Files
linux/drivers/gpu/drm/xe/xe_force_wake.c
Aravind Iddamsetty 49e134e16f drm/xe: Fix lockdep warning in xe_force_wake calls
Use spin_lock_irqsave, spin_unlock_irqrestore

Fix for below:
[13994.811263] ========================================================
[13994.811295] WARNING: possible irq lock inversion dependency detected
[13994.811326] 6.6.0-rc3-xe #2 Tainted: G     U
[13994.811358] --------------------------------------------------------
[13994.811388] swapper/0/0 just changed the state of lock:
[13994.811416] ffff895c7e044db8 (&cpuctx_lock){-...}-{2:2}, at:
__perf_event_read+0xb7/0x3a0
[13994.811494] but this lock took another, HARDIRQ-unsafe lock in the
past:
[13994.811528]  (&fw->lock){+.+.}-{2:2}
[13994.811544]

               and interrupts could create inverse lock ordering between
them.

[13994.811606]
               other info that might help us debug this:
[13994.811636]  Possible interrupt unsafe locking scenario:

[13994.811667]        CPU0                    CPU1
[13994.811691]        ----                    ----
[13994.811715]   lock(&fw->lock);
[13994.811744]                                local_irq_disable();
[13994.811773]                                lock(&cpuctx_lock);
[13994.811810]                                lock(&fw->lock);
[13994.811846]   <Interrupt>
[13994.811865]     lock(&cpuctx_lock);
[13994.811895]
                *** DEADLOCK ***

v2: Use spin_lock in atomic context and spin_lock_irq in a non atomic
context (Matthew Brost)

