Commit Graph

7 Commits

Author SHA1 Message Date
Sudeep Holla
353efd5e97 ACPI: PRM: Change handler_addr type to void pointer
handler_addr is a virtual address passed to efi_call_virt_pointer.
While x86 currently type cast it into the pointer in it's arch specific
arch_efi_call_virt() implementation, ARM64 is restrictive for right
reasons.

Convert the handler_addr type from u64 to void pointer.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-06-30 17:35:45 +02:00
Aubrey Li
c52ca71327 ACPI: PRM: Handle memory allocation and memory remap failure
Handle memory allocation and memory remap failure in acpi_parse_prmt()
when system runs out of memory to avoid the potential NULL pointer
dereference errors.

Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-10-26 15:29:07 +02:00
Aubrey Li
caa2bd07f5 ACPI: PRM: Remove unnecessary blank lines
Just remove unnecessary blank lines, no other code changes

Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-10-26 15:29:07 +02:00
Aubrey Li
3265cc3ec5 ACPI: PRM: Find PRMT table before parsing it
Find and verify PRMT before parsing it, which eliminates a
warning on machines without PRMT:

	[    7.197173] ACPI: PRMT not present

Fixes: cefc7ca462 ("ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype")
Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: 5.14+ <stable@vger.kernel.org> # 5.14+
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-09-08 20:56:57 +02:00
Aubrey Li
2bbfa0addd ACPI: PRM: Deal with table not present or no module found
On the system PRMT table is not present, dmesg output:

	$ dmesg | grep PRM
	[    1.532237] ACPI: PRMT not present
	[    1.532237] PRM: found 4294967277 modules

The result of acpi_table_parse_entries need to be checked and return
immediately if PRMT table is not present or no PRM module found.

Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-08-16 17:06:40 +02:00
Wei Yongjun
d7a188bb87 ACPI: PRM: make symbol 'prm_module_list' static
The sparse tool complains as follows:

drivers/acpi/prmt.c:53:1: warning:
 symbol 'prm_module_list' was not declared. Should it be static?

This symbol is not used outside of prmt.c, so marks it static.

Fixes: cefc7ca462 ("ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-17 14:40:29 +02:00
Erik Kaneda
cefc7ca462 ACPI: PRM: implement OperationRegion handler for the PlatformRtMechanism subtype
Platform Runtime Mechanism (PRM) is a firmware interface that exposes
a set of binary executables that can either be called from the AML
interpreter or device drivers by bypassing the AML interpreter.
This change implements the AML interpreter path.

According to the specification [1], PRM services are listed in an
ACPI table called the PRMT. This patch parses module and handler
information listed in the PRMT and registers the PlatformRtMechanism
OpRegion handler before ACPI tables are loaded.

Each service is defined by a 16-byte GUID and called from writing a
26-byte ASL buffer containing the identifier to a FieldUnit object
defined inside a PlatformRtMechanism OperationRegion.

    OperationRegion (PRMR, PlatformRtMechanism, 0, 26)
    Field (PRMR, BufferAcc, NoLock, Preserve)
    {
        PRMF, 208 // Write to this field to invoke the OperationRegion Handler
    }

The 26-byte ASL buffer is defined as the following:

Byte Offset   Byte Length    Description
=============================================================
     0             1         PRM OperationRegion handler status
     1             8         PRM service status
     9             1         PRM command
    10            16         PRM handler GUID

The ASL caller fills out a 26-byte buffer containing the PRM command
and the PRM handler GUID like so:

    /* Local0 is the PRM data buffer */
    Local0 = buffer (26){}

    /* Create byte fields over the buffer */
    CreateByteField (Local0, 0x9, CMD)
    CreateField (Local0, 0x50, 0x80, GUID)

    /* Fill in the command and data fields of the data buffer */
    CMD = 0 // run command
    GUID = ToUUID("xxxx-xx-xxx-xxxx")

    /*
     * Invoke PRM service with an ID that matches GUID and save the
     * result.
     */
    Local0 = (\_SB.PRMT.PRMF = Local0)

Byte offset 0 - 8 are written by the handler as a status passed back to AML
and used by ASL like so:

    /* Create byte fields over the buffer */
    CreateByteField (Local0, 0x0, PSTA)
    CreateQWordField (Local0, 0x1, USTA)

In this ASL code, PSTA contains a status from the OperationRegion and
USTA contains a status from the PRM service.

The 26-byte buffer is recieved by acpi_platformrt_space_handler. This
handler will look at the command value and the handler guid and take
the approperiate actions.

Command value    Action
=====================================================================
    0            Run the PRM service indicated by the PRM handler
                 GUID (bytes 10-26)

    1            Prevent PRM runtime updates from happening to the
                 service's parent module

    2            Allow PRM updates from happening to the service's parent module

This patch enables command value 0.

Link: https://uefi.org/sites/default/files/resources/Platform%20Runtime%20Mechanism%20-%20with%20legal%20notice.pdf # [1]
Signed-off-by: Erik Kaneda <erik.kaneda@intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-10 15:06:54 +02:00