diff options
Diffstat (limited to 'drivers/platform/goldfish/goldfish_pipe.c')
| -rw-r--r-- | drivers/platform/goldfish/goldfish_pipe.c | 169 |
1 files changed, 107 insertions, 62 deletions
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c index 9f6734ce1873..9973cebb4d6f 100644 --- a/drivers/platform/goldfish/goldfish_pipe.c +++ b/drivers/platform/goldfish/goldfish_pipe.c @@ -2,6 +2,7 @@ * Copyright (C) 2011 Google, Inc. * Copyright (C) 2012 Intel, Inc. * Copyright (C) 2013 Intel, Inc. + * Copyright (C) 2014 Linaro Limited * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and @@ -58,6 +59,8 @@ #include <linux/io.h> #include <linux/goldfish.h> #include <linux/dma-mapping.h> +#include <linux/mm.h> +#include <linux/acpi.h> /* * IMPORTANT: The following constants must match the ones used and defined @@ -76,6 +79,7 @@ #define PIPE_REG_PARAMS_ADDR_LOW 0x18 /* read/write: batch data address */ #define PIPE_REG_PARAMS_ADDR_HIGH 0x1c /* read/write: batch data address */ #define PIPE_REG_ACCESS_PARAMS 0x20 /* write: batch access */ +#define PIPE_REG_VERSION 0x24 /* read: device version */ /* list of commands for PIPE_REG_COMMAND */ #define CMD_OPEN 1 /* open new channel */ @@ -91,12 +95,6 @@ #define CMD_WRITE_BUFFER 4 /* send a user buffer to the emulator */ #define CMD_WAKE_ON_WRITE 5 /* tell the emulator to wake us when writing is possible */ - -/* The following commands are related to read operations, they must be - * listed in the same order than the corresponding write ones, since we - * will use (CMD_READ_BUFFER - CMD_WRITE_BUFFER) as a special offset - * in goldfish_pipe_read_write() below. - */ #define CMD_READ_BUFFER 6 /* receive a user buffer from the emulator */ #define CMD_WAKE_ON_READ 7 /* tell the emulator to wake us when reading * is possible */ @@ -131,6 +129,7 @@ struct goldfish_pipe_dev { unsigned char __iomem *base; struct access_params *aps; int irq; + u32 version; }; static struct goldfish_pipe_dev pipe_dev[1]; @@ -263,19 +262,14 @@ static int access_with_param(struct goldfish_pipe_dev *dev, const int cmd, return 0; } -/* This function is used for both reading from and writing to a given - * pipe. - */ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, - size_t bufflen, int is_write) + size_t bufflen, int is_write) { unsigned long irq_flags; struct goldfish_pipe *pipe = filp->private_data; struct goldfish_pipe_dev *dev = pipe->dev; - const int cmd_offset = is_write ? 0 - : (CMD_READ_BUFFER - CMD_WRITE_BUFFER); unsigned long address, address_end; - int ret = 0; + int count = 0, ret = -EINVAL; /* If the emulator already closed the pipe, no need to go further */ if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags)) @@ -298,79 +292,107 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, address_end = address + bufflen; while (address < address_end) { - unsigned long page_end = (address & PAGE_MASK) + PAGE_SIZE; - unsigned long next = page_end < address_end ? page_end - : address_end; - unsigned long avail = next - address; + unsigned long page_end = (address & PAGE_MASK) + PAGE_SIZE; + unsigned long next = page_end < address_end ? page_end + : address_end; + unsigned long avail = next - address; int status, wakeBit; + struct page *page; + + /* Either vaddr or paddr depending on the device version */ + unsigned long xaddr; + + /* + * We grab the pages on a page-by-page basis in case user + * space gives us a potentially huge buffer but the read only + * returns a small amount, then there's no need to pin that + * much memory to the process. + */ + down_read(¤t->mm->mmap_sem); + ret = get_user_pages(current, current->mm, address, 1, + !is_write, 0, &page, NULL); + up_read(¤t->mm->mmap_sem); + if (ret < 0) + break; - /* Ensure that the corresponding page is properly mapped */ - /* FIXME: this isn't safe or sufficient - use get_user_pages */ - if (is_write) { - char c; - /* Ensure that the page is mapped and readable */ - if (__get_user(c, (char __user *)address)) { - if (!ret) - ret = -EFAULT; - break; - } + if (dev->version) { + /* Device version 1 or newer (qemu-android) expects the + * physical address. + */ + xaddr = page_to_phys(page) | (address & ~PAGE_MASK); } else { - /* Ensure that the page is mapped and writable */ - if (__put_user(0, (char __user *)address)) { - if (!ret) - ret = -EFAULT; - break; - } + /* Device version 0 (classic emulator) expects the + * virtual address. + */ + xaddr = address; } /* Now, try to transfer the bytes in the