drm/vmwgfx: Add DRM driver for VMware Virtual GPU

This commit adds the vmwgfx driver for the VWware Virtual GPU aka SVGA.
The driver is under staging the same as Nouveau and Radeon KMS. Hopefully
the 2D ioctls are bug free and don't need changing, so that part of the
API should be stable. But there there is a pretty big chance that the 3D API
will change in the future.

Signed-off-by: Thomas Hellström <thellstrom@vmware.com>
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
new file mode 100644
index 0000000..76b0693
--- /dev/null
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
@@ -0,0 +1,521 @@
+/**************************************************************************
+ *
+ * Copyright © 2009 VMware, Inc., Palo Alto, CA., USA
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+#include "vmwgfx_drv.h"
+#include "drmP.h"
+#include "ttm/ttm_placement.h"
+
+int vmw_fifo_init(struct vmw_private *dev_priv, struct vmw_fifo_state *fifo)
+{
+	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
+	uint32_t max;
+	uint32_t min;
+	uint32_t dummy;
+	int ret;
+
+	fifo->static_buffer_size = VMWGFX_FIFO_STATIC_SIZE;
+	fifo->static_buffer = vmalloc(fifo->static_buffer_size);
+	if (unlikely(fifo->static_buffer == NULL))
+		return -ENOMEM;
+
+	fifo->last_buffer_size = VMWGFX_FIFO_STATIC_SIZE;
+	fifo->last_data_size = 0;
+	fifo->last_buffer_add = false;
+	fifo->last_buffer = vmalloc(fifo->last_buffer_size);
+	if (unlikely(fifo->last_buffer == NULL)) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	fifo->dynamic_buffer = NULL;
+	fifo->reserved_size = 0;
+	fifo->using_bounce_buffer = false;
+
+	init_rwsem(&fifo->rwsem);
+
+	/*
+	 * Allow mapping the first page read-only to user-space.
+	 */
+
+	DRM_INFO("width %d\n", vmw_read(dev_priv, SVGA_REG_WIDTH));
+	DRM_INFO("height %d\n", vmw_read(dev_priv, SVGA_REG_HEIGHT));
+	DRM_INFO("bpp %d\n", vmw_read(dev_priv, SVGA_REG_BITS_PER_PIXEL));
+
+	mutex_lock(&dev_priv->hw_mutex);
+	dev_priv->enable_state = vmw_read(dev_priv, SVGA_REG_ENABLE);
+	dev_priv->config_done_state = vmw_read(dev_priv, SVGA_REG_CONFIG_DONE);
+	vmw_write(dev_priv, SVGA_REG_ENABLE, 1);
+
+	min = 4;
+	if (dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO)
+		min = vmw_read(dev_priv, SVGA_REG_MEM_REGS);
+	min <<= 2;
+
+	if (min < PAGE_SIZE)
+		min = PAGE_SIZE;
+
+	iowrite32(min, fifo_mem + SVGA_FIFO_MIN);
+	iowrite32(dev_priv->mmio_size, fifo_mem + SVGA_FIFO_MAX);
+	wmb();
+	iowrite32(min,  fifo_mem + SVGA_FIFO_NEXT_CMD);
+	iowrite32(min,  fifo_mem + SVGA_FIFO_STOP);
+	iowrite32(0, fifo_mem + SVGA_FIFO_BUSY);
+	mb();
+
+	vmw_write(dev_priv, SVGA_REG_CONFIG_DONE, 1);
+	mutex_unlock(&dev_priv->hw_mutex);
