mailbox: pcc: Always map the shared memory communication address

Currently the shared memory communication address was mapped by the
mailbox client drivers leading to all sorts of inconsistencies.

mailbox: pcc: Always map the shared memory communication address

Currently the shared memory communication address was mapped by the
mailbox client drivers leading to all sorts of inconsistencies.

It also has resulted in the inconsistent attributes used while mapping
the shared memory regions.

In order to remove/eliminate any issues, let us ensures the shared
memory address is always mapped and unmapped when the PCC channels are
requested and release.

We need to map them as the ACPI PCCT associates these shared memory
with each channel subspace and may need use the status or the flags in
the headers of those shared memory communication address regions to
manage the transport/channel.

Note, until all the drivers using PCC start using this mapped shmem,
there might be double mapping of the shared memory address. This
shouldn't have any impact on existing mbox client drivers.

Since there are no users of pcc_chan_ioremap() and also it is mapped
by default, we can stop exporting it and merge the functionality into
pcc_mbox_request_channel().

Acked-by: Huisong Li <[email protected]>
Tested-by: Huisong Li <[email protected]>
Tested-by: Adam Young <[email protected]>
Signed-off-by: Sudeep Holla <[email protected]>
Signed-off-by: Jassi Brar <[email protected]>

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mailbox: pcc: Drop unnecessary endianness conversion of pcc_hdr.flags

The Sparse static checker flags a type mismatch warning related to
endianness conversion:

| warning: incorrect type in argum

mailbox: pcc: Drop unnecessary endianness conversion of pcc_hdr.flags

The Sparse static checker flags a type mismatch warning related to
endianness conversion:

| warning: incorrect type in argument 1 (different base types)
| expected restricted __le32 const [usertype] *p
| got unsigned int *

This is because an explicit endianness conversion (le32_to_cpu()) was
applied unnecessarily to a pcc_hdr.flags field that is already in
little-endian format.

The PCC driver is only enabled on little-endian kernels due to its
dependency on ACPI and EFI, making the explicit conversion unnecessary.

The redundant conversion occurs in pcc_chan_check_and_ack() for the
pcc_hdr.flags field. Drop this unnecessary endianness conversion of
pcc_hdr.flags.

Also drop the redundant PCC_ACK_FLAG_MASK definition and use the
more appropriate and already defined PCC_CMD_COMPLETION_NOTIFY.

Acked-by: Huisong Li <[email protected]>
Tested-by: Adam Young <[email protected]>
Signed-off-by: Sudeep Holla <[email protected]>
Signed-off-by: Jassi Brar <[email protected]>

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mailbox: pcc: Check before sending MCTP PCC response ACK

Type 4 PCC channels have an option to send back a response
to the platform when they are done processing the request.
The flag to indicate wh

mailbox: pcc: Check before sending MCTP PCC response ACK

Type 4 PCC channels have an option to send back a response
to the platform when they are done processing the request.
The flag to indicate whether or not to respond is inside
the message body, and thus is not available to the pcc
mailbox.

If the flag is not set, still set command completion
bit after processing message.

In order to read the flag, this patch maps the shared
buffer to virtual memory. To avoid duplication of mapping
the shared buffer is then made available to be used by
the driver that uses the mailbox.

Signed-off-by: Adam Young <[email protected]>
Cc: Sudeep Holla <[email protected]>
Signed-off-by: Jassi Brar <[email protected]>

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ACPI: PCC: Add PCC shared memory region command and status bitfields

Define the common macros to use when referring to various bitfields in
the PCC generic communications channel command and status

ACPI: PCC: Add PCC shared memory region command and status bitfields

Define the common macros to use when referring to various bitfields in
the PCC generic communications channel command and status fields.

Currently different drivers that need to use these bitfields have defined
these locally. This common macro is intended to consolidate and replace
those.

