In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.
Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements. This makes it easier to add further
iterator types. Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.
Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself. Only the direction is required.
Signed-off-by: David Howells <dhowells@redhat.com>
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 converts FSI sbefifo to use the new fsi-core controlled
chardev allocator and use a real cdev instead of a miscdev.
One side effect is to fix the object lifetime by removing
the use of devm_kzalloc() for something that contains kobjects,
and using proper reference counting.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Some of the exit path missed the unlock. Move the mutex to
an outer function to avoid the problem completely
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
"dev" is dereferences before it's checked.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
There was no unlock of the FFDC mutex.
Fixes: 9f4a8a2d7f ("fsi/sbefifo: Add driver for the SBE FIFO")
Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
fsi-sbefifo.c:547:58: warning: incorrect type in argument 2 (different base types)
fsi-sbefifo.c:547:58: expected restricted __be32 [usertype] *word
fsi-sbefifo.c:547:58: got unsigned int *<noident>
fsi-sbefifo.c:635:16: warning: incorrect type in assignment (different base types)
fsi-sbefifo.c:635:16: expected unsigned int [unsigned] <noident>
fsi-sbefifo.c:635:16: got restricted __be32 [usertype] <noident>
fsi-sbefifo.c:636:16: warning: incorrect type in assignment (different base types)
fsi-sbefifo.c:636:16: expected unsigned int [unsigned] <noident>
fsi-sbefifo.c:636:16: got restricted __be32 [usertype] <noident>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This driver provides an in-kernel and a user API for accessing
the command FIFO of the SBE (Self Boot Engine) of the POWER9
processor, via the FSI bus.
It provides an in-kernel interface to submit command and receive
responses, along with a helper to locate and analyse the response
status block. It's a simple synchronous submit() type API.
The user interface uses the write/read interface that an earlier
version of this driver already provided, however it has some
specific limitations in order to keep the driver simple and
avoid using up a lot of kernel memory:
- The user should perform a single write() with the command and
a single read() to get the response (with a buffer big enough
to hold the entire response).
- On a write() the command is simply "stored" into a kernel buffer,
it is submitted as one operation on the subsequent read(). This
allows to have the code write directly from the FIFO into the user
buffer and avoid hogging the SBE between the write() and read()
syscall as it's critical that the SBE be freed asap to respond
to the host. An extra write() will simply replace the previously
written command.
- A write of a single 4 bytes containing the value 0x52534554
in big endian will trigger a reset request. No read is necessary,
the write() call will return when the reset has been acknowledged
or times out.
- The command is limited to 4K bytes.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
---
David Howells
Benjamin Herrenschmidt
Eddie James
Joel Stanley