Partial revert of commit 129d8bc828e011bda0b7110a097bf3a0167f966e titled 'x86: don't compile vsmp_64 for 32bit' Commit reverted to compile vsmp_64.c if CONFIG_X86_64 is defined, since is_vsmp_box() needs to indicate that TSCs are not synchronized, and hence, not a valid time source, even when CONFIG_X86_VSMP is not defined. Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: shai@scalex86.org LKML-Reference: <20090324061429.GH7278@localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup that is only needed when CONFIG_X86_VSMP is defined with 64bit also remove dead code about PCI, because CONFIG_X86_VSMP depends on PCI Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: Optimization One of the problems with inserting a pile of C calls where previously there were none is that the register pressure is greatly increased. The C calling convention says that the caller must expect a certain set of registers may be trashed by the callee, and that the callee can use those registers without restriction. This includes the function argument registers, and several others. This patch seeks to alleviate this pressure by introducing wrapper thunks that will do the register saving/restoring, so that the callsite doesn't need to worry about it, but the callee function can be conventional compiler-generated code. In many cases (particularly performance-sensitive cases) the callee will be in assembler anyway, and need not use the compiler's calling convention. Standard calling convention is: arguments return scratch x86-32 eax edx ecx eax ? x86-64 rdi rsi rdx rcx rax r8 r9 r10 r11 The thunk preserves all argument and scratch registers. The return register is not preserved, and is available as a scratch register for unwrapped callee code (and of course the return value). Wrapped function pointers are themselves wrapped in a struct paravirt_callee_save structure, in order to get some warning from the compiler when functions with mismatched calling conventions are used. The most common paravirt ops, both statically and dynamically, are interrupt enable/disable/save/restore, so handle them first. This is particularly easy since their calls are handled specially anyway. XXX Deal with VMI. What's their calling convention? Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: fewer sparse warnings, no functional changes arch/x86/kernel/vsmp_64.c:87:14: warning: incorrect type in argument 1 (different address spaces) arch/x86/kernel/vsmp_64.c:87:14: expected void const volatile [noderef] <asn:2>*addr arch/x86/kernel/vsmp_64.c:87:14: got void *[assigned] address arch/x86/kernel/vsmp_64.c:88:22: warning: incorrect type in argument 1 (different address spaces) arch/x86/kernel/vsmp_64.c:88:22: expected void const volatile [noderef] <asn:2>*addr arch/x86/kernel/vsmp_64.c:88:22: got void * arch/x86/kernel/vsmp_64.c:100:23: warning: incorrect type in argument 2 (different address spaces) arch/x86/kernel/vsmp_64.c:100:23: expected void volatile [noderef] <asn:2>*addr arch/x86/kernel/vsmp_64.c:100:23: got void * arch/x86/kernel/vsmp_64.c:101:23: warning: incorrect type in argument 1 (different address spaces) arch/x86/kernel/vsmp_64.c:101:23: expected void const volatile [noderef] <asn:2>*addr arch/x86/kernel/vsmp_64.c:101:23: got void * arch/x86/mm/gup.c:235:6: warning: incorrect type in argument 1 (different base types) arch/x86/mm/gup.c:235:6: expected void const volatile [noderef] <asn:1>*<noident> arch/x86/mm/gup.c:235:6: got unsigned long [unsigned] [assigned] start Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
27-rc fails to boot up if configured to use modules. Turns out vsmp_patch was marked __init, and vsmp_patch being the pvops 'patch' routine for vsmp, a call to vsmp_patch just turns out to execute a code page with series of 0xcc (POISON_FREE_INITMEM -- int3). vsmp_patch has been marked with __init ever since pvops, however, apply_paravirt can be called during module load causing calls to freed memory location. Since apply_paravirt can only be called during init/module load, make vsmp_patch with "__init_or_module" Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
sparse mutters: arch/x86/kernel/vsmp_64.c:126:5: warning: symbol 'is_vsmp_box' was not declared. Should it be static? arch/x86/kernel/vsmp_64.c:145:13: warning: symbol 'vsmp_init' was not declared. Should it be static? Include the appropriate headers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
The function detect_vsmp_box is a void function in the PCI case. Change the !PCI stub to void too. Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
vSMP detection: access pci config space early in boot to detect if the system is a vSMPowered box, and cache the result in a flag, so that is_vsmp_box() retrieves the value of the flag always. Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
code got a bit smaller:
arch/x86/kernel/vsmp_64.o:
text data bss dec hex filename
205 4 0 209 d1 vsmp_64.o.before
181 4 0 185 b9 vsmp_64.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Re-arrange set_vsmp_pv_ops so that pv_ops are set only if the platform has capability to support paravirtualized irq ops Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>