cxl: Remove unused values in bare-metal environment.

The two previously fields pid and tid, located in the structure
cxl_irq_info, are only used in the guest environment. To avoid confusion,
it's not necessary to fill the fields in the bare-metal environment.
Pid_tid is now renamed to 'reserved' to avoid undefined behavior on
bare-metal. The PSL Process and Thread Identification Register
(CXL_PSL_PID_TID_An) is only used when attaching a dedicated process
for PSL8 only. This register goes away in CAIA2.

Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 4 insertions, 16 deletions

diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index 79e60ec70bd3..36bc213629ad 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -888,27 +888,15 @@ int __detach_context(struct cxl_context *ctx);
 /*
  * This must match the layout of the H_COLLECT_CA_INT_INFO retbuf defined
  * in PAPR.
- * A word about endianness: a pointer to this structure is passed when
- * calling the hcall. However, it is not a block of memory filled up by
- * the hypervisor. The return values are found in registers, and copied
- * one by one when returning from the hcall. See the end of the call to
- * plpar_hcall9() in hvCall.S
- * As a consequence:
- * - we don't need to do any endianness conversion
- * - the pid and tid are an exception. They are 32-bit values returned in
- *   the same 64-bit register. So we do need to worry about byte ordering.
+ * Field pid_tid is now 'reserved' because it's no more used on bare-metal.
+ * On a guest environment, PSL_PID_An is located on the upper 32 bits and
+ * PSL_TID_An register in the lower 32 bits.
  */
 struct cxl_irq_info {
 	u64 dsisr;
 	u64 dar;
 	u64 dsr;
-#ifndef CONFIG_CPU_LITTLE_ENDIAN
-	u32 pid;
-	u32 tid;
-#else
-	u32 tid;
-	u32 pid;
-#endif
+	u64 reserved;
 	u64 afu_err;
 	u64 errstat;
 	u64 proc_handle;