+
+	max = ioread32(fifo_mem + SVGA_FIFO_MAX);
+	min = ioread32(fifo_mem  + SVGA_FIFO_MIN);
+	fifo->capabilities = ioread32(fifo_mem + SVGA_FIFO_CAPABILITIES);
+
+	DRM_INFO("Fifo max 0x%08x min 0x%08x cap 0x%08x\n",
+		 (unsigned int) max,
+		 (unsigned int) min,
+		 (unsigned int) fifo->capabilities);
+
+	dev_priv->fence_seq = (uint32_t) -100;
+	dev_priv->last_read_sequence = (uint32_t) -100;
+	iowrite32(dev_priv->last_read_sequence, fifo_mem + SVGA_FIFO_FENCE);
+
+	return vmw_fifo_send_fence(dev_priv, &dummy);
+out_err:
+	vfree(fifo->static_buffer);
+	fifo->static_buffer = NULL;
+	return ret;
+}
+
+void vmw_fifo_ping_host(struct vmw_private *dev_priv, uint32_t reason)
+{
+	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
+
+	mutex_lock(&dev_priv->hw_mutex);
+
+	if (unlikely(ioread32(fifo_mem + SVGA_FIFO_BUSY) == 0)) {
+		iowrite32(1, fifo_mem + SVGA_FIFO_BUSY);
+		vmw_write(dev_priv, SVGA_REG_SYNC, reason);
+	}
+
+	mutex_unlock(&dev_priv->hw_mutex);
+}
+
+void vmw_fifo_release(struct vmw_private *dev_priv, struct vmw_fifo_state *fifo)
+{
+	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
+
+	mutex_lock(&dev_priv->hw_mutex);
+
+	while (vmw_read(dev_priv, SVGA_REG_BUSY) != 0)
+		vmw_write(dev_priv, SVGA_REG_SYNC, SVGA_SYNC_GENERIC);
+
+	dev_priv->last_read_sequence = ioread32(fifo_mem + SVGA_FIFO_FENCE);
+
+	vmw_write(dev_priv, SVGA_REG_CONFIG_DONE,
+		  dev_priv->config_done_state);
+	vmw_write(dev_priv, SVGA_REG_ENABLE,
+		  dev_priv->enable_state);
+
+	mutex_unlock(&dev_priv->hw_mutex);
+
+	if (likely(fifo->last_buffer != NULL)) {
+		vfree(fifo->last_buffer);
+		fifo->last_buffer = NULL;
+	}
+
+	if (likely(fifo->static_buffer != NULL)) {
+		vfree(fifo->static_buffer);
+		fifo->static_buffer = NULL;
+	}
+
+	if (likely(fifo->dynamic_buffer != NULL)) {
+		vfree(fifo->dynamic_buffer);
+		fifo->dynamic_buffer = NULL;
+	}
+}
+
+static bool vmw_fifo_is_full(struct vmw_private *dev_priv, uint32_t bytes)
+{
+	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
+	uint32_t max = ioread32(fifo_mem + SVGA_FIFO_MAX);
+	uint32_t next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
+	uint32_t min = ioread32(fifo_mem + SVGA_FIFO_MIN);
+	uint32_t stop = ioread32(fifo_mem + SVGA_FIFO_STOP);
+
+	return ((max - next_cmd) + (stop - min) <= bytes);
+}
+
+static int vmw_fifo_wait_noirq(struct vmw_private *dev_priv,
+			       uint32_t bytes, bool interruptible,
+			       unsigned long timeout)
+{
+	int ret = 0;
+	unsigned long end_jiffies = jiffies + timeout;
+	DEFINE_WAIT(__wait);
+
+	DRM_INFO("Fifo wait noirq.\n");
+
+	for (;;) {
+		prepare_to_wait(&dev_priv->fifo_queue, &__wait,
+				(interruptible) ?