Cc: "Rafael J. Wysocki" <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sudeep Holla <[email protected]>

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mailbox: pcc: Use PCC mailbox channel pointer instead of standard

Now that we have all the shared memory region information populated in
the pcc_mbox_chan, let us propagate the pointer to the same a

mailbox: pcc: Use PCC mailbox channel pointer instead of standard

Now that we have all the shared memory region information populated in
the pcc_mbox_chan, let us propagate the pointer to the same as the
return value to pcc_mbox_request channel.

This eliminates the need for the individual users of PCC mailbox to
parse the PCCT subspace entries and fetch the shmem information. This
also eliminates the need for PCC mailbox controller to set con_priv to
PCCT subspace entries. This is required as con_priv is private to the
controller driver to attach private data associated with the channel and
not meant to be used by the mailbox client/users.

Let us convert all the users of pcc_mbox_{request,free}_channel to use
new interface.

Cc: Jean Delvare <[email protected]>
Signed-off-by: Sudeep Holla <[email protected]>
Acked-by: Wolfram Sang <[email protected]>
Acked-by: Guenter Roeck <[email protected]>
Signed-off-by: Jassi Brar <[email protected]>

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mailbox: pcc: Add pcc_mbox_chan structure to hold shared memory region info

Currently PCC mailbox controller sets con_priv in each channel to hold
the pointer to pcct subspace entry it corresponds t

mailbox: pcc: Add pcc_mbox_chan structure to hold shared memory region info

Currently PCC mailbox controller sets con_priv in each channel to hold
the pointer to pcct subspace entry it corresponds to. The mailbox user
will then fetch this pointer from the channel descriptor they get when
they request for the channel. Using that pointer they then parse the
pcct entry again to fetch all the information about shared memory region.

In order to remove individual users of PCC mailbox parsing the PCCT
subspace entries to fetch same information, let us consolidate the same
in pcc mailbox controller by parsing all the shared memory region
information into a structure that can also hold the mbox_chan pointer it
represent.

This can then be used as main PCC mailbox channel pointer that we can
return as part of pcc_mbox_request_channel instead of standard mailbox
channel pointer.

Reviewed-by: Cristian Marussi <[email protected]>
Signed-off-by: Sudeep Holla <[email protected]>
Signed-off-by: Jassi Brar <[email protected]>

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of th

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 315 file(s).

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Reviewed-by: Armijn Hemel <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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mailbox: PCC: Move the MAX_PCC_SUBSPACES definition to header file

Move the MAX_PCC_SUBSPACES definition to acpi/pcc.h file in
preparation to add subspace ID support for cppc_acpi driver.

Signed-of

mailbox: PCC: Move the MAX_PCC_SUBSPACES definition to header file

Move the MAX_PCC_SUBSPACES definition to acpi/pcc.h file in
preparation to add subspace ID support for cppc_acpi driver.

Signed-off-by: George Cherian <[email protected]>
Reviewed-by: Prashanth Prakash <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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mailbox: PCC: Fix return value of pcc_mbox_request_channel()

When CONFIG_PCC is disabled, pcc_mbox_request_channel() needs to
return ERR_PTR(-ENODEV), not a NULL pointer, as the callers of
this func

mailbox: PCC: Fix return value of pcc_mbox_request_channel()

When CONFIG_PCC is disabled, pcc_mbox_request_channel() needs to
return ERR_PTR(-ENODEV), not a NULL pointer, as the callers of
this function use IS_ERR() to check for error code.

Signed-off-by: Duc Dang <[email protected]>
Signed-off-by: Hoan Tran <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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mailbox: pcc: Add PCC request and free channel declarations

Exports pcc_mbox_request_channel() and pcc_mbox_free_channel()
declarations into a pcc.h header file.

Looks-good-to: Prashanth Prakash <p

mailbox: pcc: Add PCC request and free channel declarations

Exports pcc_mbox_request_channel() and pcc_mbox_free_channel()
declarations into a pcc.h header file.

Looks-good-to: Prashanth Prakash <[email protected]>
Signed-off-by: Hoan Tran <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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