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Subject[PATCH] staging: Android: Add 'vsoc' driver for cuttlefish.
From
From: Greg Hartman <ghartman@google.com>

The cuttlefish system is a virtual SoC architecture based on QEMU. It
uses the QEMU ivshmem feature to share memory regions between guest and
host with a custom protocol.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Todd Kjos <tkjos@android.com>
Cc: Martijn Coenen <maco@android.com>
Cc: devel@driverdev.osuosl.org
Cc: kernel-team@android.com
Signed-off-by: Greg Hartman <ghartman@google.com>
[astrachan: rebased against 4.16, added TODO, fixed checkpatch issues]
Signed-off-by: Alistair Strachan <astrachan@google.com>
---
drivers/staging/android/Kconfig | 9 +
drivers/staging/android/Makefile | 1 +
drivers/staging/android/TODO | 10 +
drivers/staging/android/uapi/vsoc_shm.h | 303 ++++++
drivers/staging/android/vsoc.c | 1167 +++++++++++++++++++++++
5 files changed, 1490 insertions(+)
create mode 100644 drivers/staging/android/uapi/vsoc_shm.h
create mode 100644 drivers/staging/android/vsoc.c

diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig
index 71a50b99caff..29d891355f7a 100644
--- a/drivers/staging/android/Kconfig
+++ b/drivers/staging/android/Kconfig
@@ -14,6 +14,15 @@ config ASHMEM
It is, in theory, a good memory allocator for low-memory devices,
because it can discard shared memory units when under memory pressure.

+config ANDROID_VSOC
+ tristate "Android Virtual SoC support"
+ default n
+ depends on PCI_MSI
+ ---help---
+ This option adds support for the Virtual SoC driver needed to boot
+ a 'cuttlefish' Android image inside QEmu. The driver interacts with
+ a QEmu ivshmem device. If built as a module, it will be called vsoc.
+
source "drivers/staging/android/ion/Kconfig"

endif # if ANDROID
diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile
index 7cf1564a49a5..90e6154f11a4 100644
--- a/drivers/staging/android/Makefile
+++ b/drivers/staging/android/Makefile
@@ -3,3 +3,4 @@ ccflags-y += -I$(src) # needed for trace events
obj-y += ion/

obj-$(CONFIG_ASHMEM) += ashmem.o
+obj-$(CONFIG_ANDROID_VSOC) += vsoc.o
diff --git a/drivers/staging/android/TODO b/drivers/staging/android/TODO
index 687e0eac85bf..6aab759efa48 100644
--- a/drivers/staging/android/TODO
+++ b/drivers/staging/android/TODO
@@ -11,5 +11,15 @@ ion/
- Split /dev/ion up into multiple nodes (e.g. /dev/ion/heap0)
- Better test framework (integration with VGEM was suggested)

+vsoc.c, uapi/vsoc_shm.h
+ - The current driver uses the same wait queue for all of the futexes in a
+ region. This will cause false wakeups in regions with a large number of
+ waiting threads. We should eventually use multiple queues and select the
+ queue based on the region.
+ - Add debugfs support for examining the permissions of regions.
+ - Use ioremap_wc instead of ioremap_nocache.
+ - Remove VSOC_WAIT_FOR_INCOMING_INTERRUPT ioctl. This functionality has been
+ superseded by the futex and is there for legacy reasons.
+
Please send patches to Greg Kroah-Hartman <greg@kroah.com> and Cc:
Arve Hjønnevåg <arve@android.com> and Riley Andrews <riandrews@android.com>
diff --git a/drivers/staging/android/uapi/vsoc_shm.h b/drivers/staging/android/uapi/vsoc_shm.h
new file mode 100644
index 000000000000..741b1387c25b
--- /dev/null
+++ b/drivers/staging/android/uapi/vsoc_shm.h
@@ -0,0 +1,303 @@
+/*
+ * Copyright (C) 2017 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _UAPI_LINUX_VSOC_SHM_H
+#define _UAPI_LINUX_VSOC_SHM_H
+
+#include <linux/types.h>
+
+/**
+ * A permission is a token that permits a receiver to read and/or write an area
+ * of memory within a Vsoc region.
+ *
+ * An fd_scoped permission grants both read and write access, and can be
+ * attached to a file description (see open(2)).
+ * Ownership of the area can then be shared by passing a file descriptor
+ * among processes.
+ *
+ * begin_offset and end_offset define the area of memory that is controlled by
+ * the permission. owner_offset points to a word, also in shared memory, that
+ * controls ownership of the area.
+ *
+ * ownership of the region expires when the associated file description is
+ * released.
+ *
+ * At most one permission can be attached to each file description.
+ *
+ * This is useful when implementing HALs like gralloc that scope and pass
+ * ownership of shared resources via file descriptors.
+ *
+ * The caller is responsibe for doing any fencing.
+ *
+ * The calling process will normally identify a currently free area of
+ * memory. It will construct a proposed fd_scoped_permission_arg structure:
+ *
+ * begin_offset and end_offset describe the area being claimed
+ *
+ * owner_offset points to the location in shared memory that indicates the
+ * owner of the area.
+ *
+ * owned_value is the value that will be stored in owner_offset iff the
+ * permission can be granted. It must be different than VSOC_REGION_FREE.
+ *
+ * Two fd_scoped_permission structures are compatible if they vary only by
+ * their owned_value fields.
+ *
+ * The driver ensures that, for any group of simultaneous callers proposing
+ * compatible fd_scoped_permissions, it will accept exactly one of the
+ * propopsals. The other callers will get a failure with errno of EAGAIN.
+ *
+ * A process receiving a file descriptor can identify the region being
+ * granted using the VSOC_GET_FD_SCOPED_PERMISSION ioctl.
+ */
+struct fd_scoped_permission {
+ __u32 begin_offset;
+ __u32 end_offset;
+ __u32 owner_offset;
+ __u32 owned_value;
+};
+
+/*
+ * This value represents a free area of memory. The driver expects to see this
+ * value at owner_offset when creating a permission otherwise it will not do it,
+ * and will write this value back once the permission is no longer needed.
+ */
+#define VSOC_REGION_FREE ((__u32)0)
+
+/**
+ * ioctl argument for VSOC_CREATE_FD_SCOPE_PERMISSION
+ */
+struct fd_scoped_permission_arg {
+ struct fd_scoped_permission perm;
+ __s32 managed_region_fd;
+};
+
+#define VSOC_NODE_FREE ((__u32)0)
+
+/*
+ * Describes a signal table in shared memory. Each non-zero entry in the
+ * table indicates that the receiver should signal the futex at the given
+ * offset. Offsets are relative to the region, not the shared memory window.
+ *
+ * interrupt_signalled_offset is used to reliably signal interrupts across the
+ * vmm boundary. There are two roles: transmitter and receiver. For example,
+ * in the host_to_guest_signal_table the host is the transmitter and the
+ * guest is the receiver. The protocol is as follows:
+ *
+ * 1. The transmitter should convert the offset of the futex to an offset
+ * in the signal table [0, (1 << num_nodes_lg2))
+ * The transmitter can choose any appropriate hashing algorithm, including
+ * hash = futex_offset & ((1 << num_nodes_lg2) - 1)
+ *
+ * 3. The transmitter should atomically compare and swap futex_offset with 0
+ * at hash. There are 3 possible outcomes
+ * a. The swap fails because the futex_offset is already in the table.
