s390/ism: Introduce struct ism_dmb

Conceptually, a DMB is a structure that belongs to ISM devices. However,
SMC currently 'owns' this structure. So future exploiters of ISM devices
would be forced to include SMC headers to work - which is just weird.
Therefore, we switch ISM to struct ism_dmb, introduce a new public header
with the definition (will be populated with further API calls later on),
and, add a thin wrapper to please SMC. Since structs smcd_dmb and ism_dmb
are identical, we can simply convert between the two for now.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 0 deletions

diff --git a/include/linux/ism.h b/include/linux/ism.h
new file mode 100644
index 000000000000..69bfbf0faaa1
--- /dev/null
+++ b/include/linux/ism.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  Internal Shared Memory
+ *
+ *  Definitions for the ISM module
+ *
+ *  Copyright IBM Corp. 2022
+ */
+#ifndef _ISM_H
+#define _ISM_H
+
+struct ism_dmb {
+	u64 dmb_tok;
+	u64 rgid;
+	u32 dmb_len;
+	u32 sba_idx;
+	u32 vlan_valid;
+	u32 vlan_id;
+	void *cpu_addr;
+	dma_addr_t dma_addr;
+};
+
+#endif	/* _ISM_H */