Merge tag 'x86-irq-2021-06-29' of git://git.kernel.org/pub/scm/linux/…

…kernel/git/tip/tip

Pull x86 interrupt related updates from Thomas Gleixner:

 - Consolidate the VECTOR defines and the usage sites.

 - Cleanup GDT/IDT related code and replace open coded ASM with proper
   native helper functions.

* tag 'x86-irq-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kexec: Set_[gi]dt() -> native_[gi]dt_invalidate() in machine_kexec_*.c
  x86: Add native_[ig]dt_invalidate()
  x86/idt: Remove address argument from idt_invalidate()
  x86/irq: Add and use NR_EXTERNAL_VECTORS and NR_SYSTEM_VECTORS
  x86/irq: Remove unused vectors defines

arch/x86/include/asm/desc.h

@@ -224,6 +224,26 @@ static inline void store_idt(struct desc_ptr *dtr)
 	asm volatile("sidt %0":"=m" (*dtr));
 }
 
+static inline void native_gdt_invalidate(void)
+{
+	const struct desc_ptr invalid_gdt = {
+		.address = 0,
+		.size = 0
+	};
+
+	native_load_gdt(&invalid_gdt);
+}
+
+static inline void native_idt_invalidate(void)
+{
+	const struct desc_ptr invalid_idt = {
+		.address = 0,
+		.size = 0
+	};
+
+	native_load_idt(&invalid_idt);
+}
+
 /*
  * The LTR instruction marks the TSS GDT entry as busy. On 64-bit, the GDT is
  * a read-only remapping. To prevent a page fault, the GDT is switched to the
@@ -425,6 +445,6 @@ extern void idt_setup_early_pf(void);
 static inline void idt_setup_early_pf(void) { }
 #endif
 
-extern void idt_invalidate(void *addr);
+extern void idt_invalidate(void);
 
 #endif /* _ASM_X86_DESC_H */

arch/x86/include/asm/idtentry.h

@@ -495,7 +495,7 @@ __visible noinstr void func(struct pt_regs *regs,			\
 	.align 8
 SYM_CODE_START(irq_entries_start)
     vector=FIRST_EXTERNAL_VECTOR
-    .rept (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
+    .rept NR_EXTERNAL_VECTORS
 	UNWIND_HINT_IRET_REGS
 0 :
 	.byte	0x6a, vector
@@ -511,7 +511,7 @@ SYM_CODE_END(irq_entries_start)
 	.align 8
 SYM_CODE_START(spurious_entries_start)
     vector=FIRST_SYSTEM_VECTOR
-    .rept (NR_VECTORS - FIRST_SYSTEM_VECTOR)
+    .rept NR_SYSTEM_VECTORS
 	UNWIND_HINT_IRET_REGS
 0 :
 	.byte	0x6a, vector

arch/x86/include/asm/irq_vectors.h

@@ -26,8 +26,8 @@
  * This file enumerates the exact layout of them:
  */
 
+/* This is used as an interrupt vector when programming the APIC. */
 #define NMI_VECTOR			0x02
-#define MCE_VECTOR			0x12
 
 /*
  * IDT vectors usable for external interrupt sources start at 0x20.
@@ -84,7 +84,7 @@
  */
 #define IRQ_WORK_VECTOR			0xf6
 
-#define UV_BAU_MESSAGE			0xf5
+/* 0xf5 - unused, was UV_BAU_MESSAGE */
 #define DEFERRED_ERROR_VECTOR		0xf4
 
 /* Vector on which hypervisor callbacks will be delivered */
@@ -114,6 +114,9 @@
 #define FIRST_SYSTEM_VECTOR		NR_VECTORS
 #endif
 
+#define NR_EXTERNAL_VECTORS		(FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
+#define NR_SYSTEM_VECTORS		(NR_VECTORS - FIRST_SYSTEM_VECTOR)
+
 /*
  * Size the maximum number of interrupts.
  *

arch/x86/kernel/idt.c

@@ -315,11 +315,10 @@ void __init idt_setup_early_handler(void)
 
