[PATCH 06/13] x86/paravirt: Clean up paravirt-asm.h

From: Josh Poimboeuf
Date: Wed Oct 04 2017 - 11:59:03 EST


Some cleanup to make the code easier to read and understand:

- Use the common "PV_" prefix
- Simplify the PV_SITE macro interface
- Improve whitespace

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/include/asm/paravirt-asm.h | 95 +++++++++++++++++++------------------
1 file changed, 49 insertions(+), 46 deletions(-)

diff --git a/arch/x86/include/asm/paravirt-asm.h b/arch/x86/include/asm/paravirt-asm.h
index add8a190fdac..8bdd50ee4bf3 100644
--- a/arch/x86/include/asm/paravirt-asm.h
+++ b/arch/x86/include/asm/paravirt-asm.h
@@ -7,16 +7,18 @@
#include <asm/asm.h>
#include <asm/paravirt_types.h>

-#define _PVSITE(ptype, clobbers, ops, word, algn) \
-771:; \
- ops; \
-772:; \
- .pushsection .parainstructions,"a"; \
- .align algn; \
- word 771b; \
- .byte ptype; \
- .byte 772b-771b; \
- .short clobbers; \
+#define PV_TYPE(ops, off) ((PARAVIRT_PATCH_##ops + (off)) / __ASM_SEL(4, 8))
+
+#define PV_SITE(insns, ops, off, clobbers) \
+771:; \
+ insns; \
+772:; \
+ .pushsection .parainstructions, "a"; \
+ _ASM_ALIGN; \
+ _ASM_PTR 771b; \
+ .byte PV_TYPE(ops, off); \
+ .byte 772b-771b; \
+ .short clobbers; \
.popsection


@@ -33,62 +35,65 @@
COND_PUSH(set, CLBR_RDX, rdx); \
COND_PUSH(set, CLBR_RSI, rsi); \
COND_PUSH(set, CLBR_RDI, rdi); \
- COND_PUSH(set, CLBR_R8, r8); \
- COND_PUSH(set, CLBR_R9, r9); \
+ COND_PUSH(set, CLBR_R8, r8); \
+ COND_PUSH(set, CLBR_R9, r9); \
COND_PUSH(set, CLBR_R10, r10); \
COND_PUSH(set, CLBR_R11, r11)
+
#define PV_RESTORE_REGS(set) \
COND_POP(set, CLBR_R11, r11); \
COND_POP(set, CLBR_R10, r10); \
- COND_POP(set, CLBR_R9, r9); \
- COND_POP(set, CLBR_R8, r8); \
+ COND_POP(set, CLBR_R9, r9); \
+ COND_POP(set, CLBR_R8, r8); \
COND_POP(set, CLBR_RDI, rdi); \
COND_POP(set, CLBR_RSI, rsi); \
COND_POP(set, CLBR_RDX, rdx); \
COND_POP(set, CLBR_RCX, rcx); \
COND_POP(set, CLBR_RAX, rax)

-#define PARA_PATCH(struct, off) ((PARAVIRT_PATCH_##struct + (off)) / 8)
-#define PARA_SITE(ptype, clobbers, ops) _PVSITE(ptype, clobbers, ops, .quad, 8)
-#define PARA_INDIRECT(addr) *addr(%rip)
-#else
+#define PV_INDIRECT(addr) *addr(%rip)
+
+#else /* !CONFIG_X86_64 */
+
#define PV_SAVE_REGS(set) \
COND_PUSH(set, CLBR_EAX, eax); \
COND_PUSH(set, CLBR_EDI, edi); \
COND_PUSH(set, CLBR_ECX, ecx); \
COND_PUSH(set, CLBR_EDX, edx)
+
#define PV_RESTORE_REGS(set) \
COND_POP(set, CLBR_EDX, edx); \
COND_POP(set, CLBR_ECX, ecx); \
COND_POP(set, CLBR_EDI, edi); \
COND_POP(set, CLBR_EAX, eax)

-#define PARA_PATCH(struct, off) ((PARAVIRT_PATCH_##struct + (off)) / 4)
-#define PARA_SITE(ptype, clobbers, ops) _PVSITE(ptype, clobbers, ops, .long, 4)
-#define PARA_INDIRECT(addr) *%cs:addr
-#endif
+#define PV_INDIRECT(addr) *%cs:addr
+
+#endif /* !CONFIG_X86_64 */

#define INTERRUPT_RETURN \
- PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_iret), CLBR_NONE, \
- jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_iret))
+ PV_SITE(jmp PV_INDIRECT(pv_cpu_ops+PV_CPU_iret), \
+ pv_cpu_ops, PV_CPU_iret, CLBR_NONE)

#define DISABLE_INTERRUPTS(clobbers) \
- PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_irq_disable), clobbers, \
- PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE); \
- call PARA_INDIRECT(pv_irq_ops+PV_IRQ_irq_disable); \
- PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)
+ PV_SITE(PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE); \
+ call PV_INDIRECT(pv_irq_ops+PV_IRQ_irq_disable); \
+ PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE), \
+ pv_irq_ops, PV_IRQ_irq_disable, clobbers)

#define ENABLE_INTERRUPTS(clobbers) \
- PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_irq_enable), clobbers, \
- PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE); \
- call PARA_INDIRECT(pv_irq_ops+PV_IRQ_irq_enable); \
- PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)
+ PV_SITE(PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE); \
+ call PV_INDIRECT(pv_irq_ops+PV_IRQ_irq_enable); \
+ PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE), \
+ pv_irq_ops, PV_IRQ_irq_enable, clobbers)

#ifdef CONFIG_X86_32
-#define GET_CR0_INTO_EAX \
- push %ecx; push %edx; \
- call PARA_INDIRECT(pv_cpu_ops+PV_CPU_read_cr0); \
+
+#define GET_CR0_INTO_EAX \
+ push %ecx; push %edx; \
+ call PV_INDIRECT(pv_cpu_ops+PV_CPU_read_cr0); \
pop %edx; pop %ecx
+
#else /* !CONFIG_X86_32 */

/*
@@ -97,8 +102,7 @@
* inlined, or the swapgs instruction must be trapped and emulated.
*/
#define SWAPGS_UNSAFE_STACK \
- PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_swapgs), CLBR_NONE, \
- swapgs)
+ PV_SITE(swapgs, pv_cpu_ops, PV_CPU_swapgs, CLBR_NONE)

/*
* Note: swapgs is very special, and in practise is either going to be
@@ -107,18 +111,17 @@
* it.
*/
#define SWAPGS \
- PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_swapgs), CLBR_NONE, \
- call PARA_INDIRECT(pv_cpu_ops+PV_CPU_swapgs) \
- )
+ PV_SITE(call PV_INDIRECT(pv_cpu_ops+PV_CPU_swapgs), \
+ pv_cpu_ops, PV_CPU_swapgs, CLBR_NONE)

-#define GET_CR2_INTO_RAX \
- call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2)
+#define GET_CR2_INTO_RAX \
+ call PV_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2)

#define USERGS_SYSRET64 \
- PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret64), \
- CLBR_NONE, \
- jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usergs_sysret64))
-#endif /* CONFIG_X86_32 */
+ PV_SITE(jmp PV_INDIRECT(pv_cpu_ops+PV_CPU_usergs_sysret64), \
+ pv_cpu_ops, PV_CPU_usergs_sysret64, CLBR_NONE)
+
+#endif /* !CONFIG_X86_32 */

#endif /* __ASSEMBLY__ */
#endif /* CONFIG_PARAVIRT */
--
2.13.6