forked from Minki/linux
139ec7c416
It turns out that the most called ops, by several orders of magnitude, are the interrupt manipulation ops. These are obvious candidates for patching, so mark them up and create infrastructure for it. The method used is that the ops structure has a patch function, which is called for each place which needs to be patched: this returns a number of instructions (the rest are NOP-padded). Usually we can spare a register (%eax) for the binary patched code to use, but in a couple of critical places in entry.S we can't: we make the clobbers explicit at the call site, and manually clobber the allowed registers in debug mode as an extra check. And: Don't abuse CONFIG_DEBUG_KERNEL, add CONFIG_DEBUG_PARAVIRT. And: AK: Fix warnings in x86-64 alternative.c build And: AK: Fix compilation with defconfig And: ^From: Andrew Morton <akpm@osdl.org> Some binutlises still like to emit references to __stop_parainstructions and __start_parainstructions. And: AK: Fix warnings about unused variables when PARAVIRT is disabled. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
399 lines
12 KiB
C
399 lines
12 KiB
C
#ifndef __ASM_PARAVIRT_H
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#define __ASM_PARAVIRT_H
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/* Various instructions on x86 need to be replaced for
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* para-virtualization: those hooks are defined here. */
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#include <linux/linkage.h>
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#include <linux/stringify.h>
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#ifdef CONFIG_PARAVIRT
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/* These are the most performance critical ops, so we want to be able to patch
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* callers */
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#define PARAVIRT_IRQ_DISABLE 0
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#define PARAVIRT_IRQ_ENABLE 1
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#define PARAVIRT_RESTORE_FLAGS 2
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#define PARAVIRT_SAVE_FLAGS 3
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#define PARAVIRT_SAVE_FLAGS_IRQ_DISABLE 4
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#define PARAVIRT_INTERRUPT_RETURN 5
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#define PARAVIRT_STI_SYSEXIT 6
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/* Bitmask of what can be clobbered: usually at least eax. */
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#define CLBR_NONE 0x0
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#define CLBR_EAX 0x1
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#define CLBR_ECX 0x2
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#define CLBR_EDX 0x4
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#define CLBR_ANY 0x7
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#ifndef __ASSEMBLY__
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struct thread_struct;
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struct Xgt_desc_struct;
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struct tss_struct;
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struct paravirt_ops
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{
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unsigned int kernel_rpl;
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int paravirt_enabled;
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const char *name;
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/*
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* Patch may replace one of the defined code sequences with arbitrary
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* code, subject to the same register constraints. This generally
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* means the code is not free to clobber any registers other than EAX.
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* The patch function should return the number of bytes of code
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* generated, as we nop pad the rest in generic code.
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*/
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unsigned (*patch)(u8 type, u16 clobber, void *firstinsn, unsigned len);
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void (*arch_setup)(void);
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char *(*memory_setup)(void);
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void (*init_IRQ)(void);
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void (*banner)(void);
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unsigned long (*get_wallclock)(void);
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int (*set_wallclock)(unsigned long);
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void (*time_init)(void);
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/* All the function pointers here are declared as "fastcall"
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so that we get a specific register-based calling
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convention. This makes it easier to implement inline
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assembler replacements. */
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void (fastcall *cpuid)(unsigned int *eax, unsigned int *ebx,
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unsigned int *ecx, unsigned int *edx);
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unsigned long (fastcall *get_debugreg)(int regno);
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void (fastcall *set_debugreg)(int regno, unsigned long value);
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void (fastcall *clts)(void);
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unsigned long (fastcall *read_cr0)(void);
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void (fastcall *write_cr0)(unsigned long);
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unsigned long (fastcall *read_cr2)(void);
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void (fastcall *write_cr2)(unsigned long);
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unsigned long (fastcall *read_cr3)(void);
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void (fastcall *write_cr3)(unsigned long);
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unsigned long (fastcall *read_cr4_safe)(void);
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unsigned long (fastcall *read_cr4)(void);
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void (fastcall *write_cr4)(unsigned long);
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unsigned long (fastcall *save_fl)(void);
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void (fastcall *restore_fl)(unsigned long);
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void (fastcall *irq_disable)(void);
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void (fastcall *irq_enable)(void);
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void (fastcall *safe_halt)(void);
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void (fastcall *halt)(void);
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void (fastcall *wbinvd)(void);