+ * The transmitter should stop.
+ * b. Some other offset is in the table. This is a hash collision. The
+ * transmitter should move to another table slot and try again. One
+ * possible algorithm:
+ * hash = (hash + 1) & ((1 << num_nodes_lg2) - 1)
+ * c. The swap worked. Continue below.
+ *
+ * 3. The transmitter atomically swaps 1 with the value at the
+ * interrupt_signalled_offset. There are two outcomes:
+ * a. The prior value was 1. In this case an interrupt has already been
+ * posted. The transmitter is done.
+ * b. The prior value was 0, indicating that the receiver may be sleeping.
+ * The transmitter will issue an interrupt.
+ *
+ * 4. On waking the receiver immediately exchanges a 0 with the
+ * interrupt_signalled_offset. If it receives a 0 then this a spurious
+ * interrupt. That may occasionally happen in the current protocol, but
+ * should be rare.
+ *
+ * 5. The receiver scans the signal table by atomicaly exchanging 0 at each
+ * location. If a non-zero offset is returned from the exchange the
+ * receiver wakes all sleepers at the given offset:
+ * futex((int*)(region_base + old_value), FUTEX_WAKE, MAX_INT);
+ *
+ * 6. The receiver thread then does a conditional wait, waking immediately
+ * if the value at interrupt_signalled_offset is non-zero. This catches cases
+ * here additional signals were posted while the table was being scanned.
+ * On the guest the wait is handled via the VSOC_WAIT_FOR_INCOMING_INTERRUPT
+ * ioctl.
+ */
+struct vsoc_signal_table_layout {
+ /* log_2(Number of signal table entries) */
+ __u32 num_nodes_lg2;
+ /*
+ * Offset to the first signal table entry relative to the start of the
+ * region
+ */
+ __u32 futex_uaddr_table_offset;
+ /*
+ * Offset to an atomic_t / atomic uint32_t. A non-zero value indicates
+ * that one or more offsets are currently posted in the table.
+ * semi-unique access to an entry in the table
+ */
+ __u32 interrupt_signalled_offset;
+};
+
+#define VSOC_REGION_WHOLE ((__s32)0)
+#define VSOC_DEVICE_NAME_SZ 16
+
+/**
+ * Each HAL would (usually) talk to a single device region
+ * Mulitple entities care about these regions:
+ * - The ivshmem_server will populate the regions in shared memory
+ * - The guest kernel will read the region, create minor device nodes, and
+ * allow interested parties to register for FUTEX_WAKE events in the region
+ * - HALs will access via the minor device nodes published by the guest kernel
+ * - Host side processes will access the region via the ivshmem_server:
+ * 1. Pass name to ivshmem_server at a UNIX socket
+ * 2. ivshmemserver will reply with 2 fds:
+ * - host->guest doorbell fd
+ * - guest->host doorbell fd
+ * - fd for the shared memory region
+ * - region offset
+ * 3. Start a futex receiver thread on the doorbell fd pointed at the
+ * signal_nodes
+ */
+struct vsoc_device_region {
+ __u16 current_version;
+ __u16 min_compatible_version;
+ __u32 region_begin_offset;
+ __u32 region_end_offset;
+ __u32 offset_of_region_data;
+ struct vsoc_signal_table_layout guest_to_host_signal_table;
+ struct vsoc_signal_table_layout host_to_guest_signal_table;
+ /* Name of the device. Must always be terminated with a '\0', so
+ * the longest supported device name is 15 characters.
+ */
+ char device_name[VSOC_DEVICE_NAME_SZ];
+ /* There are two ways that permissions to access regions are handled:
+ * - When subdivided_by is VSOC_REGION_WHOLE, any process that can
+ * open the device node for the region gains complete access to it.
+ * - When subdivided is set processes that open the region cannot
+ * access it. Access to a sub-region must be established by invoking
+ * the VSOC_CREATE_FD_SCOPE_PERMISSION ioctl on the region
+ * referenced in subdivided_by, providing a fileinstance
+ * (represented by a fd) opened on this region.
+ */
+ __u32 managed_by;
+};
+
+/*
+ * The vsoc layout descriptor.
+ * The first 4K should be reserved for the shm header and region descriptors.
+ * The regions should be page aligned.
+ */
+
+struct vsoc_shm_layout_descriptor {
+ __u16 major_version;
+ __u16 minor_version;
+
+ /* size of the shm. This may be redundant but nice to have */
+ __u32 size;
+
+ /* number of shared memory regions */
+ __u32 region_count;
+
+ /* The offset to the start of region descriptors */
+ __u32 vsoc_region_desc_offset;
+};
+
+/*
+ * This specifies the current version that should be stored in
+ * vsoc_shm_layout_descriptor.major_version and
+ * vsoc_shm_layout_descriptor.minor_version.
+ * It should be updated only if the vsoc_device_region and
+ * vsoc_shm_layout_descriptor structures have changed.
+ * Versioning within each region is transferred
+ * via the min_compatible_version and current_version fields in
+ * vsoc_device_region. The driver does not consult these fields: they are left
+ * for the HALs and host processes and will change independently of the layout
+ * version.
+ */
+#define CURRENT_VSOC_LAYOUT_MAJOR_VERSION 2
+#define CURRENT_VSOC_LAYOUT_MINOR_VERSION 0
+
+#define VSOC_CREATE_FD_SCOPED_PERMISSION \
+ _IOW(0xF5, 0, struct fd_scoped_permission)
+#define VSOC_GET_FD_SCOPED_PERMISSION _IOR(0xF5, 1, struct fd_scoped_permission)
+
+/*
+ * This is used to signal the host to scan the guest_to_host_signal_table
+ * for new futexes to wake. This sends an interrupt if one is not already
+ * in flight.
+ */
+#define VSOC_MAYBE_SEND_INTERRUPT_TO_HOST _IO(0xF5, 2)
+
+/*
+ * When this returns the guest will scan host_to_guest_signal_table to
+ * check for new futexes to wake.
+ */
+/* TODO(ghartman): Consider moving this to the bottom half */
+#define VSOC_WAIT_FOR_INCOMING_INTERRUPT _IO(0xF5, 3)
+
+/*
+ * Guest HALs will use this to retrieve the region description after
+ * opening their device node.
+ */
+#define VSOC_DESCRIBE_REGION _IOR(0xF5, 4, struct vsoc_device_region)
+
+/*
+ * Wake any threads that may be waiting for a host interrupt on this region.
+ * This is mostly used during shutdown.
+ */
+#define VSOC_SELF_INTERRUPT _IO(0xF5, 5)
+
+/*
+ * This is used to signal the host to scan the guest_to_host_signal_table
+ * for new futexes to wake. This sends an interrupt unconditionally.
+ */
+#define VSOC_SEND_INTERRUPT_TO_HOST _IO(0xF5, 6)
+
+enum wait_types {
+ VSOC_WAIT_UNDEFINED = 0,
+ VSOC_WAIT_IF_EQUAL = 1,
+ VSOC_WAIT_IF_EQUAL_TIMEOUT = 2
+};
+
+/*
+ * Wait for a condition to be true
+ *
+ * Note, this is sized and aligned so the 32 bit and 64 bit layouts are
+ * identical.
