drm/lima: driver for ARM Mali4xx GPUs

- Mali 4xx GPUs have two kinds of processors GP and PP. GP is for
  OpenGL vertex shader processing and PP is for fragment shader
  processing. Each processor has its own MMU so prcessors work in
  virtual address space.
- There's only one GP but multiple PP (max 4 for mali 400 and 8
  for mali 450) in the same mali 4xx GPU. All PPs are grouped
  togather to handle a single fragment shader task divided by
  FB output tiled pixels. Mali 400 user space driver is
  responsible for assign target tiled pixels to each PP, but mali
  450 has a HW module called DLBU to dynamically balance each
  PP's load.
- User space driver allocate buffer object and map into GPU
  virtual address space, upload command stream and draw data with
  CPU mmap of the buffer object, then submit task to GP/PP with
  a register frame indicating where is the command stream and misc
  settings.
- There's no command stream validation/relocation due to each user
  process has its own GPU virtual address space. GP/PP's MMU switch
  virtual address space before running two tasks from different
  user process. Error or evil user space code just get MMU fault
  or GP/PP error IRQ, then the HW/SW will be recovered.
- Use GEM+shmem for MM. Currently just alloc and pin memory when
  gem object creation. GPU vm map of the buffer is also done in
  the alloc stage in kernel space. We may delay the memory
  allocation and real GPU vm map to command submission stage in the
  furture as improvement.
- Use drm_sched for GPU task schedule. Each OpenGL context should
  have a lima context object in the kernel to distinguish tasks
  from different user. drm_sched gets task from each lima context
  in a fair way.

mesa driver can be found here before upstreamed:
https://gitlab.freedesktop.org/lima/mesa

v8:
- add comments for in_sync
- fix ctx free miss mutex unlock

v7:
- remove lima_fence_ops with default value
- move fence slab create to device probe
- check pad ioctl args to be zero
- add comments for user/kernel interface

v6:
- fix comments by checkpatch.pl

v5:
- export gp/pp version to userspace
- rebase on drm-misc-next

v4:
- use get param interface to get info
- separate context create/free ioctl
- remove unused max sched task param
- update copyright time
- use xarray instead of idr
- stop using drmP.h

v3:
- fix comments from kbuild robot
- restrict supported arch to tested ones

v2:
- fix syscall argument check
- fix job finish fence leak since kernel 5.0
- use drm syncobj to replace native fence
- move buffer object GPU va map into kernel
- reserve syscall argument space for future info
- remove kernel gem modifier
- switch TTM back to GEM+shmem MM
- use time based io poll
- use whole register name
- adopt gem reservation obj integration
- use drm_timeout_abs_to_jiffies

Cc: Eric Anholt <eric@anholt.net>
Cc: Rob Herring <robh@kernel.org>
Cc: Christian König <ckoenig.leichtzumerken@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Andreas Baierl <ichgeh@imkreisrum.de>
Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Simon Shields <simon@lineageos.org>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Rob Herring <robh@kerrnel.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/291200/

