Hi Wei,
On 29/03/2020 15:35, Wei Liu wrote:
On Fri, Mar 27, 2020 at 07:05:46PM +0000, Julien Grall wrote:
From: Julien Grall <jgr...@amazon.com>
Since commit 9facd54a45 "x86/ioapic: Add register level checks to detect
bogus io-apic entries", Xen is able to cope with IO APICs not mapped in
the fixmap.
Therefore the whole logic to allocate a fake page for some IO APICs is
unnecessary.
With the logic removed, the code can be simplified a lot as we don't
need to go through all the IO APIC if SMP has not been detected or a
bogus zero IO-APIC address has been detected.
To avoid another level of tabulation, the simplification is now moved in
its own function.
Signed-off-by: Julien Grall <jgr...@amazon.com>
---
xen/arch/x86/io_apic.c | 63 ++++++++++++++++++++----------------------
1 file changed, 30 insertions(+), 33 deletions(-)
diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
index 9a11ee8342..3d52e4daf1 100644
--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -2537,34 +2537,25 @@ static __init bool bad_ioapic_register(unsigned int idx)
return false;
}
-void __init init_ioapic(void)
+static void __init init_ioapic_mappings(void)
{
- unsigned long ioapic_phys;
unsigned int i, idx = FIX_IO_APIC_BASE_0;
- union IO_APIC_reg_01 reg_01;
- if ( smp_found_config )
- nr_irqs_gsi = 0;
for ( i = 0; i < nr_ioapics; i++ )
{
- if ( smp_found_config )
- {
- ioapic_phys = mp_ioapics[i].mpc_apicaddr;
- if ( !ioapic_phys )
- {
- printk(KERN_ERR "WARNING: bogus zero IO-APIC address "
- "found in MPTABLE, disabling IO/APIC support!\n");
- smp_found_config = false;
- skip_ioapic_setup = true;
- goto fake_ioapic_page;
- }
- }
- else
+ union IO_APIC_reg_01 reg_01;
+ unsigned long ioapic_phys = mp_ioapics[i].mpc_apicaddr;
+
+ ioapic_phys = mp_ioapics[i].mpc_apicaddr;
ioapic_phys is set a second time here. See the line before.
Good spot! I will drop the line.
Cheers,
--
Julien Grall
