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linux-next/drivers/gpu/drm/msm/msm_gpu.c
Rob Clark a1ad352333 drm/msm: fix potential deadlock in gpu init
Somewhere along the way, the firmware loader sprouted another lock
dependency, resulting in possible deadlock scenario:

 &dev->struct_mutex --> &sb->s_type->i_mutex_key#2 --> &mm->mmap_sem

which is problematic vs things like gem mmap.

So introduce a separate mutex to synchronize gpu init.

Signed-off-by: Rob Clark <robdclark@gmail.com>
2014-08-04 11:55:29 -04:00

652 lines
15 KiB
C

/*
* Copyright (C) 2013 Red Hat
* Author: Rob Clark <robdclark@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that 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.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "msm_gpu.h"
#include "msm_gem.h"
#include "msm_mmu.h"
/*
* Power Management:
*/
#ifdef CONFIG_MSM_BUS_SCALING
#include <mach/board.h>
static void bs_init(struct msm_gpu *gpu)
{
if (gpu->bus_scale_table) {
gpu->bsc = msm_bus_scale_register_client(gpu->bus_scale_table);
DBG("bus scale client: %08x", gpu->bsc);
}
}
static void bs_fini(struct msm_gpu *gpu)
{
if (gpu->bsc) {
msm_bus_scale_unregister_client(gpu->bsc);
gpu->bsc = 0;
}
}
static void bs_set(struct msm_gpu *gpu, int idx)
{
if (gpu->bsc) {
DBG("set bus scaling: %d", idx);
msm_bus_scale_client_update_request(gpu->bsc, idx);
}
}
#else
static void bs_init(struct msm_gpu *gpu) {}
static void bs_fini(struct msm_gpu *gpu) {}
static void bs_set(struct msm_gpu *gpu, int idx) {}
#endif
static int enable_pwrrail(struct msm_gpu *gpu)
{
struct drm_device *dev = gpu->dev;
int ret = 0;
if (gpu->gpu_reg) {
ret = regulator_enable(gpu->gpu_reg);
if (ret) {
dev_err(dev->dev, "failed to enable 'gpu_reg': %d\n", ret);
return ret;
}
}
if (gpu->gpu_cx) {
ret = regulator_enable(gpu->gpu_cx);
if (ret) {
dev_err(dev->dev, "failed to enable 'gpu_cx': %d\n", ret);
return ret;
}
}
return 0;
}
static int disable_pwrrail(struct msm_gpu *gpu)
{
if (gpu->gpu_cx)
regulator_disable(gpu->gpu_cx);
if (gpu->gpu_reg)
regulator_disable(gpu->gpu_reg);
return 0;
}
static int enable_clk(struct msm_gpu *gpu)
{
struct clk *rate_clk = NULL;
int i;
/* NOTE: kgsl_pwrctrl_clk() ignores grp_clks[0].. */
for (i = ARRAY_SIZE(gpu->grp_clks) - 1; i > 0; i--) {
if (gpu->grp_clks[i]) {
clk_prepare(gpu->grp_clks[i]);
rate_clk = gpu->grp_clks[i];
}
}
if (rate_clk && gpu->fast_rate)
clk_set_rate(rate_clk, gpu->fast_rate);
for (i = ARRAY_SIZE(gpu->grp_clks) - 1; i > 0; i--)
if (gpu->grp_clks[i])
clk_enable(gpu->grp_clks[i]);
return 0;
}
static int disable_clk(struct msm_gpu *gpu)
{
struct clk *rate_clk = NULL;
int i;
/* NOTE: kgsl_pwrctrl_clk() ignores grp_clks[0].. */
for (i = ARRAY_SIZE(gpu->grp_clks) - 1; i > 0; i--) {
if (gpu->grp_clks[i]) {
clk_disable(gpu->grp_clks[i]);
rate_clk = gpu->grp_clks[i];
}
}
if (rate_clk && gpu->slow_rate)
