/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_PARAVIRT_TYPES_H #define _ASM_X86_PARAVIRT_TYPES_H #ifdef CONFIG_PARAVIRT #ifndef __ASSEMBLY__ #include <linux/types.h> #include <asm/desc_defs.h> #include <asm/pgtable_types.h> #include <asm/nospec-branch.h> struct page; struct thread_struct; struct desc_ptr; struct tss_struct; struct mm_struct; struct desc_struct; struct task_struct; struct cpumask; struct flush_tlb_info; struct mmu_gather; struct vm_area_struct; /* * Wrapper type for pointers to code which uses the non-standard * calling convention. See PV_CALL_SAVE_REGS_THUNK below. */ struct paravirt_callee_save { … }; /* general info */ struct pv_info { … }; #ifdef CONFIG_PARAVIRT_XXL struct pv_lazy_ops { … } __no_randomize_layout; #endif struct pv_cpu_ops { … } __no_randomize_layout; struct pv_irq_ops { … } __no_randomize_layout; struct pv_mmu_ops { … } __no_randomize_layout; struct arch_spinlock; #ifdef CONFIG_SMP #include <asm/spinlock_types.h> #endif struct qspinlock; struct pv_lock_ops { … } __no_randomize_layout; /* This contains all the paravirt structures: we get a convenient * number for each function using the offset which we use to indicate * what to patch. */ struct paravirt_patch_template { … } __no_randomize_layout; extern struct pv_info pv_info; extern struct paravirt_patch_template pv_ops; #define paravirt_ptr(op) … int paravirt_disable_iospace(void); /* This generates an indirect call based on the operation type number. */ #define PARAVIRT_CALL … /* * These macros are intended to wrap calls through one of the paravirt * ops structs, so that they can be later identified and patched at * runtime. * * Normally, a call to a pv_op function is a simple indirect call: * (pv_op_struct.operations)(args...). * * Unfortunately, this is a relatively slow operation for modern CPUs, * because it cannot necessarily determine what the destination * address is. In this case, the address is a runtime constant, so at * the very least we can patch the call to a simple direct call, or, * ideally, patch an inline implementation into the callsite. (Direct * calls are essentially free, because the call and return addresses * are completely predictable.) * * 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 parameters going in %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 has to clobber all caller saved registers, which * unfortunately, are quite a bit (r8 - r11) * * Unfortunately there's no way to get gcc to generate the args setup * for the call, and then allow the call itself to be generated by an * inline asm. Because of this, we must do the complete arg setup and * return value handling from within these macros. This is fairly * cumbersome. * * There are 5 sets of PVOP_* macros for dealing with 0-4 arguments. * It could be extended to more arguments, but there would be little * to be gained from that. For each number of arguments, there are * two VCALL and CALL variants for void and non-void functions. * * When there is a return value, the invoker of the macro must specify * the return type. The macro then uses sizeof() on that type to * determine whether it's 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). For x86_64 machines, it just returns in %rax regardless of * the return value size. * * 64-bit arguments are passed as a pair of adjacent 32-bit arguments; * 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 * functions must do it. * * These PVOP_* macros are only defined within this header. This * 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_CALL_ARGS … #define PVOP_CALL_ARG1 … #define PVOP_CALL_ARG2 … #define PVOP_CALL_ARG3 … #define PVOP_VCALL_CLOBBERS … #define PVOP_CALL_CLOBBERS … #define PVOP_VCALLEE_CLOBBERS … #define PVOP_CALLEE_CLOBBERS … #define EXTRA_CLOBBERS #define VEXTRA_CLOBBERS #else /* CONFIG_X86_64 */ /* [re]ax isn't an arg, but the return val */ #define PVOP_CALL_ARGS … #define PVOP_CALL_ARG1(x) … #define PVOP_CALL_ARG2(x) … #define PVOP_CALL_ARG3(x) … #define PVOP_CALL_ARG4(x) … #define PVOP_VCALL_CLOBBERS … #define PVOP_CALL_CLOBBERS … /* * void functions are still allowed [re]ax for scratch. * * The ZERO_CALL_USED REGS feature may end up zeroing out callee-saved * registers. Make sure we model this with the appropriate clobbers. */ #ifdef CONFIG_ZERO_CALL_USED_REGS #define PVOP_VCALLEE_CLOBBERS … #else #define PVOP_VCALLEE_CLOBBERS … #endif #define PVOP_CALLEE_CLOBBERS … #define EXTRA_CLOBBERS … #define VEXTRA_CLOBBERS … #endif /* CONFIG_X86_32 */ #ifdef CONFIG_PARAVIRT_DEBUG #define PVOP_TEST_NULL(op) … #else #define PVOP_TEST_NULL … #endif #define PVOP_RETVAL(rettype) … /* * Use alternative patching for paravirt calls: * - For replacing an indirect call with a direct one, use the "normal" * ALTERNATIVE() macro with the indirect call as the initial code sequence, * which will be replaced with the related direct call by using the * ALT_FLAG_DIRECT_CALL special case and the "always on" feature. * - In case the replacement is either a direct call or a short code sequence * depending on a feature bit, the ALTERNATIVE_2() macro is being used. * The indirect call is the initial code sequence again, while the special * code sequence is selected with the specified feature bit. In case the * feature is not active, the direct call is used as above via the * ALT_FLAG_DIRECT_CALL special case and the "always on" feature. */ #define ____PVOP_CALL(ret, op, call_clbr, extra_clbr, ...) … #define ____PVOP_ALT_CALL(ret, op, alt, cond, call_clbr, \ extra_clbr, ...) … #define __PVOP_CALL … #define __PVOP_ALT_CALL(rettype, op, alt, cond, ...) … #define __PVOP_CALLEESAVE(rettype, op, ...) … #define __PVOP_ALT_CALLEESAVE(rettype, op, alt, cond, ...) … #define __PVOP_VCALL … #define __PVOP_ALT_VCALL(op, alt, cond, ...) … #define __PVOP_VCALLEESAVE(op, ...) … #define __PVOP_ALT_VCALLEESAVE(op, alt, cond, ...) … #define PVOP_CALL0 … #define PVOP_VCALL0 … #define PVOP_ALT_CALL0(rettype, op, alt, cond) … #define PVOP_ALT_VCALL0(op, alt, cond) … #define PVOP_CALLEE0(rettype, op) … #define PVOP_VCALLEE0(op) … #define PVOP_ALT_CALLEE0(rettype, op, alt, cond) … #define PVOP_ALT_VCALLEE0(op, alt, cond) … #define PVOP_CALL1 … #define PVOP_VCALL1 … #define PVOP_ALT_VCALL1(op, arg1, alt, cond) … #define PVOP_CALLEE1(rettype, op, arg1) … #define PVOP_VCALLEE1(op, arg1) … #define PVOP_ALT_CALLEE1(rettype, op, arg1, alt, cond) … #define PVOP_ALT_VCALLEE1(op, arg1, alt, cond) … #define PVOP_CALL2 … #define PVOP_VCALL2 … #define PVOP_CALL3 … #define PVOP_VCALL3 … #define PVOP_CALL4 … #define PVOP_VCALL4 … unsigned long paravirt_ret0(void); #ifdef CONFIG_PARAVIRT_XXL u64 _paravirt_ident_64(u64); unsigned long pv_native_save_fl(void); void pv_native_irq_disable(void); void pv_native_irq_enable(void); unsigned long pv_native_read_cr2(void); #endif #define paravirt_nop … #endif /* __ASSEMBLY__ */ #define ALT_NOT_XEN … #endif /* CONFIG_PARAVIRT */ #endif /* _ASM_X86_PARAVIRT_TYPES_H */
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