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0909c8c2d5
This patch reworks the feature fixup mecanism so vdso's can be fixed up.
The main issue was that the construct:
.long label (or .llong on 64 bits)
will not work in the case of a shared library like the vdso. It will
generate an empty placeholder in the fixup table along with a reloc,
which is not something we can deal with in the vdso.
The idea here (thanks Alan Modra !) is to instead use something like:
1:
.long label - 1b
That is, the feature fixup tables no longer contain addresses of bits of
code to patch, but offsets of such code from the fixup table entry
itself. That is properly resolved by ld when building the .so's. I've
modified the fixup mecanism generically to use that method for the rest
of the kernel as well.
Another trick is that the 32 bits vDSO included in the 64 bits kernel
need to have a table in the 64 bits format. However, gas does not
support 32 bits code with a statement of the form:
.llong label - 1b (Or even just .llong label)
That is, it cannot emit the right fixup/relocation for the linker to use
to assign a 32 bits address to an .llong field. Thus, in the specific
case of the 32 bits vdso built as part of the 64 bits kernel, we are
using a modified macro that generates:
.long 0xffffffff
.llong label - 1b
Note that is assumes that the value is negative which is enforced by
the .lds (those offsets are always negative as the .text is always
before the fixup table and gas doesn't support emiting the reloc the
other way around).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
116 lines
4.0 KiB
C
116 lines
4.0 KiB
C
/*
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* Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org)
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*
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* Modifications for ppc64:
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* Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef __ASM_POWERPC_FIRMWARE_H
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#define __ASM_POWERPC_FIRMWARE_H
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#ifdef __KERNEL__
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#include <asm/asm-compat.h>
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/* firmware feature bitmask values */
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#define FIRMWARE_MAX_FEATURES 63
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#define FW_FEATURE_PFT ASM_CONST(0x0000000000000001)
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#define FW_FEATURE_TCE ASM_CONST(0x0000000000000002)
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#define FW_FEATURE_SPRG0 ASM_CONST(0x0000000000000004)
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#define FW_FEATURE_DABR ASM_CONST(0x0000000000000008)
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#define FW_FEATURE_COPY ASM_CONST(0x0000000000000010)
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#define FW_FEATURE_ASR ASM_CONST(0x0000000000000020)
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#define FW_FEATURE_DEBUG ASM_CONST(0x0000000000000040)
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#define FW_FEATURE_TERM ASM_CONST(0x0000000000000080)
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#define FW_FEATURE_PERF ASM_CONST(0x0000000000000100)
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#define FW_FEATURE_DUMP ASM_CONST(0x0000000000000200)
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#define FW_FEATURE_INTERRUPT ASM_CONST(0x0000000000000400)
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#define FW_FEATURE_MIGRATE ASM_CONST(0x0000000000000800)
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#define FW_FEATURE_PERFMON ASM_CONST(0x0000000000001000)
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#define FW_FEATURE_CRQ ASM_CONST(0x0000000000002000)
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#define FW_FEATURE_VIO ASM_CONST(0x0000000000004000)
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#define FW_FEATURE_RDMA ASM_CONST(0x0000000000008000)
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#define FW_FEATURE_LLAN ASM_CONST(0x0000000000010000)
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#define FW_FEATURE_BULK ASM_CONST(0x0000000000020000)
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#define FW_FEATURE_XDABR ASM_CONST(0x0000000000040000)
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#define FW_FEATURE_MULTITCE ASM_CONST(0x0000000000080000)
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#define FW_FEATURE_SPLPAR ASM_CONST(0x0000000000100000)
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#define FW_FEATURE_ISERIES ASM_CONST(0x0000000000200000)
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#define FW_FEATURE_LPAR ASM_CONST(0x0000000000400000)
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#ifndef __ASSEMBLY__
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enum {
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#ifdef CONFIG_PPC64
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FW_FEATURE_PSERIES_POSSIBLE = FW_FEATURE_PFT | FW_FEATURE_TCE |
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FW_FEATURE_SPRG0 | FW_FEATURE_DABR | FW_FEATURE_COPY |
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FW_FEATURE_ASR | FW_FEATURE_DEBUG | FW_FEATURE_TERM |
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FW_FEATURE_PERF | FW_FEATURE_DUMP | FW_FEATURE_INTERRUPT |
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FW_FEATURE_MIGRATE | FW_FEATURE_PERFMON | FW_FEATURE_CRQ |
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FW_FEATURE_VIO | FW_FEATURE_RDMA | FW_FEATURE_LLAN |
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FW_FEATURE_BULK | FW_FEATURE_XDABR | FW_FEATURE_MULTITCE |
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FW_FEATURE_SPLPAR | FW_FEATURE_LPAR,
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FW_FEATURE_PSERIES_ALWAYS = 0,
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FW_FEATURE_ISERIES_POSSIBLE = FW_FEATURE_ISERIES | FW_FEATURE_LPAR,
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FW_FEATURE_ISERIES_ALWAYS = FW_FEATURE_ISERIES | FW_FEATURE_LPAR,
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FW_FEATURE_POSSIBLE =
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#ifdef CONFIG_PPC_PSERIES
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FW_FEATURE_PSERIES_POSSIBLE |
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#endif
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#ifdef CONFIG_PPC_ISERIES
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FW_FEATURE_ISERIES_POSSIBLE |
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#endif
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0,
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FW_FEATURE_ALWAYS =
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#ifdef CONFIG_PPC_PSERIES
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FW_FEATURE_PSERIES_ALWAYS &
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#endif
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#ifdef CONFIG_PPC_ISERIES
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FW_FEATURE_ISERIES_ALWAYS &
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#endif
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FW_FEATURE_POSSIBLE,
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#else /* CONFIG_PPC64 */
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FW_FEATURE_POSSIBLE = 0,
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FW_FEATURE_ALWAYS = 0,
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#endif
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};
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/* This is used to identify firmware features which are available
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* to the kernel.
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*/
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extern unsigned long powerpc_firmware_features;
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#define firmware_has_feature(feature) \
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((FW_FEATURE_ALWAYS & (feature)) || \
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(FW_FEATURE_POSSIBLE & powerpc_firmware_features & (feature)))
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extern void system_reset_fwnmi(void);
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extern void machine_check_fwnmi(void);
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/* This is true if we are using the firmware NMI handler (typically LPAR) */
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extern int fwnmi_active;
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extern unsigned int __start___fw_ftr_fixup, __stop___fw_ftr_fixup;
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#else /* __ASSEMBLY__ */
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#define BEGIN_FW_FTR_SECTION_NESTED(label) label:
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#define BEGIN_FW_FTR_SECTION BEGIN_FW_FTR_SECTION_NESTED(97)
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#define END_FW_FTR_SECTION_NESTED(msk, val, label) \
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MAKE_FTR_SECTION_ENTRY(msk, val, label, __fw_ftr_fixup)
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#define END_FW_FTR_SECTION(msk, val) \
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END_FW_FTR_SECTION_NESTED(msk, val, 97)
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#define END_FW_FTR_SECTION_IFSET(msk) END_FW_FTR_SECTION((msk), (msk))
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#define END_FW_FTR_SECTION_IFCLR(msk) END_FW_FTR_SECTION((msk), 0)
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#endif /* __ASSEMBLY__ */
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#endif /* __KERNEL__ */
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#endif /* __ASM_POWERPC_FIRMWARE_H */
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