+				TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
+		if (!vmw_fifo_is_full(dev_priv, bytes))
+			break;
+		if (time_after_eq(jiffies, end_jiffies)) {
+			ret = -EBUSY;
+			DRM_ERROR("SVGA device lockup.\n");
+			break;
+		}
+		schedule_timeout(1);
+		if (interruptible && signal_pending(current)) {
+			ret = -ERESTART;
+			break;
+		}
+	}
+	finish_wait(&dev_priv->fifo_queue, &__wait);
+	wake_up_all(&dev_priv->fifo_queue);
+	DRM_INFO("Fifo noirq exit.\n");
+	return ret;
+}
+
+static int vmw_fifo_wait(struct vmw_private *dev_priv,
+			 uint32_t bytes, bool interruptible,
+			 unsigned long timeout)
+{
+	long ret = 1L;
+	unsigned long irq_flags;
+
+	if (likely(!vmw_fifo_is_full(dev_priv, bytes)))
+		return 0;
+
+	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_FIFOFULL);
+	if (!(dev_priv->capabilities & SVGA_CAP_IRQMASK))
+		return vmw_fifo_wait_noirq(dev_priv, bytes,
+					   interruptible, timeout);
+
+	mutex_lock(&dev_priv->hw_mutex);
+	if (atomic_add_return(1, &dev_priv->fifo_queue_waiters) > 0) {
+		spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
+		outl(SVGA_IRQFLAG_FIFO_PROGRESS,
+		     dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
+		vmw_write(dev_priv, SVGA_REG_IRQMASK,
+			  vmw_read(dev_priv, SVGA_REG_IRQMASK) |
+			  SVGA_IRQFLAG_FIFO_PROGRESS);
+		spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
+	}
+	mutex_unlock(&dev_priv->hw_mutex);
+
+	if (interruptible)
+		ret = wait_event_interruptible_timeout
+		    (dev_priv->fifo_queue,
+		     !vmw_fifo_is_full(dev_priv, bytes), timeout);
+	else
+		ret = wait_event_timeout
+		    (dev_priv->fifo_queue,
+		     !vmw_fifo_is_full(dev_priv, bytes), timeout);
+
+	if (unlikely(ret == -ERESTARTSYS))
+		ret = -ERESTART;
+	else if (unlikely(ret == 0))
+		ret = -EBUSY;
+	else if (likely(ret > 0))
+		ret = 0;
+
+	mutex_lock(&dev_priv->hw_mutex);
+	if (atomic_dec_and_test(&dev_priv->fifo_queue_waiters)) {
+		spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
+		vmw_write(dev_priv, SVGA_REG_IRQMASK,
+			  vmw_read(dev_priv, SVGA_REG_IRQMASK) &
+			  ~SVGA_IRQFLAG_FIFO_PROGRESS);
+		spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
+	}
+	mutex_unlock(&dev_priv->hw_mutex);
+
+	return ret;
+}
+
+void *vmw_fifo_reserve(struct vmw_private *dev_priv, uint32_t bytes)
+{
+	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
+	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
+	uint32_t max;
+	uint32_t min;
+	uint32_t next_cmd;
+	uint32_t reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;
+	int ret;
+
+	down_write(&fifo_state->rwsem);
+	max = ioread32(fifo_mem + SVGA_FIFO_MAX);
+	min = ioread32(fifo_mem + SVGA_FIFO_MIN);
+	next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
+
+	if (unlikely(bytes >= (max - min)))
+		goto out_err;
+
+	BUG_ON(fifo_state->reserved_size != 0);
+	BUG_ON(fifo_state->dynamic_buffer != NULL);
+
+	fifo_state->reserved_size = bytes;
+
+	while (1) {
+		uint32_t stop = ioread32(fifo_mem + SVGA_FIFO_STOP);
+		bool need_bounce = false;
+		bool reserve_in_place = false;
+
+		if (next_cmd >= stop) {
