summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/include/uapi/asm/sigcontext.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/include/uapi/asm/sigcontext.h')
-rw-r--r--arch/powerpc/include/uapi/asm/sigcontext.h87
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/powerpc/include/uapi/asm/sigcontext.h b/arch/powerpc/include/uapi/asm/sigcontext.h
new file mode 100644
index 00000000000..9c1f24fd5d1
--- /dev/null
+++ b/arch/powerpc/include/uapi/asm/sigcontext.h
@@ -0,0 +1,87 @@
+#ifndef _ASM_POWERPC_SIGCONTEXT_H
+#define _ASM_POWERPC_SIGCONTEXT_H
+
+/*
+ * 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 <linux/compiler.h>
+#include <asm/ptrace.h>
+#ifdef __powerpc64__
+#include <asm/elf.h>
+#endif
+
+struct sigcontext {
+ unsigned long _unused[4];
+ int signal;
+#ifdef __powerpc64__
+ int _pad0;
+#endif
+ unsigned long handler;
+ unsigned long oldmask;
+ struct pt_regs __user *regs;
+#ifdef __powerpc64__
+ elf_gregset_t gp_regs;
+ elf_fpregset_t fp_regs;
+/*
+ * To maintain compatibility with current implementations the sigcontext is
+ * extended by appending a pointer (v_regs) to a quadword type (elf_vrreg_t)
+ * followed by an unstructured (vmx_reserve) field of 69 doublewords. This
+ * allows the array of vector registers to be quadword aligned independent of
+ * the alignment of the containing sigcontext or ucontext. It is the
+ * responsibility of the code setting the sigcontext to set this pointer to
+ * either NULL (if this processor does not support the VMX feature) or the
+ * address of the first quadword within the allocated (vmx_reserve) area.
+ *
+ * The pointer (v_regs) of vector type (elf_vrreg_t) is type compatible with
+ * an array of 34 quadword entries (elf_vrregset_t). The entries with
+ * indexes 0-31 contain the corresponding vector registers. The entry with
+ * index 32 contains the vscr as the last word (offset 12) within the
+ * quadword. This allows the vscr to be stored as either a quadword (since
+ * it must be copied via a vector register to/from storage) or as a word.
+ * The entry with index 33 contains the vrsave as the first word (offset 0)
+ * within the quadword.
+ *
+ * Part of the VSX data is stored here also by extending vmx_restore
+ * by an additional 32 double words. Architecturally the layout of
+ * the VSR registers and how they overlap on top of the legacy FPR and
+ * VR registers is shown below:
+ *
+ * VSR doubleword 0 VSR doubleword 1
+ * ----------------------------------------------------------------
+ * VSR[0] | FPR[0] | |
+ * ----------------------------------------------------------------
+ * VSR[1] | FPR[1] | |
+ * ----------------------------------------------------------------
+ * | ... | |
+ * | ... | |
+ * ----------------------------------------------------------------
+ * VSR[30] | FPR[30] | |
+ * ----------------------------------------------------------------
+ * VSR[31] | FPR[31] | |
+ * ----------------------------------------------------------------
+ * VSR[32] | VR[0] |
+ * ----------------------------------------------------------------
+ * VSR[33] | VR[1] |
+ * ----------------------------------------------------------------
+ * | ... |
+ * | ... |
+ * ----------------------------------------------------------------
+ * VSR[62] | VR[30] |
+ * ----------------------------------------------------------------
+ * VSR[63] | VR[31] |
+ * ----------------------------------------------------------------
+ *
+ * FPR/VSR 0-31 doubleword 0 is stored in fp_regs, and VMX/VSR 32-63
+ * is stored at the start of vmx_reserve. vmx_reserve is extended for
+ * backwards compatility to store VSR 0-31 doubleword 1 after the VMX
+ * registers and vscr/vrsave.
+ */
+ elf_vrreg_t __user *v_regs;
+ long vmx_reserve[ELF_NVRREG+ELF_NVRREG+32+1];
+#endif
+};
+
+#endif /* _ASM_POWERPC_SIGCONTEXT_H */