platform/x86/amd/hsmp: Create separate ACPI, plat and common drivers

Separate the probes for HSMP ACPI and platform device drivers.

Provide a Kconfig option to choose between ACPI or the platform device
based driver. The common code which is the core part of the HSMP driver
maintained at hsmp.c is guarded by AMD_HSMP config and is selected by
these two driver configs. This will be built into separate hsmp_common.ko
module and acpi as hsmp_acpi and plat as amd_hsmp respectively.

Also add "|| COMPILE_TEST" clause in Kconfig to get build coverage for
HSMP.

Signed-off-by: Suma Hegde <suma.hegde@amd.com>
Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Link: https://lore.kernel.org/r/20241021111428.2676884-8-suma.hegde@amd.com
[ij: Fixed doc to use pre-formatted text for the ACPI dump.]
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

1 files changed, 62 insertions, 5 deletions

diff --git a/Documentation/arch/x86/amd_hsmp.rst b/Documentation/arch/x86/amd_hsmp.rst
index 1e499ecf5f4e..2fd917638e42 100644
--- a/Documentation/arch/x86/amd_hsmp.rst
+++ b/Documentation/arch/x86/amd_hsmp.rst
@@ -4,8 +4,9 @@
 AMD HSMP interface
 ============================================
 
-Newer Fam19h EPYC server line of processors from AMD support system
-management functionality via HSMP (Host System Management Port).
+Newer Fam19h(model 0x00-0x1f, 0x30-0x3f, 0x90-0x9f, 0xa0-0xaf),
+Fam1Ah(model 0x00-0x1f) EPYC server line of processors from AMD support
+system management functionality via HSMP (Host System Management Port).
 
 The Host System Management Port (HSMP) is an interface to provide
 OS-level software with access to system management functions via a
@@ -16,14 +17,25 @@ More details on the interface can be found in chapter
 Eg: https://www.amd.com/content/dam/amd/en/documents/epyc-technical-docs/programmer-references/55898_B1_pub_0_50.zip
 
 
-HSMP interface is supported on EPYC server CPU models only.
+HSMP interface is supported on EPYC line of server CPUs and MI300A (APU).
 
 
 HSMP device
 ============================================
 
-amd_hsmp driver under the drivers/platforms/x86/ creates miscdevice
-/dev/hsmp to let user space programs run hsmp mailbox commands.
+amd_hsmp driver under drivers/platforms/x86/amd/hsmp/ has separate driver files
+for ACPI object based probing, platform device based probing and for the common
+code for these two drivers.
+
+Kconfig option CONFIG_AMD_HSMP_PLAT compiles plat.c and creates amd_hsmp.ko.
+Kconfig option CONFIG_AMD_HSMP_ACPI compiles acpi.c and creates hsmp_acpi.ko.
+Selecting any of these two configs automatically selects CONFIG_AMD_HSMP. This
+compiles common code hsmp.c and creates hsmp_common.ko module.
+
+Both the ACPI and plat drivers create the miscdevice /dev/hsmp to let
+user space programs run hsmp mailbox commands.
+
+The ACPI object format supported by the driver is defined below.
 
 $ ls -al /dev/hsmp
 crw-r--r-- 1 root root 10, 123 Jan 21 21:41 /dev/hsmp
@@ -59,6 +71,51 @@ Note: lseek() is not supported as entire metrics table is read.
 Metrics table definitions will be documented as part of Public PPR.
 The same is defined in the amd_hsmp.h header.
 
+ACPI device object format
+=========================
+The ACPI object format expected from the amd_hsmp driver
+for socket with ID00 is given below::
+
+  Device(HSMP)
+		{
+			Name(_HID, "AMDI0097")
+			Name(_UID, "ID00")
+			Name(HSE0, 0x00000001)
+			Name(RBF0, ResourceTemplate()
+			{
+				Memory32Fixed(ReadWrite, 0xxxxxxx, 0x00100000)
+			})
+			Method(_CRS, 0, NotSerialized)
+			{
+				Return(RBF0)
+			}
+			Method(_STA, 0, NotSerialized)
+			{
+				If(LEqual(HSE0, One))
+				{
+					Return(0x0F)
+				}
+				Else
+				{
+					Return(Zero)
+				}
+			}
+			Name(_DSD, Package(2)
+			{
+				Buffer(0x10)
+				{
+					0x9D, 0x61, 0x4D, 0xB7, 0x07, 0x57, 0xBD, 0x48,
+					0xA6, 0x9F, 0x4E, 0xA2, 0x87, 0x1F, 0xC2, 0xF6
+				},
+				Package(3)
+				{
+					Package(2) {"MsgIdOffset", 0x00010934},
+					Package(2) {"MsgRspOffset", 0x00010980},
+					Package(2) {"MsgArgOffset", 0x000109E0}
+				}
+			})
+		}
+
 
 An example
 ==========