v3: just use spin_lock_irqsave/restore

Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2023-12-21 11:46:08 -05:00

200 lines
5.1 KiB
C

// SPDX-License-Identifier: MIT
/*
* Copyright © 2022 Intel Corporation
*/
#include "xe_force_wake.h"
#include <drm/drm_util.h>
#include "regs/xe_gt_regs.h"
#include "regs/xe_reg_defs.h"
#include "xe_gt.h"
#include "xe_mmio.h"
#define XE_FORCE_WAKE_ACK_TIMEOUT_MS 50
static struct xe_gt *
fw_to_gt(struct xe_force_wake *fw)
{
return fw->gt;
}
static struct xe_device *
fw_to_xe(struct xe_force_wake *fw)
{
return gt_to_xe(fw_to_gt(fw));
}
static void domain_init(struct xe_force_wake_domain *domain,
enum xe_force_wake_domain_id id,
struct xe_reg reg, struct xe_reg ack, u32 val, u32 mask)
{
domain->id = id;
domain->reg_ctl = reg;
domain->reg_ack = ack;
domain->val = val;
domain->mask = mask;
}
void xe_force_wake_init_gt(struct xe_gt *gt, struct xe_force_wake *fw)
{
struct xe_device *xe = gt_to_xe(gt);
fw->gt = gt;
spin_lock_init(&fw->lock);
/* Assuming gen11+ so assert this assumption is correct */
xe_gt_assert(gt, GRAPHICS_VER(gt_to_xe(gt)) >= 11);
if (xe->info.graphics_verx100 >= 1270) {
domain_init(&fw->domains[XE_FW_DOMAIN_ID_GT],
XE_FW_DOMAIN_ID_GT,
FORCEWAKE_GT,
FORCEWAKE_ACK_GT_MTL,
BIT(0), BIT(16));
} else {
domain_init(&fw->domains[XE_FW_DOMAIN_ID_GT],
XE_FW_DOMAIN_ID_GT,
FORCEWAKE_GT,
FORCEWAKE_ACK_GT,
BIT(0), BIT(16));
}
}
void xe_force_wake_init_engines(struct xe_gt *gt, struct xe_force_wake *fw)
{
int i, j;
/* Assuming gen11+ so assert this assumption is correct */
xe_gt_assert(gt, GRAPHICS_VER(gt_to_xe(gt)) >= 11);
if (!xe_gt_is_media_type(gt))
domain_init(&fw->domains[XE_FW_DOMAIN_ID_RENDER],
XE_FW_DOMAIN_ID_RENDER,
FORCEWAKE_RENDER,
FORCEWAKE_ACK_RENDER,
BIT(0), BIT(16));
for (i = XE_HW_ENGINE_VCS0, j = 0; i <= XE_HW_ENGINE_VCS7; ++i, ++j) {
if (!(gt->info.engine_mask & BIT(i)))
continue;
domain_init(&fw->domains[XE_FW_DOMAIN_ID_MEDIA_VDBOX0 + j],
XE_FW_DOMAIN_ID_MEDIA_VDBOX0 + j,
FORCEWAKE_MEDIA_VDBOX(j),
FORCEWAKE_ACK_MEDIA_VDBOX(j),
BIT(0), BIT(16));
}
for (i = XE_HW_ENGINE_VECS0, j = 0; i <= XE_HW_ENGINE_VECS3; ++i, ++j) {
if (!(gt->info.engine_mask & BIT(i)))
continue;
domain_init(&fw->domains[XE_FW_DOMAIN_ID_MEDIA_VEBOX0 + j],
XE_FW_DOMAIN_ID_MEDIA_VEBOX0 + j,
FORCEWAKE_MEDIA_VEBOX(j),
FORCEWAKE_ACK_MEDIA_VEBOX(j),
BIT(0), BIT(16));
}
if (gt->info.engine_mask & BIT(XE_HW_ENGINE_GSCCS0))
domain_init(&fw->domains[XE_FW_DOMAIN_ID_GSC],
XE_FW_DOMAIN_ID_GSC,
FORCEWAKE_GSC,
FORCEWAKE_ACK_GSC,
BIT(0), BIT(16));
}
static void domain_wake(struct xe_gt *gt, struct xe_force_wake_domain *domain)
{
xe_mmio_write32(gt, domain->reg_ctl, domain->mask | domain->val);
}
static int domain_wake_wait(struct xe_gt *gt,
struct xe_force_wake_domain *domain)
{
return xe_mmio_wait32(gt, domain->reg_ack, domain->val, domain->val,
XE_FORCE_WAKE_ACK_TIMEOUT_MS * USEC_PER_MSEC,
NULL, true);
}
static void domain_sleep(struct xe_gt *gt, struct xe_force_wake_domain *domain)
{
xe_mmio_write32(gt, domain->reg_ctl, domain->mask);
}
static int domain_sleep_wait(struct xe_gt *gt,
struct xe_force_wake_domain *domain)
{
return xe_mmio_wait32(gt, domain->reg_ack, domain->val, 0,
XE_FORCE_WAKE_ACK_TIMEOUT_MS * USEC_PER_MSEC,
NULL, true);
}
#define for_each_fw_domain_masked(domain__, mask__, fw__, tmp__) \
for (tmp__ = (mask__); tmp__; tmp__ &= ~BIT(ffs(tmp__) - 1)) \
for_each_if((domain__ = ((fw__)->domains + \
(ffs(tmp__) - 1))) && \
domain__->reg_ctl.addr)
int xe_force_wake_get(struct xe_force_wake *fw,
enum xe_force_wake_domains domains)
{
struct xe_device *xe = fw_to_xe(fw);
struct xe_gt *gt = fw_to_gt(fw);
struct xe_force_wake_domain *domain;
enum xe_force_wake_domains tmp, woken = 0;
unsigned long flags;
int ret, ret2 = 0;
spin_lock_irqsave(&fw->lock, flags);
for_each_fw_domain_masked(domain, domains, fw, tmp) {
if (!domain->ref++) {
woken |= BIT(domain->id);
domain_wake(gt, domain);
}
}
for_each_fw_domain_masked(domain, woken, fw, tmp) {
ret = domain_wake_wait(gt, domain);
ret2 |= ret;
if (ret)
drm_notice(&xe->drm, "Force wake domain (%d) failed to ack wake, ret=%d\n",
domain->id, ret);
}
fw->awake_domains |= woken;
spin_unlock_irqrestore(&fw->lock, flags);
return ret2;
}
int xe_force_wake_put(struct xe_force_wake *fw,
enum xe_force_wake_domains domains)
{
struct xe_device *xe = fw_to_xe(fw);
struct xe_gt *gt = fw_to_gt(fw);
struct xe_force_wake_domain *domain;
enum xe_force_wake_domains tmp, sleep = 0;
unsigned long flags;
int ret, ret2 = 0;
spin_lock_irqsave(&fw->lock, flags);
for_each_fw_domain_masked(domain, domains, fw, tmp) {
if (!--domain->ref) {
sleep |= BIT(domain->id);
domain_sleep(gt, domain);
}
}
for_each_fw_domain_masked(domain, sleep, fw, tmp) {
ret = domain_sleep_wait(gt, domain);
ret2 |= ret;
if (ret)
drm_notice(&xe->drm, "Force wake domain (%d) failed to ack sleep, ret=%d\n",
domain->id, ret);
}
fw->awake_domains &= ~sleep;
spin_unlock_irqrestore(&fw->lock, flags);
return ret2;
}