+ */
+struct vsoc_cond_wait {
+ /* Input: Offset of the 32 bit word to check */
+ __u32 offset;
+ /* Input: Value that will be compared with the offset */
+ __u32 value;
+ /* Monotonic time to wake at in seconds */
+ __u64 wake_time_sec;
+ /* Input: Monotonic time to wait in nanoseconds */
+ __u32 wake_time_nsec;
+ /* Input: Type of wait */
+ __u32 wait_type;
+ /* Output: Number of times the thread woke before returning. */
+ __u32 wakes;
+ /* Ensure that we're 8-byte aligned and 8 byte length for 32/64 bit
+ * compatibility.
+ */
+ __u32 reserved_1;
+};
+
+#define VSOC_COND_WAIT _IOWR(0xF5, 7, struct vsoc_cond_wait)
+
+/* Wake any local threads waiting at the offset given in arg */
+#define VSOC_COND_WAKE _IO(0xF5, 8)
+
+#endif /* _UAPI_LINUX_VSOC_SHM_H */
diff --git a/drivers/staging/android/vsoc.c b/drivers/staging/android/vsoc.c
new file mode 100644
index 000000000000..61c6f73b372a
--- /dev/null
+++ b/drivers/staging/android/vsoc.c
@@ -0,0 +1,1167 @@
+/*
+ * drivers/android/staging/vsoc.c
+ *
+ * Android Virtual System on a Chip (VSoC) driver
+ *
+ * Copyright (C) 2017 Google, Inc.
+ *
+ * Author: ghartman@google.com
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ *
+ * Based on drivers/char/kvm_ivshmem.c - driver for KVM Inter-VM shared memory
+ * Copyright 2009 Cam Macdonell <cam@cs.ualberta.ca>
+ *
+ * Based on cirrusfb.c and 8139cp.c:
+ * Copyright 1999-2001 Jeff Garzik
+ * Copyright 2001-2004 Jeff Garzik
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/freezer.h>
+#include <linux/futex.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/proc_fs.h>
+#include <linux/sched.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/cdev.h>
+#include <linux/file.h>
+#include "uapi/vsoc_shm.h"
+
+#define VSOC_DEV_NAME "vsoc"
+
+/*
+ * Description of the ivshmem-doorbell PCI device used by QEmu. These
+ * constants follow docs/specs/ivshmem-spec.txt, which can be found in
+ * the QEmu repository. This was last reconciled with the version that
+ * came out with 2.8
+ */
+
+/*
+ * These constants are determined KVM Inter-VM shared memory device
+ * register offsets
+ */
+enum {
+ INTR_MASK = 0x00, /* Interrupt Mask */
+ INTR_STATUS = 0x04, /* Interrupt Status */
+ IV_POSITION = 0x08, /* VM ID */
+ DOORBELL = 0x0c, /* Doorbell */
+};
+
+static const int REGISTER_BAR; /* Equal to 0 */
+static const int MAX_REGISTER_BAR_LEN = 0x100;
+/*
+ * The MSI-x BAR is not used directly.
+ *
+ * static const int MSI_X_BAR = 1;
+ */
+static const int SHARED_MEMORY_BAR = 2;
+
+struct vsoc_region_data {
+ char name[VSOC_DEVICE_NAME_SZ + 1];
+ wait_queue_head_t interrupt_wait_queue;
+ /* TODO(b/73664181): Use multiple futex wait queues */
+ wait_queue_head_t futex_wait_queue;
+ /* Flag indicating that an interrupt has been signalled by the host. */
+ atomic_t *incoming_signalled;
+ /* Flag indicating the guest has signalled the host. */
+ atomic_t *outgoing_signalled;
+ int irq_requested;
+ int device_created;
+};
+
+struct vsoc_device {
+ /* Kernel virtual address of REGISTER_BAR. */
+ void __iomem *regs;
+ /* Physical address of SHARED_MEMORY_BAR. */
+ phys_addr_t shm_phys_start;
+ /* Kernel virtual address of SHARED_MEMORY_BAR. */
+ void *kernel_mapped_shm;
+ /* Size of the entire shared memory window in bytes. */
+ size_t shm_size;
+ /*
+ * Pointer to the virtual address of the shared memory layout structure.
+ * This is probably identical to kernel_mapped_shm, but saving this
+ * here saves a lot of annoying casts.
+ */
+ struct vsoc_shm_layout_descriptor *layout;
+ /*
+ * Points to a table of region descriptors in the kernel's virtual
+ * address space. Calculated from
+ * vsoc_shm_layout_descriptor.vsoc_region_desc_offset
+ */
+ struct vsoc_device_region *regions;
+ /* Head of a list of permissions that have been granted. */
+ struct list_head permissions;
+ struct pci_dev *dev;
+ /* Per-region (and therefore per-interrupt) information. */
+ struct vsoc_region_data *regions_data;
+ /*
+ * Table of msi-x entries. This has to be separated from struct
+ * vsoc_region_data because the kernel deals with them as an array.
+ */
+ struct msix_entry *msix_entries;
+ /*
+ * Flags that indicate what we've initialzied. These are used to do an
+ * orderly cleanup of the device.
+ */
+ char enabled_device;
+ char requested_regions;
+ char cdev_added;
+ char msix_enabled;
+ /* Mutex that protectes the permission list */
+ struct mutex mtx;
+ /* Major number assigned by the kernel */
+ int major;
+
+ struct cdev cdev;
+ struct class *class;
+};
+
+static struct vsoc_device vsoc_dev;
+
+/*
+ * TODO(ghartman): Add a /sys filesystem entry that summarizes the permissions.
+ */
+
+struct fd_scoped_permission_node {
+ struct fd_scoped_permission permission;
+ struct list_head list;
+};
+
+struct vsoc_private_data {
+ struct fd_scoped_permission_node *fd_scoped_permission_node;
+};
+
+static long vsoc_ioctl(struct file *, unsigned int, unsigned long);
+static int vsoc_mmap(struct file *, struct vm_area_struct *);
+static int vsoc_open(struct inode *, struct file *);
+static int vsoc_release(struct inode *, struct file *);
+static ssize_t vsoc_read(struct file *, char *, size_t, loff_t *);
+static ssize_t vsoc_write(struct file *, const char *, size_t, loff_t *);
+static loff_t vsoc_lseek(struct file *filp, loff_t offset, int origin);
+static int do_create_fd_scoped_permission(
+ struct vsoc_device_region *region_p,
+ struct fd_scoped_permission_node *np,
+ struct fd_scoped_permission_arg *__user arg);
+static void do_destroy_fd_scoped_permission(
+ struct vsoc_device_region *owner_region_p,
+ struct fd_scoped_permission *perm);
+static long do_vsoc_describe_region(struct file *,
+ struct vsoc_device_region __user *);
+static ssize_t vsoc_get_area(struct file *filp, __u32 *perm_off);
+
+/**
+ * Validate arguments on entry points to the driver.
