From a4746364da0c7caa155cc945a5c10312e7925b46 Mon Sep 17 00:00:00 2001 From: Glauber de Oliveira Costa Date: Wed, 30 Jan 2008 13:32:05 +0100 Subject: [PATCH] x86: adjust PVOP_CALL/VCALL macros for 64-bit This patch adjust the PVOP_VCALL and PVOP_CALL macros to work with x86_64. It has a different calling convention, and we use auxiliary macros to account for both calling conventions as cleanly as possible Comments are adjusted accordingly. Signed-off-by: Glauber de Oliveira Costa Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/asm-x86/paravirt.h | 87 ++++++++++++++++++++++++++++---------- 1 file changed, 65 insertions(+), 22 deletions(-) diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h index 24406703007..bef93277266 100644 --- a/include/asm-x86/paravirt.h +++ b/include/asm-x86/paravirt.h @@ -320,7 +320,7 @@ int paravirt_disable_iospace(void); * runtime. * * Normally, a call to a pv_op function is a simple indirect call: - * (paravirt_ops.operations)(args...). + * (pv_op_struct.operations)(args...). * * Unfortunately, this is a relatively slow operation for modern CPUs, * because it cannot necessarily determine what the destination @@ -330,11 +330,17 @@ int paravirt_disable_iospace(void); * calls are essentially free, because the call and return addresses * are completely predictable.) * - * These macros rely on the standard gcc "regparm(3)" calling + * For i386, these macros rely on the standard gcc "regparm(3)" calling * convention, in which the first three arguments are placed in %eax, * %edx, %ecx (in that order), and the remaining arguments are placed * on the stack. All caller-save registers (eax,edx,ecx) are expected * to be modified (either clobbered or used for return values). + * X86_64, on the other hand, already specifies a register-based calling + * conventions, returning at %rax, with parameteres going on %rdi, %rsi, + * %rdx, and %rcx. Note that for this reason, x86_64 does not need any + * special handling for dealing with 4 arguments, unlike i386. + * However, x86_64 also have to clobber all caller saved registers, which + * unfortunately, are quite a bit (r8 - r11) * * The call instruction itself is marked by placing its start address * and size into the .parainstructions section, so that @@ -357,10 +363,12 @@ int paravirt_disable_iospace(void); * the return type. The macro then uses sizeof() on that type to * determine whether its a 32 or 64 bit value, and places the return * in the right register(s) (just %eax for 32-bit, and %edx:%eax for - * 64-bit). + * 64-bit). For x86_64 machines, it just returns at %rax regardless of + * the return value size. * * 64-bit arguments are passed as a pair of adjacent 32-bit arguments - * in low,high order. + * i386 also passes 64-bit arguments as a pair of adjacent 32-bit arguments + * in low,high order * * Small structures are passed and returned in registers. The macro * calling convention can't directly deal with this, so the wrapper @@ -370,46 +378,67 @@ int paravirt_disable_iospace(void); * means that all uses must be wrapped in inline functions. This also * makes sure the incoming and outgoing types are always correct. */ +#ifdef CONFIG_X86_32 +#define PVOP_VCALL_ARGS unsigned long __eax, __edx, __ecx +#define PVOP_CALL_ARGS PVOP_VCALL_ARGS +#define PVOP_VCALL_CLOBBERS "=a" (__eax), "=d" (__edx), \ + "=c" (__ecx) +#define PVOP_CALL_CLOBBERS PVOP_VCALL_CLOBBERS +#define EXTRA_CLOBBERS +#define VEXTRA_CLOBBERS +#else +#define PVOP_VCALL_ARGS unsigned long __edi, __esi, __edx, __ecx +#define PVOP_CALL_ARGS PVOP_VCALL_ARGS, __eax +#define PVOP_VCALL_CLOBBERS "=D" (__edi), \ + "=S" (__esi), "=d" (__edx), \ + "=c" (__ecx) + +#define