current page */ spin_lock_irqsave(&dev->lock, irq_flags); - if (access_with_param(dev, CMD_WRITE_BUFFER + cmd_offset, - address, avail, pipe, &status)) { + if (access_with_param(dev, + is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER, + xaddr, avail, pipe, &status)) { gf_write_ptr(pipe, dev->base + PIPE_REG_CHANNEL, dev->base + PIPE_REG_CHANNEL_HIGH); writel(avail, dev->base + PIPE_REG_SIZE); - gf_write_ptr((void *)address, + gf_write_ptr((void *)xaddr, dev->base + PIPE_REG_ADDRESS, dev->base + PIPE_REG_ADDRESS_HIGH); - writel(CMD_WRITE_BUFFER + cmd_offset, + writel(is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER, dev->base + PIPE_REG_COMMAND); status = readl(dev->base + PIPE_REG_STATUS); } spin_unlock_irqrestore(&dev->lock, irq_flags); + if (status > 0 && !is_write) + set_page_dirty(page); + put_page(page); + if (status > 0) { /* Correct transfer */ - ret += status; + count += status; address += status; continue; - } - - if (status == 0) /* EOF */ + } else if (status == 0) { /* EOF */ + ret = 0; break; - - /* An error occured. If we already transfered stuff, just - * return with its count. We expect the next call to return - * an error code */ - if (ret > 0) + } else if (status < 0 && count > 0) { + /* + * An error occurred and we already transferred + * something on one of the previous pages. + * Just return what we already copied and log this + * err. + * + * Note: This seems like an incorrect approach but + * cannot change it until we check if any user space + * ABI relies on this behavior. + */ + if (status != PIPE_ERROR_AGAIN) + pr_info_ratelimited("goldfish_pipe: backend returned error %d on %s\n", + status, is_write ? "write" : "read"); + ret = 0; break; + } - /* If the error is not PIPE_ERROR_AGAIN, or if we are not in - * non-blocking mode, just return the error code. - */ + /* + * If the error is not PIPE_ERROR_AGAIN, or if we are not in + * non-blocking mode, just return the error code. + */ if (status != PIPE_ERROR_AGAIN || (filp->f_flags & O_NONBLOCK) != 0) { ret = goldfish_pipe_error_convert(status); break; } - /* We will have to wait until more data/space is available. - * First, mark the pipe as waiting for a specific wake signal. - */ + /* + * The backend blocked the read/write, wait until the backend + * tells us it's ready to process more data. + */ wakeBit = is_write ? BIT_WAKE_ON_WRITE : BIT_WAKE_ON_READ; set_bit(wakeBit, &pipe->flags); /* Tell the emulator we're going to wait for a wake event */ - goldfish_cmd(pipe, CMD_WAKE_ON_WRITE + cmd_offset); + goldfish_cmd(pipe, + is_write ? CMD_WAKE_ON_WRITE : CMD_WAKE_ON_READ); /* Unlock the pipe, then wait for the wake signal */ mutex_unlock(&pipe->lock); @@ -388,12 +410,13 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, /* Try to re-acquire the lock */ if (mutex_lock_interruptible(&pipe->lock)) return -ERESTARTSYS; - - /* Try the transfer again */ - continue; } mutex_unlock(&pipe->lock); - return ret; + + if (ret < 0) + return ret; + else + return count; } static ssize_t goldfish_pipe_read(struct file *filp, char __user *buffer, @@ -446,10 +469,11 @@ static irqreturn_t goldfish_pipe_interrupt(int irq, void *dev_id) unsigned long irq_flags; int count = 0; - /* We're going to read from the emulator a list of (channel,flags) - * pairs corresponding to the wake events that occured on each - * blocked pipe (i.e. channel). - */ + /* + * We're going to read from the emulator a list of (channel,flags) + * pairs corresponding to the wake events that occurred on each + * blocked pipe (i.e. channel). + */ spin_lock_irqsave(&dev->lock, irq_flags); for (;;) { /* First read the channel, 0 means the end of the list */ @@ -600,6 +624,12 @@ static int goldfish_pipe_probe(struct platform_device *pdev) goto error; } setup_access_params_addr(pdev, dev); + + /* Although the pipe device in the classic Android emulator does not + * recognize the 'version' register, it won't treat this as an error + * either and will simply return 0, which is fine. + */ + dev->version = readl(dev->base + PIPE_REG_VERSION); return 0; error: @@ -615,11 +645,26 @@ static int goldfish_pipe_remove(struct platform_device *pdev) 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 = { .probe = goldfish_pipe_probe, .remove = goldfish_pipe_remove, .driver = { - .name = "goldfish_pipe" + .name = "goldfish_pipe", + .owner = THIS_MODULE, + .of_match_table = goldfish_pipe_of_match, + .acpi_match_table = ACPI_PTR(goldfish_pipe_acpi_match), } }; |