+			if (likely((next_cmd + bytes < max ||
+				    (next_cmd + bytes == max && stop > min))))
+				reserve_in_place = true;
+
+			else if (vmw_fifo_is_full(dev_priv, bytes)) {
+				ret = vmw_fifo_wait(dev_priv, bytes,
+						    false, 3 * HZ);
+				if (unlikely(ret != 0))
+					goto out_err;
+			} else
+				need_bounce = true;
+
+		} else {
+
+			if (likely((next_cmd + bytes < stop)))
+				reserve_in_place = true;
+			else {
+				ret = vmw_fifo_wait(dev_priv, bytes,
+						    false, 3 * HZ);
+				if (unlikely(ret != 0))
+					goto out_err;
+			}
+		}
+
+		if (reserve_in_place) {
+			if (reserveable || bytes <= sizeof(uint32_t)) {
+				fifo_state->using_bounce_buffer = false;
+
+				if (reserveable)
+					iowrite32(bytes, fifo_mem +
+						  SVGA_FIFO_RESERVED);
+				return fifo_mem + (next_cmd >> 2);
+			} else {
+				need_bounce = true;
+			}
+		}
+
+		if (need_bounce) {
+			fifo_state->using_bounce_buffer = true;
+			if (bytes < fifo_state->static_buffer_size)
+				return fifo_state->static_buffer;
+			else {
+				fifo_state->dynamic_buffer = vmalloc(bytes);
+				return fifo_state->dynamic_buffer;
+			}
+		}
+	}
+out_err:
+	fifo_state->reserved_size = 0;
+	up_write(&fifo_state->rwsem);
+	return NULL;
+}
+
+static void vmw_fifo_res_copy(struct vmw_fifo_state *fifo_state,
+			      __le32 __iomem *fifo_mem,
+			      uint32_t next_cmd,
+			      uint32_t max, uint32_t min, uint32_t bytes)
+{
+	uint32_t chunk_size = max - next_cmd;
+	uint32_t rest;
+	uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
+	    fifo_state->dynamic_buffer : fifo_state->static_buffer;
+
+	if (bytes < chunk_size)
+		chunk_size = bytes;
+
+	iowrite32(bytes, fifo_mem + SVGA_FIFO_RESERVED);
+	mb();
+	memcpy_toio(fifo_mem + (next_cmd >> 2), buffer, chunk_size);
+	rest = bytes - chunk_size;
+	if (rest)
+		memcpy_toio(fifo_mem + (min >> 2), buffer + (chunk_size >> 2),
+			    rest);
+}
+
+static void vmw_fifo_slow_copy(struct vmw_fifo_state *fifo_state,
+			       __le32 __iomem *fifo_mem,
+			       uint32_t next_cmd,
+			       uint32_t max, uint32_t min, uint32_t bytes)
+{
+	uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
+	    fifo_state->dynamic_buffer : fifo_state->static_buffer;
+
+	while (bytes > 0) {
+		iowrite32(*buffer++, fifo_mem + (next_cmd >> 2));
+		next_cmd += sizeof(uint32_t);
+		if (unlikely(next_cmd == max))
+			next_cmd = min;
+		mb();
+		iowrite32(next_cmd, fifo_mem + SVGA_FIFO_NEXT_CMD);
+		mb();
+		bytes -= sizeof(uint32_t);
+	}
+}
+
+void vmw_fifo_commit(struct vmw_private *dev_priv, uint32_t bytes)
+{
+	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
+	__le32 __iomem *fifo_mem = dev_priv->mmio_virt;
+	uint32_t next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
+	uint32_t max = ioread32(fifo_mem + SVGA_FIFO_MAX);
+	uint32_t min = ioread32(fifo_mem + SVGA_FIFO_MIN);
+	bool reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;
+
+	BUG_ON((bytes & 3) != 0);
+	BUG_ON(bytes > fifo_state->reserved_size);
+
+	fifo_state->reserved_size = 0;
+
+	if (fifo_state->using_bounce_buffer) {
+		if (reserveable)
+			vmw_fifo_res_copy(fifo_state, fifo_mem,
