ACPI / APEI: Use separate fixmap pages for arm64 NMI-like notifications

fix #28612342

commit b972d2eaf0c7021579755eec6b2b79e0f5bc7930 upstream

Now that ghes notification helpers provide the fixmap slots and
take the lock themselves, multiple NMI-like notifications can
be used on arm64.

These should be named after their notification method as they can't
all be called 'NMI'. x86's NOTIFY_NMI already is, change the SEA
fixmap entry to be called FIX_APEI_GHES_SEA.

Future patches can add support for FIX_APEI_GHES_SEI and
FIX_APEI_GHES_SDEI_{NORMAL,CRITICAL}.

Because all of ghes.c builds on both architectures, provide a
constant for each fixmap entry that the architecture will never
use.
Signed-off-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NBaolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: NAlex Shi <alex.shi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
Reviewed-by: Nluanshi <zhangliguang@linux.alibaba.com>

arch/arm64/include/asm/fixmap.h

@@ -55,7 +55,7 @@ enum fixed_addresses {
 #ifdef CONFIG_ACPI_APEI_GHES
 	/* Used for GHES mapping from assorted contexts */
 	FIX_APEI_GHES_IRQ,
-	FIX_APEI_GHES_NMI,
+	FIX_APEI_GHES_SEA,
 #endif /* CONFIG_ACPI_APEI_GHES */
 
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0

drivers/acpi/apei/ghes.c

@@ -957,7 +957,7 @@ int ghes_notify_sea(void)
 	int rv;
 
 	raw_spin_lock(&ghes_notify_lock_sea);
-	rv = ghes_in_nmi_spool_from_list(&ghes_sea, FIX_APEI_GHES_NMI);
+	rv = ghes_in_nmi_spool_from_list(&ghes_sea, FIX_APEI_GHES_SEA);
 	raw_spin_unlock(&ghes_notify_lock_sea);
 
 	return rv;