[Xen-ia64-devel] [patch 04/14] Kexec: Add kexec_disable_iosapic

[Simon Horman <horms@xxxxxxxxxxxx>]

Ported from Linux, this shuts down iosapic before preforming kexec.
This resolves a problem whereby the serial port on an HP RX2620
(which uses IOSAPIC) was not able to accept input. It probably
resolves a bunch of other as yet unseen problems too.

Thanks to Takebe-san for working out the solution to this puzzle.

Cc: Akio Takebe <takebe_akio@xxxxxxxxxxxxxx>
Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>

Index: xen-ia64-unstable.hg/xen/arch/ia64/linux-xen/iosapic.c
===================================================================
--- xen-ia64-unstable.hg.orig/xen/arch/ia64/linux-xen/iosapic.c 2007-05-28 
14:19:45.000000000 +0900
+++ xen-ia64-unstable.hg/xen/arch/ia64/linux-xen/iosapic.c      2007-05-28 
14:19:51.000000000 +0900
@@ -268,6 +268,24 @@ nop (unsigned int vector)
        /* do nothing... */
 }
 
+void
+kexec_disable_iosapic(void)
+{
+        struct iosapic_intr_info *info;
+        struct iosapic_rte_info *rte;
+        u8 vec = 0;
+        for (info = iosapic_intr_info; info <
+                        iosapic_intr_info + IA64_NUM_VECTORS; ++info, ++vec) {
+                list_for_each_entry(rte, &info->rtes,
+                                rte_list) {
+                        iosapic_write(rte->addr,
+                                        IOSAPIC_RTE_LOW(rte->rte_index),
+                                        IOSAPIC_MASK|vec);
+                        iosapic_eoi(rte->addr, vec);
+                }
+        }
+}
+
 static void
 mask_irq (unsigned int irq)
 {
Index: xen-ia64-unstable.hg/xen/arch/ia64/xen/crash.c
===================================================================
--- xen-ia64-unstable.hg.orig/xen/arch/ia64/xen/crash.c 2007-05-28 
14:19:51.000000000 +0900
+++ xen-ia64-unstable.hg/xen/arch/ia64/xen/crash.c      2007-05-28 
14:19:51.000000000 +0900
@@ -30,6 +30,7 @@ void machine_crash_shutdown(void)
     dom0_mm_pgd_mfn = __pa(dom0->arch.mm.pgd) >> PAGE_SHIFT;
     memcpy((char *)info + offsetof(crash_xen_info_t, dom0_mm_pgd_mfn),
           &dom0_mm_pgd_mfn, sizeof(dom0_mm_pgd_mfn));
+    kexec_disable_iosapic();
 #ifdef CONFIG_SMP
     smp_send_stop();
 #endif
Index: xen-ia64-unstable.hg/xen/include/xen/kexec.h
===================================================================
--- xen-ia64-unstable.hg.orig/xen/include/xen/kexec.h   2007-05-28 
14:19:45.000000000 +0900
+++ xen-ia64-unstable.hg/xen/include/xen/kexec.h        2007-05-28 
14:19:51.000000000 +0900
@@ -27,6 +27,7 @@ void machine_kexec_reserved(xen_kexec_re
 void machine_reboot_kexec(xen_kexec_image_t *image);
 void machine_kexec(xen_kexec_image_t *image);
 void kexec_crash(void);
+void kexec_disable_iosapic(void);
 void kexec_crash_save_cpu(void);
 crash_xen_info_t *kexec_crash_save_info(void);
 void machine_crash_shutdown(void);
Index: xen-ia64-unstable.hg/xen/arch/ia64/xen/machine_kexec.c
===================================================================
--- xen-ia64-unstable.hg.orig/xen/arch/ia64/xen/machine_kexec.c 2007-05-28 
14:19:51.000000000 +0900
+++ xen-ia64-unstable.hg/xen/arch/ia64/xen/machine_kexec.c      2007-05-28 
14:19:51.000000000 +0900
@@ -89,6 +89,7 @@ static void ia64_machine_kexec(struct un
 
 void machine_kexec(xen_kexec_image_t *image)
 {
+       kexec_disable_iosapic();
        unw_init_running(ia64_machine_kexec, image);
        for(;;);
        ia64_machine_kexec(NULL, image);

-- 

-- 
Horms
  H: http://www.vergenet.net/~horms/
  W: http://www.valinux.co.jp/en/


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