[PATCH] drivers: platform: goldfish_sync: add a driver

From: rkir
Date: Fri Jan 04 2019 - 19:54:11 EST


From: Roman Kiryanov <rkir@xxxxxxxxxx>

The Goldfish sync driver is designed to provide a interface
between the underlying host's sync device and the kernel's
fence sync framework.

Signed-off-by: Roman Kiryanov <rkir@xxxxxxxxxx>
---
drivers/platform/goldfish/Kconfig | 7 +
drivers/platform/goldfish/Makefile | 1 +
drivers/platform/goldfish/goldfish_sync.c | 833 ++++++++++++++++++++
include/uapi/linux/goldfish/goldfish_sync.h | 28 +
4 files changed, 869 insertions(+)
create mode 100644 drivers/platform/goldfish/goldfish_sync.c
create mode 100644 include/uapi/linux/goldfish/goldfish_sync.h

diff --git a/drivers/platform/goldfish/Kconfig b/drivers/platform/goldfish/Kconfig
index 479031aa4f88..fbc0c53e8f35 100644
--- a/drivers/platform/goldfish/Kconfig
+++ b/drivers/platform/goldfish/Kconfig
@@ -16,4 +16,11 @@ config GOLDFISH_PIPE
This is a virtual device to drive the QEMU pipe interface used by
the Goldfish Android Virtual Device.

+config GOLDFISH_SYNC
+ tristate "Goldfish AVD Sync Driver"
+ depends on SW_SYNC
+ depends on SYNC_FILE
+ help
+ Emulated sync fences for the Goldfish Android Virtual Device.
+
endif # GOLDFISH
diff --git a/drivers/platform/goldfish/Makefile b/drivers/platform/goldfish/Makefile
index e0c202df9674..78c8736ba55d 100644
--- a/drivers/platform/goldfish/Makefile
+++ b/drivers/platform/goldfish/Makefile
@@ -2,3 +2,4 @@
# Makefile for Goldfish platform specific drivers
#
obj-$(CONFIG_GOLDFISH_PIPE) += goldfish_pipe.o
+obj-$(CONFIG_GOLDFISH_SYNC) += goldfish_sync.o
diff --git a/drivers/platform/goldfish/goldfish_sync.c b/drivers/platform/goldfish/goldfish_sync.c
new file mode 100644
index 000000000000..e8b7903487cd
--- /dev/null
+++ b/drivers/platform/goldfish/goldfish_sync.c
@@ -0,0 +1,833 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/* The Goldfish sync driver is designed to provide a interface
+ * between the underlying host's sync device and the kernel's
+ * fence sync framework.
+ *
+ * The purpose of the device/driver is to enable lightweight creation and
+ * signaling of timelines and fences in order to synchronize the guest with
+ * host-side graphics events.
+ *
+ * Each time the interrupt trips, the driver may perform a sync operation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/dma-fence.h>
+#include <linux/fdtable.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/sync_file.h>
+#include <linux/syscalls.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include <uapi/linux/goldfish/goldfish_sync.h>
+
+struct sync_pt {
+ struct dma_fence base; /* must be the first field in this struct */
+ struct list_head active_list; /* see active_list_head below */
+};
+
+struct goldfish_sync_state;
+
+struct goldfish_sync_timeline {
+ struct goldfish_sync_state *sync_state;
+
+ /* This object is owned by userspace from open() calls and also each
+ * sync_pt refers to it.
