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-rw-r--r--arch/powerpc/kernel/head_32.h118
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diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
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+++ b/arch/powerpc/kernel/head_32.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __HEAD_32_H__
+#define __HEAD_32_H__
+
+#include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */
+
+/*
+ * Exception entry code. This code runs with address translation
+ * turned off, i.e. using physical addresses.
+ * We assume sprg3 has the physical address of the current
+ * task's thread_struct.
+ */
+
+.macro EXCEPTION_PROLOG
+ mtspr SPRN_SPRG_SCRATCH0,r10
+ mtspr SPRN_SPRG_SCRATCH1,r11
+ mfcr r10
+ EXCEPTION_PROLOG_1
+ EXCEPTION_PROLOG_2
+.endm
+
+.macro EXCEPTION_PROLOG_1
+ mfspr r11,SPRN_SRR1 /* check whether user or kernel */
+ andi. r11,r11,MSR_PR
+ tophys(r11,r1) /* use tophys(r1) if kernel */
+ beq 1f
+ mfspr r11,SPRN_SPRG_THREAD
+ lwz r11,TASK_STACK-THREAD(r11)
+ addi r11,r11,THREAD_SIZE
+ tophys(r11,r11)
+1: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
+.endm
+
+.macro EXCEPTION_PROLOG_2
+ stw r10,_CCR(r11) /* save registers */
+ stw r12,GPR12(r11)
+ stw r9,GPR9(r11)
+ mfspr r10,SPRN_SPRG_SCRATCH0
+ stw r10,GPR10(r11)
+ mfspr r12,SPRN_SPRG_SCRATCH1
+ stw r12,GPR11(r11)
+ mflr r10
+ stw r10,_LINK(r11)
+ mfspr r12,SPRN_SRR0
+ mfspr r9,SPRN_SRR1
+ stw r1,GPR1(r11)
+ stw r1,0(r11)
+ tovirt(r1,r11) /* set new kernel sp */
+ li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR) /* can take exceptions */
+ MTMSRD(r10) /* (except for mach check in rtas) */
+ stw r0,GPR0(r11)
+ lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
+ addi r10,r10,STACK_FRAME_REGS_MARKER@l
+ stw r10,8(r11)
+ SAVE_4GPRS(3, r11)
+ SAVE_2GPRS(7, r11)
+.endm
+
+/*
+ * Note: code which follows this uses cr0.eq (set if from kernel),
+ * r11, r12 (SRR0), and r9 (SRR1).
+ *
+ * Note2: once we have set r1 we are in a position to take exceptions
+ * again, and we could thus set MSR:RI at that point.
+ */
+
+/*
+ * Exception vectors.
+ */
+#ifdef CONFIG_PPC_BOOK3S
+#define START_EXCEPTION(n, label) \
+ . = n; \
+ DO_KVM n; \
+label:
+
+#else
+#define START_EXCEPTION(n, label) \
+ . = n; \
+label:
+
+#endif
+
+#define EXCEPTION(n, label, hdlr, xfer) \
+ START_EXCEPTION(n, label) \
+ EXCEPTION_PROLOG; \
+ addi r3,r1,STACK_FRAME_OVERHEAD; \
+ xfer(n, hdlr)
+
+#define EXC_XFER_TEMPLATE(n, hdlr, trap, copyee, tfer, ret) \
+ li r10,trap; \
+ stw r10,_TRAP(r11); \
+ li r10,MSR_KERNEL; \
+ copyee(r10, r9); \
+ bl tfer; \
+i##n: \
+ .long hdlr; \
+ .long ret
+
+#define COPY_EE(d, s) rlwimi d,s,0,MSR_EE
+#define NOCOPY(d, s)
+
+#define EXC_XFER_STD(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n, NOCOPY, transfer_to_handler_full, \
+ ret_from_except_full)
+
+#define EXC_XFER_LITE(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
+ ret_from_except)
+
+#define EXC_XFER_EE(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n, COPY_EE, transfer_to_handler_full, \
+ ret_from_except_full)
+
+#define EXC_XFER_EE_LITE(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n+1, COPY_EE, transfer_to_handler, \
+ ret_from_except)
+
+#endif /* __HEAD_32_H__ */