An opal_msg of type OPAL_MSG_ASYNC_COMP contains the return code in the
params[1] struct member. However this isn't intuitive or obvious when
reading the code and requires that a user look at the skiboot
documentation or opal-api.h to verify this.
Add an inline function to get the return code from an opal_msg and update
call sites accordingly.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The opal_{get,set}_param calls return internal error codes which need
to be translated in errnos in Linux.
Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
OpenPower BMC machines do not place any sysparams in the device tree, so
at every boot we get a warning:
[ 0.437176] SYSPARAM: Opal sysparam node not found
Remove the warning, and reorder the init so we don't peform allocations
when there is no sysparam node in the device tree.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Everyone can write to these files, which is not what we want.
Cc: stable@vger.kernel.org # 3.15
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The size of the sysparam sysfs files is determined from the device tree
at boot. However the buffer is hard coded to 64 bytes. If we encounter a
parameter that is larger than 64, or miss-parse the device tree, the
buffer will overflow when reading or writing to the parameter.
Check it at discovery time, and if the parameter is too large, do not
create a sysfs entry for it.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The sysparam code currently uses the userspace supplied number of
bytes when memcpy()ing in to a local 64-byte buffer.
Limit the maximum number of bytes by the size of the buffer.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The OPAL calls are returning int64_t values, which the sysparam code
stores in an int, and the sysfs callback returns ssize_t. Make code a
easier to read by consistently using ssize_t.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When a sysparam query in OPAL returned a negative value (error code),
sysfs would spew out a decent chunk of memory; almost 64K more than
expected. This was traced to a sign/unsigned mix up in the OPAL sysparam
sysfs code at sys_param_show.
The return value of sys_param_show is a ssize_t, calculated using
return ret ? ret : attr->param_size;
Alan Modra explains:
"attr->param_size" is an unsigned int, "ret" an int, so the overall
expression has type unsigned int. Result is that ret is cast to
unsigned int before being cast to ssize_t.
Instead of using the ternary operator, set ret to the param_size if an
error is not detected. The same bug exists in the sysfs write callback;
this patch fixes it in the same way.
A note on debugging this next time: on my system gcc will warn about
this if compiled with -Wsign-compare, which is not enabled by -Wall,
only -Wextra.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
OPAL defines opal_msg as a big endian struct so we have to
byte swap it on little endian builds.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch enables reading and updating of system parameters through
OPAL call.
Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
