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fsi: sbefifo: Bump max command length

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Otherwise cronus putmem fails istep and BML fails to upload skiboot

To do that, we still use our one-page command buffer for small commands
for speed, and for anything bigger, with a limit of 1MB plus a page,
we vmalloc a temporary buffer.

The limit was chosen because Cronus will break up any data transfer
into 1M chunks (the extra page is for the command header).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
This commit is contained in:
Benjamin Herrenschmidt 2018-08-07 11:51:52 +10:00
parent aa1221b258
commit 15e2a7218c
1 changed files with 32 additions and 7 deletions
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39
drivers/fsi/fsi-sbefifo.c
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@ -30,6 +30,7 @@
#include <linux/delay.h>
#include <linux/uio.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
/*
* The SBEFIFO is a pipe-like FSI device for communicating with
@ -110,7 +111,7 @@ enum sbe_state
#define SBEFIFO_TIMEOUT_IN_RSP 1000
/* Other constants */
#define SBEFIFO_MAX_CMD_LEN PAGE_SIZE
#define SBEFIFO_MAX_USER_CMD_LEN (0x100000 + PAGE_SIZE)
#define SBEFIFO_RESET_MAGIC 0x52534554 /* "RSET" */
struct sbefifo {
@ -128,6 +129,7 @@ struct sbefifo {
struct sbefifo_user {
struct sbefifo *sbefifo;
struct mutex file_lock;
void *cmd_page;
void *pending_cmd;
size_t pending_len;
};
@ -726,7 +728,7 @@ int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len,
return -ENODEV;
if (WARN_ON_ONCE(sbefifo->magic != SBEFIFO_MAGIC))
return -ENODEV;
if (!resp_len || !command || !response || cmd_len > SBEFIFO_MAX_CMD_LEN)
if (!resp_len || !command || !response)
return -EINVAL;
/* Prepare iov iterator */
@ -751,6 +753,15 @@ EXPORT_SYMBOL_GPL(sbefifo_submit);
/*
* Char device interface
*/
static void sbefifo_release_command(struct sbefifo_user *user)
{
if (is_vmalloc_addr(user->pending_cmd))
vfree(user->pending_cmd);
user->pending_cmd = NULL;
user->pending_len = 0;
}
static int sbefifo_user_open(struct inode *inode, struct file *file)
{
struct sbefifo *sbefifo = container_of(inode->i_cdev, struct sbefifo, cdev);
@ -762,8 +773,8 @@ static int sbefifo_user_open(struct inode *inode, struct file *file)
file->private_data = user;
user->sbefifo = sbefifo;
user->pending_cmd = (void *)__get_free_page(GFP_KERNEL);
if (!user->pending_cmd) {
user->cmd_page = (void *)__get_free_page(GFP_KERNEL);
if (!user->cmd_page) {
kfree(user);
return -ENOMEM;
}
@ -816,7 +827,7 @@ static ssize_t sbefifo_user_read(struct file *file, char __user *buf,
/* Extract the response length */
rc = len - iov_iter_count(&resp_iter);
bail:
user->pending_len = 0;
sbefifo_release_command(user);
mutex_unlock(&user->file_lock);
return rc;
}
@ -831,13 +842,23 @@ static ssize_t sbefifo_user_write(struct file *file, const char __user *buf,
if (!user)
return -EINVAL;
sbefifo = user->sbefifo;
if (len > SBEFIFO_MAX_CMD_LEN)
if (len > SBEFIFO_MAX_USER_CMD_LEN)
return -EINVAL;
if (len & 3)
return -EINVAL;
mutex_lock(&user->file_lock);
/* Can we use the pre-allocate buffer ? If not, allocate */
if (len <= PAGE_SIZE)
user->pending_cmd = user->cmd_page;
else
user->pending_cmd = vmalloc(len);
if (!user->pending_cmd) {
rc = -ENOMEM;
goto bail;
}
/* Copy the command into the staging buffer */
if (copy_from_user(user->pending_cmd, buf, len)) {
rc = -EFAULT;
@ -863,6 +884,9 @@ static ssize_t sbefifo_user_write(struct file *file, const char __user *buf,
/* Update the staging buffer size */
user->pending_len = len;
bail:
if (!user->pending_len)
sbefifo_release_command(user);
mutex_unlock(&user->file_lock);
/* And that's it, we'll issue the command on a read */
@ -876,7 +900,8 @@ static int sbefifo_user_release(struct inode *inode, struct file *file)
if (!user)
return -EINVAL;
free_page((unsigned long)user->pending_cmd);
sbefifo_release_command(user);
free_page((unsigned long)user->cmd_page);
kfree(user);
return 0;