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/* err = 0/-EFAULT. wrmsr returns 0/-EFAULT. */
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u64 (fastcall *read_msr)(unsigned int msr, int *err);
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int (fastcall *write_msr)(unsigned int msr, u64 val);
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u64 (fastcall *read_tsc)(void);
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u64 (fastcall *read_pmc)(void);
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void (fastcall *load_tr_desc)(void);
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void (fastcall *load_gdt)(const struct Xgt_desc_struct *);
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void (fastcall *load_idt)(const struct Xgt_desc_struct *);
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void (fastcall *store_gdt)(struct Xgt_desc_struct *);
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void (fastcall *store_idt)(struct Xgt_desc_struct *);
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void (fastcall *set_ldt)(const void *desc, unsigned entries);
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unsigned long (fastcall *store_tr)(void);
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void (fastcall *load_tls)(struct thread_struct *t, unsigned int cpu);
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void (fastcall *write_ldt_entry)(void *dt, int entrynum,
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u32 low, u32 high);
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void (fastcall *write_gdt_entry)(void *dt, int entrynum,
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u32 low, u32 high);
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void (fastcall *write_idt_entry)(void *dt, int entrynum,
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u32 low, u32 high);
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void (fastcall *load_esp0)(struct tss_struct *tss,
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struct thread_struct *thread);
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void (fastcall *set_iopl_mask)(unsigned mask);
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void (fastcall *io_delay)(void);
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void (*const_udelay)(unsigned long loops);
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/* These two are jmp to, not actually called. */
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void (fastcall *irq_enable_sysexit)(void);
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void (fastcall *iret)(void);
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};
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extern struct paravirt_ops paravirt_ops;
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#define paravirt_enabled() (paravirt_ops.paravirt_enabled)
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static inline void load_esp0(struct tss_struct *tss,
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struct thread_struct *thread)
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{
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paravirt_ops.load_esp0(tss, thread);
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}
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#define ARCH_SETUP paravirt_ops.arch_setup();
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static inline unsigned long get_wallclock(void)
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{
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return paravirt_ops.get_wallclock();
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}
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static inline int set_wallclock(unsigned long nowtime)
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{
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return paravirt_ops.set_wallclock(nowtime);
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}
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static inline void do_time_init(void)
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{
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return paravirt_ops.time_init();
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}
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/* The paravirtualized CPUID instruction. */
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static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
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unsigned int *ecx, unsigned int *edx)
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{
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paravirt_ops.cpuid(eax, ebx, ecx, edx);
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}
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/*
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* These special macros can be used to get or set a debugging register
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*/
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#define get_debugreg(var, reg) var = paravirt_ops.get_debugreg(reg)
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#define set_debugreg(val, reg) paravirt_ops.set_debugreg(reg, val)
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#define clts() paravirt_ops.clts()
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#define read_cr0() paravirt_ops.read_cr0()
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#define write_cr0(x) paravirt_ops.write_cr0(x)
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#define read_cr2() paravirt_ops.read_cr2()
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#define write_cr2(x) paravirt_ops.write_cr2(x)
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#define read_cr3() paravirt_ops.read_cr3()
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#define write_cr3(x) paravirt_ops.write_cr3(x)
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#define read_cr4() paravirt_ops.read_cr4()
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#define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
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#define write_cr4(x) paravirt_ops.write_cr4(x)
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static inline void raw_safe_halt(void)
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{
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paravirt_ops.safe_halt();
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}
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static inline void halt(void)
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{
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paravirt_ops.safe_halt();
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}
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#define wbinvd() paravirt_ops.wbinvd()
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#define get_kernel_rpl() (paravirt_ops.kernel_rpl)
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#define rdmsr(msr,val1,val2) do { \
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int _err; \
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u64 _l = paravirt_ops.read_msr(msr,&_err); \
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val1 = (u32)_l; \