+					  next_cmd, max, min, bytes);
+		else
+			vmw_fifo_slow_copy(fifo_state, fifo_mem,
+					   next_cmd, max, min, bytes);
+
+		if (fifo_state->dynamic_buffer) {
+			vfree(fifo_state->dynamic_buffer);
+			fifo_state->dynamic_buffer = NULL;
+		}
+
+	}
+
+	if (fifo_state->using_bounce_buffer || reserveable) {
+		next_cmd += bytes;
+		if (next_cmd >= max)
+			next_cmd -= max - min;
+		mb();
+		iowrite32(next_cmd, fifo_mem + SVGA_FIFO_NEXT_CMD);
+	}
+
+	if (reserveable)
+		iowrite32(0, fifo_mem + SVGA_FIFO_RESERVED);
+	mb();
+	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
+	up_write(&fifo_state->rwsem);
+}
+
+int vmw_fifo_send_fence(struct vmw_private *dev_priv, uint32_t *sequence)
+{
+	struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
+	struct svga_fifo_cmd_fence *cmd_fence;
+	void *fm;
+	int ret = 0;
+	uint32_t bytes = sizeof(__le32) + sizeof(*cmd_fence);
+
+	fm = vmw_fifo_reserve(dev_priv, bytes);
+	if (unlikely(fm == NULL)) {
+		down_write(&fifo_state->rwsem);
+		*sequence = dev_priv->fence_seq;
+		up_write(&fifo_state->rwsem);
+		ret = -ENOMEM;
+		(void)vmw_fallback_wait(dev_priv, false, true, *sequence,
+					false, 3*HZ);
+		goto out_err;
+	}
+
+	do {
+		*sequence = dev_priv->fence_seq++;
+	} while (*sequence == 0);
+
+	if (!(fifo_state->capabilities & SVGA_FIFO_CAP_FENCE)) {
+
+		/*
+		 * Don't request hardware to send a fence. The
+		 * waiting code in vmwgfx_irq.c will emulate this.
+		 */
+
+		vmw_fifo_commit(dev_priv, 0);
+		return 0;
+	}
+
+	*(__le32 *) fm = cpu_to_le32(SVGA_CMD_FENCE);
+	cmd_fence = (struct svga_fifo_cmd_fence *)
+	    ((unsigned long)fm + sizeof(__le32));
+
+	iowrite32(*sequence, &cmd_fence->fence);
+	fifo_state->last_buffer_add = true;
+	vmw_fifo_commit(dev_priv, bytes);
+	fifo_state->last_buffer_add = false;
+
+out_err:
+	return ret;
+}
+
+/**
+ * Map the first page of the FIFO read-only to user-space.
+ */
+
+static int vmw_fifo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	int ret;
+	unsigned long address = (unsigned long)vmf->virtual_address;
+
+	if (address != vma->vm_start)
+		return VM_FAULT_SIGBUS;
+
+	ret = vm_insert_pfn(vma, address, vma->vm_pgoff);
+	if (likely(ret == -EBUSY || ret == 0))
+		return VM_FAULT_NOPAGE;
+	else if (ret == -ENOMEM)
+		return VM_FAULT_OOM;
+
+	return VM_FAULT_SIGBUS;
+}
+
+static struct vm_operations_struct vmw_fifo_vm_ops = {
+	.fault = vmw_fifo_vm_fault,
+	.open = NULL,
+	.close = NULL
+};
+
+int vmw_fifo_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct drm_file *file_priv;
+	struct vmw_private *dev_priv;
+
+	file_priv = (struct drm_file *)filp->private_data;
+	dev_priv = vmw_priv(file_priv->minor->dev);
+
+	if (vma->vm_pgoff != (dev_priv->mmio_start >> PAGE_SHIFT) ||
+	    (vma->vm_end - vma->vm_start) != PAGE_SIZE)
+		return -EINVAL;
+
+	vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
+	vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_SHARED;
+	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+	vma->vm_page_prot = ttm_io_prot(TTM_PL_FLAG_UNCACHED,
+					vma->vm_page_prot);
+	vma->vm_ops = &vmw_fifo_vm_ops;
+	return 0;
+}