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-rw-r--r--arch/s390/include/asm/mem_detect.h94
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/s390/include/asm/mem_detect.h b/arch/s390/include/asm/mem_detect.h
new file mode 100644
index 000000000..a7c922a69
--- /dev/null
+++ b/arch/s390/include/asm/mem_detect.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_MEM_DETECT_H
+#define _ASM_S390_MEM_DETECT_H
+
+#include <linux/types.h>
+
+enum mem_info_source {
+ MEM_DETECT_NONE = 0,
+ MEM_DETECT_SCLP_STOR_INFO,
+ MEM_DETECT_DIAG260,
+ MEM_DETECT_SCLP_READ_INFO,
+ MEM_DETECT_BIN_SEARCH
+};
+
+struct mem_detect_block {
+ u64 start;
+ u64 end;
+};
+
+/*
+ * Storage element id is defined as 1 byte (up to 256 storage elements).
+ * In practise only storage element id 0 and 1 are used).
+ * According to architecture one storage element could have as much as
+ * 1020 subincrements. 255 mem_detect_blocks are embedded in mem_detect_info.
+ * If more mem_detect_blocks are required, a block of memory from already
+ * known mem_detect_block is taken (entries_extended points to it).
+ */
+#define MEM_INLINED_ENTRIES 255 /* (PAGE_SIZE - 16) / 16 */
+
+struct mem_detect_info {
+ u32 count;
+ u8 info_source;
+ struct mem_detect_block entries[MEM_INLINED_ENTRIES];
+ struct mem_detect_block *entries_extended;
+};
+extern struct mem_detect_info mem_detect;
+
+void add_mem_detect_block(u64 start, u64 end);
+
+static inline int __get_mem_detect_block(u32 n, unsigned long *start,
+ unsigned long *end)
+{
+ if (n >= mem_detect.count) {
+ *start = 0;
+ *end = 0;
+ return -1;
+ }
+
+ if (n < MEM_INLINED_ENTRIES) {
+ *start = (unsigned long)mem_detect.entries[n].start;
+ *end = (unsigned long)mem_detect.entries[n].end;
+ } else {
+ *start = (unsigned long)mem_detect.entries_extended[n - MEM_INLINED_ENTRIES].start;
+ *end = (unsigned long)mem_detect.entries_extended[n - MEM_INLINED_ENTRIES].end;
+ }
+ return 0;
+}
+
+/**
+ * for_each_mem_detect_block - early online memory range iterator
+ * @i: an integer used as loop variable
+ * @p_start: ptr to unsigned long for start address of the range
+ * @p_end: ptr to unsigned long for end address of the range
+ *
+ * Walks over detected online memory ranges.
+ */
+#define for_each_mem_detect_block(i, p_start, p_end) \
+ for (i = 0, __get_mem_detect_block(i, p_start, p_end); \
+ i < mem_detect.count; \
+ i++, __get_mem_detect_block(i, p_start, p_end))
+
+static inline void get_mem_detect_reserved(unsigned long *start,
+ unsigned long *size)
+{
+ *start = (unsigned long)mem_detect.entries_extended;
+ if (mem_detect.count > MEM_INLINED_ENTRIES)
+ *size = (mem_detect.count - MEM_INLINED_ENTRIES) * sizeof(struct mem_detect_block);
+ else
+ *size = 0;
+}
+
+static inline unsigned long get_mem_detect_end(void)
+{
+ unsigned long start;
+ unsigned long end;
+
+ if (mem_detect.count) {
+ __get_mem_detect_block(mem_detect.count - 1, &start, &end);
+ return end;
+ }
+ return 0;
+}
+
+#endif