From 42c4aaadb737e0e672b3fb86b2c41ff59f0fb8bc Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 24 Oct 2006 16:42:40 +1000 Subject: [POWERPC] Consolidate feature fixup code There are currently two versions of the functions for applying the feature fixups, one for CPU features and one for firmware features. In addition, they are both in assembly and with separate implementations for 32 and 64 bits. identify_cpu() is also implemented in assembly and separately for 32 and 64 bits. This patch replaces them with a pair of C functions. The call sites are slightly moved on ppc64 as well to be called from C instead of from assembly, though it's a very small change, and thus shouldn't cause any problem. Signed-off-by: Benjamin Herrenschmidt Acked-by: Olof Johansson Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/setup_32.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/kernel/setup_32.c') diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index 191d0ab09222..769e511783b0 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -91,6 +91,7 @@ int ucache_bsize; unsigned long __init early_init(unsigned long dt_ptr) { unsigned long offset = reloc_offset(); + struct cpu_spec *spec; /* First zero the BSS -- use memset_io, some platforms don't have * caches on yet */ @@ -100,8 +101,11 @@ unsigned long __init early_init(unsigned long dt_ptr) * Identify the CPU type and fix up code sections * that depend on which cpu we have. */ - identify_cpu(offset, 0); - do_cpu_ftr_fixups(offset); + spec = identify_cpu(offset); + + do_feature_fixups(offset, spec->cpu_features, + PTRRELOC(&__start___ftr_fixup), + PTRRELOC(&__stop___ftr_fixup)); return KERNELBASE + offset; } -- cgit v1.2.2 From 0909c8c2d547e45ca50e2492b08ec93a37b35237 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Fri, 20 Oct 2006 11:47:18 +1000 Subject: [POWERPC] Support feature fixups in vdso's 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 Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/setup_32.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/kernel/setup_32.c') diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index 769e511783b0..a4c2964a3ca6 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -103,7 +103,7 @@ unsigned long __init early_init(unsigned long dt_ptr) */ spec = identify_cpu(offset); - do_feature_fixups(offset, spec->cpu_features, + do_feature_fixups(spec->cpu_features, PTRRELOC(&__start___ftr_fixup), PTRRELOC(&__stop___ftr_fixup)); -- cgit v1.2.2