* [PATCH v3 2/8] android_pipe: don't be clever with #define offsets
2015-12-02 19:35 [PATCH v3 1/8] goldfish: refactor goldfish platform configs Jin Qian
@ 2015-12-02 19:35 ` Jin Qian
2015-12-02 20:11 ` Joe Perches
2015-12-02 19:35 ` [PATCH v3 3/8] android_pipe: Pin pages to memory while copying and other cleanups Jin Qian
` (5 subsequent siblings)
6 siblings, 1 reply; 10+ messages in thread
From: Jin Qian @ 2015-12-02 19:35 UTC (permalink / raw)
To: Greg Kroah-Hartman, Greg Hackmann, Joe Perches, Christoffer Dall,
Peter Senna Tschudin, Jason Hu, Alex Bennée, Yu Ning,
linux-kernel
Cc: Jin Qian
From: Alex Bennée <alex.bennee@linaro.org>
You just make it harder to figure out when commands are being used.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Jin Qian <jinqian@android.com>
---
drivers/platform/goldfish/goldfish_pipe.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index e7a29e2..0fb3a34 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -90,12 +90,6 @@
#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 */
@@ -272,8 +266,6 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
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;
@@ -325,7 +317,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
/* 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,
+ if (access_with_param(dev,
+ is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
address, avail, pipe, &status)) {
gf_write_ptr(pipe, dev->base + PIPE_REG_CHANNEL,
dev->base + PIPE_REG_CHANNEL_HIGH);
@@ -333,7 +326,7 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
gf_write_ptr((void *)address,
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);
}
@@ -370,7 +363,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
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);
--
2.6.0.rc2.230.g3dd15c0
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH v3 2/8] android_pipe: don't be clever with #define offsets
2015-12-02 19:35 ` [PATCH v3 2/8] android_pipe: don't be clever with #define offsets Jin Qian
@ 2015-12-02 20:11 ` Joe Perches
0 siblings, 0 replies; 10+ messages in thread
From: Joe Perches @ 2015-12-02 20:11 UTC (permalink / raw)
To: Jin Qian, Greg Kroah-Hartman, Greg Hackmann, Christoffer Dall,
Peter Senna Tschudin, Jason Hu, Alex Bennée, Yu Ning,
linux-kernel
On Wed, 2015-12-02 at 11:35 -0800, Jin Qian wrote:
> From: Alex Bennée <alex.bennee@linaro.org>
>
> You just make it harder to figure out when commands are being used.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Jin Qian <jinqian@android.com>
> ---
> drivers/platform/goldfish/goldfish_pipe.c | 16 +++++-----------
> 1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
> index e7a29e2..0fb3a34 100644
> --- a/drivers/platform/goldfish/goldfish_pipe.c
> +++ b/drivers/platform/goldfish/goldfish_pipe.c
> @@ -90,12 +90,6 @@
> #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 */
> @@ -272,8 +266,6 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
> 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);
This one could be
int cmd_type = is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER;
@@ -325,7 +317,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
>
> /* 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,
> + if (access_with_param(dev,
> + is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
> address, avail, pipe, &status)) {
> gf_write_ptr(pipe, dev->base + PIPE_REG_CHANNEL,
> dev->base + PIPE_REG_CHANNEL_HIGH);
> @@ -333,7 +326,7 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
> gf_write_ptr((void *)address,
> 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);
> }
and the loop could use cmd_type instead of the ?:
> @@ -370,7 +363,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
> 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);
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v3 3/8] android_pipe: Pin pages to memory while copying and other cleanups
2015-12-02 19:35 [PATCH v3 1/8] goldfish: refactor goldfish platform configs Jin Qian
2015-12-02 19:35 ` [PATCH v3 2/8] android_pipe: don't be clever with #define offsets Jin Qian
@ 2015-12-02 19:35 ` Jin Qian
2015-12-02 19:35 ` [PATCH v3 4/8] platform: goldfish: pipe: add devicetree bindings Jin Qian
` (4 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: Jin Qian @ 2015-12-02 19:35 UTC (permalink / raw)
To: Greg Kroah-Hartman, Greg Hackmann, Peter Senna Tschudin,
Christoffer Dall, Jason Hu, Alex Bennée, Joe Perches,
Yu Ning, linux-kernel
Cc: Jin Qian
From: Christoffer Dall <christoffer.dall@linaro.org>
The existing code had a troubling TODO statement concerning the fact
that it just did a check if the page that the QEMU backend was going to
read from / write to was there before the call to the QEMU backend and
then relying on the fact that the page stayed around, even in a
preemptible SMP kernel. Obviously the page could go away or be
reassigned, and strange things may happen.