+ */
+ struct kref kref;
+ char name[32]; /* for debugging */
+
+ u64 context;
+ unsigned int seqno;
+ /* list of active (unsignaled/errored) sync_pts */
+ struct list_head active_list_head;
+ spinlock_t lock; /* protects the fields above */
+};
+
+/* The above definitions (command codes, register layout, ioctl definitions)
+ * need to be in sync with the following files:
+ *
+ * Host-side (emulator):
+ * external/qemu/android/emulation/goldfish_sync.h
+ * external/qemu-android/hw/misc/goldfish_sync.c
+ *
+ * Guest-side (system image):
+ * device/generic/goldfish-opengl/system/egl/goldfish_sync.h
+ * device/generic/goldfish/ueventd.ranchu.rc
+ * platform/build/target/board/generic/sepolicy/file_contexts
+ */
+struct goldfish_sync_hostcmd {
+ /* sorted for alignment */
+ u64 handle;
+ u64 hostcmd_handle;
+ u32 cmd;
+ u32 time_arg;
+};
+
+struct goldfish_sync_guestcmd {
+ u64 host_command; /* u64 for alignment */
+ u64 glsync_handle;
+ u64 thread_handle;
+ u64 guest_timeline_handle;
+};
+
+/* The host operations are: */
+enum cmd_id {
+ /* Ready signal - used to mark when irq should lower */
+ CMD_SYNC_READY = 0,
+
+ /* Create a new timeline. writes timeline handle */
+ CMD_CREATE_SYNC_TIMELINE = 1,
+
+ /* Create a fence object. reads timeline handle and time argument.
+ * Writes fence fd to the SYNC_REG_HANDLE register.
+ */
+ CMD_CREATE_SYNC_FENCE = 2,
+
+ /* Increments timeline. reads timeline handle and time argument */
+ CMD_SYNC_TIMELINE_INC = 3,
+
+ /* Destroys a timeline. reads timeline handle */
+ CMD_DESTROY_SYNC_TIMELINE = 4,
+
+ /* Starts a wait on the host with the given glsync object and
+ * sync thread handle.
+ */
+ CMD_TRIGGER_HOST_WAIT = 5,
+};
+
+/* The host register layout is: */
+enum sync_reg_id {
+ /* host->guest batch commands */
+ SYNC_REG_BATCH_COMMAND = 0x00,
+
+ /* guest->host batch commands */
+ SYNC_REG_BATCH_GUESTCOMMAND = 0x04,
+
+ /* communicate physical address of host->guest batch commands */
+ SYNC_REG_BATCH_COMMAND_ADDR = 0x08,
+ SYNC_REG_BATCH_COMMAND_ADDR_HIGH = 0x0C, /* 64-bit part */
+
+ /* communicate physical address of guest->host commands */
+ SYNC_REG_BATCH_GUESTCOMMAND_ADDR = 0x10,
+ SYNC_REG_BATCH_GUESTCOMMAND_ADDR_HIGH = 0x14, /* 64-bit part */
+
+ /* signals that the device has been probed */
+ SYNC_REG_INIT = 0x18,
+};
+
+#define GOLDFISH_SYNC_MAX_CMDS 32
+
+/* The driver state: */
+struct goldfish_sync_state {
+ struct miscdevice miscdev;
+
+ char __iomem *reg_base;
+ int irq;
+
+ /* Used to generate unique names, see goldfish_sync_timeline::name. */
+ u64 id_counter;
+
+ /* |mutex_lock| protects all concurrent access
+ * to timelines for both kernel and user space.
+ */
+ struct mutex mutex_lock;
+
+ /* Buffer holding commands issued from host. */
+ struct goldfish_sync_hostcmd to_do[GOLDFISH_SYNC_MAX_CMDS];
+ u32 to_do_end;
+ /* Protects to_do and to_do_end */
+ spinlock_t to_do_lock;
+
+ /* Buffers for the reading or writing
+ * of individual commands. The host can directly write
+ * to |batch_hostcmd| (and then this driver immediately
+ * copies contents to |to_do|). This driver either replies
+ * through |batch_hostcmd| or simply issues a
+ * guest->host command through |batch_guestcmd|.
+ */
+ struct goldfish_sync_hostcmd batch_hostcmd;
+ struct goldfish_sync_guestcmd batch_guestcmd;
+
+ /* Used to give this struct itself to a work queue
+ * function for executing actual sync commands.
