staging: vme: make vme_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the vme_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240208-bus_cleanup-staging2-v1-2-cfe906133a2c@marliere.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: print more detailed infomation when an error occurs

when the slave_get function pointer belongs to the struct vme_bridge
member is NULL, it prompts that the detailed function name
"vme_slave_set" equivalent to __func__ not supported.

it is similar to the vme_slave_get function:
when vme_bridge->slave_set function pointer is NULL to print detailed
function name by using __func__.

Signed-off-by: Piro Yang <piroyangg@gmail.com>
Link: https://lore.kernel.org/r/20231227154739.6951-1-piroyangg@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: Fix the issue of return the wrong error code

Fix the issue of returning the -ENOSYS error code when an error occurs.

The error code of -ENOSYS indicates Invalid system call number, but
there is not system call error. So replace -ENOSYS error code by the
return -EINVAL error code.

Signed-off-by: Piro Yang <piroyangg@gmail.com>
Link: https://lore.kernel.org/r/20231219170447.51237-1-piroyangg@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: Use dev_err() in vme_check_window()

vme_check_window() uses printk() for logging error message. This
leads to the following checkpatch warning:
WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ... then
dev_err(dev, ... then pr_err(... to printk(KERN_ERR ...

Use dev_err() instead. Pass VME bridge device to vme_check_window() so
that the error message can be logged with the bridge device context.

Signed-off-by: Soumya Negi <soumya.negi97@gmail.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/221344ede933b1d9e6c31310b0f4dbb8be809c86.1697763267.git.soumya.negi97@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: Remove NULL-checks

Don't check for empty bridge device & resource in vme_alloc_consistent()
& vme_free_consistent() since they can not be NULL. Both the VME bridge
device and the VME resource that are used in these functions are set at
probe time.

Signed-off-by: Soumya Negi <soumya.negi97@gmail.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/049bbedf458e8ac40f3dfff9c9b25dce89f5b642.1697763267.git.soumya.negi97@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: Remove printk() in find_bridge()

Don't log error message in find_bridge(). The printk() triggers a
checkpatch warning:
WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ... then
dev_err(dev, ... then pr_err(... to printk(KERN_ERR ...

It can't be replaced by dev_err() & using pr_err() is not helpful as it
doesn't give much context to the user. It is better to remove it.

Signed-off-by: Soumya Negi <soumya.negi97@gmail.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/028725ebbc522f73c39f5b1ec4cc2bdbdf588971.1697763267.git.soumya.negi97@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: Use __func__ instead of function name

Replace function names in message strings with __func__ to fix
all checkpatch warnings like:

WARNING: Prefer using '"%s...", __func__' to using 'vme_lm_get',
this function's name, in a string

Signed-off-by: Soumya Negi <soumya.negi97@gmail.com>
Acked-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/db4ad6b878c4bb08fd5d15cf4a9287d7bb8c30df.1697763267.git.soumya.negi97@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: Replace printk() with dev_*()

vme.c uses printk() to log messages. To improve and standardize message
formatting, use logging mechanisms dev_err()/dev_warn() instead. Retain
the printk log levels of the messages during replacement.

Issue found by checkpatch.pl

Signed-off-by: Soumya Negi <soumya.negi97@gmail.com>
Acked-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/a36a0b839f9c21efe1f2df6f9272ae882fd04fb8.1697763267.git.soumya.negi97@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: Fix unbalanced {} in if-else blocks

Add missing braces so that {} are balanced in all arms of if-else
statements as per Linux coding style. Issue found by checkpatch.pl

Signed-off-by: Soumya Negi <soumya.negi97@gmail.com>
Link: https://lore.kernel.org/r/b0fad6de7405a105235b3b595e0bb2c51be7dcf0.1697240381.git.soumya.negi97@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: Correct spelling mistakes in comments

Fix misspelled words in vme.c. Issue found by checkpatch.pl

Signed-off-by: Soumya Negi <soumya.negi97@gmail.com>
Link: https://lore.kernel.org/r/f41caa8e7c987fdc010942838117fece8151affe.1697240381.git.soumya.negi97@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: Use list_for_each_entry() helper

Convert list_for_each() to list_for_each_entry() so that the
slave/master/dma/handler/lm_pos list_head pointer and list_entry()
call are no longer needed, which can reduce a few lines
of code. No functional changed.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/r/20230823071437.450460-1-ruanjinjie@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: fix check lines should not end with a '('

Fixed all CHECK: Lines should not end with a '('
as reported by checkpatch to adhere to the Linux kernel
coding-style guidelines.

Signed-off-by: Alexon Oliveira <alexondunkan@gmail.com>
Link: https://lore.kernel.org/r/ZNqbDtRjGWq67lDJ@alolivei-thinkpadt480s.gru.csb
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: fix check blank lines not necessary

Fixed all CHECK: Blank lines aren't necessary after an open brace '{'
and CHECK: Blank lines aren't necessary before a close brace '}'
as reported by checkpatch to adhere to the Linux kernel
coding-style guidelines.

Signed-off-by: Alexon Oliveira <alexondunkan@gmail.com>
Link: https://lore.kernel.org/r/ZNqYXAe/wIRl8qEe@alolivei-thinkpadt480s.gru.csb
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: vme_user: fix alignment of open parenthesis

Fixed all CHECK: Alignment should match open parenthesis
as reported by checkpatch to adhere to the Linux kernel
coding-style guidelines.

Signed-off-by: Alexon Oliveira <alexondunkan@gmail.com>
Link: https://lore.kernel.org/r/ZNO6HohffQlbh7jn@alolivei-thinkpadt480s.gru.csb
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vme: move back to staging

The VME subsystem graduated from staging into a top-level subsystem in
2012, with commit db3b9e990e75 ("Staging: VME: move VME drivers out of
staging") stating:

The VME device drivers have not moved out yet due to some API
questions they are still working through, that should happen soon,
hopefully.

However, this never happened: maintenance of drivers/vme effectively
stopped in 2017, with all subsequent changes being treewide cleanups.
No hardware driver remains in staging, only the limited user-level
access, and I just removed one of the two bridge drivers and the only
remaining board.

drivers/staging/vme/devices/ was recently moved to
drivers/staging/vme_user/, but as the vme_user driver is the only one
remaining for this subsystem, it is easier to just move the remaining
three source files into this directory rather than keeping the original
hierarchy.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20220606084109.4108188-3-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>