soc: qcom: Switch to EXPORT_SYMBOL_GPL()

Switch to GPL version of EXPORT_SYMBOL for Qualcomm SoC drivers.

Signed-off-by: Unnathi Chalicheemala <quic_uchalich@quicinc.com>
Reviewed-by: Trilok Soni <quic_tsoni@quicinc.com>
Link: https://lore.kernel.org/r/20230922184817.5183-1-quic_uchalich@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

soc: qcom: cmd-db: Drop NUL bytes from debugfs output

The debugfs dump of Command DB relies uses %*pEp to print the resource
identifiers, with escaping of non-printable characters.
But p (ESCAPE_NP) does not escape NUL characters, so for identifiers
less than 8 bytes in length the output will retain these.

This does not cause an issue while looking at the dump in the terminal
(no known complaints at least), but when programmatically consuming the
debugfs output the extra characters are unwanted.

Change the fixed 8-byte sizeof() to a dynamic strnlen() to avoid
printing these NUL characters.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230620213703.283583-1-quic_bjorande@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

soc: qcom: cmd-db: Mark device as having no PM support

This driver purely exposes information from memory to the kernel. Let's
mark it as not having any device PM functionality, so that during
suspend we skip even trying to call a suspend function on this device.
This clears up suspend logs more than anything else, but it also shaves
a few cycles off suspend.

Cc: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221015004934.3930651-1-swboyd@chromium.org

soc: qcom: cmd-db: replace strscpy_pad() with strncpy()

Commit ac0126a01735 ("soc: qcom: cmd-db: replace strncpy() with
strscpy_pad()") breaks booting on my sc7280-herobrine-herobrine
device. From printouts I see that at bootup the function is called
with an id of "lnbclka2" which is 8 bytes big.

Previously all 8 bytes of this string were copied to the
destination. Now only 7 bytes will be copied since strscpy_pad() saves
a byte for '\0' termination.

We don't need the '\0' termination in the destination. Let's go back
to strncpy(). According to the warning:
If a caller is using non-NUL-terminated strings, strncpy() can still
be used, but destinations should be marked with the __nonstring
attribute to avoid future compiler warnings.
...so we'll do that.

While we're at it, let's change the query array to use
"sizeof(ent->id)" so it can't possibly go out of sync with our later
copy.

Fixes: ac0126a01735 ("soc: qcom: cmd-db: replace strncpy() with strscpy_pad()")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220628064301.v3.1.Ie7b480cd99e2c13319220cbc108caf2bcd41286b@changeid

soc: qcom: cmd-db: replace strncpy() with strscpy_pad()

The use of strncpy() is considered deprecated for NUL-terminated
strings[1]. Replace strncpy() with strscpy_pad(), to keep existing
pad-behavior of strncpy. This fixes W=1 warning:

drivers/soc/qcom/cmd-db.c: In function ‘cmd_db_get_header.part.0’:
drivers/soc/qcom/cmd-db.c:151:9: warning: ‘strncpy’ specified bound 8 equals destination size [-Wstringop-truncation]
151 | strncpy(query, id, sizeof(query));

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220519073301.7072-1-krzysztof.kozlowski@linaro.org

soc: qcom: cmd-db: allow loading as a module

This patch enables Command DB driver to be loaded as a module. Command
DB is inherent to RPMH interaction and as such would never be unloaded.
Add supress_bind_attrs to make it a permanently loaded module.

Reviewed-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Link: https://lore.kernel.org/r/20201001154144.5226-1-ilina@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

soc: qcom: cmd-db: Properly endian swap the slv_id for debugfs

Read the slv_id properly by making sure the 16-bit number is endian
swapped from little endian to CPU native before we read it to figure out
what to print for the human readable name. Otherwise we may just show
that all the elements in the cmd-db are "Unknown" which isn't right.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: kbuild test robot <lkp@intel.com>
Cc: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200417000645.234693-1-swboyd@chromium.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

soc: qcom: cmd-db: Use 5 digits for printing address

The top few bits aren't relevant to pad out because they're always zero.
Let's just print 5 digits instead of 8 so that it's a little shorter and
more readable.

Reviewed-by: Lina Iyer <ilina@codeaurora.org>
Suggested-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200415192916.78339-1-swboyd@chromium.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

soc: qcom: cmd-db: Cast sizeof() to int to silence field width warning

We pass the result of sizeof() here to tell the printk format specifier
how many bytes to print. That expects an int though and sizeof() isn't
that type. Cast to int to silence this warning:

drivers/soc/qcom/cmd-db.c: In function 'cmd_db_debugfs_dump':
drivers/soc/qcom/cmd-db.c:281:30: warning: field width specifier '*' expects argument of type 'int', but argument 4 has type 'long unsigned int' [-Wformat=]

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Fixes: d6815c5c43d4 ("soc: qcom: cmd-db: Add debugfs dumping file")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200415062033.66406-1-swboyd@chromium.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

soc: qcom: cmd-db: Add debugfs dumping file

It's useful for kernel devs to understand what resources and data is
stored inside command db. Add a file in debugufs called 'cmd-db' to dump
the memory contents and strings for resources along with their
addresses. E.g.

Command DB DUMP
Slave ARC (v16.0)
-------------------------
0x00030000: cx.lvl [00 00 10 00 40 00 80 00 c0 00 00 01 80 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00]
0x00030004: cx.tmr
0x00030010: mx.lvl [00 00 10 00 00 01 80 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00]
0x00030014: mx.tmr

Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Maulik Shah <mkshah@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200309185704.2491-1-swboyd@chromium.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

soc: qcom: cmd-db: Fix an error code in cmd_db_dev_probe()

The memremap() function doesn't return error pointers, it returns NULL.
This code is returning "ret = PTR_ERR(NULL);" which is success, but it
should return -ENOMEM.

Fixes: 312416d9171a ("drivers: qcom: add command DB driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

soc: qcom: cmd-db: Stop memcpy()ing in cmd_db_read_aux_data()

Let's change the function signature to return the pointer to memory or
an error pointer on failure, and take an argument that lets us return
the size of the aux data read. This way we can remove the
cmd_db_read_aux_data_len() API entirely and also get rid of the memcpy
operation from cmd_db to the caller. Updating the only user of this code
shows that making this change allows us to remove a function and put the
lookup where the user is.

Cc: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Evan Green <evgreen@chromium.org>
Cc: Jordan Crouse <jcrouse@codeaurora.org>
Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

soc: qcom: cmd-db: Remove memcpy()ing from cmd_db_get_header()

The cmd_db_get_header() function is a static local function that doesn't
need to copy anything from one place to another. Instead, it can just
point into the region by returning pointers to what we're looking for.
If we do that, we should mark what we're returning as const so that code
can't modify cmd-db without an obvious cast.

Cc: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Evan Green <evgreen@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

soc: qcom: cmd-db: Make endian-agnostic

This driver deals with memory that is stored in little-endian format.
Update the structures with the proper little-endian types and then
do the proper conversions when reading the fields. Note that we compare
the ids with a memcmp() because we already pad out the string 'id' field
to exactly 8 bytes with the strncpy() onto the stack.

Cc: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Evan Green <evgreen@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

drivers: qcom: add command DB driver

Command DB is a simple database in the shared memory of QCOM SoCs, that
provides information regarding shared resources. Some shared resources
in the SoC have properties that are probed dynamically at boot by the
remote processor. The information pertaining to the SoC and the platform
are made available in the shared memory. Drivers can query this
information using predefined strings.

Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>