+ */
+inline int vsoc_validate_inode(struct inode *inode)
+{
+ if (iminor(inode) >= vsoc_dev.layout->region_count) {
+ dev_err(&vsoc_dev.dev->dev,
+ "describe_region: invalid region %d\n", iminor(inode));
+ return -ENODEV;
+ }
+ return 0;
+}
+
+inline int vsoc_validate_filep(struct file *filp)
+{
+ int ret = vsoc_validate_inode(file_inode(filp));
+
+ if (ret)
+ return ret;
+ if (!filp->private_data) {
+ dev_err(&vsoc_dev.dev->dev,
+ "No private data on fd, region %d\n",
+ iminor(file_inode(filp)));
+ return -EBADFD;
+ }
+ return 0;
+}
+
+/* Converts from shared memory offset to virtual address */
+static inline void *shm_off_to_virtual_addr(__u32 offset)
+{
+ return vsoc_dev.kernel_mapped_shm + offset;
+}
+
+/* Converts from shared memory offset to physical address */
+static inline phys_addr_t shm_off_to_phys_addr(__u32 offset)
+{
+ return vsoc_dev.shm_phys_start + offset;
+}
+
+/**
+ * Convenience functions to obtain the region from the inode or file.
+ * Dangerous to call before validating the inode/file.
+ */
+static inline struct vsoc_device_region *vsoc_region_from_inode(
+ struct inode *inode)
+{
+ return &vsoc_dev.regions[iminor(inode)];
+}
+
+static inline struct vsoc_device_region *vsoc_region_from_filep(
+ struct file *inode)
+{
+ return vsoc_region_from_inode(file_inode(inode));
+}
+
+static inline uint32_t vsoc_device_region_size(struct vsoc_device_region *r)
+{
+ return r->region_end_offset - r->region_begin_offset;
+}
+
+static const struct file_operations vsoc_ops = {
+ .owner = THIS_MODULE,
+ .open = vsoc_open,
+ .mmap = vsoc_mmap,
+ .read = vsoc_read,
+ .unlocked_ioctl = vsoc_ioctl,
+ .compat_ioctl = vsoc_ioctl,
+ .write = vsoc_write,
+ .llseek = vsoc_lseek,
+ .release = vsoc_release,
+};
+
+static struct pci_device_id vsoc_id_table[] = {
+ {0x1af4, 0x1110, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
+ {0},
+};
+
+MODULE_DEVICE_TABLE(pci, vsoc_id_table);
+
+static void vsoc_remove_device(struct pci_dev *pdev);
+static int vsoc_probe_device(struct pci_dev *pdev,
+ const struct pci_device_id *ent);
+
+static struct pci_driver vsoc_pci_driver = {
+ .name = "vsoc",
+ .id_table = vsoc_id_table,
+ .probe = vsoc_probe_device,
+ .remove = vsoc_remove_device,
+};
+
+static int do_create_fd_scoped_permission(
+ struct vsoc_device_region *region_p,
+ struct fd_scoped_permission_node *np,
+ struct fd_scoped_permission_arg *__user arg)
+{
+ struct file *managed_filp;
+ s32 managed_fd;
+ atomic_t *owner_ptr = NULL;
+ struct vsoc_device_region *managed_region_p;
+
+ if (copy_from_user(&np->permission, &arg->perm, sizeof(*np)) ||
+ copy_from_user(&managed_fd,
+ &arg->managed_region_fd, sizeof(managed_fd))) {
+ return -EFAULT;
+ }
+ managed_filp = fdget(managed_fd).file;
+ /* Check that it's a valid fd, */
+ if (!managed_filp || vsoc_validate_filep(managed_filp))
+ return -EPERM;
+ /* EEXIST if the given fd already has a permission. */
+ if (((struct vsoc_private_data *)managed_filp->private_data)->
+ fd_scoped_permission_node)
+ return -EEXIST;
+ managed_region_p = vsoc_region_from_filep(managed_filp);
+ /* Check that the provided region is managed by this one */
+ if (&vsoc_dev.regions[managed_region_p->managed_by] != region_p)
+ return -EPERM;
+ /* The area must be well formed and have non-zero size */
+ if (np->permission.begin_offset >= np->permission.end_offset)
+ return -EINVAL;
+ /* The area must fit in the memory window */
+ if (np->permission.end_offset >
+ vsoc_device_region_size(managed_region_p))
+ return -ERANGE;
+ /* The area must be in the region data section */
+ if (np->permission.begin_offset <
+ managed_region_p->offset_of_region_data)
+ return -ERANGE;
+ /* The area must be page aligned */
+ if (!PAGE_ALIGNED(np->permission.begin_offset) ||
+ !PAGE_ALIGNED(np->permission.end_offset))
+ return -EINVAL;
+ /* The owner flag must reside in the owner memory */
+ if (np->permission.owner_offset + sizeof(np->permission.owner_offset) >
+ vsoc_device_region_size(region_p))
+ return -ERANGE;
+ /* The owner flag must reside in the data section */
+ if (np->permission.owner_offset < region_p->offset_of_region_data)
+ return -EINVAL;
+ /* Owner offset must be naturally aligned in the window */
+ if (np->permission.owner_offset &
+ (sizeof(np->permission.owner_offset) - 1))
+ return -EINVAL;
+ /* The owner value must change to claim the memory */
+ if (np->permission.owned_value == VSOC_REGION_FREE)
+ return -EINVAL;
+ owner_ptr =
+ (atomic_t *)shm_off_to_virtual_addr(region_p->region_begin_offset +
+ np->permission.owner_offset);
+ /* We've already verified that this is in the shared memory window, so
+ * it should be safe to write to this address.
+ */
+ if (atomic_cmpxchg(owner_ptr,
+ VSOC_REGION_FREE,
+ np->permission.owned_value) != VSOC_REGION_FREE) {
+ return -EBUSY;
+ }
+ ((struct vsoc_private_data *)managed_filp->private_data)->
+ fd_scoped_permission_node = np;
+ /* The file offset needs to be adjusted if the calling
+ * process did any read/write operations on the fd
+ * before creating the permission.
+ */
+ if (managed_filp->f_pos) {
+ if (managed_filp->f_pos > np->permission.end_offset) {
+ /* If the offset is beyond the permission end, set it
+ * to the end.
+ */
+ managed_filp->f_pos = np->permission.end_offset;
+ } else {
+ /* If the offset is within the permission interval
+ * keep it there otherwise reset it to zero.
+ */
+ if (managed_filp->f_pos < np->permission.begin_offset) {
+ managed_filp->f_pos = 0;
+ } else {
+ managed_filp->f_pos -=
+ np->permission.begin_offset;
+ }
+ }
+ }
+ return 0;
+}
+
+static void do_destroy_fd_scoped_permission_node(
+ struct vsoc_device_region *owner_region_p,
+ struct fd_scoped_permission_node *node)
+{
+ if (node) {
+ do_destroy_fd_scoped_permission(owner_region_p,
+ &node->permission);
+ mutex_lock(&vsoc_dev.mtx);
+ list_del(&node->list);
+ mutex_unlock(&vsoc_dev.mtx);
+ kfree(node);
+ }
+}
+
+static void do_destroy_fd_scoped_permission(
+ struct vsoc_device_region *owner_region_p,
+ struct fd_scoped_permission *perm)
+{
+ atomic_t *owner_ptr = NULL;
+ int prev = 0;
+
+ if (!perm)
+ return;
+ owner_ptr = (atomic_t *)shm_off_to_virtual_addr(
+ owner_region_p->region_begin_offset + perm->owner_offset);
+ prev = atomic_xchg(owner_ptr, VSOC_REGION_FREE);
+ if (prev != perm->owned_value)
+ dev_err(&vsoc_dev.dev->dev,
+ "%x-%x: owner (%s) %x: expected to be %x was %x",
+ perm->begin_offset, perm->end_offset,
+ owner_region_p->device_name, perm->owner_offset,
+ perm->owned_value, prev);
+}
+
+static long do_vsoc_describe_region(struct file *filp,
+ struct vsoc_device_region __user *dest)
+{
+ struct vsoc_device_region *region_p;
+ int retval = vsoc_validate_filep(filp);
+
+ if (retval)
+ return retval;
+ region_p = vsoc_region_from_filep(filp);
+ if (copy_to_user(dest, region_p, sizeof(*region_p)))
+ return -EFAULT;
+ return 0;
+}
+
+/**
+ * Implements the inner logic of cond_wait. Copies to and from userspace are
+ * done in the helper function below.
