linux-stable/arch/powerpc/include/asm/exception-64s.h
Nicholas Piggin 04ece7b60b KVM: PPC: Book3S 64: Move hcall early register setup to KVM
System calls / hcalls have a different calling convention than
other interrupts, so there is code in the KVMTEST to massage these
into the same form as other interrupt handlers.

Move this work into the KVM hcall handler. This means teaching KVM
a little more about the low level interrupt handler setup, PACA save
areas, etc., although that's not obviously worse than the current
approach of coming up with an entirely different interrupt register
/ save convention.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-5-npiggin@gmail.com
2021-06-10 22:12:12 +10:00

178 lines
4.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _ASM_POWERPC_EXCEPTION_H
#define _ASM_POWERPC_EXCEPTION_H
/*
* Extracted from head_64.S
*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
* Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
* Adapted for Power Macintosh by Paul Mackerras.
* Low-level exception handlers and MMU support
* rewritten by Paul Mackerras.
* Copyright (C) 1996 Paul Mackerras.
*
* Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
* Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
*
* This file contains the low-level support and setup for the
* PowerPC-64 platform, including trap and interrupt dispatch.
*/
/*
* The following macros define the code that appears as
* the prologue to each of the exception handlers. They
* are split into two parts to allow a single kernel binary
* to be used for pSeries and iSeries.
*
* We make as much of the exception code common between native
* exception handlers (including pSeries LPAR) and iSeries LPAR
* implementations as possible.
*/
#include <asm/feature-fixups.h>
/* PACA save area size in u64 units (exgen, exmc, etc) */
#define EX_SIZE 10
/* PACA save area offsets */
#define EX_R9 0
#define EX_R10 8
#define EX_R11 16
#define EX_R12 24
#define EX_R13 32
#define EX_DAR 40
#define EX_DSISR 48
#define EX_CCR 52
#define EX_CFAR 56
#define EX_PPR 64
#define EX_CTR 72
/*
* maximum recursive depth of MCE exceptions
*/
#define MAX_MCE_DEPTH 4
#ifdef __ASSEMBLY__
#define STF_ENTRY_BARRIER_SLOT \
STF_ENTRY_BARRIER_FIXUP_SECTION; \
nop; \
nop; \
nop
#define STF_EXIT_BARRIER_SLOT \
STF_EXIT_BARRIER_FIXUP_SECTION; \
nop; \
nop; \
nop; \
nop; \
nop; \
nop
#define ENTRY_FLUSH_SLOT \
ENTRY_FLUSH_FIXUP_SECTION; \
nop; \
nop; \
nop;
#define SCV_ENTRY_FLUSH_SLOT \
SCV_ENTRY_FLUSH_FIXUP_SECTION; \
nop; \
nop; \
nop;
/*
* r10 must be free to use, r13 must be paca
*/
#define INTERRUPT_TO_KERNEL \
STF_ENTRY_BARRIER_SLOT; \
ENTRY_FLUSH_SLOT
/*
* r10, ctr must be free to use, r13 must be paca
*/
#define SCV_INTERRUPT_TO_KERNEL \
STF_ENTRY_BARRIER_SLOT; \
SCV_ENTRY_FLUSH_SLOT
/*
* Macros for annotating the expected destination of (h)rfid
*
* The nop instructions allow us to insert one or more instructions to flush the
* L1-D cache when returning to userspace or a guest.
*
* powerpc relies on return from interrupt/syscall being context synchronising
* (which hrfid, rfid, and rfscv are) to support ARCH_HAS_MEMBARRIER_SYNC_CORE
* without additional synchronisation instructions.
*
* soft-masked interrupt replay does not include a context-synchronising rfid,
* but those always return to kernel, the sync is only required when returning
* to user.
*/
#define RFI_FLUSH_SLOT \
RFI_FLUSH_FIXUP_SECTION; \
nop; \
nop; \
nop
#define RFI_TO_KERNEL \
rfid
#define RFI_TO_USER \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
rfid; \
b rfi_flush_fallback
#define RFI_TO_USER_OR_KERNEL \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
rfid; \
b rfi_flush_fallback
#define RFI_TO_GUEST \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
rfid; \
b rfi_flush_fallback
#define HRFI_TO_KERNEL \
hrfid
#define HRFI_TO_USER \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
hrfid; \
b hrfi_flush_fallback
#define HRFI_TO_USER_OR_KERNEL \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
hrfid; \
b hrfi_flush_fallback
#define HRFI_TO_GUEST \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
hrfid; \
b hrfi_flush_fallback
#define HRFI_TO_UNKNOWN \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
hrfid; \
b hrfi_flush_fallback
#define RFSCV_TO_USER \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
RFSCV; \
b rfscv_flush_fallback
#else /* __ASSEMBLY__ */
/* Prototype for function defined in exceptions-64s.S */
void do_uaccess_flush(void);
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_EXCEPTION_H */