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val2 = _l >> 32; \
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} while(0)
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#define wrmsr(msr,val1,val2) do { \
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u64 _l = ((u64)(val2) << 32) | (val1); \
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paravirt_ops.write_msr((msr), _l); \
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} while(0)
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#define rdmsrl(msr,val) do { \
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int _err; \
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val = paravirt_ops.read_msr((msr),&_err); \
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} while(0)
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#define wrmsrl(msr,val) (paravirt_ops.write_msr((msr),(val)))
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#define wrmsr_safe(msr,a,b) ({ \
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u64 _l = ((u64)(b) << 32) | (a); \
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paravirt_ops.write_msr((msr),_l); \
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})
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/* rdmsr with exception handling */
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#define rdmsr_safe(msr,a,b) ({ \
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int _err; \
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u64 _l = paravirt_ops.read_msr(msr,&_err); \
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(*a) = (u32)_l; \
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(*b) = _l >> 32; \
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_err; })
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#define rdtsc(low,high) do { \
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u64 _l = paravirt_ops.read_tsc(); \
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low = (u32)_l; \
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high = _l >> 32; \
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} while(0)
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#define rdtscl(low) do { \
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u64 _l = paravirt_ops.read_tsc(); \
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low = (int)_l; \
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} while(0)
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#define rdtscll(val) (val = paravirt_ops.read_tsc())
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#define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
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#define rdpmc(counter,low,high) do { \
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u64 _l = paravirt_ops.read_pmc(); \
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low = (u32)_l; \
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high = _l >> 32; \
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} while(0)
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#define load_TR_desc() (paravirt_ops.load_tr_desc())
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#define load_gdt(dtr) (paravirt_ops.load_gdt(dtr))
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#define load_idt(dtr) (paravirt_ops.load_idt(dtr))
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#define set_ldt(addr, entries) (paravirt_ops.set_ldt((addr), (entries)))
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#define store_gdt(dtr) (paravirt_ops.store_gdt(dtr))
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#define store_idt(dtr) (paravirt_ops.store_idt(dtr))
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#define store_tr(tr) ((tr) = paravirt_ops.store_tr())
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#define load_TLS(t,cpu) (paravirt_ops.load_tls((t),(cpu)))
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#define write_ldt_entry(dt, entry, low, high) \
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(paravirt_ops.write_ldt_entry((dt), (entry), (low), (high)))
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#define write_gdt_entry(dt, entry, low, high) \
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(paravirt_ops.write_gdt_entry((dt), (entry), (low), (high)))
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#define write_idt_entry(dt, entry, low, high) \
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(paravirt_ops.write_idt_entry((dt), (entry), (low), (high)))
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#define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))
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/* The paravirtualized I/O functions */
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static inline void slow_down_io(void) {
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paravirt_ops.io_delay();
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#ifdef REALLY_SLOW_IO
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paravirt_ops.io_delay();
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paravirt_ops.io_delay();
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paravirt_ops.io_delay();
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#endif
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}
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/* These all sit in the .parainstructions section to tell us what to patch. */
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struct paravirt_patch {
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u8 *instr; /* original instructions */
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u8 instrtype; /* type of this instruction */
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u8 len; /* length of original instruction */
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u16 clobbers; /* what registers you may clobber */
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};
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#define paravirt_alt(insn_string, typenum, clobber) \
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"771:\n\t" insn_string "\n" "772:\n" \
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".pushsection .parainstructions,\"a\"\n" \
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" .long 771b\n" \
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" .byte " __stringify(typenum) "\n" \
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" .byte 772b-771b\n" \
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" .short " __stringify(clobber) "\n" \
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".popsection"
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static inline unsigned long __raw_local_save_flags(void)
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{
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unsigned long f;
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__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
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"call *%1;"
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"popl %%edx; popl %%ecx",
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PARAVIRT_SAVE_FLAGS, CLBR_NONE)
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: "=a"(f): "m"(paravirt_ops.save_fl)