+ */
+static int handle_vsoc_cond_wait(struct file *filp, struct vsoc_cond_wait *arg)
+{
+ DEFINE_WAIT(wait);
+ u32 region_number = iminor(file_inode(filp));
+ struct vsoc_region_data *data = vsoc_dev.regions_data + region_number;
+ struct hrtimer_sleeper timeout, *to = NULL;
+ int ret = 0;
+ struct vsoc_device_region *region_p = vsoc_region_from_filep(filp);
+ atomic_t *address = NULL;
+ struct timespec ts;
+
+ /* Ensure that the offset is aligned */
+ if (arg->offset & (sizeof(uint32_t) - 1))
+ return -EADDRNOTAVAIL;
+ /* Ensure that the offset is within shared memory */
+ if (((uint64_t)arg->offset) + region_p->region_begin_offset +
+ sizeof(uint32_t) > region_p->region_end_offset)
+ return -E2BIG;
+ address = shm_off_to_virtual_addr(region_p->region_begin_offset +
+ arg->offset);
+
+ /* Ensure that the type of wait is valid */
+ switch (arg->wait_type) {
+ case VSOC_WAIT_IF_EQUAL:
+ break;
+ case VSOC_WAIT_IF_EQUAL_TIMEOUT:
+ to = &timeout;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (to) {
+ /* Copy the user-supplied timesec into the kernel structure.
+ * We do things this way to flatten differences between 32 bit
+ * and 64 bit timespecs.
+ */
+ ts.tv_sec = arg->wake_time_sec;
+ ts.tv_nsec = arg->wake_time_nsec;
+
+ if (!timespec_valid(&ts))
+ return -EINVAL;
+ hrtimer_init_on_stack(&to->timer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_ABS);
+ hrtimer_set_expires_range_ns(&to->timer, timespec_to_ktime(ts),
+ current->timer_slack_ns);
+
+ hrtimer_init_sleeper(to, current);
+ }
+
+ while (1) {
+ prepare_to_wait(&data->futex_wait_queue, &wait,
+ TASK_INTERRUPTIBLE);
+ /*
+ * Check the sentinel value after prepare_to_wait. If the value
+ * changes after this check the writer will call signal,
+ * changing the task state from INTERRUPTIBLE to RUNNING. That
+ * will ensure that schedule() will eventually schedule this
+ * task.
+ */
+ if (atomic_read(address) != arg->value) {
+ ret = 0;
+ break;
+ }
+ if (to) {
+ hrtimer_start_expires(&to->timer, HRTIMER_MODE_ABS);
+ if (likely(to->task))
+ freezable_schedule();
+ hrtimer_cancel(&to->timer);
+ if (!to->task) {
+ ret = -ETIMEDOUT;
+ break;
+ }
+ } else {
+ freezable_schedule();
+ }
+ /* Count the number of times that we woke up. This is useful
+ * for unit testing.
+ */
+ ++arg->wakes;
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+ }
+ finish_wait(&data->futex_wait_queue, &wait);
+ if (to)
+ destroy_hrtimer_on_stack(&to->timer);
+ return ret;
+}
+
+/**
+ * Handles the details of copying from/to userspace to ensure that the copies
+ * happen on all of the return paths of cond_wait.
+ */
+static int do_vsoc_cond_wait(struct file *filp,
+ struct vsoc_cond_wait __user *untrusted_in)
+{
+ struct vsoc_cond_wait arg;
+ int rval = 0;
+
+ if (copy_from_user(&arg, untrusted_in, sizeof(arg)))
+ return -EFAULT;
+ /* wakes is an out parameter. Initialize it to something sensible. */
+ arg.wakes = 0;
+ rval = handle_vsoc_cond_wait(filp, &arg);
+ if (copy_to_user(untrusted_in, &arg, sizeof(arg)))
+ return -EFAULT;
+ return rval;
+}
+
+static int do_vsoc_cond_wake(struct file *filp, uint32_t offset)
+{
+ struct vsoc_device_region *region_p = vsoc_region_from_filep(filp);
+ u32 region_number = iminor(file_inode(filp));
+ struct vsoc_region_data *data = vsoc_dev.regions_data + region_number;
+ /* Ensure that the offset is aligned */
+ if (offset & (sizeof(uint32_t) - 1))
+ return -EADDRNOTAVAIL;
+ /* Ensure that the offset is within shared memory */
+ if (((uint64_t)offset) + region_p->region_begin_offset +
+ sizeof(uint32_t) > region_p->region_end_offset)
+ return -E2BIG;
+ /*
+ * TODO(b/73664181): Use multiple futex wait queues.
+ * We need to wake every sleeper when the condition changes. Typically
+ * only a single thread will be waiting on the condition, but there
+ * are exceptions. The worst case is about 10 threads.
