On Thu, 7 Sep 2006 09:32:38 +0800, "Zou, Nanhai" wrote: >> On Thu, 7 Sep 2006 08:57:13 +0800, "Zou, Nanhai" wrote: >> >> >> On Wed, 06 Sep 2006 18:06:53 +0900, Takao Indoh wrote: >> >> >> >> >>>+ /* change region of gp to region5 */ >> >> >>>+ asm volatile ("movl gp=__gp"::: "memory"); >> >> >> >> >> >>Why? gp is already pointing at the kernel code before we enter >> >> >>ia64_init_handler(). >> >> > >> >> >The purpose of this code is just changing region of gp from region7 to >> >> >region5. For example, if gp is e000000004ace170, I want to change gp to >> >> ~~~~~~~~~~~~~~~~e000000000ace170 >> >> Sorry, I mistook address... >> >> >> >> >> >> Regards, >> >> Takao Indoh >> >> >> > You don't need to set gp here. Control page does not use GP, and >> >purgatory code will set GP to a physical address which was pre-calculated >> >at the time of crash kernel loading. >> >> If gp points region7, panic occurs at kdump_disable_iosapic. >> >> kdump_disable_iosapic(void) >> { >> u32 low32; >> struct iosapic_intr_info *info; >> struct iosapic_rte_info *rte; >> for (info = iosapic_intr_info; info < >> iosapic_intr_info + IA64_NUM_VECTORS; ++info) { >> low32 = info->low32 |= IOSAPIC_MASK; >> list_for_each_entry(rte, &info->rtes, >> rte_list) { >> (snip) >> >> The panic occurs at list_for_each_entry. When I found this problem, >> &info->rtes and rte->rte_list pointed same data but they had different >> address. >> >> &info->rtes => 0xe0000000049231e0 >> rte->rte_list => 0xa0000001009231e0 >> >> info->rtes points region7 because its address is calculated from gp. >> This difference of address caused panic. >> >> Regards, >> Takao Indoh >> > > Ok, ia64_setreg should be better. >We should avoid put inline asm code in C file. Yes, at first I used ia64_setreg, but this problem was not solved. if (sos->rv_rc != 1 && (kdump_send_ipi || kdump_on_init)) { extern char __gp[]; local_irq_disable(); set_curr_task(cpu, previous_current); /* change region of gp to region5 */ ia64_setreg(_IA64_REG_GP, __gp); crash_kexec(regs); The disassemble code: a000000100047080: 0b 38 01 02 00 24 [MMI] addl r39=0,r1;; a000000100047086: 50 02 9c 00 42 00 mov r37=r39 a00000010004708c: 00 00 04 00 nop.i 0x0;; a000000100047090: 0a 08 00 4a 00 21 [MMI] mov r1=r37;; a000000100047096: c0 02 80 00 42 00 mov r44=r32 a00000010004709c: 00 00 04 00 nop.i 0x0 a0000001000470a0: 17 00 02 51 02 14 [BBB] br.call.sptk.many b0=a0000001000db4a0 <crash_kexec> This disassembled code does not change content of r1. Am I missing something? Regards, Takao Indoh - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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