[PATCH v9 28/36] x86/idtentry: Incorporate declaration/definition of the FRED exception handler type

From: Xin Li
Date: Mon Jul 31 2023 - 03:12:27 EST


The existing IDT exception C-handlers of X86_TRAP_TS, X86_TRAP_NP,
X86_TRAP_SS, X86_TRAP_GP, X86_TRAP_AC and X86_TRAP_CP take an error
code as the second argument, thus their FRED version handlers simply
call the corresponding existing IDT handlers with orig_ax from the
pt_regs structure as the second argument.

Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
---
arch/x86/include/asm/idtentry.h | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index e67d111bf932..3b743c3fbe91 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -11,6 +11,7 @@
#include <linux/entry-common.h>
#include <linux/hardirq.h>

+#include <asm/fred.h>
#include <asm/irq_stack.h>

/**
@@ -67,13 +68,16 @@ static __always_inline void __##func(struct pt_regs *regs)

/**
* DECLARE_IDTENTRY_ERRORCODE - Declare functions for simple IDT entry points
+ * and their corresponding software based
+ * dispatch handler
* Error code pushed by hardware
* @vector: Vector number (ignored for C)
* @func: Function name of the entry point
*
- * Declares three functions:
+ * Declares four functions:
* - The ASM entry point: asm_##func
* - The XEN PV trap entry point: xen_##func (maybe unused)
+ * - The C handler called from the FRED event dispatch framework
* - The C handler called from the ASM entry point
*
* Same as DECLARE_IDTENTRY, but has an extra error_code argument for the
@@ -82,14 +86,19 @@ static __always_inline void __##func(struct pt_regs *regs)
#define DECLARE_IDTENTRY_ERRORCODE(vector, func) \
asmlinkage void asm_##func(void); \
asmlinkage void xen_asm_##func(void); \
+ __visible DECLARE_FRED_HANDLER(fred_##func); \
__visible void func(struct pt_regs *regs, unsigned long error_code)

/**
* DEFINE_IDTENTRY_ERRORCODE - Emit code for simple IDT entry points
+ * and their corresponding software based
+ * dispatch handler
* Error code pushed by hardware
* @func: Function name of the entry point
*
- * Same as DEFINE_IDTENTRY, but has an extra error_code argument
+ * Same as DEFINE_IDTENTRY, but has an extra error_code argument. The
+ * fred_func() simply calls func() with passing orig_ax as its second
+ * argument.
*/
#define DEFINE_IDTENTRY_ERRORCODE(func) \
static __always_inline void __##func(struct pt_regs *regs, \
@@ -106,6 +115,11 @@ __visible noinstr void func(struct pt_regs *regs, \
irqentry_exit(regs, state); \
} \
\
+__visible DEFINE_FRED_HANDLER(fred_##func) \
+{ \
+ func(regs, regs->orig_ax); \
+} \
+ \
static __always_inline void __##func(struct pt_regs *regs, \
unsigned long error_code)

--
2.34.1