+ */
+ wake_up_interruptible_all(&data->futex_wait_queue);
+ return 0;
+}
+
+static long vsoc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ int rv = 0;
+ struct vsoc_device_region *region_p;
+ u32 reg_num;
+ struct vsoc_region_data *reg_data;
+ int retval = vsoc_validate_filep(filp);
+
+ if (retval)
+ return retval;
+ region_p = vsoc_region_from_filep(filp);
+ reg_num = iminor(file_inode(filp));
+ reg_data = vsoc_dev.regions_data + reg_num;
+ switch (cmd) {
+ case VSOC_CREATE_FD_SCOPED_PERMISSION:
+ {
+ struct fd_scoped_permission_node *node = NULL;
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ /* We can't allocate memory for the permission */
+ if (!node)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&node->list);
+ rv = do_create_fd_scoped_permission(
+ region_p,
+ node,
+ (struct fd_scoped_permission_arg __user *)arg);
+ if (!rv) {
+ mutex_lock(&vsoc_dev.mtx);
+ list_add(&node->list, &vsoc_dev.permissions);
+ mutex_unlock(&vsoc_dev.mtx);
+ } else {
+ kfree(node);
+ return rv;
+ }
+ }
+ break;
+
+ case VSOC_GET_FD_SCOPED_PERMISSION:
+ {
+ struct fd_scoped_permission_node *node =
+ ((struct vsoc_private_data *)filp->private_data)->
+ fd_scoped_permission_node;
+ if (!node)
+ return -ENOENT;
+ if (copy_to_user
+ ((struct fd_scoped_permission __user *)arg,
+ &node->permission, sizeof(node->permission)))
+ return -EFAULT;
+ }
+ break;
+
+ case VSOC_MAYBE_SEND_INTERRUPT_TO_HOST:
+ if (!atomic_xchg(
+ reg_data->outgoing_signalled,
+ 1)) {
+ writel(reg_num, vsoc_dev.regs + DOORBELL);
+ return 0;
+ } else {
+ return -EBUSY;
+ }
+ break;
+
+ case VSOC_SEND_INTERRUPT_TO_HOST:
+ writel(reg_num, vsoc_dev.regs + DOORBELL);
+ return 0;
+
+ case VSOC_WAIT_FOR_INCOMING_INTERRUPT:
+ wait_event_interruptible(
+ reg_data->interrupt_wait_queue,
+ (atomic_read(reg_data->incoming_signalled) != 0));
+ break;
+
+ case VSOC_DESCRIBE_REGION:
+ return do_vsoc_describe_region(
+ filp,
+ (struct vsoc_device_region __user *)arg);
+
+ case VSOC_SELF_INTERRUPT:
+ atomic_set(reg_data->incoming_signalled, 1);
+ wake_up_interruptible(&reg_data->interrupt_wait_queue);
+ break;
+
+ case VSOC_COND_WAIT:
+ return do_vsoc_cond_wait(filp,
+ (struct vsoc_cond_wait __user *)arg);
+ case VSOC_COND_WAKE:
+ return do_vsoc_cond_wake(filp, arg);
+
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static ssize_t vsoc_read(struct file *filp, char *buffer, size_t len,
+ loff_t *poffset)
+{
+ __u32 area_off;
+ void *area_p;
+ ssize_t area_len;
+ int retval = vsoc_validate_filep(filp);
+
+ if (retval)
+ return retval;
+ area_len = vsoc_get_area(filp, &area_off);
+ area_p = shm_off_to_virtual_addr(area_off);
+ area_p += *poffset;
+ area_len -= *poffset;
+ if (area_len <= 0)
+ return 0;
+ if (area_len < len)
+ len = area_len;
+ if (copy_to_user(buffer, area_p, len))
+ return -EFAULT;
+ *poffset += len;
+ return len;
+}
+
+static loff_t vsoc_lseek(struct file *filp, loff_t offset, int origin)
+{
+ ssize_t area_len = 0;
+ int retval = vsoc_validate_filep(filp);
+
+ if (retval)
+ return retval;
+ area_len = vsoc_get_area(filp, NULL);
+ switch (origin) {
+ case SEEK_SET:
+ break;
+
+ case SEEK_CUR:
+ if (offset > 0 && offset + filp->f_pos < 0)
+ return -EOVERFLOW;
+ offset += filp->f_pos;
+ break;
+
+ case SEEK_END:
+ if (offset > 0 && offset + area_len < 0)
+ return -EOVERFLOW;
+ offset += area_len;
+ break;
+
+ case SEEK_DATA:
+ if (offset >= area_len)
+ return -EINVAL;
+ if (offset < 0)
+ offset = 0;
+ break;
+
+ case SEEK_HOLE:
+ /* Next hole is always the end of the region, unless offset is
+ * beyond that
+ */
+ if (offset < area_len)
+ offset = area_len;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (offset < 0 || offset > area_len)
+ return -EINVAL;
+ filp->f_pos = offset;
+
+ return offset;
+}
+
+static ssize_t vsoc_write(struct file *filp, const char *buffer,
+ size_t len, loff_t *poffset)
+{
+ __u32 area_off;
+ void *area_p;
+ ssize_t area_len;
+ int retval = vsoc_validate_filep(filp);
+
+ if (retval)
+ return retval;
+ area_len = vsoc_get_area(filp, &area_off);
+ area_p = shm_off_to_virtual_addr(area_off);
+ area_p += *poffset;
+ area_len -= *poffset;
+ if (area_len <= 0)
+ return 0;
+ if (area_len < len)
+ len = area_len;
+ if (copy_from_user(area_p, buffer, len))
+ return -EFAULT;
+ *poffset += len;
+ return len;
+}
+
+static irqreturn_t vsoc_interrupt(int irq, void *region_data_v)
+{
+ struct vsoc_region_data *region_data =
+ (struct vsoc_region_data *)region_data_v;
+ int reg_num = region_data - vsoc_dev.regions_data;
+
+ if (unlikely(!region_data))
+ return IRQ_NONE;
+
+ if (unlikely(reg_num < 0 ||
+ reg_num >= vsoc_dev.layout->region_count)) {
+ dev_err(&vsoc_dev.dev->dev,
+ "invalid irq @%p reg_num=0x%04x\n",
+ region_data, reg_num);
+ return IRQ_NONE;
+ }
+ if (unlikely(vsoc_dev.regions_data + reg_num != region_data)) {
+ dev_err(&vsoc_dev.dev->dev,
+ "irq not aligned @%p reg_num=0x%04x\n",
+ region_data, reg_num);
+ return IRQ_NONE;
+ }
+ wake_up_interruptible(&region_data->interrupt_wait_queue);
+ return IRQ_HANDLED;
+}
+
+static int vsoc_probe_device(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ int result;
+ int i;
+ resource_size_t reg_size;
+ dev_t devt;
+
+ vsoc_dev.dev = pdev;
+ result = pci_enable_device(pdev);
+ if (result) {
+ dev_err(&pdev->dev,
+ "pci_enable_device failed %s: error %d\n",
+ pci_name(pdev), result);
+ return result;
+ }
+ vsoc_dev.enabled_device = 1;
+ result = pci_request_regions(pdev, "vsoc");
+ if (result < 0) {
+ dev_err(&pdev->dev, "pci_request_regions failed\n");
+ vsoc_remove_device(pdev);
+ return -EBUSY;
+ }
+ vsoc_dev.requested_regions = 1;
+ /* Set up the control registers in BAR 0 */
+ reg_size = pci_resource_len(pdev, REGISTER_BAR);
+ if (reg_size > MAX_REGISTER_BAR_LEN)
+ vsoc_dev.regs =
+ pci_iomap(pdev, REGISTER_BAR, MAX_REGISTER_BAR_LEN);
+ else
+ vsoc_dev.regs = pci_iomap(pdev, REGISTER_BAR, reg_size);
+
+ if (!vsoc_dev.regs) {