+ */
+ struct work_struct work_item;
+};
+
+static struct goldfish_sync_timeline
+*goldfish_dma_fence_parent(struct dma_fence *fence)
+{
+ return container_of(fence->lock, struct goldfish_sync_timeline, lock);
+}
+
+static struct sync_pt *goldfish_sync_fence_to_sync_pt(struct dma_fence *fence)
+{
+ return container_of(fence, struct sync_pt, base);
+}
+
+/* sync_state->mutex_lock must be locked. */
+struct goldfish_sync_timeline __must_check
+*goldfish_sync_timeline_create(struct goldfish_sync_state *sync_state)
+{
+ struct goldfish_sync_timeline *tl;
+
+ tl = kzalloc(sizeof(*tl), GFP_KERNEL);
+ if (!tl)
+ return NULL;
+
+ tl->sync_state = sync_state;
+ kref_init(&tl->kref);
+ snprintf(tl->name, sizeof(tl->name),
+ "%s:%llu", GOLDFISH_SYNC_DEVICE_NAME,
+ ++sync_state->id_counter);
+ tl->context = dma_fence_context_alloc(1);
+ tl->seqno = 0;
+ INIT_LIST_HEAD(&tl->active_list_head);
+ spin_lock_init(&tl->lock);
+
+ return tl;
+}
+
+static void goldfish_sync_timeline_free(struct kref *kref)
+{
+ struct goldfish_sync_timeline *tl =
+ container_of(kref, struct goldfish_sync_timeline, kref);
+
+ kfree(tl);
+}
+
+static void goldfish_sync_timeline_get(struct goldfish_sync_timeline *tl)
+{
+ kref_get(&tl->kref);
+}
+
+void goldfish_sync_timeline_put(struct goldfish_sync_timeline *tl)
+{
+ kref_put(&tl->kref, goldfish_sync_timeline_free);
+}
+
+void goldfish_sync_timeline_signal(struct goldfish_sync_timeline *tl,
+ unsigned int inc)
+{
+ unsigned long flags;
+ struct sync_pt *pt, *next;
+
+ spin_lock_irqsave(&tl->lock, flags);
+ tl->seqno += inc;
+
+ list_for_each_entry_safe(pt, next, &tl->active_list_head, active_list) {
+ /* dma_fence_is_signaled_locked has side effects */
+ if (dma_fence_is_signaled_locked(&pt->base))
+ list_del_init(&pt->active_list);
+ }
+ spin_unlock_irqrestore(&tl->lock, flags);
+}
+
+static const struct dma_fence_ops goldfish_sync_timeline_fence_ops;
+
+static struct sync_pt __must_check
+*goldfish_sync_pt_create(struct goldfish_sync_timeline *tl,
+ unsigned int value)
+{
+ struct sync_pt *pt = kzalloc(sizeof(*pt), GFP_KERNEL);
+
+ if (!pt)
+ return NULL;
+
+ dma_fence_init(&pt->base,
+ &goldfish_sync_timeline_fence_ops,
+ &tl->lock,
+ tl->context,
+ value);
+ INIT_LIST_HEAD(&pt->active_list);
+ goldfish_sync_timeline_get(tl); /* pt refers to tl */
+
+ return pt;
+}
+
+static void goldfish_sync_pt_destroy(struct sync_pt *pt)
+{
+ struct goldfish_sync_timeline *tl =
+ goldfish_dma_fence_parent(&pt->base);
+ unsigned long flags;
+
+ spin_lock_irqsave(&tl->lock, flags);
+ if (!list_empty(&pt->active_list))
+ list_del(&pt->active_list);
+ spin_unlock_irqrestore(&tl->lock, flags);
+
+ goldfish_sync_timeline_put(tl); /* unref pt from tl */
+ dma_fence_free(&pt->base);
+}
+
+static const char
+*goldfish_sync_timeline_fence_get_driver_name(struct dma_fence *fence)
+{
+ return "sw_sync";
+}
+
+static const char
+*goldfish_sync_timeline_fence_get_timeline_name(struct dma_fence *fence)
+{
+ struct goldfish_sync_timeline *tl = goldfish_dma_fence_parent(fence);
+
+ return tl->name;
+}
+
+static void goldfish_sync_timeline_fence_release(struct dma_fence *fence)
+{
+ goldfish_sync_pt_destroy(goldfish_sync_fence_to_sync_pt(fence));
+}
+
+static bool goldfish_sync_timeline_fence_signaled(struct dma_fence *fence)
+{
+ struct goldfish_sync_timeline *tl = goldfish_dma_fence_parent(fence);
+
+ return tl->seqno >= fence->seqno;
+}
+
+static bool
+goldfish_sync_timeline_fence_enable_signaling(struct dma_fence *fence)
+{
+ struct sync_pt *pt;
+ struct goldfish_sync_timeline *tl;
+
+ if (goldfish_sync_timeline_fence_signaled(fence))
