[PATCH] drm/amdgpu: use HMM mirror callback to replace mmu notifier v3
Philip Yang
philip.yang at amd.com
Thu Sep 13 20:45:38 UTC 2018
On 2018-09-13 02:24 PM, Christian König wrote:
> Am 13.09.2018 um 20:00 schrieb Philip Yang:
>> Replace our MMU notifier with hmm_mirror_ops.sync_cpu_device_pagetables
>> callback. Enable CONFIG_HMM and CONFIG_HMM_MIRROR as a dependency in
>> DRM_AMDGPU_USERPTR Kconfig.
>>
>> It supports both KFD userptr and gfx userptr paths.
>>
>> This depends on several HMM patchset from Jérôme Glisse queued for
>> upstream. See
>> http://172.27.226.38/root/kernel_amd/commits/hmm-dev-v01 (for AMD
>> intranet)
>>
>> Change-Id: Ie62c3c5e3c5b8521ab3b438d1eff2aa2a003835e
>> Signed-off-by: Philip Yang <Philip.Yang at amd.com>
>> ---
>> drivers/gpu/drm/amd/amdgpu/Kconfig | 6 +--
>> drivers/gpu/drm/amd/amdgpu/Makefile | 2 +-
>> drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 88
>> +++++++++++++++++++++++++++-------
>> 3 files changed, 75 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/Kconfig
>> b/drivers/gpu/drm/amd/amdgpu/Kconfig
>> index 9221e54..960a633 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/Kconfig
>> +++ b/drivers/gpu/drm/amd/amdgpu/Kconfig
>> @@ -26,10 +26,10 @@ config DRM_AMDGPU_CIK
>> config DRM_AMDGPU_USERPTR
>> bool "Always enable userptr write support"
>> depends on DRM_AMDGPU
>> - select MMU_NOTIFIER
>> + select HMM_MIRROR
>> help
>> - This option selects CONFIG_MMU_NOTIFIER if it isn't already
>> - selected to enabled full userptr support.
>> + This option selects CONFIG_HMM and CONFIG_HMM_MIRROR if it
>> + isn't already selected to enabled full userptr support.
>> config DRM_AMDGPU_GART_DEBUGFS
>> bool "Allow GART access through debugfs"
>> diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile
>> b/drivers/gpu/drm/amd/amdgpu/Makefile
>> index 138cb78..c1e5d43 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/Makefile
>> +++ b/drivers/gpu/drm/amd/amdgpu/Makefile
>> @@ -171,7 +171,7 @@ endif
>> amdgpu-$(CONFIG_COMPAT) += amdgpu_ioc32.o
>> amdgpu-$(CONFIG_VGA_SWITCHEROO) += amdgpu_atpx_handler.o
>> amdgpu-$(CONFIG_ACPI) += amdgpu_acpi.o
>> -amdgpu-$(CONFIG_MMU_NOTIFIER) += amdgpu_mn.o
>> +amdgpu-$(CONFIG_HMM) += amdgpu_mn.o
>> include $(FULL_AMD_PATH)/powerplay/Makefile
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
>> index e55508b..ea8671f6 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
>> @@ -46,6 +46,7 @@
>> #include <linux/firmware.h>
>> #include <linux/module.h>
>> #include <linux/mmu_notifier.h>
>> +#include <linux/hmm.h>
>
> Can we now drop including linux/mmu_notifier.h?
Yes, will use hmm_mirror_ops to replace gfx and kfd mmu_notifier_ops
>> #include <linux/interval_tree.h>
>> #include <drm/drmP.h>
>> #include <drm/drm.h>
>> @@ -66,6 +67,7 @@
>> * @objects: interval tree containing amdgpu_mn_nodes
>> * @read_lock: mutex for recursive locking of @lock
>> * @recursion: depth of recursion
>> + * @mirror: HMM mirror function support
>> *
>> * Data for each amdgpu device and process address space.
>> */
>> @@ -87,6 +89,9 @@ struct amdgpu_mn {
>> struct rb_root_cached objects;
>> struct mutex read_lock;
>> atomic_t recursion;
>> +
>> + /* HMM mirror */
>> + struct hmm_mirror mirror;
>> };
>> /**
>> @@ -103,7 +108,7 @@ struct amdgpu_mn_node {
>> };
>> /**
>> - * amdgpu_mn_destroy - destroy the MMU notifier
>> + * amdgpu_mn_destroy - destroy the HMM mirror
>> *
>> * @work: previously sheduled work item
>> *
>> @@ -129,28 +134,27 @@ static void amdgpu_mn_destroy(struct
>> work_struct *work)
>> }
>> up_write(&amn->lock);
>> mutex_unlock(&adev->mn_lock);
>> - mmu_notifier_unregister_no_release(&amn->mn, amn->mm);
>> +
>> + hmm_mirror_unregister(&amn->mirror);
>> +
>> kfree(amn);
>> }
>> /**
>> * amdgpu_mn_release - callback to notify about mm destruction
>> *
>> - * @mn: our notifier
>> - * @mm: the mm this callback is about
>> + * @mirror: the HMM mirror (mm) this callback is about
>> *
>> - * Shedule a work item to lazy destroy our notifier.
>> + * Shedule a work item to lazy destroy HMM mirror.