+ dev_err(&pdev->dev,
+ "cannot ioremap registers of size %zu\n",
+ (size_t)reg_size);
+ vsoc_remove_device(pdev);
+ return -EBUSY;
+ }
+
+ /* Map the shared memory in BAR 2 */
+ vsoc_dev.shm_phys_start = pci_resource_start(pdev, SHARED_MEMORY_BAR);
+ vsoc_dev.shm_size = pci_resource_len(pdev, SHARED_MEMORY_BAR);
+
+ dev_info(&pdev->dev, "shared memory @ DMA %p size=0x%zx\n",
+ (void *)vsoc_dev.shm_phys_start, vsoc_dev.shm_size);
+ /* TODO(ghartman): ioremap_wc should work here */
+ vsoc_dev.kernel_mapped_shm = ioremap_nocache(
+ vsoc_dev.shm_phys_start, vsoc_dev.shm_size);
+ if (!vsoc_dev.kernel_mapped_shm) {
+ dev_err(&vsoc_dev.dev->dev, "cannot iomap region\n");
+ vsoc_remove_device(pdev);
+ return -EBUSY;
+ }
+
+ vsoc_dev.layout =
+ (struct vsoc_shm_layout_descriptor *)vsoc_dev.kernel_mapped_shm;
+ dev_info(&pdev->dev, "major_version: %d\n",
+ vsoc_dev.layout->major_version);
+ dev_info(&pdev->dev, "minor_version: %d\n",
+ vsoc_dev.layout->minor_version);
+ dev_info(&pdev->dev, "size: 0x%x\n", vsoc_dev.layout->size);
+ dev_info(&pdev->dev, "regions: %d\n", vsoc_dev.layout->region_count);
+ if (vsoc_dev.layout->major_version !=
+ CURRENT_VSOC_LAYOUT_MAJOR_VERSION) {
+ dev_err(&vsoc_dev.dev->dev,
+ "driver supports only major_version %d\n",
+ CURRENT_VSOC_LAYOUT_MAJOR_VERSION);
+ vsoc_remove_device(pdev);
+ return -EBUSY;
+ }
+ result = alloc_chrdev_region(&devt, 0, vsoc_dev.layout->region_count,
+ VSOC_DEV_NAME);
+ if (result) {
+ dev_err(&vsoc_dev.dev->dev, "alloc_chrdev_region failed\n");
+ vsoc_remove_device(pdev);
+ return -EBUSY;
+ }
+ vsoc_dev.major = MAJOR(devt);
+ cdev_init(&vsoc_dev.cdev, &vsoc_ops);
+ vsoc_dev.cdev.owner = THIS_MODULE;
+ result = cdev_add(&vsoc_dev.cdev, devt, vsoc_dev.layout->region_count);
+ if (result) {
+ dev_err(&vsoc_dev.dev->dev, "cdev_add error\n");
+ vsoc_remove_device(pdev);
+ return -EBUSY;
+ }
+ vsoc_dev.cdev_added = 1;
+ vsoc_dev.class = class_create(THIS_MODULE, VSOC_DEV_NAME);
+ if (!vsoc_dev.class) {
+ dev_err(&vsoc_dev.dev->dev, "class_create failed\n");
+ vsoc_remove_device(pdev);
+ return -EBUSY;
+ }
+ vsoc_dev.regions = (struct vsoc_device_region *)
+ (vsoc_dev.kernel_mapped_shm +
+ vsoc_dev.layout->vsoc_region_desc_offset);
+ vsoc_dev.msix_entries = kcalloc(
+ vsoc_dev.layout->region_count,
+ sizeof(vsoc_dev.msix_entries[0]), GFP_KERNEL);
+ if (!vsoc_dev.msix_entries) {
+ dev_err(&vsoc_dev.dev->dev,
+ "unable to allocate msix_entries\n");
+ vsoc_remove_device(pdev);
+ return -ENOSPC;
+ }
+ vsoc_dev.regions_data = kcalloc(
+ vsoc_dev.layout->region_count,
+ sizeof(vsoc_dev.regions_data[0]), GFP_KERNEL);
+ if (!vsoc_dev.regions_data) {
+ dev_err(&vsoc_dev.dev->dev,
+ "unable to allocate regions' data\n");
+ vsoc_remove_device(pdev);
+ return -ENOSPC;
+ }
+ for (i = 0; i < vsoc_dev.layout->region_count; ++i)
+ vsoc_dev.msix_entries[i].entry = i;
+
+ result = pci_enable_msix_exact(vsoc_dev.dev, vsoc_dev.msix_entries,
+ vsoc_dev.layout->region_count);
+ if (result) {
+ dev_info(&pdev->dev, "pci_enable_msix failed: %d\n", result);
+ vsoc_remove_device(pdev);
+ return -ENOSPC;
+ }
+ /* Check that all regions are well formed */
+ for (i = 0; i < vsoc_dev.layout->region_count; ++i) {
+ const struct vsoc_device_region *region = vsoc_dev.regions + i;
+
+ if (!PAGE_ALIGNED(region->region_begin_offset) ||
+ !PAGE_ALIGNED(region->region_end_offset)) {
+ dev_err(&vsoc_dev.dev->dev,
+ "region %d not aligned (%x:%x)", i,
+ region->region_begin_offset,
+ region->region_end_offset);
+ vsoc_remove_device(pdev);
+ return -EFAULT;
+ }
+ if (region->region_begin_offset >= region->region_end_offset ||
+ region->region_end_offset > vsoc_dev.shm_size) {
+ dev_err(&vsoc_dev.dev->dev,
+ "region %d offsets are wrong: %x %x %zx",
+ i, region->region_begin_offset,
+ region->region_end_offset, vsoc_dev.shm_size);
+ vsoc_remove_device(pdev);
+ return -EFAULT;
+ }
+ if (region->managed_by >= vsoc_dev.layout->region_count) {
+ dev_err(&vsoc_dev.dev->dev,
+ "region %d has invalid owner: %u",
+ i, region->managed_by);
+ vsoc_remove_device(pdev);
+ return -EFAULT;
+ }
+ }
+ vsoc_dev.msix_enabled = 1;
+ for (i = 0; i < vsoc_dev.layout->region_count; ++i) {
+ const struct vsoc_device_region *region = vsoc_dev.regions + i;
+ size_t name_sz = sizeof(vsoc_dev.regions_data[i].name) - 1;
+ const struct vsoc_signal_table_layout *h_to_g_signal_table =
+ &region->host_to_guest_signal_table;
+ const struct vsoc_signal_table_layout *g_to_h_signal_table =
+ &region->guest_to_host_signal_table;
+
+ vsoc_dev.regions_data[i].name[name_sz] = '\0';
+ memcpy(vsoc_dev.regions_data[i].name, region->device_name,
+ name_sz);
+ dev_info(&pdev->dev, "region %d name=%s\n",
+ i, vsoc_dev.regions_data[i].name);
+ init_waitqueue_head(
+ &vsoc_dev.regions_data[i].interrupt_wait_queue);
+ init_waitqueue_head(&vsoc_dev.regions_data[i].futex_wait_queue);
+ vsoc_dev.regions_data[i].incoming_signalled =
+ vsoc_dev.kernel_mapped_shm +
+ region->region_begin_offset +
+ h_to_g_signal_table->interrupt_signalled_offset;
+ vsoc_dev.regions_data[i].outgoing_signalled =
+ vsoc_dev.kernel_mapped_shm +
+ region->region_begin_offset +
+ g_to_h_signal_table->interrupt_signalled_offset;
+
+ result = request_irq(
+ vsoc_dev.msix_entries[i].vector,
+ vsoc_interrupt, 0,
+ vsoc_dev.regions_data[i].name,
+ vsoc_dev.regions_data + i);
+ if (result) {
+ dev_info(&pdev->dev,
+ "request_irq failed irq=%d vector=%d\n",
+ i, vsoc_dev.msix_entries[i].vector);
+ vsoc_remove_device(pdev);
+ return -ENOSPC;
+ }
+ vsoc_dev.regions_data[i].irq_requested = 1;
+ if (!device_create(vsoc_dev.class, NULL,
+ MKDEV(vsoc_dev.major, i),
+ NULL, vsoc_dev.regions_data[i].name)) {
+ dev_err(&vsoc_dev.dev->dev, "device_create failed\n");
+ vsoc_remove_device(pdev);
+ return -EBUSY;
+ }
+ vsoc_dev.regions_data[i].device_created = 1;
+ }
+ return 0;
+}
+
+/*
+ * This should undo all of the allocations in the probe function in reverse
+ * order.