+ return false;
+
+ pt = goldfish_sync_fence_to_sync_pt(fence);
+ tl = goldfish_dma_fence_parent(fence);
+ list_add_tail(&pt->active_list, &tl->active_list_head);
+ return true;
+}
+
+static void goldfish_sync_timeline_fence_value_str(struct dma_fence *fence,
+ char *str, int size)
+{
+ snprintf(str, size, "%d", fence->seqno);
+}
+
+static void goldfish_sync_timeline_fence_timeline_value_str(
+ struct dma_fence *fence,
+ char *str, int size)
+{
+ struct goldfish_sync_timeline *tl = goldfish_dma_fence_parent(fence);
+
+ snprintf(str, size, "%d", tl->seqno);
+}
+
+static const struct dma_fence_ops goldfish_sync_timeline_fence_ops = {
+ .get_driver_name = goldfish_sync_timeline_fence_get_driver_name,
+ .get_timeline_name = goldfish_sync_timeline_fence_get_timeline_name,
+ .enable_signaling = goldfish_sync_timeline_fence_enable_signaling,
+ .signaled = goldfish_sync_timeline_fence_signaled,
+ .wait = dma_fence_default_wait,
+ .release = goldfish_sync_timeline_fence_release,
+ .fence_value_str = goldfish_sync_timeline_fence_value_str,
+ .timeline_value_str = goldfish_sync_timeline_fence_timeline_value_str,
+};
+
+static int __must_check
+goldfish_sync_fence_create(struct goldfish_sync_timeline *tl, u32 val)
+{
+ struct sync_pt *pt;
+ struct sync_file *sync_file_obj = NULL;
+ int fd;
+
+ pt = goldfish_sync_pt_create(tl, val);
+ if (!pt)
+ return -1;
+
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0)
+ goto err_cleanup_pt;
+
+ sync_file_obj = sync_file_create(&pt->base);
+ if (!sync_file_obj)
+ goto err_cleanup_fd_pt;
+
+ fd_install(fd, sync_file_obj->file);
+
+ dma_fence_put(&pt->base); /* sync_file_obj now owns the fence */
+ return fd;
+
+err_cleanup_fd_pt:
+ put_unused_fd(fd);
+err_cleanup_pt:
+ goldfish_sync_pt_destroy(pt);
+
+ return -1;
+}
+
+static inline void
+goldfish_sync_cmd_queue(struct goldfish_sync_state *sync_state,
+ u32 cmd,
+ u64 handle,
+ u32 time_arg,
+ u64 hostcmd_handle)
+{
+ struct goldfish_sync_hostcmd *to_add;
+
+ WARN_ON(sync_state->to_do_end == GOLDFISH_SYNC_MAX_CMDS);
+
+ to_add = &sync_state->to_do[sync_state->to_do_end];
+
+ to_add->cmd = cmd;
+ to_add->handle = handle;
+ to_add->time_arg = time_arg;
+ to_add->hostcmd_handle = hostcmd_handle;
+
+ ++sync_state->to_do_end;
+}
+
+static inline void
+goldfish_sync_hostcmd_reply(struct goldfish_sync_state *sync_state,
+ u32 cmd,
+ u64 handle,
+ u32 time_arg,
+ u64 hostcmd_handle)
+{
+ unsigned long irq_flags;
+ struct goldfish_sync_hostcmd *batch_hostcmd =
+ &sync_state->batch_hostcmd;
+
+ spin_lock_irqsave(&sync_state->to_do_lock, irq_flags);
+
+ batch_hostcmd->cmd = cmd;
+ batch_hostcmd->handle = handle;
+ batch_hostcmd->time_arg = time_arg;
+ batch_hostcmd->hostcmd_handle = hostcmd_handle;
+ writel(0, sync_state->reg_base + SYNC_REG_BATCH_COMMAND);
+
+ spin_unlock_irqrestore(&sync_state->to_do_lock, irq_flags);
+}
+
+static inline void
+goldfish_sync_send_guestcmd(struct goldfish_sync_state *sync_state,
+ u32 cmd,
+ u64 glsync_handle,
+ u64 thread_handle,
+ u64 timeline_handle)
+{
+ unsigned long irq_flags;
+ struct goldfish_sync_guestcmd *batch_guestcmd =
+ &sync_state->batch_guestcmd;
+
+ spin_lock_irqsave(&sync_state->to_do_lock, irq_flags);
+
+ batch_guestcmd->host_command = cmd;
+ batch_guestcmd->glsync_handle = glsync_handle;
+ batch_guestcmd->thread_handle = thread_handle;
+ batch_guestcmd->guest_timeline_handle = timeline_handle;
+ writel(0, sync_state->reg_base + SYNC_REG_BATCH_GUESTCOMMAND);
+
+ spin_unlock_irqrestore(&sync_state->to_do_lock, irq_flags);
+}
+
+/* |goldfish_sync_interrupt| handles IRQ raises from the virtual device.
