forked from Minki/linux
73b0140bf0
To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Mike Marshall <hubcap@omnibond.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
970 lines
26 KiB
C
970 lines
26 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2012 Intel, Inc.
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* Copyright (C) 2013 Intel, Inc.
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* Copyright (C) 2014 Linaro Limited
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* Copyright (C) 2011-2016 Google, Inc.
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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/* This source file contains the implementation of a special device driver
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* that intends to provide a *very* fast communication channel between the
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* guest system and the QEMU emulator.
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*
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* Usage from the guest is simply the following (error handling simplified):
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*
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* int fd = open("/dev/qemu_pipe",O_RDWR);
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* .... write() or read() through the pipe.
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*
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* This driver doesn't deal with the exact protocol used during the session.
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* It is intended to be as simple as something like:
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*
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* // do this _just_ after opening the fd to connect to a specific
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* // emulator service.
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* const char* msg = "<pipename>";
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* if (write(fd, msg, strlen(msg)+1) < 0) {
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* ... could not connect to <pipename> service
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* close(fd);
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* }
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*
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* // after this, simply read() and write() to communicate with the
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* // service. Exact protocol details left as an exercise to the reader.
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*
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* This driver is very fast because it doesn't copy any data through
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* intermediate buffers, since the emulator is capable of translating
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* guest user addresses into host ones.
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*
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* Note that we must however ensure that each user page involved in the
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* exchange is properly mapped during a transfer.
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*/
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/spinlock.h>
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#include <linux/miscdevice.h>
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#include <linux/platform_device.h>
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#include <linux/poll.h>
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#include <linux/sched.h>
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#include <linux/bitops.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/dma-mapping.h>
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#include <linux/mm.h>
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#include <linux/acpi.h>
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#include <linux/bug.h>
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#include "goldfish_pipe_qemu.h"
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/*
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* Update this when something changes in the driver's behavior so the host
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* can benefit from knowing it
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*/
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enum {
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PIPE_DRIVER_VERSION = 2,
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PIPE_CURRENT_DEVICE_VERSION = 2
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};
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enum {
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MAX_BUFFERS_PER_COMMAND = 336,
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MAX_SIGNALLED_PIPES = 64,
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INITIAL_PIPES_CAPACITY = 64
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};
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struct goldfish_pipe_dev;
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/* A per-pipe command structure, shared with the host */
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struct goldfish_pipe_command {
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s32 cmd; /* PipeCmdCode, guest -> host */
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s32 id; /* pipe id, guest -> host */
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s32 status; /* command execution status, host -> guest */
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s32 reserved; /* to pad to 64-bit boundary */
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union {
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/* Parameters for PIPE_CMD_{READ,WRITE} */
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struct {
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/* number of buffers, guest -> host */
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u32 buffers_count;
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/* number of consumed bytes, host -> guest */
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s32 consumed_size;
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/* buffer pointers, guest -> host */
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u64 ptrs[MAX_BUFFERS_PER_COMMAND];
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/* buffer sizes, guest -> host */
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u32 sizes[MAX_BUFFERS_PER_COMMAND];
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} rw_params;
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};
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};
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/* A single signalled pipe information */
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struct signalled_pipe_buffer {
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u32 id;
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u32 flags;
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};
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/* Parameters for the PIPE_CMD_OPEN command */
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struct open_command_param {
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u64 command_buffer_ptr;
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u32 rw_params_max_count;
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};
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/* Device-level set of buffers shared with the host */
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struct goldfish_pipe_dev_buffers {
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struct open_command_param open_command_params;
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struct signalled_pipe_buffer
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signalled_pipe_buffers[MAX_SIGNALLED_PIPES];
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};
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/* This data type models a given pipe instance */
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struct goldfish_pipe {
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/* pipe ID - index into goldfish_pipe_dev::pipes array */
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u32 id;
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/* The wake flags pipe is waiting for
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* Note: not protected with any lock, uses atomic operations
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* and barriers to make it thread-safe.
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*/
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unsigned long flags;
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/* wake flags host have signalled,
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* - protected by goldfish_pipe_dev::lock
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*/
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unsigned long signalled_flags;
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/* A pointer to command buffer */
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struct goldfish_pipe_command *command_buffer;
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/* doubly linked list of signalled pipes, protected by
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* goldfish_pipe_dev::lock
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*/
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struct goldfish_pipe *prev_signalled;
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struct goldfish_pipe *next_signalled;
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/*
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* A pipe's own lock. Protects the following:
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* - *command_buffer - makes sure a command can safely write its
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* parameters to the host and read the results back.
