From 2ca7633dc73405ee775a2e9b7961b47a38bc882d Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Sun, 11 May 2008 10:40:47 +1000 Subject: [POWERPC] Tweak VDSO linker script to avoid upsetting old binutils This works around bugs in older binutils' objcopy. The placement of these sections does not really matter, but it confused the buggy old BFD libraries. Signed-off-by: Roland McGrath Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/vdso64/vdso64.lds.S | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/powerpc/kernel/vdso64') diff --git a/arch/powerpc/kernel/vdso64/vdso64.lds.S b/arch/powerpc/kernel/vdso64/vdso64.lds.S index 932b3fdb34b9..7d6585f90277 100644 --- a/arch/powerpc/kernel/vdso64/vdso64.lds.S +++ b/arch/powerpc/kernel/vdso64/vdso64.lds.S @@ -43,15 +43,15 @@ SECTIONS .rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) } .rodata1 : { *(.rodata1) } + .dynamic : { *(.dynamic) } :text :dynamic + .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr .eh_frame : { KEEP (*(.eh_frame)) } :text .gcc_except_table : { *(.gcc_except_table) } + .rela.dyn ALIGN(8) : { *(.rela.dyn) } .opd ALIGN(8) : { KEEP (*(.opd)) } .got ALIGN(8) : { *(.got .toc) } - .rela.dyn ALIGN(8) : { *(.rela.dyn) } - - .dynamic : { *(.dynamic) } :text :dynamic _end = .; PROVIDE(end = .); -- cgit v1.2.3 From fac23fe4be23259a8eaa9bad822f5b14dd07d15c Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 24 Jun 2008 11:32:54 +1000 Subject: powerpc: Introduce infrastructure for feature sections with alternatives The current feature section logic only supports nop'ing out code, this means if you want to choose at runtime between instruction sequences, one or both cases will have to execute the nop'ed out contents of the other section, eg: BEGIN_FTR_SECTION or 1,1,1 END_FTR_SECTION_IFSET(FOO) BEGIN_FTR_SECTION or 2,2,2 END_FTR_SECTION_IFCLR(FOO) and the resulting code will be either, or 1,1,1 nop or, nop or 2,2,2 For small code segments this is fine, but for larger code blocks and in performance criticial code segments, it would be nice to avoid the nops. This commit starts to implement logic to allow the following: BEGIN_FTR_SECTION or 1,1,1 FTR_SECTION_ELSE or 2,2,2 ALT_FTR_SECTION_END_IFSET(FOO) and the resulting code will be: or 1,1,1 or, or 2,2,2 We achieve this by extending the existing FTR macros. The current feature section semantic just becomes a special case, ie. if the else case is empty we nop out the default case. The key limitation is that the size of the else case must be less than or equal to the size of the default case. If the else case is smaller the remainder of the section is nop'ed. We let the linker put the else case code in with the rest of the text, so that relative branches from the else case are more likley to link, this has the disadvantage that we can't free the unused else cases. This commit introduces the required macro and linker script changes, but does not enable the patching of the alternative sections. We also need to update two hand-made section entries in reg.h and timex.h Signed-off-by: Michael Ellerman Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/vdso64/vdso64.lds.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/kernel/vdso64') diff --git a/arch/powerpc/kernel/vdso64/vdso64.lds.S b/arch/powerpc/kernel/vdso64/vdso64.lds.S index 7d6585f90277..e608d1bd3bff 100644 --- a/arch/powerpc/kernel/vdso64/vdso64.lds.S +++ b/arch/powerpc/kernel/vdso64/vdso64.lds.S @@ -24,7 +24,7 @@ SECTIONS . = ALIGN(16); .text : { - *(.text .stub .text.* .gnu.linkonce.t.*) + *(.text .stub .text.* .gnu.linkonce.t.* __ftr_alt_*) *(.sfpr .glink) } :text PROVIDE(__etext = .); -- cgit v1.2.3 From 2d1b2027626d5151fff8ef7c06ca8e7876a1a510 Mon Sep 17 00:00:00 2001 From: Kumar Gala Date: Wed, 2 Jul 2008 01:16:40 +1000 Subject: powerpc: Fixup lwsync at runtime To allow for a single kernel image on e500 v1/v2/mc we need to fixup lwsync at runtime. On e500v1/v2 lwsync causes an illop so we need to patch up the code. We default to 'sync' since that is always safe and if the cpu is capable we will replace 'sync' with 'lwsync'. We introduce CPU_FTR_LWSYNC as a way to determine at runtime if this is needed. This flag could be moved elsewhere since we dont really use it for the normal CPU_FTR purpose. Finally we only store the relative offset in the fixup section to keep it as small as possible rather than using a full fixup_entry. Signed-off-by: Kumar Gala Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/vdso64/vdso64.lds.S | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/powerpc/kernel/vdso64') diff --git a/arch/powerpc/kernel/vdso64/vdso64.lds.S b/arch/powerpc/kernel/vdso64/vdso64.lds.S index e608d1bd3bff..d0b2526dd38d 100644 --- a/arch/powerpc/kernel/vdso64/vdso64.lds.S +++ b/arch/powerpc/kernel/vdso64/vdso64.lds.S @@ -34,6 +34,9 @@ SECTIONS . = ALIGN(8); __ftr_fixup : { *(__ftr_fixup) } + . = ALIGN(8); + __lwsync_fixup : { *(__lwsync_fixup) } + . = ALIGN(8); __fw_ftr_fixup : { *(__fw_ftr_fixup) } -- cgit v1.2.3