Files
linux-nvgpu/drivers/gpu/nvgpu/os/linux/intr.c
shashank singh d34bad0a27 nvgpu: gpu: simplify waiting logic for interrupt handler
The atomic counter in interrupt handler can overflow and result in
calling of BUG() which will crash the process. The equivalent
functionality can be implemented with just setting an atomic variable at
start of handler and resetting at end of handler. The wait can be longer
in case there is constant interrupts coming but ultimately it will end.
Generally the wait path is not time critical so it should not be an
issue. Also, fix the unit tests for mc.

Change-Id: I9b8a236f72e057e89a969d2e98d4d3f9be81b379
Signed-off-by: shashank singh <shashsingh@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2247819
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-mobile-misra <svc-mobile-misra@nvidia.com>
Reviewed-by: svc-mobile-cert <svc-mobile-cert@nvidia.com>
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit
2020-12-15 14:10:29 -06:00

152 lines
3.6 KiB
C

/*
* Copyright (c) 2014-2020, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#ifdef CONFIG_NVGPU_TRACE
#include <trace/events/gk20a.h>
#endif
#include <linux/irqreturn.h>
#include <nvgpu/gk20a.h>
#include <nvgpu/mc.h>
#include <nvgpu/nvgpu_init.h>
#include <nvgpu/gops_mc.h>
#include <nvgpu/atomic.h>
#include "os_linux.h"
irqreturn_t nvgpu_intr_stall(struct gk20a *g)
{
u32 mc_intr_0;
#ifdef CONFIG_NVGPU_TRACE
trace_mc_gk20a_intr_stall(g->name);
#endif
if (nvgpu_is_powered_off(g))
return IRQ_NONE;
/* not from gpu when sharing irq with others */
mc_intr_0 = g->ops.mc.intr_stall(g);
if (unlikely(!mc_intr_0))
return IRQ_NONE;
nvgpu_mc_intr_stall_pause(g);
#ifndef CONFIG_NVGPU_RECOVERY
if (g->sw_quiesce_pending) {
return IRQ_NONE;
}
#endif
nvgpu_atomic_set(&g->mc.sw_irq_stall_pending, 1);
#ifdef CONFIG_NVGPU_TRACE
trace_mc_gk20a_intr_stall_done(g->name);
#endif
return IRQ_WAKE_THREAD;
}
irqreturn_t nvgpu_intr_thread_stall(struct gk20a *g)
{
nvgpu_log(g, gpu_dbg_intr, "interrupt thread launched");
#ifdef CONFIG_NVGPU_TRACE
trace_mc_gk20a_intr_thread_stall(g->name);
#endif
g->ops.mc.isr_stall(g);
/* sync handled irq counter before re-enabling interrupts */
nvgpu_atomic_set(&g->mc.sw_irq_stall_pending, 0);
nvgpu_mc_intr_stall_resume(g);
nvgpu_cond_broadcast(&g->mc.sw_irq_stall_last_handled_cond);
#ifdef CONFIG_NVGPU_TRACE
trace_mc_gk20a_intr_thread_stall_done(g->name);
#endif
return IRQ_HANDLED;
}
irqreturn_t nvgpu_intr_nonstall(struct gk20a *g)
{
u32 non_stall_intr_val;
int ops_old, ops_new, ops = 0;
struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
if (nvgpu_is_powered_off(g))
return IRQ_NONE;
/* not from gpu when sharing irq with others */
non_stall_intr_val = g->ops.mc.intr_nonstall(g);
if (unlikely(!non_stall_intr_val))
return IRQ_NONE;
nvgpu_mc_intr_nonstall_pause(g);
#ifndef CONFIG_NVGPU_RECOVERY
if (g->sw_quiesce_pending) {
return IRQ_NONE;
}
#endif
nvgpu_atomic_set(&g->mc.sw_irq_nonstall_pending, 1);
ops = g->ops.mc.isr_nonstall(g);
if (ops) {
do {
ops_old = atomic_read(&l->nonstall_ops);
ops_new = ops_old | ops;
} while (ops_old != atomic_cmpxchg(&l->nonstall_ops,
ops_old, ops_new));
queue_work(l->nonstall_work_queue, &l->nonstall_fn_work);
}
/* sync handled irq counter before re-enabling interrupts */
nvgpu_atomic_set(&g->mc.sw_irq_nonstall_pending, 0);
nvgpu_mc_intr_nonstall_resume(g);
nvgpu_cond_broadcast(&g->mc.sw_irq_nonstall_last_handled_cond);
return IRQ_HANDLED;
}
static void mc_gk20a_handle_intr_nonstall(struct gk20a *g, u32 ops)
{
bool semaphore_wakeup, post_events;
semaphore_wakeup =
(((ops & NVGPU_NONSTALL_OPS_WAKEUP_SEMAPHORE) != 0U) ?
true : false);
post_events = (((ops & NVGPU_NONSTALL_OPS_POST_EVENTS) != 0U) ?
true: false);
if (semaphore_wakeup) {
g->ops.semaphore_wakeup(g, post_events);
}
}
void nvgpu_intr_nonstall_cb(struct work_struct *work)
{
struct nvgpu_os_linux *l =
container_of(work, struct nvgpu_os_linux, nonstall_fn_work);
struct gk20a *g = &l->g;
do {
u32 ops;
ops = atomic_xchg(&l->nonstall_ops, 0);
mc_gk20a_handle_intr_nonstall(g, ops);
} while (atomic_read(&l->nonstall_ops) != 0);
}