}
|
|
|
|
static void init_array_page(event_word_t *array_page)
|
|
{
|
|
unsigned i;
|
|
|
|
for (i = 0; i < EVENT_WORDS_PER_PAGE; i++)
|
|
array_page[i] = 1 << EVTCHN_FIFO_MASKED;
|
|
}
|
|
|
|
static int evtchn_fifo_setup(struct irq_info *info)
|
|
{
|
|
unsigned port = info->evtchn;
|
|
unsigned new_array_pages;
|
|
int ret;
|
|
|
|
new_array_pages = port / EVENT_WORDS_PER_PAGE + 1;
|
|
|
|
if (new_array_pages > MAX_EVENT_ARRAY_PAGES)
|
|
return -EINVAL;
|
|
|
|
while (event_array_pages < new_array_pages) {
|
|
void *array_page;
|
|
struct evtchn_expand_array expand_array;
|
|
|
|
/* Might already have a page if we've resumed. */
|
|
array_page = event_array[event_array_pages];
|
|
if (!array_page) {
|
|
array_page = (void *)__get_free_page(GFP_KERNEL);
|
|
if (array_page == NULL) {
|
|
ret = -ENOMEM;
|
|
goto error;
|
|
}
|
|
event_array[event_array_pages] = array_page;
|
|
}
|
|
|
|
/* Mask all events in this page before adding it. */
|
|
init_array_page(array_page);
|
|
|
|
expand_array.array_gfn = virt_to_mfn(array_page);
|
|
|
|
ret = HYPERVISOR_event_channel_op(EVTCHNOP_expand_array, &expand_array);
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
event_array_pages++;
|
|
}
|
|
return 0;
|
|
|
|
error:
|
|
if (event_array_pages == 0)
|
|
panic("xen: unable to expand event array with initial page (%d)\n", ret);
|
|
else
|
|
pr_err("unable to expand event array (%d)\n", ret);
|
|
free_unused_array_pages();
|
|
return ret;
|
|
}
|
|
|
|
static void evtchn_fifo_bind_to_cpu(struct irq_info *info, unsigned cpu)
|
|
{
|
|
/* no-op */
|
|
}
|
|
|
|
static void evtchn_fifo_clear_pending(unsigned port)
|
|
{
|
|
event_word_t *word = event_word_from_port(port);
|
|
sync_clear_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
|
|
}
|
|
|
|
static void evtchn_fifo_set_pending(unsigned port)
|
|
{
|
|
event_word_t *word = event_word_from_port(port);
|
|
sync_set_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
|
|
}
|
|
|
|
static bool evtchn_fifo_is_pending(unsigned port)
|
|
{
|
|
event_word_t *word = event_word_from_port(port);
|
|
return sync_test_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
|
|
}
|
|
|
|
static bool evtchn_fifo_test_and_set_mask(unsigned port)
|
|
{
|
|
event_word_t *word = event_word_from_port(port);
|
|
return sync_test_and_set_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
|
|
}
|
|
|
|
static void evtchn_fifo_mask(unsigned port)
|
|
{
|
|
event_word_t *word = event_word_from_port(port);
|
|
sync_set_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
|
|
}
|
|
|
|
static bool evtchn_fifo_is_masked(unsigned port)
|
|
{
|
|
event_word_t *word = event_word_from_port(port);
|
|
return sync_test_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
|
|
}
|
|
/*
|
|
* Clear MASKED, spinning if BUSY is set.
|
|
*/
|
|
static void clear_masked(volatile event_word_t *word)
|
|
{
|
|
event_word_t new, old, w;
|
|
|
|
w = *word;
|
|
|
|
do {
|
|
old = w & ~(1 << EVTCHN_FIFO_BUSY);
|
|
new = old & ~(1 << EVTCHN_FIFO_MASKED);
|
|
w = sync_cmpxchg(word, old, new);
|
|
} while (w != old);
|
|
}
|
|
|
|
static void evtchn_fifo_unmask(unsigned port)
|
|
{
|
|
event_word_t *word = event_word_from_port(port);
|
|
|
|
BUG_ON(!irqs_disabled());
|
|
|
|
clear_masked(word);
|
|
if (evtchn_fifo_is_pending(port)) {
|
|
struct evtchn_unmask unmask = { .port = port };
|
|
(void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
|
|
}
|
|
}
|
|
|
|
static uint32_t clear_linked(volatile event_word_t *word)
|
|
{
|
|
event_word_t new, old, w;
|
|
|
|
w = *word;
|
|
|
|
do {
|
|
old = w;
|
|
new = (w & ~((1 << EVTCHN_FIFO_LINKED)
|
|
| EVTCHN_FIFO_LINK_MASK));
|
|
} while ((w = sync_cmpxchg(word, old, new)) != old);
|
|
|
|
return w & EVTCHN_FIFO_LINK_MASK;
|
|
}
|
|
|
|
static void handle_irq_for_port(unsigned port)
|
|
{
|
|
int irq;
|
|
|
|
irq = get_evtchn_to_irq(port);
|
|
if (irq != -1)
|
|
generic_handle_irq(irq);
|
|
}
|
|
|
|
static void consume_one_event(unsigned cpu,
|
|
struct evtchn_fifo_control_block *control_block,
|
|
unsigned priority, unsigned long *ready)
|
|
{
|
|
struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu);
|
|
uint32_t head;
|
|
unsigned port;
|
|
event_word_t *word;
|
|
|
|
head = q->head[priority];
|
|
|
|
/*
|
|
* Reached the tail last time? Read the new HEAD from the
|
|
* control block.