+ * In the context of OpenGL, this interrupt will fire whenever we need
+ * to signal a fence fd in the guest, with the command
+ * |CMD_SYNC_TIMELINE_INC|.
+ * However, because this function will be called in an interrupt context,
+ * it is necessary to do the actual work of signaling off of interrupt context.
+ * The shared work queue is used for this purpose. At the end when
+ * all pending commands are intercepted by the interrupt handler,
+ * we call |schedule_work|, which will later run the actual
+ * desired sync command in |goldfish_sync_work_item_fn|.
+ */
+static irqreturn_t
+goldfish_sync_interrupt_impl(struct goldfish_sync_state *sync_state)
+{
+ struct goldfish_sync_hostcmd *batch_hostcmd =
+ &sync_state->batch_hostcmd;
+
+ spin_lock(&sync_state->to_do_lock);
+ for (;;) {
+ u32 nextcmd;
+ u32 command_r;
+ u64 handle_rw;
+ u32 time_r;
+ u64 hostcmd_handle_rw;
+
+ readl(sync_state->reg_base + SYNC_REG_BATCH_COMMAND);
+ nextcmd = batch_hostcmd->cmd;
+
+ if (nextcmd == 0)
+ break;
+
+ command_r = nextcmd;
+ handle_rw = batch_hostcmd->handle;
+ time_r = batch_hostcmd->time_arg;
+ hostcmd_handle_rw = batch_hostcmd->hostcmd_handle;
+
+ goldfish_sync_cmd_queue(sync_state,
+ command_r,
+ handle_rw,
+ time_r,
+ hostcmd_handle_rw);
+ }
+ spin_unlock(&sync_state->to_do_lock);
+
+ schedule_work(&sync_state->work_item);
+ return IRQ_HANDLED;
+}
+
+static const struct file_operations goldfish_sync_fops;
+
+static irqreturn_t goldfish_sync_interrupt(int irq, void *dev_id)
+{
+ struct goldfish_sync_state *sync_state = dev_id;
+
+ return (sync_state->miscdev.fops == &goldfish_sync_fops) ?
+ goldfish_sync_interrupt_impl(sync_state) : IRQ_NONE;
+}
+
+/* We expect that commands will come in at a slow enough rate
+ * so that incoming items will not be more than
+ * GOLDFISH_SYNC_MAX_CMDS.
+ *
+ * This is because the way the sync device is used,
+ * it's only for managing buffer data transfers per frame,
+ * with a sequential dependency between putting things in
+ * to_do and taking them out. Once a set of commands is
+ * queued up in to_do, the user of the device waits for
+ * them to be processed before queuing additional commands,
+ * which limits the rate at which commands come in
+ * to the rate at which we take them out here.
+ *
+ * We also don't expect more than MAX_CMDS to be issued
+ * at once; there is a correspondence between
+ * which buffers need swapping to the (display / buffer queue)
+ * to particular commands, and we don't expect there to be
+ * enough display or buffer queues in operation at once
+ * to overrun GOLDFISH_SYNC_MAX_CMDS.