+ *
+ * Notes:
+ *
+ * The device may have been partially initialized, so double check
+ * that the allocations happened.
+ *
+ * This function may be called multiple times, so mark resources as freed
+ * as they are deallocated.
+ */
+static void vsoc_remove_device(struct pci_dev *pdev)
+{
+ int i;
+ /*
+ * pdev is the first thing to be set on probe and the last thing
+ * to be cleared here. If it's NULL then there is no cleanup.
+ */
+ if (!pdev || !vsoc_dev.dev)
+ return;
+ dev_info(&pdev->dev, "remove_device\n");
+ if (vsoc_dev.regions_data) {
+ for (i = 0; i < vsoc_dev.layout->region_count; ++i) {
+ if (vsoc_dev.regions_data[i].device_created) {
+ device_destroy(vsoc_dev.class,
+ MKDEV(vsoc_dev.major, i));
+ vsoc_dev.regions_data[i].device_created = 0;
+ }
+ if (vsoc_dev.regions_data[i].irq_requested)
+ free_irq(vsoc_dev.msix_entries[i].vector, NULL);
+ vsoc_dev.regions_data[i].irq_requested = 0;
+ }
+ kfree(vsoc_dev.regions_data);
+ vsoc_dev.regions_data = 0;
+ }
+ if (vsoc_dev.msix_enabled) {
+ pci_disable_msix(pdev);
+ vsoc_dev.msix_enabled = 0;
+ }
+ kfree(vsoc_dev.msix_entries);
+ vsoc_dev.msix_entries = 0;
+ vsoc_dev.regions = 0;
+ if (vsoc_dev.class) {
+ class_destroy(vsoc_dev.class);
+ vsoc_dev.class = 0;
+ }
+ if (vsoc_dev.cdev_added) {
+ cdev_del(&vsoc_dev.cdev);
+ vsoc_dev.cdev_added = 0;
+ }
+ if (vsoc_dev.major && vsoc_dev.layout) {
+ unregister_chrdev_region(MKDEV(vsoc_dev.major, 0),
+ vsoc_dev.layout->region_count);
+ vsoc_dev.major = 0;
+ }
+ vsoc_dev.layout = 0;
+ if (vsoc_dev.kernel_mapped_shm && pdev) {
+ pci_iounmap(pdev, vsoc_dev.kernel_mapped_shm);
+ vsoc_dev.kernel_mapped_shm = 0;
+ }
+ if (vsoc_dev.regs && pdev) {
+ pci_iounmap(pdev, vsoc_dev.regs);
+ vsoc_dev.regs = 0;
+ }
+ if (vsoc_dev.requested_regions && pdev) {
+ pci_release_regions(pdev);
+ vsoc_dev.requested_regions = 0;
+ }
+ if (vsoc_dev.enabled_device && pdev) {
+ pci_disable_device(pdev);
+ vsoc_dev.enabled_device = 0;
+ }
+ /* Do this last: it indicates that the device is not initialized. */
+ vsoc_dev.dev = NULL;
+}
+
+static void __exit vsoc_cleanup_module(void)
+{
+ vsoc_remove_device(vsoc_dev.dev);
+ pci_unregister_driver(&vsoc_pci_driver);
+}
+
+static int __init vsoc_init_module(void)
+{
+ int err = -ENOMEM;
+
+ INIT_LIST_HEAD(&vsoc_dev.permissions);
+ mutex_init(&vsoc_dev.mtx);
+
+ err = pci_register_driver(&vsoc_pci_driver);
+ if (err < 0)
+ return err;
+ return 0;
+}
+
+static int vsoc_open(struct inode *inode, struct file *filp)
+{
+ /* Can't use vsoc_validate_filep because filp is still incomplete */
+ int ret = vsoc_validate_inode(inode);
+
+ if (ret)
+ return ret;
+ filp->private_data =
+ kzalloc(sizeof(struct vsoc_private_data), GFP_KERNEL);
+ if (!filp->private_data)
+ return -ENOMEM;
+ return 0;
+}
+
+static int vsoc_release(struct inode *inode, struct file *filp)
+{
+ struct vsoc_private_data *private_data = NULL;
+ struct fd_scoped_permission_node *node = NULL;
+ struct vsoc_device_region *owner_region_p = NULL;
+ int retval = vsoc_validate_filep(filp);
+
+ if (retval)
+ return retval;
+ private_data = (struct vsoc_private_data *)filp->private_data;
+ if (!private_data)
+ return 0;
+
+ node = private_data->fd_scoped_permission_node;
+ if (node) {
+ owner_region_p = vsoc_region_from_inode(inode);
+ if (owner_region_p->managed_by != VSOC_REGION_WHOLE) {
+ owner_region_p =
+ &vsoc_dev.regions[owner_region_p->managed_by];
+ }
+ do_destroy_fd_scoped_permission_node(owner_region_p, node);
+ private_data->fd_scoped_permission_node = NULL;
+ }
+ kfree(private_data);
+ filp->private_data = NULL;
+
+ return 0;
+}
+
+/*
+ * Returns the device relative offset and length of the area specified by the
+ * fd scoped permission. If there is no fd scoped permission set, a default
+ * permission covering the entire region is assumed, unless the region is owned
+ * by another one, in which case the default is a permission with zero size.
+ */
+static ssize_t vsoc_get_area(struct file *filp, __u32 *area_offset)
+{
+ __u32 off = 0;
+ ssize_t length = 0;
+ struct vsoc_device_region *region_p;
+ struct fd_scoped_permission *perm;
+
+ region_p = vsoc_region_from_filep(filp);
+ off = region_p->region_begin_offset;
+ perm = &((struct vsoc_private_data *)filp->private_data)->
+ fd_scoped_permission_node->permission;
+ if (perm) {
+ off += perm->begin_offset;
+ length = perm->end_offset - perm->begin_offset;
+ } else if (region_p->managed_by == VSOC_REGION_WHOLE) {
+ /* No permission set and the regions is not owned by another,
+ * default to full region access.
+ */
+ length = vsoc_device_region_size(region_p);
+ } else {
+ /* return zero length, access is denied. */
+ length = 0;
+ }
+ if (area_offset)
+ *area_offset = off;
+ return length;
+}
+
+static int vsoc_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ unsigned long len = vma->vm_end - vma->vm_start;
+ __u32 area_off;
+ phys_addr_t mem_off;
+ ssize_t area_len;
+ int retval = vsoc_validate_filep(filp);
+
+ if (retval)
+ return retval;
+ area_len = vsoc_get_area(filp, &area_off);
+ /* Add the requested offset */
+ area_off += (vma->vm_pgoff << PAGE_SHIFT);
+ area_len -= (vma->vm_pgoff << PAGE_SHIFT);
+ if (area_len < len)
+ return -EINVAL;
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ mem_off = shm_off_to_phys_addr(area_off);
+ if (io_remap_pfn_range(vma, vma->vm_start, mem_off >> PAGE_SHIFT,
+ len, vma->vm_page_prot))
+ return -EAGAIN;
+ return 0;
+}
+
+module_init(vsoc_init_module);
+module_exit(vsoc_cleanup_module);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Greg Hartman <ghartman@google.com>");
+MODULE_DESCRIPTION("VSoC interpretation of QEmu's ivshmem device");
+MODULE_VERSION("1.0");
--
2.17.0.484.g0c8726318c-goog
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