|
|
*/
|
|
if (head == 0) {
|
|
rmb(); /* Ensure word is up-to-date before reading head. */
|
|
head = control_block->head[priority];
|
|
}
|
|
|
|
port = head;
|
|
word = event_word_from_port(port);
|
|
head = clear_linked(word);
|
|
|
|
/*
|
|
* If the link is non-zero, there are more events in the
|
|
* queue, otherwise the queue is empty.
|
|
*
|
|
* If the queue is empty, clear this priority from our local
|
|
* copy of the ready word.
|
|
*/
|
|
if (head == 0)
|
|
clear_bit(priority, ready);
|
|
|
|
if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port))
|
|
handle_irq_for_port(port);
|
|
|
|
q->head[priority] = head;
|
|
}
|
|
|
|
static void evtchn_fifo_handle_events(unsigned cpu)
|
|
{
|
|
struct evtchn_fifo_control_block *control_block;
|
|
unsigned long ready;
|
|
unsigned q;
|
|
|
|
control_block = per_cpu(cpu_control_block, cpu);
|
|
|
|
ready = xchg(&control_block->ready, 0);
|
|
|
|
while (ready) {
|
|
q = find_first_bit(&ready, EVTCHN_FIFO_MAX_QUEUES);
|
|
consume_one_event(cpu, control_block, q, &ready);
|
|
ready |= xchg(&control_block->ready, 0);
|
|
}
|
|
}
|
|
|
|
static void evtchn_fifo_resume(void)
|
|
{
|
|
unsigned cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
void *control_block = per_cpu(cpu_control_block, cpu);
|
|
int ret;
|
|
|
|
if (!control_block)
|
|
continue;
|
|
|
|
/*
|
|
* If this CPU is offline, take the opportunity to
|
|
* free the control block while it is not being
|
|
* used.
|
|
*/
|
|
if (!cpu_online(cpu)) {
|
|
free_page((unsigned long)control_block);
|
|
per_cpu(cpu_control_block, cpu) = NULL;
|
|
continue;
|
|
}
|
|
|
|
ret = init_control_block(cpu, control_block);
|
|
if (ret < 0)
|
|
BUG();
|
|
}
|
|
|
|
/*
|
|
* The event array starts out as empty again and is extended
|
|
* as normal when events are bound. The existing pages will
|
|
* be reused.
|
|
*/
|
|
event_array_pages = 0;
|
|
}
|
|
|
|
static const struct evtchn_ops evtchn_ops_fifo = {
|
|
.max_channels = evtchn_fifo_max_channels,
|
|
.nr_channels = evtchn_fifo_nr_channels,
|
|
.setup = evtchn_fifo_setup,
|
|
.bind_to_cpu = evtchn_fifo_bind_to_cpu,
|
|
.clear_pending = evtchn_fifo_clear_pending,
|
|
.set_pending = evtchn_fifo_set_pending,
|
|
.is_pending = evtchn_fifo_is_pending,
|
|
.test_and_set_mask = evtchn_fifo_test_and_set_mask,
|
|
.mask = evtchn_fifo_mask,
|
|
.unmask = evtchn_fifo_unmask,
|
|
.handle_events = evtchn_fifo_handle_events,
|
|
.resume = evtchn_fifo_resume,
|
|
};
|
|
|
|
static int evtchn_fifo_alloc_control_block(unsigned cpu)
|
|
{
|
|
void *control_block = NULL;
|
|
int ret = -ENOMEM;
|
|
|
|
control_block = (void *)__get_free_page(GFP_KERNEL);
|
|
if (control_block == NULL)
|
|
goto error;
|
|
|
|
ret = init_control_block(cpu, control_block);
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
per_cpu(cpu_control_block, cpu) = control_block;
|
|
|
|
return 0;
|
|
|
|
error:
|
|
free_page((unsigned long)control_block);
|
|
return ret;
|
|
}
|
|
|
|
static int evtchn_fifo_cpu_notification(struct notifier_block *self,
|
|
unsigned long action,
|
|
void *hcpu)
|
|
{
|
|
int cpu = (long)hcpu;
|
|
int ret = 0;
|
|
|
|
switch (action) {
|
|
case CPU_UP_PREPARE:
|
|
if (!per_cpu(cpu_control_block, cpu))
|
|
ret = evtchn_fifo_alloc_control_block(cpu);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return ret < 0 ? NOTIFY_BAD : NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block evtchn_fifo_cpu_notifier = {
|
|
.notifier_call = evtchn_fifo_cpu_notification,
|
|
};
|
|
|
|
int __init xen_evtchn_fifo_init(void)
|
|
{
|
|
int cpu = get_cpu();
|
|
int ret;
|
|
|
|
ret = evtchn_fifo_alloc_control_block(cpu);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
pr_info("Using FIFO-based ABI\n");
|
|
|
|
evtchn_ops = &evtchn_ops_fifo;
|
|
|
|
register_cpu_notifier(&evtchn_fifo_cpu_notifier);
|
|
out:
|
|
put_cpu();
|
|
return ret;
|
|
}
|