1 files changed, 381 insertions, 0 deletions

diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c
new file mode 100644
index 000000000000..2d3cf96f6c58
--- /dev/null
+++ b/drivers/gpu/drm/lima/lima_gem.c
@@ -0,0 +1,381 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/* Copyright 2017-2019 Qiang Yu <yuq825@gmail.com> */
+
+#include <linux/sync_file.h>
+#include <linux/pfn_t.h>
+
+#include <drm/drm_file.h>
+#include <drm/drm_syncobj.h>
+#include <drm/drm_utils.h>
+
+#include <drm/lima_drm.h>
+
+#include "lima_drv.h"
+#include "lima_gem.h"
+#include "lima_gem_prime.h"
+#include "lima_vm.h"
+#include "lima_object.h"
+
+int lima_gem_create_handle(struct drm_device *dev, struct drm_file *file,
+			   u32 size, u32 flags, u32 *handle)
+{
+	int err;
+	struct lima_bo *bo;
+	struct lima_device *ldev = to_lima_dev(dev);
+
+	bo = lima_bo_create(ldev, size, flags, NULL, NULL);
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+
+	err = drm_gem_handle_create(file, &bo->gem, handle);
+
+	/* drop reference from allocate - handle holds it now */
+	drm_gem_object_put_unlocked(&bo->gem);
+
+	return err;
+}
+
+void lima_gem_free_object(struct drm_gem_object *obj)
+{
+	struct lima_bo *bo = to_lima_bo(obj);
+
+	if (!list_empty(&bo->va))
+		dev_err(obj->dev->dev, "lima gem free bo still has va\n");
+
+	lima_bo_destroy(bo);
+}
+
+int lima_gem_object_open(struct drm_gem_object *obj, struct drm_file *file)
+{
+	struct lima_bo *bo = to_lima_bo(obj);
+	struct lima_drm_priv *priv = to_lima_drm_priv(file);
+	struct lima_vm *vm = priv->vm;
+
+	return lima_vm_bo_add(vm, bo, true);
+}
+
+void lima_gem_object_close(struct drm_gem_object *obj, struct drm_file *file)
+{
+	struct lima_bo *bo = to_lima_bo(obj);
+	struct lima_drm_priv *priv = to_lima_drm_priv(file);
+	struct lima_vm *vm = priv->vm;
+
+	lima_vm_bo_del(vm, bo);
+}
+
+int lima_gem_get_info(struct drm_file *file, u32 handle, u32 *va, u64 *offset)
+{
+	struct drm_gem_object *obj;
+	struct lima_bo *bo;
+	struct lima_drm_priv *priv = to_lima_drm_priv(file);
+	struct lima_vm *vm = priv->vm;
+	int err;
+
+	obj = drm_gem_object_lookup(file, handle);
+	if (!obj)
+		return -ENOENT;
+
+	bo = to_lima_bo(obj);
+
+	*va = lima_vm_get_va(vm, bo);
+
+	err = drm_gem_create_mmap_offset(obj);
+	if (!err)
+		*offset = drm_vma_node_offset_addr(&obj->vma_node);
+
+	drm_gem_object_put_unlocked(obj);
+	return err;
+}
+
+static vm_fault_t lima_gem_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct drm_gem_object *obj = vma->vm_private_data;
+	struct lima_bo *bo = to_lima_bo(obj);
+	pfn_t pfn;
+	pgoff_t pgoff;
+
+	/* We don't use vmf->pgoff since that has the fake offset: */
+	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+	pfn = __pfn_to_pfn_t(page_to_pfn(bo->pages[pgoff]), PFN_DEV);
+
+	return vmf_insert_mixed(vma, vmf->address, pfn);
+}
+
+const struct vm_operations_struct lima_gem_vm_ops = {
+	.fault = lima_gem_fault,
+	.open = drm_gem_vm_open,
+	.close = drm_gem_vm_close,
+};
+
+void lima_set_vma_flags(struct vm_area_struct *vma)
+{
+	pgprot_t prot = vm_get_page_prot(vma->vm_flags);
+
+	vma->vm_flags |= VM_MIXEDMAP;
+	vma->vm_flags &= ~VM_PFNMAP;
+	vma->vm_page_prot = pgprot_writecombine(prot);
+}
+
+int lima_gem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	int ret;
+
+	ret = drm_gem_mmap(filp, vma);
+	if (ret)
+		return ret;
+
+	lima_set_vma_flags(vma);
+	return 0;
+}
+
+static int lima_gem_sync_bo(struct lima_sched_task *task, struct lima_bo *bo,
+			    bool write, bool explicit)
+{
+	int err = 0;
+
+	if (!write) {
+		err = reservation_object_reserve_shared(bo->gem.resv, 1);
+		if (err)
+			return err;
+	}
+
+	/* explicit sync use user passed dep fence */
+	if (explicit)
+		return 0;
+
+	/* implicit sync use bo fence in resv obj */
+	if (write) {
+		unsigned nr_fences;
+		struct dma_fence **fences;
+		int i;
+
+		err = reservation_object_get_fences_rcu(
+			bo->gem.resv, NULL, &nr_fences, &fences);
+		if (err || !nr_fences)
+			return err;
+
+		for (i = 0; i < nr_fences; i++) {
+			err = lima_sched_task_add_dep(task, fences[i]);
+			if (err)
+				break;
+		}
+
+		/* for error case free remaining fences */
+		for ( ; i < nr_fences; i++)
+			dma_fence_put(fences[i]);
+
+		kfree(fences);
+	} else {
+		struct dma_fence *fence;
+
+		fence = reservation_object_get_excl_rcu(bo->gem.resv);
+		if (fence) {
+			err = lima_sched_task_add_dep(task, fence);
+			if (err)
+				dma_fence_put(fence);
+		}
+	}
+
+	return err;
+}
+