+ */
+static u32 __must_check
+goldfish_sync_grab_commands(struct goldfish_sync_state *sync_state,
+ struct goldfish_sync_hostcmd *dst)
+{
+ u32 to_do_end;
+ u32 i;
+ unsigned long irq_flags;
+
+ spin_lock_irqsave(&sync_state->to_do_lock, irq_flags);
+
+ to_do_end = sync_state->to_do_end;
+ for (i = 0; i < to_do_end; i++)
+ dst[i] = sync_state->to_do[i];
+ sync_state->to_do_end = 0;
+
+ spin_unlock_irqrestore(&sync_state->to_do_lock, irq_flags);
+
+ return to_do_end;
+}
+
+void goldfish_sync_run_hostcmd(struct goldfish_sync_state *sync_state,
+ struct goldfish_sync_hostcmd *todo)
+{
+ struct goldfish_sync_timeline *tl =
+ (struct goldfish_sync_timeline *)(uintptr_t)todo->handle;
+ int sync_fence_fd;
+
+ switch (todo->cmd) {
+ case CMD_SYNC_READY:
+ break;
+
+ case CMD_CREATE_SYNC_TIMELINE:
+ tl = goldfish_sync_timeline_create(sync_state);
+ WARN_ON(!tl);
+ goldfish_sync_hostcmd_reply(sync_state,
+ CMD_CREATE_SYNC_TIMELINE,
+ (uintptr_t)tl,
+ 0,
+ todo->hostcmd_handle);
+ break;
+
+ case CMD_CREATE_SYNC_FENCE:
+ WARN_ON(!tl);
+ sync_fence_fd = goldfish_sync_fence_create(tl, todo->time_arg);
+ goldfish_sync_hostcmd_reply(sync_state,
+ CMD_CREATE_SYNC_FENCE,
+ sync_fence_fd,
+ 0,
+ todo->hostcmd_handle);
+ break;
+
+ case CMD_SYNC_TIMELINE_INC:
+ WARN_ON(!tl);
+ goldfish_sync_timeline_signal(tl, todo->time_arg);
+ break;
+
+ case CMD_DESTROY_SYNC_TIMELINE:
+ WARN_ON(!tl);
+ goldfish_sync_timeline_put(tl);
+ break;
+ }
+}
+
+/* |goldfish_sync_work_item_fn| does the actual work of servicing
+ * host->guest sync commands. This function is triggered whenever
+ * the IRQ for the goldfish sync device is raised. Once it starts
+ * running, it grabs the contents of the buffer containing the
+ * commands it needs to execute (there may be multiple, because
+ * our IRQ is active high and not edge triggered), and then
+ * runs all of them one after the other.
+ */
+static void goldfish_sync_work_item_fn(struct work_struct *input)
+{
+ struct goldfish_sync_state *sync_state =
+ container_of(input, struct goldfish_sync_state, work_item);
+
+ struct goldfish_sync_hostcmd to_run[GOLDFISH_SYNC_MAX_CMDS];
+ u32 to_do_end;
+ u32 i;
+
+ mutex_lock(&sync_state->mutex_lock);
+
+ to_do_end = goldfish_sync_grab_commands(sync_state, to_run);
+
+ for (i = 0; i < to_do_end; i++)
+ goldfish_sync_run_hostcmd(sync_state, &to_run[i]);
+
+ mutex_unlock(&sync_state->mutex_lock);
+}
+
+static int goldfish_sync_open(struct inode *inode, struct file *filp)
+{
+ struct goldfish_sync_state *sync_state =
+ container_of(filp->private_data,
+ struct goldfish_sync_state,
+ miscdev);
+
+ if (mutex_lock_interruptible(&sync_state->mutex_lock))
+ return -ERESTARTSYS;
+
+ filp->private_data = goldfish_sync_timeline_create(sync_state);
+ mutex_unlock(&sync_state->mutex_lock);
+
+ return filp->private_data ? 0 : -ENOMEM;
+}
+
+static int goldfish_sync_release(struct inode *inode, struct file *filp)
+{
+ struct goldfish_sync_timeline *tl = filp->private_data;
+
+ goldfish_sync_timeline_put(tl);
+ return 0;
+}
+
+/* |goldfish_sync_ioctl| is the guest-facing interface of goldfish sync
+ * and is used in conjunction with eglCreateSyncKHR to queue up the
+ * actual work of waiting for the EGL sync command to complete,
+ * possibly returning a fence fd to the guest.