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*/
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struct mutex lock;
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/* A wake queue for sleeping until host signals an event */
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wait_queue_head_t wake_queue;
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/* Pointer to the parent goldfish_pipe_dev instance */
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struct goldfish_pipe_dev *dev;
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/* A buffer of pages, too large to fit into a stack frame */
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struct page *pages[MAX_BUFFERS_PER_COMMAND];
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};
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/* The global driver data. Holds a reference to the i/o page used to
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* communicate with the emulator, and a wake queue for blocked tasks
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* waiting to be awoken.
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*/
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struct goldfish_pipe_dev {
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/* A magic number to check if this is an instance of this struct */
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void *magic;
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/*
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* Global device spinlock. Protects the following members:
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* - pipes, pipes_capacity
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* - [*pipes, *pipes + pipes_capacity) - array data
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* - first_signalled_pipe,
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* goldfish_pipe::prev_signalled,
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* goldfish_pipe::next_signalled,
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* goldfish_pipe::signalled_flags - all singnalled-related fields,
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* in all allocated pipes
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* - open_command_params - PIPE_CMD_OPEN-related buffers
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*
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* It looks like a lot of different fields, but the trick is that
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* the only operation that happens often is the signalled pipes array
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* manipulation. That's why it's OK for now to keep the rest of the
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* fields under the same lock. If we notice too much contention because
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* of PIPE_CMD_OPEN, then we should add a separate lock there.
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*/
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spinlock_t lock;
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/*
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* Array of the pipes of |pipes_capacity| elements,
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* indexed by goldfish_pipe::id
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*/
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struct goldfish_pipe **pipes;
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u32 pipes_capacity;
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/* Pointers to the buffers host uses for interaction with this driver */
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struct goldfish_pipe_dev_buffers *buffers;
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/* Head of a doubly linked list of signalled pipes */
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struct goldfish_pipe *first_signalled_pipe;
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/* ptr to platform device's device struct */
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struct device *pdev_dev;
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/* Some device-specific data */
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int irq;
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int version;
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unsigned char __iomem *base;
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/* an irq tasklet to run goldfish_interrupt_task */
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struct tasklet_struct irq_tasklet;
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struct miscdevice miscdev;
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};
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static int goldfish_pipe_cmd_locked(struct goldfish_pipe *pipe,
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enum PipeCmdCode cmd)
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{
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pipe->command_buffer->cmd = cmd;
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/* failure by default */
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pipe->command_buffer->status = PIPE_ERROR_INVAL;
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writel(pipe->id, pipe->dev->base + PIPE_REG_CMD);
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return pipe->command_buffer->status;
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}
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static int goldfish_pipe_cmd(struct goldfish_pipe *pipe, enum PipeCmdCode cmd)
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{
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int status;
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if (mutex_lock_interruptible(&pipe->lock))
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return PIPE_ERROR_IO;
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status = goldfish_pipe_cmd_locked(pipe, cmd);
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mutex_unlock(&pipe->lock);
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return status;
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}
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/*
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* This function converts an error code returned by the emulator through
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* the PIPE_REG_STATUS i/o register into a valid negative errno value.
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*/
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static int goldfish_pipe_error_convert(int status)
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{
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switch (status) {
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case PIPE_ERROR_AGAIN:
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return -EAGAIN;
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case PIPE_ERROR_NOMEM:
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return -ENOMEM;
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case PIPE_ERROR_IO:
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return -EIO;
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default:
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return -EINVAL;
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}
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}
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static int pin_user_pages(unsigned long first_page,
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unsigned long last_page,
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unsigned int last_page_size,
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int is_write,
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struct page *pages[MAX_BUFFERS_PER_COMMAND],
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unsigned int *iter_last_page_size)
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{
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int ret;
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int requested_pages = ((last_page - first_page) >> PAGE_SHIFT) + 1;
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if (requested_pages > MAX_BUFFERS_PER_COMMAND) {
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requested_pages = MAX_BUFFERS_PER_COMMAND;
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*iter_last_page_size = PAGE_SIZE;
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} else {
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*iter_last_page_size = last_page_size;
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}
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ret = get_user_pages_fast(first_page, requested_pages,
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!is_write ? FOLL_WRITE : 0,
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pages);
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if (ret <= 0)
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return -EFAULT;
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if (ret < requested_pages)
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*iter_last_page_size = PAGE_SIZE;
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return ret;
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}
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static void release_user_pages(struct page **pages, int pages_count,
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int is_write, s32 consumed_size)
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{
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int i;
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for (i = 0; i < pages_count; i++) {
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if (!is_write && consumed_size > 0)
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set_page_dirty(pages[i]);
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put_page(pages[i]);
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}
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}
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/* Populate the call parameters, merging adjacent pages together */
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static void populate_rw_params(struct page **pages,
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int pages_count,
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unsigned long address,
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unsigned long address_end,
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unsigned long first_page,
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unsigned long last_page,
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unsigned int iter_last_page_size,
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int is_write,
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struct goldfish_pipe_command *command)
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{
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/*
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* Process the first page separately - it's the only page that
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* needs special handling for its start address.