+static int lima_gem_lock_bos(struct lima_bo **bos, u32 nr_bos,
+			     struct ww_acquire_ctx *ctx)
+{
+	int i, ret = 0, contended, slow_locked = -1;
+
+	ww_acquire_init(ctx, &reservation_ww_class);
+
+retry:
+	for (i = 0; i < nr_bos; i++) {
+		if (i == slow_locked) {
+			slow_locked = -1;
+			continue;
+		}
+
+		ret = ww_mutex_lock_interruptible(&bos[i]->gem.resv->lock, ctx);
+		if (ret < 0) {
+			contended = i;
+			goto err;
+		}
+	}
+
+	ww_acquire_done(ctx);
+	return 0;
+
+err:
+	for (i--; i >= 0; i--)
+		ww_mutex_unlock(&bos[i]->gem.resv->lock);
+
+	if (slow_locked >= 0)
+		ww_mutex_unlock(&bos[slow_locked]->gem.resv->lock);
+
+	if (ret == -EDEADLK) {
+		/* we lost out in a seqno race, lock and retry.. */
+		ret = ww_mutex_lock_slow_interruptible(
+			&bos[contended]->gem.resv->lock, ctx);
+		if (!ret) {
+			slow_locked = contended;
+			goto retry;
+		}
+	}
+	ww_acquire_fini(ctx);
+
+	return ret;
+}
+
+static void lima_gem_unlock_bos(struct lima_bo **bos, u32 nr_bos,
+				struct ww_acquire_ctx *ctx)
+{
+	int i;
+
+	for (i = 0; i < nr_bos; i++)
+		ww_mutex_unlock(&bos[i]->gem.resv->lock);
+	ww_acquire_fini(ctx);
+}
+
+static int lima_gem_add_deps(struct drm_file *file, struct lima_submit *submit)
+{
+	int i, err;
+
+	for (i = 0; i < ARRAY_SIZE(submit->in_sync); i++) {
+		struct dma_fence *fence = NULL;
+
+		if (!submit->in_sync[i])
+			continue;
+
+		err = drm_syncobj_find_fence(file, submit->in_sync[i],
+					     0, 0, &fence);
+		if (err)
+			return err;
+
+		err = lima_sched_task_add_dep(submit->task, fence);
+		if (err) {
+			dma_fence_put(fence);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+int lima_gem_submit(struct drm_file *file, struct lima_submit *submit)
+{
+	int i, err = 0;
+	struct ww_acquire_ctx ctx;
+	struct lima_drm_priv *priv = to_lima_drm_priv(file);
+	struct lima_vm *vm = priv->vm;
+	struct drm_syncobj *out_sync = NULL;
+	struct dma_fence *fence;
+	struct lima_bo **bos = submit->lbos;
+
+	if (submit->out_sync) {
+		out_sync = drm_syncobj_find(file, submit->out_sync);
+		if (!out_sync)
+			return -ENOENT;
+	}
+
+	for (i = 0; i < submit->nr_bos; i++) {
+		struct drm_gem_object *obj;
+		struct lima_bo *bo;
+
+		obj = drm_gem_object_lookup(file, submit->bos[i].handle);
+		if (!obj) {
+			err = -ENOENT;
+			goto err_out0;
+		}
+
+		bo = to_lima_bo(obj);
+
+		/* increase refcnt of gpu va map to prevent unmapped when executing,
+		 * will be decreased when task done
+		 */
+		err = lima_vm_bo_add(vm, bo, false);
+		if (err) {
+			drm_gem_object_put_unlocked(obj);
+			goto err_out0;
+		}
+
+		bos[i] = bo;
+	}
+
+	err = lima_gem_lock_bos(bos, submit->nr_bos, &ctx);
+	if (err)
+		goto err_out0;
+
+	err = lima_sched_task_init(
+		submit->task, submit->ctx->context + submit->pipe,
+		bos, submit->nr_bos, vm);
+	if (err)
+		goto err_out1;
+
+	err = lima_gem_add_deps(file, submit);
+	if (err)
+		goto err_out2;
+
+	for (i = 0; i < submit->nr_bos; i++) {
+		err = lima_gem_sync_bo(
+			submit->task, bos[i],
+			submit->bos[i].flags & LIMA_SUBMIT_BO_WRITE,
+			submit->flags & LIMA_SUBMIT_FLAG_EXPLICIT_FENCE);
+		if (err)
+			goto err_out2;
+	}
+
+	fence = lima_sched_context_queue_task(
+		submit->ctx->context + submit->pipe, submit->task);
+
+	for (i = 0; i < submit->nr_bos; i++) {
+		if (submit->bos[i].flags & LIMA_SUBMIT_BO_WRITE)
+			reservation_object_add_excl_fence(bos[i]->gem.resv, fence);
+		else
+			reservation_object_add_shared_fence(bos[i]->gem.resv, fence);
+	}
+
+	lima_gem_unlock_bos(bos, submit->nr_bos, &ctx);
+
+	for (i = 0; i < submit->nr_bos; i++)
+		drm_gem_object_put_unlocked(&bos[i]->gem);
+
+	if (out_sync) {
+		drm_syncobj_replace_fence(out_sync, fence);
+		drm_syncobj_put(out_sync);
+	}
+
+	dma_fence_put(fence);
+
+	return 0;
+
+err_out2:
+	lima_sched_task_fini(submit->task);
+err_out1:
+	lima_gem_unlock_bos(bos, submit->nr_bos, &ctx);
+err_out0:
+	for (i = 0; i < submit->nr_bos; i++) {
+		if (!bos[i])
+			break;
+		lima_vm_bo_del(vm, bos[i]);
+		drm_gem_object_put_unlocked(&bos[i]->gem);
+	}
+	if (out_sync)
+		drm_syncobj_put(out_sync);
+	return err;
+}
+
+int lima_gem_wait(struct drm_file *file, u32 handle, u32 op, s64 timeout_ns)
+{
+	bool write = op & LIMA_GEM_WAIT_WRITE;
+	long ret, timeout;
+
+	if (!op)
+		return 0;
+
+	timeout = drm_timeout_abs_to_jiffies(timeout_ns);
+
+	ret = drm_gem_reservation_object_wait(file, handle, write, timeout);
+	if (ret == 0)
+		ret = timeout ? -ETIMEDOUT : -EBUSY;
+
+	return ret;
+}