+ */
+static long
+goldfish_sync_ioctl_locked(struct goldfish_sync_timeline *tl,
+ unsigned int cmd,
+ unsigned long arg)
+{
+ struct goldfish_sync_ioctl_info ioctl_data;
+ int fd_out = -1;
+
+ switch (cmd) {
+ case GOLDFISH_SYNC_IOC_QUEUE_WORK:
+ if (copy_from_user(&ioctl_data,
+ (void __user *)arg,
+ sizeof(ioctl_data)))
+ return -EFAULT;
+
+ if (!ioctl_data.host_syncthread_handle_in)
+ return -EFAULT;
+
+ fd_out = goldfish_sync_fence_create(tl, tl->seqno + 1);
+ ioctl_data.fence_fd_out = fd_out;
+
+ if (copy_to_user((void __user *)arg,
+ &ioctl_data,
+ sizeof(ioctl_data))) {
+ ksys_close(fd_out);
+ return -EFAULT;
+ }
+
+ /* We are now about to trigger a host-side wait;
+ * accumulate on |pending_waits|.
+ */
+ goldfish_sync_send_guestcmd(tl->sync_state,
+ CMD_TRIGGER_HOST_WAIT,
+ ioctl_data.host_glsync_handle_in,
+ ioctl_data.host_syncthread_handle_in,
+ (u64)(uintptr_t)tl);
+ return 0;
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+static long goldfish_sync_ioctl(struct file *filp,
+ unsigned int cmd,
+ unsigned long arg)
+{
+ struct goldfish_sync_timeline *tl = filp->private_data;
+ struct goldfish_sync_state *x = tl->sync_state;
+ long res;
+
+ if (mutex_lock_interruptible(&x->mutex_lock))
+ return -ERESTARTSYS;
+
+ res = goldfish_sync_ioctl_locked(tl, cmd, arg);
+ mutex_unlock(&x->mutex_lock);
+
+ return res;
+}
+
+static bool setup_verify_batch_cmd_addr(char *reg_base,
+ void *batch_addr,
+ u32 addr_offset,
+ u32 addr_offset_high)
+{
+ u64 batch_addr_phys;
+ u64 batch_addr_phys_test_lo;
+ u64 batch_addr_phys_test_hi;
+
+ batch_addr_phys = virt_to_phys(batch_addr);
+ writel(lower_32_bits(batch_addr_phys), reg_base + addr_offset);
+ writel(upper_32_bits(batch_addr_phys), reg_base + addr_offset_high);
+
+ batch_addr_phys_test_lo = readl(reg_base + addr_offset);
+ batch_addr_phys_test_hi = readl(reg_base + addr_offset_high);
+
+ batch_addr_phys = batch_addr_phys_test_lo |
+ (batch_addr_phys_test_hi << 32);
+
+ return virt_to_phys(batch_addr) == batch_addr_phys;
+}
+
+static const struct file_operations goldfish_sync_fops = {
+ .owner = THIS_MODULE,
+ .open = goldfish_sync_open,
+ .release = goldfish_sync_release,
+ .unlocked_ioctl = goldfish_sync_ioctl,
+ .compat_ioctl = goldfish_sync_ioctl,
+};
+
+static void fill_miscdevice(struct miscdevice *misc)
+{
+ misc->name = GOLDFISH_SYNC_DEVICE_NAME;
+ misc->minor = MISC_DYNAMIC_MINOR;
+ misc->fops = &goldfish_sync_fops;
+}
+
+static int goldfish_sync_probe(struct platform_device *pdev)
+{
+ struct goldfish_sync_state *sync_state;
+ struct resource *ioresource;
+ int result;
+
+ sync_state = devm_kzalloc(&pdev->dev, sizeof(*sync_state), GFP_KERNEL);
+ if (!sync_state)
+ return -ENOMEM;
+
+ spin_lock_init(&sync_state->to_do_lock);
+ mutex_init(&sync_state->mutex_lock);
+ INIT_WORK(&sync_state->work_item, goldfish_sync_work_item_fn);
+
+ ioresource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!ioresource)
+ return -ENODEV;
+
+ sync_state->reg_base =
