Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / powerpc / kernel / vdso32 / datapage.S

diff --git a/kernel/arch/powerpc/kernel/vdso32/datapage.S b/kernel/arch/powerpc/kernel/vdso32/datapage.S
new file mode 100644 (file)
index 0000000..dc21e89
--- /dev/null
+++ b/kernel/arch/powerpc/kernel/vdso32/datapage.S
@@ -0,0 +1,85 @@
+/*
+ * Access to the shared data page by the vDSO & syscall map
+ *
+ * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+#include <asm/vdso.h>
+
+       .text
+V_FUNCTION_BEGIN(__get_datapage)
+  .cfi_startproc
+       /* We don't want that exposed or overridable as we want other objects
+        * to be able to bl directly to here
+        */
+       .protected __get_datapage
+       .hidden __get_datapage
+
+       mflr    r0
+  .cfi_register lr,r0
+
+       bcl     20,31,1f
+       .global __kernel_datapage_offset;
+__kernel_datapage_offset:
+       .long   0
+1:
+       mflr    r3
+       mtlr    r0
+       lwz     r0,0(r3)
+       add     r3,r0,r3
+       blr
+  .cfi_endproc
+V_FUNCTION_END(__get_datapage)
+
+/*
+ * void *__kernel_get_syscall_map(unsigned int *syscall_count) ;
+ *
+ * returns a pointer to the syscall map. the map is agnostic to the
+ * size of "long", unlike kernel bitops, it stores bits from top to
+ * bottom so that memory actually contains a linear bitmap
+ * check for syscall N by testing bit (0x80000000 >> (N & 0x1f)) of
+ * 32 bits int at N >> 5.
+ */
+V_FUNCTION_BEGIN(__kernel_get_syscall_map)
+  .cfi_startproc
+       mflr    r12
+  .cfi_register lr,r12
+       mr      r4,r3
+       bl      __get_datapage@local
+       mtlr    r12
+       addi    r3,r3,CFG_SYSCALL_MAP32
+       cmpli   cr0,r4,0
+       beqlr
+       li      r0,__NR_syscalls
+       stw     r0,0(r4)
+       crclr   cr0*4+so
+       blr
+  .cfi_endproc
+V_FUNCTION_END(__kernel_get_syscall_map)
+
+/*
+ * void unsigned long long  __kernel_get_tbfreq(void);
+ *
+ * returns the timebase frequency in HZ
+ */
+V_FUNCTION_BEGIN(__kernel_get_tbfreq)
+  .cfi_startproc
+       mflr    r12
+  .cfi_register lr,r12
+       bl      __get_datapage@local
+       lwz     r4,(CFG_TB_TICKS_PER_SEC + 4)(r3)
+       lwz     r3,CFG_TB_TICKS_PER_SEC(r3)
+       mtlr    r12
+       crclr   cr0*4+so
+       blr
+  .cfi_endproc
+V_FUNCTION_END(__kernel_get_tbfreq)