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*/
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unsigned long xaddr = page_to_phys(pages[0]);
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unsigned long xaddr_prev = xaddr;
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int buffer_idx = 0;
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int i = 1;
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int size_on_page = first_page == last_page
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? (int)(address_end - address)
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: (PAGE_SIZE - (address & ~PAGE_MASK));
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command->rw_params.ptrs[0] = (u64)(xaddr | (address & ~PAGE_MASK));
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command->rw_params.sizes[0] = size_on_page;
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for (; i < pages_count; ++i) {
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xaddr = page_to_phys(pages[i]);
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size_on_page = (i == pages_count - 1) ?
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iter_last_page_size : PAGE_SIZE;
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if (xaddr == xaddr_prev + PAGE_SIZE) {
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command->rw_params.sizes[buffer_idx] += size_on_page;
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} else {
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++buffer_idx;
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command->rw_params.ptrs[buffer_idx] = (u64)xaddr;
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command->rw_params.sizes[buffer_idx] = size_on_page;
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}
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xaddr_prev = xaddr;
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}
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command->rw_params.buffers_count = buffer_idx + 1;
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}
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static int transfer_max_buffers(struct goldfish_pipe *pipe,
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unsigned long address,
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unsigned long address_end,
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int is_write,
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unsigned long last_page,
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unsigned int last_page_size,
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s32 *consumed_size,
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int *status)
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{
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unsigned long first_page = address & PAGE_MASK;
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unsigned int iter_last_page_size;
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int pages_count;
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/* Serialize access to the pipe command buffers */
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if (mutex_lock_interruptible(&pipe->lock))
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return -ERESTARTSYS;
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pages_count = pin_user_pages(first_page, last_page,
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last_page_size, is_write,
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pipe->pages, &iter_last_page_size);
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if (pages_count < 0) {
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mutex_unlock(&pipe->lock);
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return pages_count;
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}
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populate_rw_params(pipe->pages, pages_count, address, address_end,
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first_page, last_page, iter_last_page_size, is_write,
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pipe->command_buffer);
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/* Transfer the data */
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*status = goldfish_pipe_cmd_locked(pipe,
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is_write ? PIPE_CMD_WRITE : PIPE_CMD_READ);
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*consumed_size = pipe->command_buffer->rw_params.consumed_size;
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release_user_pages(pipe->pages, pages_count, is_write, *consumed_size);
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mutex_unlock(&pipe->lock);
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return 0;
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}
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static int wait_for_host_signal(struct goldfish_pipe *pipe, int is_write)
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{
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u32 wake_bit = is_write ? BIT_WAKE_ON_WRITE : BIT_WAKE_ON_READ;
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set_bit(wake_bit, &pipe->flags);
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/* Tell the emulator we're going to wait for a wake event */
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goldfish_pipe_cmd(pipe,
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is_write ? PIPE_CMD_WAKE_ON_WRITE : PIPE_CMD_WAKE_ON_READ);
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while (test_bit(wake_bit, &pipe->flags)) {
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if (wait_event_interruptible(pipe->wake_queue,
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!test_bit(wake_bit, &pipe->flags)))
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return -ERESTARTSYS;
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if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))
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return -EIO;
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}
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return 0;
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}
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static ssize_t goldfish_pipe_read_write(struct file *filp,
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char __user *buffer,
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size_t bufflen,
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int is_write)
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{
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struct goldfish_pipe *pipe = filp->private_data;
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int count = 0, ret = -EINVAL;
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unsigned long address, address_end, last_page;
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unsigned int last_page_size;
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/* If the emulator already closed the pipe, no need to go further */
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if (unlikely(test_bit(BIT_CLOSED_ON_HOST, &pipe->flags)))
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return -EIO;
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/* Null reads or writes succeeds */
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if (unlikely(bufflen == 0))
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return 0;
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/* Check the buffer range for access */
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if (unlikely(!access_ok(buffer, bufflen)))
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return -EFAULT;
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address = (unsigned long)buffer;
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address_end = address + bufflen;
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last_page = (address_end - 1) & PAGE_MASK;
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last_page_size = ((address_end - 1) & ~PAGE_MASK) + 1;
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while (address < address_end) {
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s32 consumed_size;
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int status;
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ret = transfer_max_buffers(pipe, address, address_end, is_write,
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last_page, last_page_size,
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&consumed_size, &status);
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if (ret < 0)
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break;
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if (consumed_size > 0) {
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/* No matter what's the status, we've transferred
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* something.
