Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751921AbYHREDz (ORCPT ); Mon, 18 Aug 2008 00:03:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750720AbYHREDr (ORCPT ); Mon, 18 Aug 2008 00:03:47 -0400 Received: from SpacedOut.fries.net ([67.64.210.234]:41690 "EHLO SpacedOut.fries.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716AbYHREDq (ORCPT ); Mon, 18 Aug 2008 00:03:46 -0400 Date: Sun, 17 Aug 2008 23:03:40 -0500 From: David Fries To: linux-kernel@vger.kernel.org Subject: [PATCH] Fix i486 suspend to disk CR4 oops Message-ID: <20080818040340.GB17528@spacedout.fries.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.4i X-Greylist: Sender is SPF-compliant, not delayed by milter-greylist-3.0 (SpacedOut.fries.net [127.0.0.1]); Sun, 17 Aug 2008 23:03:44 -0500 (CDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4706 Lines: 147 arch/x86/power/cpu_32.c __save_processor_state calls read_cr4() only a i486 CPU doesn't have the CR4 register. Trying to read it produces an invalid opcode oops during suspend to disk. Added the check (boot_cpu_data.x86 >= 5) before reading the register. If the value to be written is zero the write is skipped. arch/x86/power/hibernate_asm_32.S done: swapped the use of %eax and %ecx to use jecxz for the zero test and jump over store to %cr4. restore_image: s/%ecx/%eax/ to be consistent with done: In addition to __save_processor_state, acpi_save_state_mem, efi_call_phys_prelog, and efi_call_phys_epilog had checks added (acpi restore was in assembly and already had a check for non-zero). There were other reads and writes of CR4, but MCE and virtualization shouldn't be executed on a i486 anyway. Signed-off-by: David Fries --- arch/x86/kernel/acpi/sleep.c | 4 +++- arch/x86/kernel/efi_32.c | 6 ++++-- arch/x86/power/cpu_32.c | 8 ++++++-- arch/x86/power/hibernate_asm_32.S | 26 +++++++++++++++----------- 4 files changed, 28 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index 81e5ab6..bd0f2a3 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -86,7 +86,9 @@ int acpi_save_state_mem(void) #endif /* !CONFIG_64BIT */ header->pmode_cr0 = read_cr0(); - header->pmode_cr4 = read_cr4(); + /* cr4 was introduced in the Pentium CPU */ + if (boot_cpu_data.x86 >= 5) + header->pmode_cr4 = read_cr4(); header->realmode_flags = acpi_realmode_flags; header->real_magic = 0x12345678; diff --git a/arch/x86/kernel/efi_32.c b/arch/x86/kernel/efi_32.c index 4b63c8e..ad62d31 100644 --- a/arch/x86/kernel/efi_32.c +++ b/arch/x86/kernel/efi_32.c @@ -53,7 +53,8 @@ void efi_call_phys_prelog(void) * directory. If I have PAE, I just need to duplicate one entry in * page directory. */ - cr4 = read_cr4(); + /* cr4 was introduced in the Pentium CPU */ + cr4 = boot_cpu_data.x86 >= 5 ? read_cr4() : 0; if (cr4 & X86_CR4_PAE) { efi_bak_pg_dir_pointer[0].pgd = @@ -91,7 +92,8 @@ void efi_call_phys_epilog(void) gdt_descr.size = GDT_SIZE - 1; load_gdt(&gdt_descr); - cr4 = read_cr4(); + /* cr4 was introduced in the Pentium CPU */ + cr4 = boot_cpu_data.x86 >= 5 ? read_cr4() : 0; if (cr4 & X86_CR4_PAE) { swapper_pg_dir[pgd_index(0)].pgd = diff --git a/arch/x86/power/cpu_32.c b/arch/x86/power/cpu_32.c index 7dc5d5c..c5647ea 100644 --- a/arch/x86/power/cpu_32.c +++ b/arch/x86/power/cpu_32.c @@ -45,7 +45,9 @@ static void __save_processor_state(struct saved_context *ctxt) ctxt->cr0 = read_cr0(); ctxt->cr2 = read_cr2(); ctxt->cr3 = read_cr3(); - ctxt->cr4 = read_cr4(); + /* cr4 was introduced in the Pentium CPU */ + if (boot_cpu_data.x86 >= 5) + ctxt->cr4 = read_cr4(); } /* Needed by apm.c */ @@ -98,7 +100,9 @@ static void __restore_processor_state(struct saved_context *ctxt) /* * control registers */ - write_cr4(ctxt->cr4); + /* cr4 was introduced in the Pentium CPU */ + if (ctxt->cr4) + write_cr4(ctxt->cr4); write_cr3(ctxt->cr3); write_cr2(ctxt->cr2); write_cr0(ctxt->cr0); diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S index b95aa6c..4fc7e87 100644 --- a/arch/x86/power/hibernate_asm_32.S +++ b/arch/x86/power/hibernate_asm_32.S @@ -28,9 +28,9 @@ ENTRY(swsusp_arch_suspend) ret ENTRY(restore_image) - movl resume_pg_dir, %ecx - subl $__PAGE_OFFSET, %ecx - movl %ecx, %cr3 + movl resume_pg_dir, %eax + subl $__PAGE_OFFSET, %eax + movl %eax, %cr3 movl restore_pblist, %edx .p2align 4,,7 @@ -52,17 +52,21 @@ copy_loop: done: /* go back to the original page tables */ - movl $swapper_pg_dir, %ecx - subl $__PAGE_OFFSET, %ecx - movl %ecx, %cr3 + movl $swapper_pg_dir, %eax + subl $__PAGE_OFFSET, %eax + movl %eax, %cr3 /* Flush TLB, including "global" things (vmalloc) */ - movl mmu_cr4_features, %eax - movl %eax, %edx + movl mmu_cr4_features, %ecx + jecxz 1f # cr4 Pentium and higher, skip if zero + movl %ecx, %edx andl $~(1<<7), %edx; # PGE movl %edx, %cr4; # turn off PGE - movl %cr3, %ecx; # flush TLB - movl %ecx, %cr3 - movl %eax, %cr4; # turn PGE back on +1: + movl %cr3, %eax; # flush TLB + movl %eax, %cr3 + jecxz 1f # cr4 Pentium and higher, skip if zero + movl %ecx, %cr4; # turn PGE back on +1: movl saved_context_esp, %esp movl saved_context_ebp, %ebp -- 1.4.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/