clk_set_rate(rate_clk, gpu->slow_rate);
for (i = ARRAY_SIZE(gpu->grp_clks) - 1; i > 0; i--)
if (gpu->grp_clks[i])
clk_unprepare(gpu->grp_clks[i]);
return 0;
}
static int enable_axi(struct msm_gpu *gpu)
{
if (gpu->ebi1_clk)
clk_prepare_enable(gpu->ebi1_clk);
if (gpu->bus_freq)
bs_set(gpu, gpu->bus_freq);
return 0;
}
static int disable_axi(struct msm_gpu *gpu)
{
if (gpu->ebi1_clk)
clk_disable_unprepare(gpu->ebi1_clk);
if (gpu->bus_freq)
bs_set(gpu, 0);
return 0;
}
int msm_gpu_pm_resume(struct msm_gpu *gpu)
{
struct drm_device *dev = gpu->dev;
int ret;
DBG("%s: active_cnt=%d", gpu->name, gpu->active_cnt);
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
if (gpu->active_cnt++ > 0)
return 0;
if (WARN_ON(gpu->active_cnt <= 0))
return -EINVAL;
ret = enable_pwrrail(gpu);
if (ret)
return ret;
ret = enable_clk(gpu);
if (ret)
return ret;
ret = enable_axi(gpu);
if (ret)
return ret;
return 0;
}
int msm_gpu_pm_suspend(struct msm_gpu *gpu)
{
struct drm_device *dev = gpu->dev;
int ret;
DBG("%s: active_cnt=%d", gpu->name, gpu->active_cnt);
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
if (--gpu->active_cnt > 0)
return 0;
if (WARN_ON(gpu->active_cnt < 0))
return -EINVAL;
ret = disable_axi(gpu);
if (ret)
return ret;
ret = disable_clk(gpu);
if (ret)
return ret;
ret = disable_pwrrail(gpu);
if (ret)
return ret;
return 0;
}
/*
* Inactivity detection (for suspend):
*/
static void inactive_worker(struct work_struct *work)
{
struct msm_gpu *gpu = container_of(work, struct msm_gpu, inactive_work);
struct drm_device *dev = gpu->dev;
if (gpu->inactive)
return;
DBG("%s: inactive!\n", gpu->name);
mutex_lock(&dev->struct_mutex);
if (!(msm_gpu_active(gpu) || gpu->inactive)) {
disable_axi(gpu);
disable_clk(gpu);
gpu->inactive = true;
}
mutex_unlock(&dev->struct_mutex);
}
static void inactive_handler(unsigned long data)
{
struct msm_gpu *gpu = (struct msm_gpu *)data;
struct msm_drm_private *priv = gpu->dev->dev_private;
queue_work(priv->wq, &gpu->inactive_work);
}
/* cancel inactive timer and make sure we are awake: */
static void inactive_cancel(struct msm_gpu *gpu)
{
DBG("%s", gpu->name);
del_timer(&gpu->inactive_timer);
if (gpu->inactive) {
enable_clk(gpu);
enable_axi(gpu);
gpu->inactive = false;
}
}
static void inactive_start(struct msm_gpu *gpu)
{
DBG("%s", gpu->name);
mod_timer(&gpu->inactive_timer,
round_jiffies_up(jiffies + DRM_MSM_INACTIVE_JIFFIES));
}
/*
* Hangcheck detection for locked gpu:
*/
static void recover_worker(struct work_struct *work)
{
struct msm_gpu *gpu = container_of(work, struct msm_gpu, recover_work);
struct drm_device *dev = gpu->dev;
dev_err(dev->dev, "%s: hangcheck recover!\n", gpu->name);
mutex_lock(&dev->struct_mutex);
if (msm_gpu_active(gpu)) {
inactive_cancel(gpu);
gpu->funcs->recover(gpu);
}
mutex_unlock(&dev->struct_mutex);
msm_gpu_retire(gpu);
}
static void hangcheck_timer_reset(struct msm_gpu *gpu)
{
DBG("%s", gpu->name);
