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authorRalf Baechle <ralf@linux-mips.org>1999-10-09 00:00:47 +0000
committerRalf Baechle <ralf@linux-mips.org>1999-10-09 00:00:47 +0000
commitd6434e1042f3b0a6dfe1b1f615af369486f9b1fa (patch)
treee2be02f33984c48ec019c654051d27964e42c441 /include/asm-sh/shmparam.h
parent609d1e803baf519487233b765eb487f9ec227a18 (diff)
Merge with 2.3.19.
Diffstat (limited to 'include/asm-sh/shmparam.h')
-rw-r--r--include/asm-sh/shmparam.h46
1 files changed, 46 insertions, 0 deletions
diff --git a/include/asm-sh/shmparam.h b/include/asm-sh/shmparam.h
new file mode 100644
index 000000000..cf58a95e8
--- /dev/null
+++ b/include/asm-sh/shmparam.h
@@ -0,0 +1,46 @@
+#ifndef __ASM_SH_SHMPARAM_H
+#define __ASM_SH_SHMPARAM_H
+
+/* address range for shared memory attaches if no address passed to shmat() */
+#define SHM_RANGE_START 0x50000000
+#define SHM_RANGE_END 0x60000000
+
+/*
+ * Format of a swap-entry for shared memory pages currently out in
+ * swap space (see also mm/swap.c).
+ *
+ * SWP_TYPE = SHM_SWP_TYPE
+ * SWP_OFFSET is used as follows:
+ *
+ * bits 0..6 : id of shared memory segment page belongs to (SHM_ID)
+ * bits 7..21: index of page within shared memory segment (SHM_IDX)
+ * (actually fewer bits get used since SHMMAX is so low)
+ */
+
+/*
+ * Keep _SHM_ID_BITS as low as possible since SHMMNI depends on it and
+ * there is a static array of size SHMMNI.
+ */
+#define _SHM_ID_BITS 7
+#define SHM_ID_MASK ((1<<_SHM_ID_BITS)-1)
+
+#define SHM_IDX_SHIFT (_SHM_ID_BITS)
+#define _SHM_IDX_BITS 15
+#define SHM_IDX_MASK ((1<<_SHM_IDX_BITS)-1)
+
+/*
+ * _SHM_ID_BITS + _SHM_IDX_BITS must be <= 24 on the i386 and
+ * SHMMAX <= (PAGE_SIZE << _SHM_IDX_BITS).
+ */
+
+#define SHMMAX 0x2000000 /* max shared seg size (bytes) */
+/* Try not to change the default shipped SHMMAX - people rely on it */
+
+#define SHMMIN 1 /* really PAGE_SIZE */ /* min shared seg size (bytes) */
+#define SHMMNI (1<<_SHM_ID_BITS) /* max num of segs system wide */
+#define SHMALL /* max shm system wide (pages) */ \
+ (1<<(_SHM_IDX_BITS+_SHM_ID_BITS))
+#define SHMLBA PAGE_SIZE /* attach addr a multiple of this */
+#define SHMSEG SHMMNI /* max shared segs per process */
+
+#endif /* __ASM_SH_SHMPARAM_H */