Further, writes were not tracked, so any use of COW or KSM-like
features would break completely. Probably that was never used by adbd
(the only current active user of the pipe), but could prove much more
dangerous for the GPU passthrough mechanism.
Instead, use get_user_pages() as the comment suggested and cleanup the
error path and add the set_page_dirt() call on a successful read
operation.
Also clarify the count used to return from successful read/write calls
and use Linux style commentary in various places of the file.
Note: The "just ignore error and return whatever we read so far" error
handling is really quite horrific. I cannot change it without a more
careful study of all user space ABIs reliance on this 'feature'.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Jin Qian <jinqian@android.com>
---
drivers/platform/goldfish/goldfish_pipe.c | 129 +++++++++++++++++-------------
1 file changed, 72 insertions(+), 57 deletions(-)
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 0fb3a34..20a9337 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
@@ -57,6 +58,7 @@
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/goldfish.h>
+#include <linux/mm.h>
/*
* IMPORTANT: The following constants must match the ones used and defined
@@ -257,17 +259,14 @@ 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;
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))
@@ -290,30 +289,23 @@ 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;
-
- /* 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;
- }
- } else {
- /* Ensure that the page is mapped and writable */
- if (__put_user(0, (char __user *)address)) {
- if (!ret)
- ret = -EFAULT;
- break;
- }
- }
+ struct page *page;
+
+ /*
+ * 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.
+ */
+ ret = get_user_pages(current, current->mm, address, 1,
+ !is_write, 0, &page, NULL);
+ if (ret < 0)
+ return ret;
/* Now, try to transfer the bytes in the current page */
spin_lock_irqsave(&dev->lock, irq_flags);
@@ -332,33 +324,48 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
}
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.
+ */
+ pr_info_ratelimited("android_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);
@@ -372,22 +379,29 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
while (test_bit(wakeBit, &pipe->flags)) {
if (wait_event_interruptible(
pipe->wake_queue,
- !test_bit(wakeBit, &pipe->flags)))
- return -ERESTARTSYS;
+ !test_bit(wakeBit, &pipe->flags))) {
+ ret = -ERESTARTSYS;
+ break;
+ }
- if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))
- return -EIO;
+ if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags)) {
+ ret = -EIO;
+ break;
+ }
}
/* Try to re-acquire the lock */
- if (mutex_lock_interruptible(&pipe->lock))
- return -ERESTARTSYS;
-
- /* Try the transfer again */
- continue;
+ if (mutex_lock_interruptible(&pipe->lock)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
}
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,
@@ -440,10 +454,11 @@ 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 */
--
2.6.0.rc2.230.g3dd15c0
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH v3 4/8] platform: goldfish: pipe: add devicetree bindings
2015-12-02 19:35 [PATCH v3 1/8] goldfish: refactor goldfish platform configs Jin Qian
2015-12-02 19:35 ` [PATCH v3 2/8] android_pipe: don't be clever with #define offsets Jin Qian
2015-12-02 19:35 ` [PATCH v3 3/8] android_pipe: Pin pages to memory while copying and other cleanups Jin Qian
@ 2015-12-02 19:35 ` Jin Qian
2015-12-04 14:57 ` Rob Herring
2015-12-02 19:36 ` [PATCH v3 5/8] platform: goldfish: pipe: don't log when dropping PIPE_ERROR_AGAIN Jin Qian
` (3 subsequent siblings)
6 siblings, 1 reply; 10+ messages in thread
From: Jin Qian @ 2015-12-02 19:35 UTC (permalink / raw)
To: Rob Herring, Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala,
Greg Hackmann, Greg Kroah-Hartman, Yu Ning, Alex Bennée,
Christoffer Dall, Peter Senna Tschudin, Jason Hu, devicetree,
linux-kernel
Cc: Jin Qian
From: Greg Hackmann <ghackmann@google.com>
Add bindings so we don't need to rely on goldfish virtual bus for
probing any more, which means we don't need ARM and MIPS goldfish
board code for instantiating the bus.