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: "memory", "cc");
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return f;
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}
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static inline void raw_local_irq_restore(unsigned long f)
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{
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__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
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"call *%1;"
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"popl %%edx; popl %%ecx",
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PARAVIRT_RESTORE_FLAGS, CLBR_EAX)
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: "=a"(f) : "m" (paravirt_ops.restore_fl), "0"(f)
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: "memory", "cc");
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}
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static inline void raw_local_irq_disable(void)
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{
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__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
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"call *%0;"
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"popl %%edx; popl %%ecx",
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PARAVIRT_IRQ_DISABLE, CLBR_EAX)
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: : "m" (paravirt_ops.irq_disable)
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: "memory", "eax", "cc");
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}
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static inline void raw_local_irq_enable(void)
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{
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__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
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"call *%0;"
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"popl %%edx; popl %%ecx",
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PARAVIRT_IRQ_ENABLE, CLBR_EAX)
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: : "m" (paravirt_ops.irq_enable)
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: "memory", "eax", "cc");
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}
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static inline unsigned long __raw_local_irq_save(void)
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{
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unsigned long f;
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__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
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"call *%1; pushl %%eax;"
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"call *%2; popl %%eax;"
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"popl %%edx; popl %%ecx",
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PARAVIRT_SAVE_FLAGS_IRQ_DISABLE,
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CLBR_NONE)
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: "=a"(f)
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: "m" (paravirt_ops.save_fl),
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"m" (paravirt_ops.irq_disable)
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: "memory", "cc");
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return f;
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}
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#define CLI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;" \
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"call *paravirt_ops+%c[irq_disable];" \
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"popl %%edx; popl %%ecx", \
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PARAVIRT_IRQ_DISABLE, CLBR_EAX)
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#define STI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;" \
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"call *paravirt_ops+%c[irq_enable];" \
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"popl %%edx; popl %%ecx", \
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PARAVIRT_IRQ_ENABLE, CLBR_EAX)
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#define CLI_STI_CLOBBERS , "%eax"
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#define CLI_STI_INPUT_ARGS \
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, \
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[irq_disable] "i" (offsetof(struct paravirt_ops, irq_disable)), \
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[irq_enable] "i" (offsetof(struct paravirt_ops, irq_enable))
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#else /* __ASSEMBLY__ */
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#define PARA_PATCH(ptype, clobbers, ops) \
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771:; \
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ops; \
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772:; \
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.pushsection .parainstructions,"a"; \
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.long 771b; \
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.byte ptype; \
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.byte 772b-771b; \
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.short clobbers; \
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.popsection
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#define INTERRUPT_RETURN \
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PARA_PATCH(PARAVIRT_INTERRUPT_RETURN, CLBR_ANY, \
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jmp *%cs:paravirt_ops+PARAVIRT_iret)
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#define DISABLE_INTERRUPTS(clobbers) \
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PARA_PATCH(PARAVIRT_IRQ_DISABLE, clobbers, \
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pushl %ecx; pushl %edx; \
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call *paravirt_ops+PARAVIRT_irq_disable; \
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popl %edx; popl %ecx) \
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#define ENABLE_INTERRUPTS(clobbers) \
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PARA_PATCH(PARAVIRT_IRQ_ENABLE, clobbers, \
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pushl %ecx; pushl %edx; \
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call *%cs:paravirt_ops+PARAVIRT_irq_enable; \
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popl %edx; popl %ecx)
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#define ENABLE_INTERRUPTS_SYSEXIT \
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PARA_PATCH(PARAVIRT_STI_SYSEXIT, CLBR_ANY, \
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jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
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#define GET_CR0_INTO_EAX \
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call *paravirt_ops+PARAVIRT_read_cr0
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#endif /* __ASSEMBLY__ */
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#endif /* CONFIG_PARAVIRT */
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#endif /* __ASM_PARAVIRT_H */
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