mod_timer(&gpu->hangcheck_timer,
round_jiffies_up(jiffies + DRM_MSM_HANGCHECK_JIFFIES));
}
static void hangcheck_handler(unsigned long data)
{
struct msm_gpu *gpu = (struct msm_gpu *)data;
struct drm_device *dev = gpu->dev;
struct msm_drm_private *priv = dev->dev_private;
uint32_t fence = gpu->funcs->last_fence(gpu);
if (fence != gpu->hangcheck_fence) {
/* some progress has been made.. ya! */
gpu->hangcheck_fence = fence;
} else if (fence < gpu->submitted_fence) {
/* no progress and not done.. hung! */
gpu->hangcheck_fence = fence;
dev_err(dev->dev, "%s: hangcheck detected gpu lockup!\n",
gpu->name);
dev_err(dev->dev, "%s: completed fence: %u\n",
gpu->name, fence);
dev_err(dev->dev, "%s: submitted fence: %u\n",
gpu->name, gpu->submitted_fence);
queue_work(priv->wq, &gpu->recover_work);
}
/* if still more pending work, reset the hangcheck timer: */
if (gpu->submitted_fence > gpu->hangcheck_fence)
hangcheck_timer_reset(gpu);
/* workaround for missing irq: */
queue_work(priv->wq, &gpu->retire_work);
}
/*
* Performance Counters:
*/
/* called under perf_lock */
static int update_hw_cntrs(struct msm_gpu *gpu, uint32_t ncntrs, uint32_t *cntrs)
{
uint32_t current_cntrs[ARRAY_SIZE(gpu->last_cntrs)];
int i, n = min(ncntrs, gpu->num_perfcntrs);
/* read current values: */
for (i = 0; i < gpu->num_perfcntrs; i++)
current_cntrs[i] = gpu_read(gpu, gpu->perfcntrs[i].sample_reg);
/* update cntrs: */
for (i = 0; i < n; i++)
cntrs[i] = current_cntrs[i] - gpu->last_cntrs[i];
/* save current values: */
for (i = 0; i < gpu->num_perfcntrs; i++)
gpu->last_cntrs[i] = current_cntrs[i];
return n;
}
static void update_sw_cntrs(struct msm_gpu *gpu)
{
ktime_t time;
uint32_t elapsed;
unsigned long flags;
spin_lock_irqsave(&gpu->perf_lock, flags);
if (!gpu->perfcntr_active)
goto out;
time = ktime_get();
elapsed = ktime_to_us(ktime_sub(time, gpu->last_sample.time));
gpu->totaltime += elapsed;
if (gpu->last_sample.active)
gpu->activetime += elapsed;
gpu->last_sample.active = msm_gpu_active(gpu);
gpu->last_sample.time = time;
out:
spin_unlock_irqrestore(&gpu->perf_lock, flags);
}
void msm_gpu_perfcntr_start(struct msm_gpu *gpu)
{
unsigned long flags;
spin_lock_irqsave(&gpu->perf_lock, flags);
/* we could dynamically enable/disable perfcntr registers too.. */
gpu->last_sample.active = msm_gpu_active(gpu);
gpu->last_sample.time = ktime_get();
gpu->activetime = gpu->totaltime = 0;
gpu->perfcntr_active = true;
update_hw_cntrs(gpu, 0, NULL);
spin_unlock_irqrestore(&gpu->perf_lock, flags);
}
void msm_gpu_perfcntr_stop(struct msm_gpu *gpu)
{
gpu->perfcntr_active = false;
}
/* returns -errno or # of cntrs sampled */
int msm_gpu_perfcntr_sample(struct msm_gpu *gpu, uint32_t *activetime,
uint32_t *totaltime, uint32_t ncntrs, uint32_t *cntrs)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&gpu->perf_lock, flags);
if (!gpu->perfcntr_active) {
ret = -EINVAL;