In the long term we would like to move towards replacing the Android
pipe with virtio-vsock that is currently under development.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Jin Qian <jinqian@android.com>
---
Documentation/devicetree/bindings/goldfish/pipe.txt | 17 +++++++++++++++++
drivers/platform/goldfish/goldfish_pipe.c | 10 +++++++++-
2 files changed, 26 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/goldfish/pipe.txt
diff --git a/Documentation/devicetree/bindings/goldfish/pipe.txt b/Documentation/devicetree/bindings/goldfish/pipe.txt
new file mode 100644
index 0000000..e417a31
--- /dev/null
+++ b/Documentation/devicetree/bindings/goldfish/pipe.txt
@@ -0,0 +1,17 @@
+Android Goldfish QEMU Pipe
+
+Andorid pipe virtual device generated by android emulator.
+
+Required properties:
+
+- compatible : should contain "google,android-pipe" to match emulator
+- reg : <registers mapping>
+- interrupts : <interrupt mapping>
+
+Example:
+
+ android_pipe@a010000 {
+ compatible = "google,android-pipe";
+ reg = <ff018000 0x2000>;
+ interrupts = <0x12>;
+ };
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 20a9337..0b187ff 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -624,11 +624,19 @@ static int goldfish_pipe_remove(struct platform_device *pdev)
return 0;
}
+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,
}
};
--
2.6.0.rc2.230.g3dd15c0
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH v3 4/8] platform: goldfish: pipe: add devicetree bindings
2015-12-02 19:35 ` [PATCH v3 4/8] platform: goldfish: pipe: add devicetree bindings Jin Qian
@ 2015-12-04 14:57 ` Rob Herring
0 siblings, 0 replies; 10+ messages in thread
From: Rob Herring @ 2015-12-04 14:57 UTC (permalink / raw)
To: Jin Qian
Cc: Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala,
Greg Hackmann, Greg Kroah-Hartman, Yu Ning, Alex Bennée,
Christoffer Dall, Peter Senna Tschudin, Jason Hu, devicetree,
linux-kernel
On Wed, Dec 02, 2015 at 11:35:59AM -0800, Jin Qian wrote:
> From: Greg Hackmann <ghackmann@google.com>
>
> Add bindings so we don't need to rely on goldfish virtual bus for
> probing any more, which means we don't need ARM and MIPS goldfish
> board code for instantiating the bus.
>
> In the long term we would like to move towards replacing the Android
> pipe with virtio-vsock that is currently under development.
>
> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Signed-off-by: Jin Qian <jinqian@android.com>
Acked-by: Rob Herring <robh@kernel.org>
> ---
> Documentation/devicetree/bindings/goldfish/pipe.txt | 17 +++++++++++++++++
> drivers/platform/goldfish/goldfish_pipe.c | 10 +++++++++-
> 2 files changed, 26 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/devicetree/bindings/goldfish/pipe.txt
>
> diff --git a/Documentation/devicetree/bindings/goldfish/pipe.txt b/Documentation/devicetree/bindings/goldfish/pipe.txt
> new file mode 100644
> index 0000000..e417a31
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/goldfish/pipe.txt
> @@ -0,0 +1,17 @@
> +Android Goldfish QEMU Pipe
> +
> +Andorid pipe virtual device generated by android emulator.
> +
> +Required properties:
> +
> +- compatible : should contain "google,android-pipe" to match emulator
> +- reg : <registers mapping>
> +- interrupts : <interrupt mapping>
> +
> +Example:
> +
> + android_pipe@a010000 {
> + compatible = "google,android-pipe";
> + reg = <ff018000 0x2000>;
> + interrupts = <0x12>;
> + };
> diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
> index 20a9337..0b187ff 100644
> --- a/drivers/platform/goldfish/goldfish_pipe.c
> +++ b/drivers/platform/goldfish/goldfish_pipe.c
> @@ -624,11 +624,19 @@ static int goldfish_pipe_remove(struct platform_device *pdev)
> return 0;
> }
>
> +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,
> }
> };
>
> --
> 2.6.0.rc2.230.g3dd15c0
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v3 5/8] platform: goldfish: pipe: don't log when dropping PIPE_ERROR_AGAIN
2015-12-02 19:35 [PATCH v3 1/8] goldfish: refactor goldfish platform configs Jin Qian
` (2 preceding siblings ...)