PVOP_CALL_CLOBBERS PVOP_VCALL_CLOBBERS, "=a" (__eax) + +#define EXTRA_CLOBBERS , "r8", "r9", "r10", "r11" +#define VEXTRA_CLOBBERS , "rax", "r8", "r9", "r10", "r11" +#endif + #define __PVOP_CALL(rettype, op, pre, post, ...) \ ({ \ rettype __ret; \ - unsigned long __eax, __edx, __ecx; \ + PVOP_CALL_ARGS; \ + /* This is 32-bit specific, but is okay in 64-bit */ \ + /* since this condition will never hold */ \ if (sizeof(rettype) > sizeof(unsigned long)) { \ asm volatile(pre \ paravirt_alt(PARAVIRT_CALL) \ post \ - : "=a" (__eax), "=d" (__edx), \ - "=c" (__ecx) \ + : PVOP_CALL_CLOBBERS \ : paravirt_type(op), \ paravirt_clobber(CLBR_ANY), \ ##__VA_ARGS__ \ - : "memory", "cc"); \ + : "memory", "cc" EXTRA_CLOBBERS); \ __ret = (rettype)((((u64)__edx) << 32) | __eax); \ } else { \ asm volatile(pre \ paravirt_alt(PARAVIRT_CALL) \ post \ - : "=a" (__eax), "=d" (__edx), \ - "=c" (__ecx) \ + : PVOP_CALL_CLOBBERS \ : paravirt_type(op), \ paravirt_clobber(CLBR_ANY), \ ##__VA_ARGS__ \ - : "memory", "cc"); \ + : "memory", "cc" EXTRA_CLOBBERS); \ __ret = (rettype)__eax; \ } \ __ret; \ }) #define __PVOP_VCALL(op, pre, post, ...) \ ({ \ - unsigned long __eax, __edx, __ecx; \ + PVOP_VCALL_ARGS; \ asm volatile(pre \ paravirt_alt(PARAVIRT_CALL) \ post \ - : "=a" (__eax), "=d" (__edx), "=c" (__ecx) \ + : PVOP_VCALL_CLOBBERS \ : paravirt_type(op), \ paravirt_clobber(CLBR_ANY), \ ##__VA_ARGS__ \ - : "memory", "cc"); \ + : "memory", "cc" VEXTRA_CLOBBERS); \ }) #define PVOP_CALL0(rettype, op) \ @@ -418,22 +447,26 @@ int paravirt_disable_iospace(void); __PVOP_VCALL(op, "", "") #define PVOP_CALL1(rettype, op, arg1) \ - __PVOP_CALL(rettype, op, "", "", "0" ((u32)(arg1))) + __PVOP_CALL(rettype, op, "", "", "0" ((unsigned long)(arg1))) #define PVOP_VCALL1(op, arg1) \ - __PVOP_VCALL(op, "", "", "0" ((u32)(arg1))) + __PVOP_VCALL(op, "", "", "0" ((unsigned long)(arg1))) #define PVOP_CALL2(rettype, op, arg1, arg2) \ - __PVOP_CALL(rettype, op, "", "", "0" ((u32)(arg1)), "1" ((u32)(arg2))) + __PVOP_CALL(rettype, op, "", "", "0" ((unsigned long)(arg1)), \ + "1" ((unsigned long)(arg2))) #define PVOP_VCALL2(op, arg1, arg2) \ - __PVOP_VCALL(op, "", "", "0" ((u32)(arg1)), "1" ((u32)(arg2))) + __PVOP_VCALL(op, "", "", "0" ((unsigned long)(arg1)), \ + "1" ((unsigned long)(arg2))) #define PVOP_CALL3(rettype, op, arg1, arg2, arg3) \ - __PVOP_CALL(rettype, op, "", "", "0" ((u32)(arg1)), \ - "1"((u32)(arg2)), "2"((u32)(arg3))) + __PVOP_CALL(rettype, op, "", "", "0" ((unsigned long)(arg1)), \ + "1"((unsigned long)(arg2)), "2"((unsigned long)(arg3))) #define PVOP_VCALL3(op, arg1, arg2, arg3) \ - __PVOP_VCALL(op, "", "", "0" ((u32)(arg1)), "1"((u32)(arg2)), \ - "2"((u32)(arg3))) + __PVOP_VCALL(op, "", "", "0" ((unsigned long)(arg1)), \ + "1"((unsigned long)(arg2)), "2"((unsigned long)(arg3))) +/* This is the only difference in x86_64. We can make it much simpler */ +#ifdef CONFIG_X86_32 #define PVOP_CALL4(rettype, op, arg1, arg2, arg3, arg4) \ __PVOP_CALL(rettype, op, \ "push %[_arg4];", "lea 4(%%esp),%%esp;", \ @@ -444,6 +477,16 @@ int paravirt_disable_iospace(void); "push %[_arg4];", "lea 4(%%esp),%%esp;", \ "0" ((u32)(arg1)), "1" ((u32)(arg2)), \ "2" ((u32)(arg3)), [_arg4] "mr" ((u32)(arg4))) +#else +#define PVOP_CALL4(rettype, op, arg1, arg2, arg3, arg4) \ + __PVOP_CALL(rettype, op, "", "", "0" ((unsigned long)(arg1)), \ + "1"((unsigned long)(arg2)), "2"((unsigned long)(arg3)), \ + "3"((unsigned long)(arg4))) +#define PVOP_VCALL4(op, arg1, arg2, arg3, arg4) \ + __PVOP_VCALL(op, "", "", "0" ((unsigned long)(arg1)), \ + "1"((unsigned long)(arg2)), "2"((unsigned long)(arg3)), \ + "3"((unsigned long)(arg4))) +#endif static inline int paravirt_enabled(void) { -- 2.20.1