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*/
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count += consumed_size;
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address += consumed_size;
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}
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if (status > 0)
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continue;
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if (status == 0) {
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/* EOF */
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ret = 0;
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break;
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}
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if (count > 0) {
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/*
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* An error occurred, but we already transferred
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* something on one of the previous iterations.
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* Just return what we already copied and log this
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* err.
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*/
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if (status != PIPE_ERROR_AGAIN)
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dev_err_ratelimited(pipe->dev->pdev_dev,
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"backend error %d on %s\n",
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status, is_write ? "write" : "read");
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break;
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}
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/*
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* If the error is not PIPE_ERROR_AGAIN, or if we are in
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* non-blocking mode, just return the error code.
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*/
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if (status != PIPE_ERROR_AGAIN ||
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(filp->f_flags & O_NONBLOCK) != 0) {
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ret = goldfish_pipe_error_convert(status);
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break;
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}
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status = wait_for_host_signal(pipe, is_write);
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if (status < 0)
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return status;
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}
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if (count > 0)
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return count;
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return ret;
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}
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|
|
static ssize_t goldfish_pipe_read(struct file *filp, char __user *buffer,
|
|
size_t bufflen, loff_t *ppos)
|
|
{
|
|
return goldfish_pipe_read_write(filp, buffer, bufflen,
|
|
/* is_write */ 0);
|
|
}
|
|
|
|
static ssize_t goldfish_pipe_write(struct file *filp,
|
|
const char __user *buffer, size_t bufflen,
|
|
loff_t *ppos)
|
|
{
|
|
/* cast away the const */
|
|
char __user *no_const_buffer = (char __user *)buffer;
|
|
|
|
return goldfish_pipe_read_write(filp, no_const_buffer, bufflen,
|
|
/* is_write */ 1);
|
|
}
|
|
|
|
static __poll_t goldfish_pipe_poll(struct file *filp, poll_table *wait)
|
|
{
|
|
struct goldfish_pipe *pipe = filp->private_data;
|
|
__poll_t mask = 0;
|
|
int status;
|
|
|
|
poll_wait(filp, &pipe->wake_queue, wait);
|
|
|
|
status = goldfish_pipe_cmd(pipe, PIPE_CMD_POLL);
|
|
if (status < 0)
|
|
return -ERESTARTSYS;
|
|
|
|
if (status & PIPE_POLL_IN)
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
if (status & PIPE_POLL_OUT)
|
|
mask |= EPOLLOUT | EPOLLWRNORM;
|
|
if (status & PIPE_POLL_HUP)
|
|
mask |= EPOLLHUP;
|
|
if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))
|
|
mask |= EPOLLERR;
|
|
|
|
return mask;
|
|
}
|
|
|
|
static void signalled_pipes_add_locked(struct goldfish_pipe_dev *dev,
|
|
u32 id, u32 flags)
|
|
{
|
|
struct goldfish_pipe *pipe;
|
|
|
|
if (WARN_ON(id >= dev->pipes_capacity))