2015-12-02 19:35 ` [PATCH v3 4/8] platform: goldfish: pipe: add devicetree bindings Jin Qian
@ 2015-12-02 19:36 ` Jin Qian
2015-12-02 19:36 ` [PATCH v3 6/8] [MIPS] Enable platform support for Goldfish virtual devices Jin Qian
` (2 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: Jin Qian @ 2015-12-02 19:36 UTC (permalink / raw)
To: Greg Kroah-Hartman, Greg Hackmann, Christoffer Dall, Joe Perches,
Jason Hu, Yu Ning, Peter Senna Tschudin, Alex Bennée,
linux-kernel
Cc: Jin Qian
From: Greg Hackmann <ghackmann@google.com>
On PIPE_ERROR_AGAIN, just stopping in the middle of a transfer and
returning the number of bytes actually handled is the right behavior.
Other errors should be returned on the next read() or write() call.
Continue logging those until we confirm nothing actually relies on the
existing (wrong) behavior of dropping errors on the floor.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Jin Qian <jinqian@android.com>
---
drivers/platform/goldfish/goldfish_pipe.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 0b187ff..7a56be9 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -346,7 +346,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
* cannot change it until we check if any user space
* ABI relies on this behavior.
*/
- pr_info_ratelimited("android_pipe: backend returned error %d on %s\n",
+ 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;
--
2.6.0.rc2.230.g3dd15c0
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH v3 6/8] [MIPS] Enable platform support for Goldfish virtual devices
2015-12-02 19:35 [PATCH v3 1/8] goldfish: refactor goldfish platform configs Jin Qian
` (3 preceding siblings ...)
2015-12-02 19:36 ` [PATCH v3 5/8] platform: goldfish: pipe: don't log when dropping PIPE_ERROR_AGAIN Jin Qian
@ 2015-12-02 19:36 ` Jin Qian
2015-12-02 19:36 ` [PATCH v3 7/8] goldfish_pipe: Pass physical addresses to the device if supported Jin Qian
2015-12-02 19:36 ` [PATCH v3 8/8] goldfish: Enable ACPI-based enumeration for android pipe Jin Qian
6 siblings, 0 replies; 10+ messages in thread
From: Jin Qian @ 2015-12-02 19:36 UTC (permalink / raw)
To: Miodrag Dinic, Greg Hackmann, linux-kernel; +Cc: Jin Qian
From: Miodrag Dinic <miodrag.dinic@imgtec.com>
Enable CONFIG_GOLDFISH for MIPS platforms.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Jin Qian <jinqian@android.com>
---
drivers/platform/goldfish/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/platform/goldfish/Kconfig b/drivers/platform/goldfish/Kconfig
index 1ae3690..f4f00f7 100644
--- a/drivers/platform/goldfish/Kconfig
+++ b/drivers/platform/goldfish/Kconfig
@@ -1,6 +1,6 @@
menuconfig GOLDFISH
bool "Platform support for Goldfish virtual devices"
- depends on X86_32 || X86_64 || ARM || ARM64
+ depends on X86_32 || X86_64 || ARM || ARM64 || MIPS
---help---
Say Y here to get to see options for the Goldfish virtual platform.
This option alone does not add any kernel code.
--
2.6.0.rc2.230.g3dd15c0
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH v3 7/8] goldfish_pipe: Pass physical addresses to the device if supported
2015-12-02 19:35 [PATCH v3 1/8] goldfish: refactor goldfish platform configs Jin Qian
` (4 preceding siblings ...)
2015-12-02 19:36 ` [PATCH v3 6/8] [MIPS] Enable platform support for Goldfish virtual devices Jin Qian
@ 2015-12-02 19:36 ` Jin Qian
2015-12-02 19:36 ` [PATCH v3 8/8] goldfish: Enable ACPI-based enumeration for android pipe Jin Qian
6 siblings, 0 replies; 10+ messages in thread
From: Jin Qian @ 2015-12-02 19:36 UTC (permalink / raw)
To: Greg Hackmann, Greg Kroah-Hartman, Alex Bennée, Yu Ning,
Joe Perches, Peter Senna Tschudin, Jason Hu, Christoffer Dall,
linux-kernel
Cc: Jin Qian
From: Yu Ning <yu.ning@intel.com>
For reading and writing guest user space buffers, currently the kernel
sends the guest virtual address of the buffer to the pipe device. This
virtual address has to be first converted to a guest physical address.
