x86/ras/mce_amd_inj: Trigger deferred and thresholding errors interrupts

Add the capability to trigger deferred error interrupts and
threshold interrupts in order to test the APIC interrupt handler
functionality for these type of errors.

Update README section about the same too.

Reported by: kbuild test robot <[e-mail]>
Signed-off-by: Aravind Gopalakrishnan <[e-mail]>
[ Cleanup comments. ]
[ Include asm/irq_vectors.h directly so that misc randbuilds don't fail. ]
Signed-off-by: Borislav Petkov <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: H. Peter Anvin <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Tony Luck <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/ras/mce_amd_inj.c

···
 #include <linux/cpu.h>
 #include <linux/string.h>
 #include <linux/uaccess.h>
+
 #include <asm/mce.h>
+#include <asm/irq_vectors.h>
 
 #include "../kernel/cpu/mcheck/mce-internal.h"
 
···
 enum injection_type {
 	SW_INJ = 0,	/* SW injection, simply decode the error */
 	HW_INJ,		/* Trigger a #MC */
+	DFR_INT_INJ,    /* Trigger Deferred error interrupt */
+	THR_INT_INJ,    /* Trigger threshold interrupt */
 	N_INJ_TYPES,
 };
 
 static const char * const flags_options[] = {
 	[SW_INJ] = "sw",
 	[HW_INJ] = "hw",
+	[DFR_INT_INJ] = "df",
+	[THR_INT_INJ] = "th",
 	NULL
 };
 
···
 	asm volatile("int $18");
 }
 
+static void trigger_dfr_int(void *info)
+{
+	asm volatile("int %0" :: "i" (DEFERRED_ERROR_VECTOR));
+}
+
+static void trigger_thr_int(void *info)
+{
+	asm volatile("int %0" :: "i" (THRESHOLD_APIC_VECTOR));
+}
+
 static void do_inject(void)
 {
 	u64 mcg_status = 0;
···
 
 	if (!(i_mce.status & MCI_STATUS_PCC))
 		mcg_status |= MCG_STATUS_RIPV;
+
+	/*
+	 * Ensure necessary status bits for deferred errors:
+	 * - MCx_STATUS[Deferred]: make sure it is a deferred error
+	 * - MCx_STATUS[UC] cleared: deferred errors are _not_ UC
+	 */
+	if (inj_type == DFR_INT_INJ) {
+		i_mce.status |= MCI_STATUS_DEFERRED;
+		i_mce.status |= (i_mce.status & ~MCI_STATUS_UC);
+	}
 
 	get_online_cpus();
 	if (!cpu_online(cpu))
···
 
 	toggle_hw_mce_inject(cpu, false);
 
-	smp_call_function_single(cpu, trigger_mce, NULL, 0);
+	switch (inj_type) {
+	case DFR_INT_INJ:
+		smp_call_function_single(cpu, trigger_dfr_int, NULL, 0);
+		break;
+	case THR_INT_INJ:
+		smp_call_function_single(cpu, trigger_thr_int, NULL, 0);
+		break;
+	default:
+		smp_call_function_single(cpu, trigger_mce, NULL, 0);
+	}
 
 err:
 	put_online_cpus();
···
 "\t    handle the error. Be warned: might cause system panic if MCi_STATUS[PCC] \n"
 "\t    is set. Therefore, consider setting (debugfs_mountpoint)/mce/fake_panic \n"
 "\t    before injecting.\n"
+"\t  - \"df\": Trigger APIC interrupt for Deferred error. Causes deferred \n"
+"\t    error APIC interrupt handler to handle the error if the feature is \n"
+"\t    is present in hardware. \n"
+"\t  - \"th\": Trigger APIC interrupt for Threshold errors. Causes threshold \n"
+"\t    APIC interrupt handler to handle the error. \n"
 "\n";
 
 static ssize_t