|
|
return;
|
|
|
|
pipe = dev->pipes[id];
|
|
if (!pipe)
|
|
return;
|
|
pipe->signalled_flags |= flags;
|
|
|
|
if (pipe->prev_signalled || pipe->next_signalled ||
|
|
dev->first_signalled_pipe == pipe)
|
|
return; /* already in the list */
|
|
pipe->next_signalled = dev->first_signalled_pipe;
|
|
if (dev->first_signalled_pipe)
|
|
dev->first_signalled_pipe->prev_signalled = pipe;
|
|
dev->first_signalled_pipe = pipe;
|
|
}
|
|
|
|
static void signalled_pipes_remove_locked(struct goldfish_pipe_dev *dev,
|
|
struct goldfish_pipe *pipe)
|
|
{
|
|
if (pipe->prev_signalled)
|
|
pipe->prev_signalled->next_signalled = pipe->next_signalled;
|
|
if (pipe->next_signalled)
|
|
pipe->next_signalled->prev_signalled = pipe->prev_signalled;
|
|
if (pipe == dev->first_signalled_pipe)
|
|
dev->first_signalled_pipe = pipe->next_signalled;
|
|
pipe->prev_signalled = NULL;
|
|
pipe->next_signalled = NULL;
|
|
}
|
|
|
|
static struct goldfish_pipe *signalled_pipes_pop_front(
|
|
struct goldfish_pipe_dev *dev, int *wakes)
|
|
{
|
|
struct goldfish_pipe *pipe;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&dev->lock, flags);
|
|
|
|
pipe = dev->first_signalled_pipe;
|
|
if (pipe) {
|
|
*wakes = pipe->signalled_flags;
|
|
pipe->signalled_flags = 0;
|
|
/*
|
|
* This is an optimized version of
|
|
* signalled_pipes_remove_locked()
|
|
* - We want to make it as fast as possible to
|
|
* wake the sleeping pipe operations faster.
|
|
*/
|
|
dev->first_signalled_pipe = pipe->next_signalled;
|
|
if (dev->first_signalled_pipe)
|
|
dev->first_signalled_pipe->prev_signalled = NULL;
|
|
pipe->next_signalled = NULL;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&dev->lock, flags);
|
|
return pipe;
|
|
}
|
|
|
|
static void goldfish_interrupt_task(unsigned long dev_addr)
|
|
{
|
|
/* Iterate over the signalled pipes and wake them one by one */
|
|
struct goldfish_pipe_dev *dev = (struct goldfish_pipe_dev *)dev_addr;
|
|
struct goldfish_pipe *pipe;
|
|
int wakes;
|
|
|
|
while ((pipe = signalled_pipes_pop_front(dev, &wakes)) != NULL) {
|
|
if (wakes & PIPE_WAKE_CLOSED) {
|
|
pipe->flags = 1 << BIT_CLOSED_ON_HOST;
|
|
} else {
|
|
if (wakes & PIPE_WAKE_READ)
|
|
clear_bit(BIT_WAKE_ON_READ, &pipe->flags);
|
|
if (wakes & PIPE_WAKE_WRITE)
|
|
clear_bit(BIT_WAKE_ON_WRITE, &pipe->flags);
|
|
}
|
|
/*
|
|
* wake_up_interruptible() implies a write barrier, so don't
|
|
* explicitly add another one here.
|
|
*/
|
|
wake_up_interruptible(&pipe->wake_queue);
|
|
}
|
|
}
|
|
|
|
static void goldfish_pipe_device_deinit(struct platform_device *pdev,
|
|
struct goldfish_pipe_dev *dev);
|
|
|
|
/*
|
|
* The general idea of the interrupt handling:
|
|
*
|
|
* 1. device raises an interrupt if there's at least one signalled pipe
|
|
* 2. IRQ handler reads the signalled pipes and their count from the device
|
|
* 3. device writes them into a shared buffer and returns the count
|
|
* it only resets the IRQ if it has returned all signalled pipes,
|
|
* otherwise it leaves it raised, so IRQ handler will be called
|
|
* again for the next chunk
|
|
* 4. IRQ handler adds all returned pipes to the device's signalled pipes list
|
|
* 5. IRQ handler launches a tasklet to process the signalled pipes from the
|
|
* list in a separate context
|
|
*/
|
|
static irqreturn_t goldfish_pipe_interrupt(int irq, void *dev_id)
|
|
{
|
|
u32 count;
|
|
u32 i;
|
|
unsigned long flags;
|
|
struct goldfish_pipe_dev *dev = dev_id;
|
|
|
|
if (dev->magic != &goldfish_pipe_device_deinit)
|
|
return IRQ_NONE;
|
|
|
|
/* Request the signalled pipes from the device */
|
|
spin_lock_irqsave(&dev->lock, flags);
|
|
|
|
count = readl(dev->base + PIPE_REG_GET_SIGNALLED);
|
|
if (count == 0) {
|
|
spin_unlock_irqrestore(&dev->lock, flags);
|
|
return IRQ_NONE;
|
|
}
|
|
if (count > MAX_SIGNALLED_PIPES)
|
|
count = MAX_SIGNALLED_PIPES;
|
|
|
|
for (i = 0; i < count; ++i)
|
|
signalled_pipes_add_locked(dev,
|
|
dev->buffers->signalled_pipe_buffers[i].id,
|
|
dev->buffers->signalled_pipe_buffers[i].flags);
|
|
|
|
spin_unlock_irqrestore(&dev->lock, flags);
|
|
|
|
tasklet_schedule(&dev->irq_tasklet);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int get_free_pipe_id_locked(struct goldfish_pipe_dev *dev)
|
|
{
|
|
int id;
|
|
|
|
for (id = 0; id < dev->pipes_capacity; ++id)
|
|
if (!dev->pipes[id])
|
|
return id;
|
|
|
|
{
|
|
/* Reallocate the array.