 /**
  * idt_invalidate - Invalidate interrupt descriptor table
- * @addr:	The virtual address of the 'invalid' IDT
  */
-void idt_invalidate(void *addr)
+void idt_invalidate(void)
 {
-	struct desc_ptr idt = { .address = (unsigned long) addr, .size = 0 };
+	static const struct desc_ptr idt = { .address = 0, .size = 0 };
 
 	load_idt(&idt);
 }

arch/x86/kernel/machine_kexec_32.c

@@ -23,17 +23,6 @@
 #include <asm/set_memory.h>
 #include <asm/debugreg.h>
 
-static void set_gdt(void *newgdt, __u16 limit)
-{
-	struct desc_ptr curgdt;
-
-	/* ia32 supports unaligned loads & stores */
-	curgdt.size    = limit;
-	curgdt.address = (unsigned long)newgdt;
-
-	load_gdt(&curgdt);
-}
-
 static void load_segments(void)
 {
 #define __STR(X) #X
@@ -232,8 +221,8 @@ void machine_kexec(struct kimage *image)
 	 * The gdt & idt are now invalid.
 	 * If you want to load them you must set up your own idt & gdt.
 	 */
-	idt_invalidate(phys_to_virt(0));
-	set_gdt(phys_to_virt(0), 0);
+	native_idt_invalidate();
+	native_gdt_invalidate();
 
 	/* now call it */
 	image->start = relocate_kernel_ptr((unsigned long)image->head,

arch/x86/kernel/machine_kexec_64.c

@@ -256,35 +256,6 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
 	return init_transition_pgtable(image, level4p);
 }
 
-static void set_idt(void *newidt, u16 limit)
-{
-	struct desc_ptr curidt;
-
-	/* x86-64 supports unaligned loads & stores */
-	curidt.size    = limit;
-	curidt.address = (unsigned long)newidt;
-
-	__asm__ __volatile__ (
-		"lidtq %0\n"
-		: : "m" (curidt)
-		);
-};
-
-
-static void set_gdt(void *newgdt, u16 limit)
-{
-	struct desc_ptr curgdt;
-
-	/* x86-64 supports unaligned loads & stores */
-	curgdt.size    = limit;
-	curgdt.address = (unsigned long)newgdt;
-
-	__asm__ __volatile__ (
-		"lgdtq %0\n"
-		: : "m" (curgdt)
-		);
-};
-
 static void load_segments(void)
 {
 	__asm__ __volatile__ (
@@ -379,8 +350,8 @@ void machine_kexec(struct kimage *image)
 	 * The gdt & idt are now invalid.
 	 * If you want to load them you must set up your own idt & gdt.
 	 */
-	set_gdt(phys_to_virt(0), 0);
-	set_idt(phys_to_virt(0), 0);
+	native_idt_invalidate();
+	native_gdt_invalidate();
 
 	/* now call it */
 	image->start = relocate_kernel((unsigned long)image->head,

arch/x86/kernel/reboot.c

@@ -669,7 +669,7 @@ static void native_machine_emergency_restart(void)
 			break;
 
 		case BOOT_TRIPLE:
-			idt_invalidate(NULL);
+			idt_invalidate();
 			__asm__ __volatile__("int3");
 
 			/* We're probably dead after this, but... */

tools/arch/x86/include/asm/irq_vectors.h

@@ -26,8 +26,8 @@
  * This file enumerates the exact layout of them:
  */
 
+/* This is used as an interrupt vector when programming the APIC. */
 #define NMI_VECTOR			0x02
-#define MCE_VECTOR			0x12
 
 /*
  * IDT vectors usable for external interrupt sources start at 0x20.
@@ -84,7 +84,7 @@
  */
 #define IRQ_WORK_VECTOR			0xf6
 
-#define UV_BAU_MESSAGE			0xf5
+/* 0xf5 - unused, was UV_BAU_MESSAGE */
 #define DEFERRED_ERROR_VECTOR		0xf4
 
 /* Vector on which hypervisor callbacks will be delivered */
@@ -114,6 +114,9 @@
 #define FIRST_SYSTEM_VECTOR		NR_VECTORS
 #endif
 
+#define NR_EXTERNAL_VECTORS		(FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
+#define NR_SYSTEM_VECTORS		(NR_VECTORS - FIRST_SYSTEM_VECTOR)
+
 /*
  * Size the maximum number of interrupts.
  *