x86/cpu: Add Lunar Lake to list of CPUs with a broken MONITOR implementation

[ Upstream commit c9a4b55 ]

Under some conditions, MONITOR wakeups on Lunar Lake processors
can be lost, resulting in significant user-visible delays.

Add Lunar Lake to X86_BUG_MONITOR so that wake_up_idle_cpu()
always sends an IPI, avoiding this potential delay.

Reported originally here:

	https://bugzilla.kernel.org/show_bug.cgi?id=219364

[ dhansen: tweak subject ]

Signed-off-by: Len Brown <[email protected]>
Signed-off-by: Dave Hansen <[email protected]>
Reviewed-by: Rafael J. Wysocki <[email protected]>
Cc:[email protected]
Link: https://lore.kernel.org/all/a4aa8842a3c3bfdb7fe9807710eef159cbf0e705.1731463305.git.len.brown%40intel.com
Signed-off-by: Sasha Levin <[email protected]>

Author: lenb

arch/x86/kernel/cpu/intel.c

@@ -666,7 +666,9 @@ static void init_intel(struct cpuinfo_x86 *c)
 	     c->x86_vfm == INTEL_WESTMERE_EX))
 		set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);
 
-	if (boot_cpu_has(X86_FEATURE_MWAIT) && c->x86_vfm == INTEL_ATOM_GOLDMONT)
+	if (boot_cpu_has(X86_FEATURE_MWAIT) &&
+	    (c->x86_vfm == INTEL_ATOM_GOLDMONT ||
+	     c->x86_vfm == INTEL_LUNARLAKE_M))
 		set_cpu_bug(c, X86_BUG_MONITOR);
 
 #ifdef CONFIG_X86_64