|
|
* Since get_free_pipe_id_locked runs with interrupts disabled,
|
|
* we don't want to make calls that could lead to sleep.
|
|
*/
|
|
u32 new_capacity = 2 * dev->pipes_capacity;
|
|
struct goldfish_pipe **pipes =
|
|
kcalloc(new_capacity, sizeof(*pipes), GFP_ATOMIC);
|
|
if (!pipes)
|
|
return -ENOMEM;
|
|
memcpy(pipes, dev->pipes, sizeof(*pipes) * dev->pipes_capacity);
|
|
kfree(dev->pipes);
|
|
dev->pipes = pipes;
|
|
id = dev->pipes_capacity;
|
|
dev->pipes_capacity = new_capacity;
|
|
}
|
|
return id;
|
|
}
|
|
|
|
/* A helper function to get the instance of goldfish_pipe_dev from file */
|
|
static struct goldfish_pipe_dev *to_goldfish_pipe_dev(struct file *file)
|
|
{
|
|
struct miscdevice *miscdev = file->private_data;
|
|
|
|
return container_of(miscdev, struct goldfish_pipe_dev, miscdev);
|
|
}
|
|
|
|
/**
|
|
* goldfish_pipe_open - open a channel to the AVD
|
|
* @inode: inode of device
|
|
* @file: file struct of opener
|
|
*
|
|
* Create a new pipe link between the emulator and the use application.
|
|
* Each new request produces a new pipe.
|
|
*
|
|
* Note: we use the pipe ID as a mux. All goldfish emulations are 32bit
|
|
* right now so this is fine. A move to 64bit will need this addressing
|
|
*/
|
|
static int goldfish_pipe_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct goldfish_pipe_dev *dev = to_goldfish_pipe_dev(file);
|
|
unsigned long flags;
|
|
int id;
|
|
int status;
|
|
|
|
/* Allocate new pipe kernel object */
|
|
struct goldfish_pipe *pipe = kzalloc(sizeof(*pipe), GFP_KERNEL);
|
|
|
|
if (!pipe)
|
|
return -ENOMEM;
|
|
|
|
pipe->dev = dev;
|
|
mutex_init(&pipe->lock);
|
|
init_waitqueue_head(&pipe->wake_queue);
|
|
|
|
/*
|
|
* Command buffer needs to be allocated on its own page to make sure
|
|
* it is physically contiguous in host's address space.
