soc: qcom: cmd-db: Map shared memory as WC, not WB

Linux does not write into cmd-db region. This region of memory is write
protected by XPU. XPU may sometime falsely detect clean cache eviction
as "

soc: qcom: cmd-db: Map shared memory as WC, not WB

Linux does not write into cmd-db region. This region of memory is write
protected by XPU. XPU may sometime falsely detect clean cache eviction
as "write" into the write protected region leading to secure interrupt
which causes an endless loop somewhere in Trust Zone.

The only reason it is working right now is because Qualcomm Hypervisor
maps the same region as Non-Cacheable memory in Stage 2 translation
tables. The issue manifests if we want to use another hypervisor (like
Xen or KVM), which does not know anything about those specific mappings.

Changing the mapping of cmd-db memory from MEMREMAP_WB to MEMREMAP_WT/WC
removes dependency on correct mappings in Stage 2 tables. This patch
fixes the issue by updating the mapping to MEMREMAP_WC.

I tested this on SA8155P with Xen.

Fixes: 312416d9171a ("drivers: qcom: add command DB driver")
Cc: [email protected] # 5.4+
Signed-off-by: Volodymyr Babchuk <[email protected]>
Tested-by: Nikita Travkin <[email protected]> # sc7180 WoA in EL2
Signed-off-by: Maulik Shah <[email protected]>
Tested-by: Pavankumar Kondeti <[email protected]>
Reviewed-by: Caleb Connolly <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

soc: qcom: cmd-db: replace deprecated strncpy with strtomem

strncpy() is an ambiguous and potentially dangerous interface [1]. We
should prefer more robust and less ambiguous alternatives.

@query i

soc: qcom: cmd-db: replace deprecated strncpy with strtomem

strncpy() is an ambiguous and potentially dangerous interface [1]. We
should prefer more robust and less ambiguous alternatives.

@query is marked as __nonstring and doesn't need to be NUL-terminated.

Since we are doing a string to memory copy, we can use the aptly named
"strtomem" -- specifically, the "pad" variant to also ensure NUL-padding
throughout the destination buffer.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: [email protected]
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Justin Stitt <[email protected]>
Link: https://lore.kernel.org/r/20240319-strncpy-drivers-soc-qcom-cmd-db-c-v3-1-aeb5c5180c32@google.com
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

soc: qcom: rpmh-rsc: Enhance check for VRM in-flight request

Each RPMh VRM accelerator resource has 3 or 4 contiguous 4-byte aligned
addresses associated with it. These control voltage, enable state

soc: qcom: rpmh-rsc: Enhance check for VRM in-flight request

Each RPMh VRM accelerator resource has 3 or 4 contiguous 4-byte aligned
addresses associated with it. These control voltage, enable state, mode,
and in legacy targets, voltage headroom. The current in-flight request
checking logic looks for exact address matches. Requests for different
addresses of the same RPMh resource as thus not detected as in-flight.

Add new cmd-db API cmd_db_match_resource_addr() to enhance the in-flight
request check for VRM requests by ignoring the address offset.

This ensures that only one request is allowed to be in-flight for a given
VRM resource. This is needed to avoid scenarios where request commands are
carried out by RPMh hardware out-of-order leading to LDO regulator
over-current protection triggering.

Fixes: 658628e7ef78 ("drivers: qcom: rpmh-rsc: add RPMH controller for QCOM SoCs")
Cc: [email protected]
Reviewed-by: Konrad Dybcio <[email protected]>
Tested-by: Elliot Berman <[email protected]> # sm8650-qrd
Signed-off-by: Maulik Shah <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

soc: qcom: Update init level to core_initcall() for cmd-db and rpmh-rsc

cmd-db and rpmh-rsc are used by clients like regulators, interconnects and
clocks for resource voting. These clients are in co

soc: qcom: Update init level to core_initcall() for cmd-db and rpmh-rsc

cmd-db and rpmh-rsc are used by clients like regulators, interconnects and
clocks for resource voting. These clients are in core_initcall() while
cmd-db and rpmh-rsc are in arch_initcall(). Update init level for these
drivers also to core_initcall() to avoid unnecessary probe defer during
boot up.

Signed-off-by: Maulik Shah <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

soc: qcom: Switch to EXPORT_SYMBOL_GPL()

Switch to GPL version of EXPORT_SYMBOL for Qualcomm SoC drivers.

Signed-off-by: Unnathi Chalicheemala <[email protected]>
Reviewed-by: Trilok Soni <

soc: qcom: Switch to EXPORT_SYMBOL_GPL()

Switch to GPL version of EXPORT_SYMBOL for Qualcomm SoC drivers.

Signed-off-by: Unnathi Chalicheemala <[email protected]>
Reviewed-by: Trilok Soni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

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)

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 <[email protected]>
Reviewed-by: Konrad Dybcio <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

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
suspe

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 <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

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 p

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 <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20220628064301.v3.1.Ie7b480cd99e2c13319220cbc108caf2bcd41286b@changeid

show more ...

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-behav

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 <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

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 supres

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 <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Tested-by: John Stultz <[email protected]>
Signed-off-by: Lina Iyer <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

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 figur

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 <[email protected]>
Reported-by: kbuild test robot <[email protected]>
Cc: Lina Iyer <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

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

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 <[email protected]>
Suggested-by: Lina Iyer <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

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

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 <[email protected]>
Fixes: d6815c5c43d4 ("soc: qcom: cmd-db: Add debugfs dumping file")
Reported-by: Stephen Rothwell <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

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 c

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 <[email protected]>
Cc: Maulik Shah <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Andersson <[email protected]>

show more ...

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

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 <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Signed-off-by: Andy Gross <[email protected]>

show more ...

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 re

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 <[email protected]>
Cc: Lina Iyer <[email protected]>
Cc: Bjorn Andersson <[email protected]>
Cc: Evan Green <[email protected]>
Cc: Jordan Crouse <[email protected]>
Cc: Rob Clark <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Andy Gross <[email protected]>

show more ...

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 c

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 <[email protected]>
Cc: Lina Iyer <[email protected]>
Cc: Bjorn Andersson <[email protected]>
Cc: Evan Green <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Andy Gross <[email protected]>

show more ...

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 convers

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 <[email protected]>
Cc: Lina Iyer <[email protected]>
Cc: Bjorn Andersson <[email protected]>
Cc: Evan Green <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Andy Gross <[email protected]>

show more ...

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 pr

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 <[email protected]>
Signed-off-by: Lina Iyer <[email protected]>
Reviewed-by: Bjorn Andersson <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Signed-off-by: Andy Gross <[email protected]>

show more ...