goto out;
}
*activetime = gpu->activetime;
*totaltime = gpu->totaltime;
gpu->activetime = gpu->totaltime = 0;
ret = update_hw_cntrs(gpu, ncntrs, cntrs);
out:
spin_unlock_irqrestore(&gpu->perf_lock, flags);
return ret;
}
/*
* Cmdstream submission/retirement:
*/
static void retire_worker(struct work_struct *work)
{
struct msm_gpu *gpu = container_of(work, struct msm_gpu, retire_work);
struct drm_device *dev = gpu->dev;
uint32_t fence = gpu->funcs->last_fence(gpu);
msm_update_fence(gpu->dev, fence);
mutex_lock(&dev->struct_mutex);
while (!list_empty(&gpu->active_list)) {
struct msm_gem_object *obj;
obj = list_first_entry(&gpu->active_list,
struct msm_gem_object, mm_list);
if ((obj->read_fence <= fence) &&
(obj->write_fence <= fence)) {
/* move to inactive: */
msm_gem_move_to_inactive(&obj->base);
msm_gem_put_iova(&obj->base, gpu->id);
drm_gem_object_unreference(&obj->base);
} else {
break;
}
}
mutex_unlock(&dev->struct_mutex);
if (!msm_gpu_active(gpu))
inactive_start(gpu);
}
/* call from irq handler to schedule work to retire bo's */
void msm_gpu_retire(struct msm_gpu *gpu)
{
struct msm_drm_private *priv = gpu->dev->dev_private;
queue_work(priv->wq, &gpu->retire_work);
update_sw_cntrs(gpu);
}
/* add bo's to gpu's ring, and kick gpu: */
int msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
struct msm_file_private *ctx)
{
struct drm_device *dev = gpu->dev;
struct msm_drm_private *priv = dev->dev_private;
int i, ret;
submit->fence = ++priv->next_fence;
gpu->submitted_fence = submit->fence;
inactive_cancel(gpu);
msm_rd_dump_submit(submit);
gpu->submitted_fence = submit->fence;
update_sw_cntrs(gpu);
ret = gpu->funcs->submit(gpu, submit, ctx);
priv->lastctx = ctx;
for (i = 0; i < submit->nr_bos; i++) {
struct msm_gem_object *msm_obj = submit->bos[i].obj;
/* can't happen yet.. but when we add 2d support we'll have
* to deal w/ cross-ring synchronization:
*/
WARN_ON(is_active(msm_obj) && (msm_obj->gpu != gpu));
if (!is_active(msm_obj)) {
uint32_t iova;
/* ring takes a reference to the bo and iova: */
drm_gem_object_reference(&msm_obj->base);
msm_gem_get_iova_locked(&msm_obj->base,
submit->gpu->id, &iova);
}
if (submit->bos[i].flags & MSM_SUBMIT_BO_READ)
msm_gem_move_to_active(&msm_obj->base, gpu, false, submit->fence);
if (submit->bos[i].flags & MSM_SUBMIT_BO_WRITE)
msm_gem_move_to_active(&msm_obj->base, gpu, true, submit->fence);
}
hangcheck_timer_reset(gpu);
return ret;
}
/*
* Init/Cleanup:
*/
static irqreturn_t irq_handler(int irq, void *data)
{
struct msm_gpu *gpu = data;
return gpu->funcs->irq(gpu);
}
static const char *clk_names[] = {
"src_clk", "core_clk", "iface_clk", "mem_clk", "mem_iface_clk",
};
int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
struct msm_gpu *gpu, const struct msm_gpu_funcs *funcs,
const char *name, const char *ioname, const char *irqname, int ringsz)
{
struct iommu_domain *iommu;