|
|
*/
|
|
BUILD_BUG_ON(sizeof(struct goldfish_pipe_command) > PAGE_SIZE);
|
|
pipe->command_buffer =
|
|
(struct goldfish_pipe_command *)__get_free_page(GFP_KERNEL);
|
|
if (!pipe->command_buffer) {
|
|
status = -ENOMEM;
|
|
goto err_pipe;
|
|
}
|
|
|
|
spin_lock_irqsave(&dev->lock, flags);
|
|
|
|
id = get_free_pipe_id_locked(dev);
|
|
if (id < 0) {
|
|
status = id;
|
|
goto err_id_locked;
|
|
}
|
|
|
|
dev->pipes[id] = pipe;
|
|
pipe->id = id;
|
|
pipe->command_buffer->id = id;
|
|
|
|
/* Now tell the emulator we're opening a new pipe. */
|
|
dev->buffers->open_command_params.rw_params_max_count =
|
|
MAX_BUFFERS_PER_COMMAND;
|
|
dev->buffers->open_command_params.command_buffer_ptr =
|
|
(u64)(unsigned long)__pa(pipe->command_buffer);
|
|
status = goldfish_pipe_cmd_locked(pipe, PIPE_CMD_OPEN);
|
|
spin_unlock_irqrestore(&dev->lock, flags);
|
|
if (status < 0)
|
|
goto err_cmd;
|
|
/* All is done, save the pipe into the file's private data field */
|
|
file->private_data = pipe;
|
|
return 0;
|
|
|
|
err_cmd:
|
|
spin_lock_irqsave(&dev->lock, flags);
|
|
dev->pipes[id] = NULL;
|
|
err_id_locked:
|
|
spin_unlock_irqrestore(&dev->lock, flags);
|
|
free_page((unsigned long)pipe->command_buffer);
|
|
err_pipe:
|
|
kfree(pipe);
|
|
return status;
|
|
}
|
|
|
|
static int goldfish_pipe_release(struct inode *inode, struct file *filp)
|
|
{
|
|
unsigned long flags;
|
|
struct goldfish_pipe *pipe = filp->private_data;
|
|
struct goldfish_pipe_dev *dev = pipe->dev;
|
|
|
|
/* The guest is closing the channel, so tell the emulator right now */
|
|
goldfish_pipe_cmd(pipe, PIPE_CMD_CLOSE);
|
|
|
|
spin_lock_irqsave(&dev->lock, flags);
|
|
dev->pipes[pipe->id] = NULL;
|
|
signalled_pipes_remove_locked(dev, pipe);
|
|
spin_unlock_irqrestore(&dev->lock, flags);
|
|
|
|
filp->private_data = NULL;
|
|
free_page((unsigned long)pipe->command_buffer);
|
|
kfree(pipe);
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations goldfish_pipe_fops = {
|
|
.owner = THIS_MODULE,
|
|
.read = goldfish_pipe_read,
|
|
.write = goldfish_pipe_write,
|
|
.poll = goldfish_pipe_poll,
|
|
.open = goldfish_pipe_open,
|
|
.release = goldfish_pipe_release,
|
|
};
|
|
|
|
static void init_miscdevice(struct miscdevice *miscdev)
|
|
{
|
|
memset(miscdev, 0, sizeof(*miscdev));
|
|
|
|
miscdev->minor = MISC_DYNAMIC_MINOR;
|
|
miscdev->name = "goldfish_pipe";
|
|
miscdev->fops = &goldfish_pipe_fops;
|
|
}
|
|
|
|
static void write_pa_addr(void *addr, void __iomem *portl, void __iomem *porth)
|
|
{
|
|
const unsigned long paddr = __pa(addr);
|
|
|
|
writel(upper_32_bits(paddr), porth);
|
|
writel(lower_32_bits(paddr), portl);
|
|
}
|
|
|
|
static int goldfish_pipe_device_init(struct platform_device *pdev,
|
|
struct goldfish_pipe_dev *dev)
|
|
{
|
|
int err;
|
|
|
|
tasklet_init(&dev->irq_tasklet, &goldfish_interrupt_task,
|
|
(unsigned long)dev);
|
|
|
|
err = devm_request_irq(&pdev->dev, dev->irq,
|
|
goldfish_pipe_interrupt,
|
|
IRQF_SHARED, "goldfish_pipe", dev);
|
|
if (err) {
|
|
dev_err(&pdev->dev, "unable to allocate IRQ for v2\n");
|
|
return err;
|
|
}
|
|
|
|
init_miscdevice(&dev->miscdev);
|
|
err = misc_register(&dev->miscdev);
|
|
if (err) {
|
|
dev_err(&pdev->dev, "unable to register v2 device\n");
|
|
return err;
|
|
}
|
|
|
|
dev->pdev_dev = &pdev->dev;
|
|
dev->first_signalled_pipe = NULL;
|
|
dev->pipes_capacity = INITIAL_PIPES_CAPACITY;
|
|
dev->pipes = kcalloc(dev->pipes_capacity, sizeof(*dev->pipes),
|
|
GFP_KERNEL);
|
|
if (!dev->pipes) {
|
|
misc_deregister(&dev->miscdev);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* We're going to pass two buffers, open_command_params and
|
|
* signalled_pipe_buffers, to the host. This means each of those buffers
|
|
* needs to be contained in a single physical page. The easiest choice
|
|
* is to just allocate a page and place the buffers in it.