>> */
>> -static void amdgpu_mn_release(struct mmu_notifier *mn,
>> - struct mm_struct *mm)
>> +static void amdgpu_hmm_mirror_release(struct hmm_mirror *mirror)
>> {
>> - struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn);
>> + struct amdgpu_mn *amn = container_of(mirror, struct amdgpu_mn,
>> mirror);
>> INIT_WORK(&amn->work, amdgpu_mn_destroy);
>> schedule_work(&amn->work);
>> }
>> -
>> /**
>> * amdgpu_mn_lock - take the write side lock for this notifier
>> *
>> @@ -355,12 +359,10 @@ static void
>> amdgpu_mn_invalidate_range_end(struct mmu_notifier *mn,
>> static const struct mmu_notifier_ops amdgpu_mn_ops[] = {
>> [AMDGPU_MN_TYPE_GFX] = {
>> - .release = amdgpu_mn_release,
>> .invalidate_range_start =
>> amdgpu_mn_invalidate_range_start_gfx,
>> .invalidate_range_end = amdgpu_mn_invalidate_range_end,
>> },
>> [AMDGPU_MN_TYPE_HSA] = {
>> - .release = amdgpu_mn_release,
>> .invalidate_range_start =
>> amdgpu_mn_invalidate_range_start_hsa,
>> .invalidate_range_end = amdgpu_mn_invalidate_range_end,
>> },
>> @@ -373,12 +375,63 @@ static const struct mmu_notifier_ops
>> amdgpu_mn_ops[] = {
>> #define AMDGPU_MN_KEY(mm, type) ((unsigned long)(mm) + (type))
>> /**
>> - * amdgpu_mn_get - create notifier context
>> + * amdgpu_hmm_sync_cpu_device_pagetables - synchronize CPU/GPU page
>> tables
>> + *
>> + * @mirror: the hmm_mirror (mm) is about to update
>> + * @update: the update start, end address
>> + *
>> + * This callback is called from mmu_notifiers when the CPU page
>> table is
>> + * updated.
>> + */
>> +static int amdgpu_hmm_sync_cpu_device_pagetables(struct hmm_mirror
>> *mirror,
>> + const struct hmm_update *update)
>> +{
>> + struct amdgpu_mn *amn;
>> + struct hmm *hmm;
>> + struct mm_struct *mm;
>> + unsigned long start;
>> + unsigned long end;
>> + unsigned long key;
>> + int r = 0;
>> +
>> + start = update->start;
>> + end = update->end;
>> + hmm = mirror->hmm;
>> + mm = *(struct mm_struct **)hmm;
>> +
>> + pr_debug("mirror %p start %lx end %lx\n", mirror, start, end);
>
> You should probably remove those pr_debug lines before upstreaming.
>
> Alternatively we could turn them into trace points.
>
>> +
>> + amn = container_of(mirror, struct amdgpu_mn, mirror);
>> + key = AMDGPU_MN_KEY(mm, amn->type);
>> +
>> + hash_for_each_possible(amn->adev->mn_hash, amn, node, key)
>> + if (AMDGPU_MN_KEY(amn->mm, amn->type) == key) {
>> + r = amn->mn.ops->invalidate_range_start(&amn->mn, mm,
>> + start, end,
>> + update->blockable);
>> + amn->mn.ops->invalidate_range_end(&amn->mn, mm,
>> + start, end);
>> + if (r) {
>> + DRM_ERROR("Failed to invalidate %lx\n", start);
>> + break;
>> + }
>> + }
>
> That looks fishy to me, why is this necessary?
>
Yeah, it is unnecessary, one process (mm) register once hmm mirror amn
for each adev,
so one mm will get individual call back, do not need use mm to lookup
amn from adev->mn_hash.
>> +
>> + return r;
>> +}
>> +
>> +static struct hmm_mirror_ops amdgpu_hmm_mirror_ops = {
>> + .sync_cpu_device_pagetables =
>> amdgpu_hmm_sync_cpu_device_pagetables,
>> + .release = amdgpu_hmm_mirror_release
>> +};
>
> You should probably clean that up as well and have a separate one for
> each AMDGPU_MN_TYPE_*.
>
Done, will submit v4.
> Christian.
>
>> +
>> +/**
>> + * amdgpu_mn_get - create HMM mirror context
>> *
>> * @adev: amdgpu device pointer
>> * @type: type of MMU notifier context
>> *
>> - * Creates a notifier context for current->mm.
>> + * Creates a HMM mirror context for current->mm.
>> */
>> struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
>> enum amdgpu_mn_type type)
>> @@ -413,7 +466,8 @@ struct amdgpu_mn *amdgpu_mn_get(struct
>> amdgpu_device *adev,
>> mutex_init(&amn->read_lock);
>> atomic_set(&amn->recursion, 0);
>> - r = __mmu_notifier_register(&amn->mn, mm);
>> + amn->mirror.ops = &amdgpu_hmm_mirror_ops;
>> + r = hmm_mirror_register(&amn->mirror, mm);
>> if (r)
>> goto free_amn;
>> @@ -439,7 +493,7 @@ struct amdgpu_mn *amdgpu_mn_get(struct
>> amdgpu_device *adev,
>> * @bo: amdgpu buffer object
>> * @addr: userptr addr we should monitor
>> *
>> - * Registers an MMU notifier for the given BO at the specified address.
>> + * Registers an HMM mirror for the given BO at the specified address.
>> * Returns 0 on success, -ERRNO if anything goes wrong.
>> */
>> int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
>> @@ -495,11 +549,11 @@ int amdgpu_mn_register(struct amdgpu_bo *bo,
>> unsigned long addr)
>> }
>> /**
>> - * amdgpu_mn_unregister - unregister a BO for notifier updates
>> + * amdgpu_mn_unregister - unregister a BO for HMM mirror updates
>> *
>> * @bo: amdgpu buffer object
>> *
>> - * Remove any registration of MMU notifier updates from the buffer
>> object.
>> + * Remove any registration of HMM mirror updates from the buffer
>> object.
>> */
>> void amdgpu_mn_unregister(struct amdgpu_bo *bo)
>> {
>
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