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>

diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index 79e60ec70bd3933e6931c2aa3ccb3bd9348f0a66..36bc213629ad8baad2eec499e7e22132a3ff623f 100644 (file)
--- 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;

diff --git a/drivers/misc/cxl/hcalls.c b/drivers/misc/cxl/hcalls.c
index d6d11f4056d75f4182174f626da304471379002c..9b8bb0f80c3bbc04791ef93cfe13dbbdaa53e3dc 100644 (file)
--- a/drivers/misc/cxl/hcalls.c
+++ b/drivers/misc/cxl/hcalls.c
@@ -413,9 +413,9 @@ long cxl_h_collect_int_info(u64 unit_address, u64 process_token,
 
        switch (rc) {
        case H_SUCCESS:     /* The interrupt info is returned in return registers. */
-               pr_devel("dsisr:%#llx, dar:%#llx, dsr:%#llx, pid:%u, tid:%u, afu_err:%#llx, errstat:%#llx\n",
-                       info->dsisr, info->dar, info->dsr, info->pid,
-                       info->tid, info->afu_err, info->errstat);
+               pr_devel("dsisr:%#llx, dar:%#llx, dsr:%#llx, pid_tid:%#llx, afu_err:%#llx, errstat:%#llx\n",
+                       info->dsisr, info->dar, info->dsr, info->reserved,
+                       info->afu_err, info->errstat);
                return 0;
        case H_PARAMETER:   /* An incorrect parameter was supplied. */
                return -EINVAL;

diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c
index 7ae710585267a5d37366490108adc4e744e609b2..7257e8b8b52d35c7807528593cd416c7bb133f83 100644 (file)
--- a/drivers/misc/cxl/native.c
+++ b/drivers/misc/cxl/native.c
@@ -859,8 +859,6 @@ static int native_detach_process(struct cxl_context *ctx)
 
 static int native_get_irq_info(struct cxl_afu *afu, struct cxl_irq_info *info)
 {
-       u64 pidtid;
-
        /* If the adapter has gone away, we can't get any meaningful
         * information.
         */
@@ -870,9 +868,6 @@ static int native_get_irq_info(struct cxl_afu *afu, struct cxl_irq_info *info)
        info->dsisr = cxl_p2n_read(afu, CXL_PSL_DSISR_An);
        info->dar = cxl_p2n_read(afu, CXL_PSL_DAR_An);
        info->dsr = cxl_p2n_read(afu, CXL_PSL_DSR_An);
-       pidtid = cxl_p2n_read(afu, CXL_PSL_PID_TID_An);
-       info->pid = pidtid >> 32;
-       info->tid = pidtid & 0xffffffff;
        info->afu_err = cxl_p2n_read(afu, CXL_AFU_ERR_An);
        info->errstat = cxl_p2n_read(afu, CXL_PSL_ErrStat_An);
        info->proc_handle = 0;