c78d0c7484
The dma section name is confusing, since the code which resides within that section has nothing to do with direct memory access. Instead the limitation is that the code has to run in 31 bit addressing mode, and therefore has to reside below 2GB. So the name was chosen since ZONE_DMA is the same region. To reduce confusion rename the section to amode31, which hopefully describes better what this is about. Note: this will also change vmcoreinfo strings - SDMA=... gets renamed to SAMODE31=... - EDMA=... gets renamed to EAMODE31=... Acked-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
77 lines
2.0 KiB
C
77 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __S390_EXTABLE_H
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#define __S390_EXTABLE_H
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#include <asm/ptrace.h>
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#include <linux/compiler.h>
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/*
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* The exception table consists of three addresses:
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*
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* - Address of an instruction that is allowed to fault.
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* - Address at which the program should continue.
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* - Optional address of handler that takes pt_regs * argument and runs in
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* interrupt context.
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*
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* No registers are modified, so it is entirely up to the continuation code
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* to figure out what to do.
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*
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* All the routines below use bits of fixup code that are out of line
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* with the main instruction path. This means when everything is well,
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* we don't even have to jump over them. Further, they do not intrude
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* on our cache or tlb entries.
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*/
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struct exception_table_entry
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{
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int insn, fixup;
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long handler;
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};
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extern struct exception_table_entry *__start_amode31_ex_table;
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extern struct exception_table_entry *__stop_amode31_ex_table;
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const struct exception_table_entry *s390_search_extables(unsigned long addr);
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static inline unsigned long extable_fixup(const struct exception_table_entry *x)
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{
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return (unsigned long)&x->fixup + x->fixup;
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}
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typedef bool (*ex_handler_t)(const struct exception_table_entry *,
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struct pt_regs *);
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static inline ex_handler_t
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ex_fixup_handler(const struct exception_table_entry *x)
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{
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if (likely(!x->handler))
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return NULL;
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return (ex_handler_t)((unsigned long)&x->handler + x->handler);
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}
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static inline bool ex_handle(const struct exception_table_entry *x,
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struct pt_regs *regs)
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{
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ex_handler_t handler = ex_fixup_handler(x);
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if (unlikely(handler))
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return handler(x, regs);
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regs->psw.addr = extable_fixup(x);
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return true;
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}
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#define ARCH_HAS_RELATIVE_EXTABLE
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static inline void swap_ex_entry_fixup(struct exception_table_entry *a,
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struct exception_table_entry *b,
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struct exception_table_entry tmp,
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int delta)
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{
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a->fixup = b->fixup + delta;
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b->fixup = tmp.fixup - delta;
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a->handler = b->handler + delta;
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b->handler = tmp.handler - delta;
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}
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#endif
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