[tip:x86/apic] x86/idt: Switch early trap init to IDT tables
From: tip-bot for Thomas Gleixner
Date: Tue Aug 29 2017 - 07:24:13 EST
Commit-ID: 433f8924fa8e55a50ce57f3b8a33ed095c405644
Gitweb: http://git.kernel.org/tip/433f8924fa8e55a50ce57f3b8a33ed095c405644
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Mon, 28 Aug 2017 08:47:50 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 29 Aug 2017 12:07:27 +0200
x86/idt: Switch early trap init to IDT tables
Add the initialization table for the early trap setup and replace the early
trap init code.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20170828064958.929139008@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/idt.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/setup.c | 4 ++--
arch/x86/kernel/traps.c | 27 -------------------------
3 files changed, 55 insertions(+), 29 deletions(-)
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index ae6fc12..64e2211 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -48,6 +48,28 @@ struct idt_data {
#define TSKG(_vector, _gdt) \
G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3)
+/*
+ * Early traps running on the DEFAULT_STACK because the other interrupt
+ * stacks work only after cpu_init().
+ */
+static const __initdata struct idt_data early_idts[] = {
+ INTG(X86_TRAP_DB, debug),
+ SYSG(X86_TRAP_BP, int3),
+#ifdef CONFIG_X86_32
+ INTG(X86_TRAP_PF, page_fault),
+#endif
+};
+
+#ifdef CONFIG_X86_64
+/*
+ * Early traps running on the DEFAULT_STACK because the other interrupt
+ * stacks work only after cpu_init().
+ */
+static const __initdata struct idt_data early_pf_idts[] = {
+ INTG(X86_TRAP_PF, page_fault),
+};
+#endif
+
/* Must be page-aligned because the real IDT is used in a fixmap. */
gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;
@@ -93,6 +115,37 @@ idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size)
}
/**
+ * idt_setup_early_traps - Initialize the idt table with early traps
+ *
+ * On X8664 these traps do not use interrupt stacks as they can't work
+ * before cpu_init() is invoked and sets up TSS. The IST variants are
+ * installed after that.
+ */
+void __init idt_setup_early_traps(void)
+{
+ idt_setup_from_table(idt_table, early_idts, ARRAY_SIZE(early_idts));
+ load_idt(&idt_descr);
+}
+
+#ifdef CONFIG_X86_64
+/**
+ * idt_setup_early_pf - Initialize the idt table with early pagefault handler
+ *
+ * On X8664 this does not use interrupt stacks as they can't work before
+ * cpu_init() is invoked and sets up TSS. The IST variant is installed
+ * after that.
+ *
+ * FIXME: Why is 32bit and 64bit installing the PF handler at different
+ * places in the early setup code?
+ */
+void __init idt_setup_early_pf(void)
+{
+ idt_setup_from_table(idt_table, early_pf_idts,
+ ARRAY_SIZE(early_pf_idts));
+}
+#endif
+
+/**
* idt_setup_early_handler - Initializes the idt table with early handlers
*/
void __init idt_setup_early_handler(void)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index ecab322..30dc84e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -891,7 +891,7 @@ void __init setup_arch(char **cmdline_p)
*/
olpc_ofw_detect();
- early_trap_init();
+ idt_setup_early_traps();
early_cpu_init();
early_ioremap_init();
@@ -1162,7 +1162,7 @@ void __init setup_arch(char **cmdline_p)
init_mem_mapping();
- early_trap_pf_init();
+ idt_setup_early_pf();
/*
* Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 41f4cd3..835c7e8 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -923,33 +923,6 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
}
#endif
-/* Set of traps needed for early debugging. */
-void __init early_trap_init(void)
-{
- /*
- * Don't use IST to set DEBUG_STACK as it doesn't work until TSS
- * is ready in cpu_init() <-- trap_init(). Before trap_init(),
- * CPU runs at ring 0 so it is impossible to hit an invalid
- * stack. Using the original stack works well enough at this
- * early stage. DEBUG_STACK will be equipped after cpu_init() in
- * trap_init().
- */
- set_intr_gate(X86_TRAP_DB, debug);
- /* int3 can be called from all */
- set_system_intr_gate(X86_TRAP_BP, &int3);
-#ifdef CONFIG_X86_32
- set_intr_gate(X86_TRAP_PF, page_fault);
-#endif
- load_idt(&idt_descr);
-}
-
-void __init early_trap_pf_init(void)
-{
-#ifdef CONFIG_X86_64
- set_intr_gate(X86_TRAP_PF, page_fault);
-#endif
-}
-
void __init trap_init(void)
{
int i;