Doing this translation on the QEMU side is inefficient and requires
additional handling when KVM is enabled, whose implementation would
either incur intrusive changes to QEMU's KVM support code or suffer
from poor performance, see commit 08c7228c50f8 ("x86-kvm: only sync
SREGS when doing address translation") of $AOSP/external/qemu for
details, and thus should be avoided if possible.
There is a TODO comment in hw/misc/android_pipe.c in the new Android
emulator source tree ($AOSP/external/qemu-android) which requests that
the translation be done on the kernel side and that physical addresses
be passed to the device instead of virtual ones. Once the QEMU-side
implementation is done, the kernel will need to support both the new
paddr-based pipe device and the old vaddr-based one (which will
continue to be used by the classic emulator). This patch achieves that
by leveraging the device version register available in the new device.
See https://android-review.googlesource.com/128280 for the QEMU-side
patch.
In addition, use the mmap semaphore (in read mode) to safeguard the
call to get_user_pages().
Signed-off-by: Yu Ning <yu.ning@intel.com>
Signed-off-by: Jin Qian <jinqian@android.com>
---
drivers/platform/goldfish/goldfish_pipe.c | 29 +++++++++++++++++++++++++++--
1 file changed, 27 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 7a56be9..c214434 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -77,6 +77,7 @@
#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 */
@@ -126,6 +127,7 @@ struct goldfish_pipe_dev {
unsigned char __iomem *base;
struct access_params *aps;
int irq;
+ u32 version;
};
static struct goldfish_pipe_dev pipe_dev[1];
@@ -296,26 +298,43 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
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)
return ret;
+ if (dev->version) {
+ /* Device version 1 or newer (qemu-android) expects the
+ * physical address.
+ */
+ xaddr = page_to_phys(page) | (address & ~PAGE_MASK);
+ } else {
+ /* 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,
is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
- address, avail, pipe, &status)) {
+ 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(is_write ? CMD_WRITE_BUFFER : CMD_READ_BUFFER,
@@ -610,6 +629,12 @@ 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:
--
2.6.0.rc2.230.g3dd15c0
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH v3 8/8] goldfish: Enable ACPI-based enumeration for android pipe
2015-12-02 19:35 [PATCH v3 1/8] goldfish: refactor goldfish platform configs Jin Qian
` (5 preceding siblings ...)
2015-12-02 19:36 ` [PATCH v3 7/8] goldfish_pipe: Pass physical addresses to the device if supported Jin Qian
@ 2015-12-02 19:36 ` Jin Qian
6 siblings, 0 replies; 10+ messages in thread
From: Jin Qian @ 2015-12-02 19:36 UTC (permalink / raw)
To: Greg Kroah-Hartman, Greg Hackmann, Joe Perches, Christoffer Dall,
Peter Senna Tschudin, Yu Ning, Jason Hu, Alex Bennée,
linux-kernel
Cc: Jin Qian
From: Jason Hu <jia-cheng.hu@intel.com>
Add ACPI binding to the android pipe driver
Signed-off-by: Jason Hu <jia-cheng.hu@intel.com>
Signed-off-by: Jin Qian <jinqian@android.com>
---
drivers/platform/goldfish/goldfish_pipe.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index c214434..e3fab9a 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -59,6 +59,7 @@
#include <linux/io.h>
#include <linux/goldfish.h>
#include <linux/mm.h>
+#include <linux/acpi.h>
/*
* IMPORTANT: The following constants must match the ones used and defined
@@ -650,6 +651,12 @@ 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", },
{},
@@ -663,6 +670,7 @@ static struct platform_driver goldfish_pipe = {
.name = "goldfish_pipe",
.owner = THIS_MODULE,
.of_match_table = goldfish_pipe_of_match,
+ .acpi_match_table = ACPI_PTR(goldfish_pipe_acpi_match),
}
};
--
2.6.0.rc2.230.g3dd15c0
^ permalink raw reply related [flat|nested] 10+ messages in thread