int i, ret;
if (WARN_ON(gpu->num_perfcntrs > ARRAY_SIZE(gpu->last_cntrs)))
gpu->num_perfcntrs = ARRAY_SIZE(gpu->last_cntrs);
gpu->dev = drm;
gpu->funcs = funcs;
gpu->name = name;
gpu->inactive = true;
INIT_LIST_HEAD(&gpu->active_list);
INIT_WORK(&gpu->retire_work, retire_worker);
INIT_WORK(&gpu->inactive_work, inactive_worker);
INIT_WORK(&gpu->recover_work, recover_worker);
setup_timer(&gpu->inactive_timer, inactive_handler,
(unsigned long)gpu);
setup_timer(&gpu->hangcheck_timer, hangcheck_handler,
(unsigned long)gpu);
spin_lock_init(&gpu->perf_lock);
BUG_ON(ARRAY_SIZE(clk_names) != ARRAY_SIZE(gpu->grp_clks));
/* Map registers: */
gpu->mmio = msm_ioremap(pdev, ioname, name);
if (IS_ERR(gpu->mmio)) {
ret = PTR_ERR(gpu->mmio);
goto fail;
}
/* Get Interrupt: */
gpu->irq = platform_get_irq_byname(pdev, irqname);
if (gpu->irq < 0) {
ret = gpu->irq;
dev_err(drm->dev, "failed to get irq: %d\n", ret);
goto fail;
}
ret = devm_request_irq(&pdev->dev, gpu->irq, irq_handler,
IRQF_TRIGGER_HIGH, gpu->name, gpu);
if (ret) {
dev_err(drm->dev, "failed to request IRQ%u: %d\n", gpu->irq, ret);
goto fail;
}
/* Acquire clocks: */
for (i = 0; i < ARRAY_SIZE(clk_names); i++) {
gpu->grp_clks[i] = devm_clk_get(&pdev->dev, clk_names[i]);
DBG("grp_clks[%s]: %p", clk_names[i], gpu->grp_clks[i]);
if (IS_ERR(gpu->grp_clks[i]))
gpu->grp_clks[i] = NULL;
}
gpu->ebi1_clk = devm_clk_get(&pdev->dev, "bus_clk");
DBG("ebi1_clk: %p", gpu->ebi1_clk);
if (IS_ERR(gpu->ebi1_clk))
gpu->ebi1_clk = NULL;
/* Acquire regulators: */
gpu->gpu_reg = devm_regulator_get(&pdev->dev, "vdd");
DBG("gpu_reg: %p", gpu->gpu_reg);
if (IS_ERR(gpu->gpu_reg))
gpu->gpu_reg = NULL;
gpu->gpu_cx = devm_regulator_get(&pdev->dev, "vddcx");
DBG("gpu_cx: %p", gpu->gpu_cx);
if (IS_ERR(gpu->gpu_cx))
gpu->gpu_cx = NULL;
/* Setup IOMMU.. eventually we will (I think) do this once per context
* and have separate page tables per context. For now, to keep things
* simple and to get something working, just use a single address space:
*/
iommu = iommu_domain_alloc(&platform_bus_type);
if (iommu) {
dev_info(drm->dev, "%s: using IOMMU\n", name);
gpu->mmu = msm_iommu_new(&pdev->dev, iommu);
} else {
dev_info(drm->dev, "%s: no IOMMU, fallback to VRAM carveout!\n", name);
}
gpu->id = msm_register_mmu(drm, gpu->mmu);
/* Create ringbuffer: */
mutex_lock(&drm->struct_mutex);
gpu->rb = msm_ringbuffer_new(gpu, ringsz);
mutex_unlock(&drm->struct_mutex);
if (IS_ERR(gpu->rb)) {
ret = PTR_ERR(gpu->rb);
gpu->rb = NULL;
dev_err(drm->dev, "could not create ringbuffer: %d\n", ret);
goto fail;
}
bs_init(gpu);
return 0;
fail:
return ret;
}
void msm_gpu_cleanup(struct msm_gpu *gpu)
{
DBG("%s", gpu->name);
WARN_ON(!list_empty(&gpu->active_list));
bs_fini(gpu);
if (gpu->rb) {
if (gpu->rb_iova)
msm_gem_put_iova(gpu->rb->bo, gpu->id);
msm_ringbuffer_destroy(gpu->rb);
}
if (gpu->mmu)
gpu->mmu->funcs->destroy(gpu->mmu);
}