+ devm_ioremap(&pdev->dev, ioresource->start, PAGE_SIZE);
+ if (!sync_state->reg_base)
+ return -ENOMEM;
+
+ result = platform_get_irq(pdev, 0);
+ if (result < 0)
+ return -ENODEV;
+
+ sync_state->irq = result;
+
+ result = devm_request_irq(&pdev->dev,
+ sync_state->irq,
+ goldfish_sync_interrupt,
+ IRQF_SHARED,
+ pdev->name,
+ sync_state);
+ if (result)
+ return -ENODEV;
+
+ if (!setup_verify_batch_cmd_addr(sync_state->reg_base,
+ &sync_state->batch_hostcmd,
+ SYNC_REG_BATCH_COMMAND_ADDR,
+ SYNC_REG_BATCH_COMMAND_ADDR_HIGH))
+ return -ENODEV;
+
+ if (!setup_verify_batch_cmd_addr(sync_state->reg_base,
+ &sync_state->batch_guestcmd,
+ SYNC_REG_BATCH_GUESTCOMMAND_ADDR,
+ SYNC_REG_BATCH_GUESTCOMMAND_ADDR_HIGH))
+ return -ENODEV;
+
+ fill_miscdevice(&sync_state->miscdev);
+ result = misc_register(&sync_state->miscdev);
+ if (result)
+ return -ENODEV;
+
+ writel(0, sync_state->reg_base + SYNC_REG_INIT);
+
+ platform_set_drvdata(pdev, sync_state);
+
+ return 0;
+}
+
+static int goldfish_sync_remove(struct platform_device *pdev)
+{
+ struct goldfish_sync_state *sync_state = platform_get_drvdata(pdev);
+
+ misc_deregister(&sync_state->miscdev);
+ return 0;
+}
+
+static const struct of_device_id goldfish_sync_of_match[] = {
+ { .compatible = "google,goldfish-sync", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, goldfish_sync_of_match);
+
+static const struct acpi_device_id goldfish_sync_acpi_match[] = {
+ { "GFSH0006", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, goldfish_sync_acpi_match);
+
+static struct platform_driver goldfish_sync = {
+ .probe = goldfish_sync_probe,
+ .remove = goldfish_sync_remove,
+ .driver = {
+ .name = GOLDFISH_SYNC_DEVICE_NAME,
+ .of_match_table = goldfish_sync_of_match,
+ .acpi_match_table = ACPI_PTR(goldfish_sync_acpi_match),
+ }
+};
+module_platform_driver(goldfish_sync);
+
+MODULE_AUTHOR("Google, Inc.");
+MODULE_DESCRIPTION("Android QEMU Sync Driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("2.0");
diff --git a/include/uapi/linux/goldfish/goldfish_sync.h b/include/uapi/linux/goldfish/goldfish_sync.h
new file mode 100644
index 000000000000..01d762f77308
--- /dev/null
+++ b/include/uapi/linux/goldfish/goldfish_sync.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef UAPI_GOLDFISH_SYNC_H
+#define UAPI_GOLDFISH_SYNC_H
+
+#include <linux/types.h>
+
+#define GOLDFISH_SYNC_DEVICE_NAME "goldfish_sync"
+
+struct goldfish_sync_ioctl_info {
+ __u64 host_glsync_handle_in;
+ __u64 host_syncthread_handle_in;
+ __s32 fence_fd_out;
+};
+
+/* There is an ioctl associated with goldfish sync driver.
+ * Make it conflict with ioctls that are not likely to be used
+ * in the emulator.
+ *
+ * '@' 00-0F linux/radeonfb.h conflict!
+ * '@' 00-0F drivers/video/aty/aty128fb.c conflict!
+ */
+#define GOLDFISH_SYNC_IOC_MAGIC '@'
+
+#define GOLDFISH_SYNC_IOC_QUEUE_WORK \
+ _IOWR(GOLDFISH_SYNC_IOC_MAGIC, 0, struct goldfish_sync_ioctl_info)
+
+#endif /* UAPI_GOLDFISH_SYNC_H */
--
2.20.1.97.g81188d93c3-goog