x86/microcode/intel: Do not print microcode revision and processor flags

mainline inclusion
from mainline-v6.2-rc1
commit 5b1586ab
category: feature
feature: Backport Intel In Field Scan(IFS) multi-blob images support
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I6L337
CVE: N/A
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
commit/?id=5b1586ab

Intel-SIG: commit 5b1586ab ("x86/microcode/intel: Do not print microcode revision and processor flags")

-------------------------------------

x86/microcode/intel: Do not print microcode revision and processor flags

collect_cpu_info() is used to collect the current microcode revision and
processor flags on every CPU.

It had a weird mechanism to try to mimick a "once" functionality in the
sense that, that information should be issued only when it is differing
from the previous CPU.

However (1):

the new calling sequence started doing that in parallel:

  microcode_init()
  |-> schedule_on_each_cpu(setup_online_cpu)
      |-> collect_cpu_info()

resulting in multiple redundant prints:

  microcode: sig=0x50654, pf=0x80, revision=0x2006e05
  microcode: sig=0x50654, pf=0x80, revision=0x2006e05
  microcode: sig=0x50654, pf=0x80, revision=0x2006e05

However (2):

dumping this here is not that important because the kernel does not
support mixed silicon steppings microcode. Finally!

Besides, there is already a pr_info() in microcode_reload_late() that
shows both the old and new revisions.

What is more, the CPU signature (sig=0x50654) and Processor Flags
(pf=0x80) above aren't that useful to the end user, they are available
via /proc/cpuinfo and they don't change anyway.

Remove the redundant pr_info().

  [ bp: Heavily massage. ]

Fixes: b6f86689 ("x86/microcode: Rip out the subsys interface gunk")
Reported-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Signed-off-by: NBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20221103175901.164783-2-ashok.raj@intel.comSigned-off-by: NAichun Shi <aichun.shi@intel.com>

arch/x86/kernel/cpu/microcode/intel.c

@@ -547,7 +547,6 @@ void reload_ucode_intel(void)
 
 static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
 {
-	static struct cpu_signature prev;
 	struct cpuinfo_x86 *c = &cpu_data(cpu_num);
 	unsigned int val[2];
 
@@ -563,13 +562,6 @@ static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
 
 	csig->rev = c->microcode;
 
-	/* No extra locking on prev, races are harmless. */
-	if (csig->sig != prev.sig || csig->pf != prev.pf || csig->rev != prev.rev) {
-		pr_info("sig=0x%x, pf=0x%x, revision=0x%x\n",
-			csig->sig, csig->pf, csig->rev);
-		prev = *csig;
-	}
-
 	return 0;
 }