From f1280394109a3a3a7ef1c37950d4356b12e75cb9 Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Wed, 1 Nov 2017 03:56:19 +1000 Subject: [PATCH] drm/nouveau/mmu: implement page table sub-allocation GP100 "big" (which is a funny name, when it supports "even bigger") page tables are small enough that we want to be able to suballocate them from a larger block of memory. This builds on the previous page table cache interfaces so that the VMM code doesn't need to know the difference. Signed-off-by: Ben Skeggs --- drivers/gpu/drm/nouveau/include/nvkm/subdev/mmu.h | 2 +- drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c | 98 +++++++++++++++++++++++ drivers/gpu/drm/nouveau/nvkm/subdev/mmu/priv.h | 2 + 3 files changed, 101 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/nouveau/include/nvkm/subdev/mmu.h b/drivers/gpu/drm/nouveau/include/nvkm/subdev/mmu.h index 61cc4e3..40e21f2 100644 --- a/drivers/gpu/drm/nouveau/include/nvkm/subdev/mmu.h +++ b/drivers/gpu/drm/nouveau/include/nvkm/subdev/mmu.h @@ -67,7 +67,7 @@ struct nvkm_mmu { struct { struct mutex mutex; struct list_head list; - } ptc; + } ptc, ptp; }; int nv04_mmu_new(struct nvkm_device *, int, struct nvkm_mmu **); diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c index 1e4a92e..1bdae02 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c @@ -26,6 +26,85 @@ #include #include +struct nvkm_mmu_ptp { + struct nvkm_mmu_pt *pt; + struct list_head head; + u8 shift; + u16 mask; + u16 free; +}; + +static void +nvkm_mmu_ptp_put(struct nvkm_mmu *mmu, bool force, struct nvkm_mmu_pt *pt) +{ + const int slot = pt->base >> pt->ptp->shift; + struct nvkm_mmu_ptp *ptp = pt->ptp; + + /* If there were no free slots in the parent allocation before, + * there will be now, so return PTP to the cache. + */ + if (!ptp->free) + list_add(&ptp->head, &mmu->ptp.list); + ptp->free |= BIT(slot); + + /* If there's no more sub-allocations, destroy PTP. */ + if (ptp->free == ptp->mask) { + nvkm_mmu_ptc_put(mmu, force, &ptp->pt); + list_del(&ptp->head); + kfree(ptp); + } + + kfree(pt); +} + +struct nvkm_mmu_pt * +nvkm_mmu_ptp_get(struct nvkm_mmu *mmu, u32 size, bool zero) +{ + struct nvkm_mmu_pt *pt; + struct nvkm_mmu_ptp *ptp; + int slot; + + if (!(pt = kzalloc(sizeof(*pt), GFP_KERNEL))) + return NULL; + + ptp = list_first_entry_or_null(&mmu->ptp.list, typeof(*ptp), head); + if (!ptp) { + /* Need to allocate a new parent to sub-allocate from. */ + if (!(ptp = kmalloc(sizeof(*ptp), GFP_KERNEL))) { + kfree(pt); + return NULL; + } + + ptp->pt = nvkm_mmu_ptc_get(mmu, 0x1000, 0x1000, false); + if (!ptp->pt) { + kfree(ptp); + kfree(pt); + return NULL; + } + + ptp->shift = order_base_2(size); + slot = nvkm_memory_size(ptp->pt->memory) >> ptp->shift; + ptp->mask = (1 << slot) - 1; + ptp->free = ptp->mask; + list_add(&ptp->head, &mmu->ptp.list); + } + pt->ptp = ptp; + pt->sub = true; + + /* Sub-allocate from parent object, removing PTP from cache + * if there's no more free slots left. + */ + slot = __ffs(ptp->free); + ptp->free &= ~BIT(slot); + if (!ptp->free) + list_del(&ptp->head); + + pt->memory = pt->ptp->pt->memory; + pt->base = slot << ptp->shift; + pt->addr = pt->ptp->pt->addr + pt->base; + return pt; +} + struct nvkm_mmu_ptc { struct list_head head; struct list_head item; @@ -59,6 +138,14 @@ nvkm_mmu_ptc_put(struct nvkm_mmu *mmu, bool force, struct nvkm_mmu_pt **ppt) { struct nvkm_mmu_pt *pt = *ppt; if (pt) { + /* Handle sub-allocated page tables. */ + if (pt->sub) { + mutex_lock(&mmu->ptp.mutex); + nvkm_mmu_ptp_put(mmu, force, pt); + mutex_unlock(&mmu->ptp.mutex); + return; + } + /* Either cache or free the object. */ mutex_lock(&mmu->ptc.mutex); if (pt->ptc->refs < 8 /* Heuristic. */ && !force) { @@ -79,6 +166,14 @@ nvkm_mmu_ptc_get(struct nvkm_mmu *mmu, u32 size, u32 align, bool zero) struct nvkm_mmu_pt *pt; int ret; + /* Sub-allocated page table (ie. GP100 LPT). */ + if (align < 0x1000) { + mutex_lock(&mmu->ptp.mutex); + pt = nvkm_mmu_ptp_get(mmu, align, zero); + mutex_unlock(&mmu->ptp.mutex); + return pt; + } + /* Lookup cache for this page table size. */ mutex_lock(&mmu->ptc.mutex); ptc = nvkm_mmu_ptc_find(mmu, size); @@ -103,6 +198,7 @@ nvkm_mmu_ptc_get(struct nvkm_mmu *mmu, u32 size, u32 align, bool zero) if (!(pt = kmalloc(sizeof(*pt), GFP_KERNEL))) return NULL; pt->ptc = ptc; + pt->sub = false; ret = nvkm_memory_new(mmu->subdev.device, NVKM_MEM_TARGET_INST, size, align, zero, &pt->memory); @@ -147,6 +243,8 @@ nvkm_mmu_ptc_init(struct nvkm_mmu *mmu) { mutex_init(&mmu->ptc.mutex); INIT_LIST_HEAD(&mmu->ptc.list); + mutex_init(&mmu->ptp.mutex); + INIT_LIST_HEAD(&mmu->ptp.list); } void diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/priv.h b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/priv.h index ea56f78..0f3bb31 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/priv.h +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/priv.h @@ -60,8 +60,10 @@ void gf100_vm_flush(struct nvkm_vm *); struct nvkm_mmu_pt { union { struct nvkm_mmu_ptc *ptc; + struct nvkm_mmu_ptp *ptp; }; struct nvkm_memory *memory; + bool sub; u16 base; u64 addr; struct list_head head; -- 2.7.4