|
|
*/
|
|
BUILD_BUG_ON(sizeof(struct goldfish_pipe_dev_buffers) > PAGE_SIZE);
|
|
dev->buffers = (struct goldfish_pipe_dev_buffers *)
|
|
__get_free_page(GFP_KERNEL);
|
|
if (!dev->buffers) {
|
|
kfree(dev->pipes);
|
|
misc_deregister(&dev->miscdev);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Send the buffer addresses to the host */
|
|
write_pa_addr(&dev->buffers->signalled_pipe_buffers,
|
|
dev->base + PIPE_REG_SIGNAL_BUFFER,
|
|
dev->base + PIPE_REG_SIGNAL_BUFFER_HIGH);
|
|
|
|
writel(MAX_SIGNALLED_PIPES,
|
|
dev->base + PIPE_REG_SIGNAL_BUFFER_COUNT);
|
|
|
|
write_pa_addr(&dev->buffers->open_command_params,
|
|
dev->base + PIPE_REG_OPEN_BUFFER,
|
|
dev->base + PIPE_REG_OPEN_BUFFER_HIGH);
|
|
|
|
platform_set_drvdata(pdev, dev);
|
|
return 0;
|
|
}
|
|
|
|
static void goldfish_pipe_device_deinit(struct platform_device *pdev,
|
|
struct goldfish_pipe_dev *dev)
|
|
{
|
|
misc_deregister(&dev->miscdev);
|
|
tasklet_kill(&dev->irq_tasklet);
|
|
kfree(dev->pipes);
|
|
free_page((unsigned long)dev->buffers);
|
|
}
|
|
|
|
static int goldfish_pipe_probe(struct platform_device *pdev)
|
|
{
|
|
struct resource *r;
|
|
struct goldfish_pipe_dev *dev;
|
|
|
|
dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
|
|
if (!dev)
|
|
return -ENOMEM;
|
|
|
|
dev->magic = &goldfish_pipe_device_deinit;
|
|
spin_lock_init(&dev->lock);
|
|
|
|
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (!r || resource_size(r) < PAGE_SIZE) {
|
|
dev_err(&pdev->dev, "can't allocate i/o page\n");
|
|
return -EINVAL;
|
|
}
|
|
dev->base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
|
|
if (!dev->base) {
|
|
dev_err(&pdev->dev, "ioremap failed\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
|
|
if (!r)
|
|
return -EINVAL;
|
|
|
|
dev->irq = r->start;
|
|
|
|
/*
|
|
* Exchange the versions with the host device
|
|
*
|
|
* Note: v1 driver used to not report its version, so we write it before
|
|
* reading device version back: this allows the host implementation to
|
|
* detect the old driver (if there was no version write before read).
|
|
*/
|
|
writel(PIPE_DRIVER_VERSION, dev->base + PIPE_REG_VERSION);
|
|
dev->version = readl(dev->base + PIPE_REG_VERSION);
|
|
if (WARN_ON(dev->version < PIPE_CURRENT_DEVICE_VERSION))
|
|
return -EINVAL;
|
|
|
|
return goldfish_pipe_device_init(pdev, dev);
|
|
}
|
|
|
|
static int goldfish_pipe_remove(struct platform_device *pdev)
|
|
{
|
|
struct goldfish_pipe_dev *dev = platform_get_drvdata(pdev);
|
|
|
|
goldfish_pipe_device_deinit(pdev, dev);
|
|
return 0;
|
|
}
|
|
|
|
static const struct acpi_device_id goldfish_pipe_acpi_match[] = {
|
|
{ "GFSH0003", 0 },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(acpi, goldfish_pipe_acpi_match);
|
|
|
|
static const struct of_device_id goldfish_pipe_of_match[] = {
|
|
{ .compatible = "google,android-pipe", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, goldfish_pipe_of_match);
|
|
|
|
static struct platform_driver goldfish_pipe_driver = {
|
|
.probe = goldfish_pipe_probe,
|
|
.remove = goldfish_pipe_remove,
|
|
.driver = {
|
|
.name = "goldfish_pipe",
|
|
.of_match_table = goldfish_pipe_of_match,
|
|
.acpi_match_table = ACPI_PTR(goldfish_pipe_acpi_match),
|
|
}
|
|
};
|
|
|
|
module_platform_driver(goldfish_pipe_driver);
|
|
MODULE_AUTHOR("David Turner <digit@google.com>");
|
|
MODULE_LICENSE("GPL v2");
|