diff options
Diffstat (limited to 'trunk/2.6.22/20003_linux-2.6.19-rc1-kexec-move_segment_code-i386.patch1')
| -rw-r--r-- | trunk/2.6.22/20003_linux-2.6.19-rc1-kexec-move_segment_code-i386.patch1 | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/trunk/2.6.22/20003_linux-2.6.19-rc1-kexec-move_segment_code-i386.patch1 b/trunk/2.6.22/20003_linux-2.6.19-rc1-kexec-move_segment_code-i386.patch1 new file mode 100644 index 0000000..0e266e1 --- /dev/null +++ b/trunk/2.6.22/20003_linux-2.6.19-rc1-kexec-move_segment_code-i386.patch1 @@ -0,0 +1,172 @@ +Subject: kexec: Move asm segment handling code to the assembly file (i386) +From: http://xenbits.xensource.com/xen-unstable.hg (tip 13816) +Patch-mainline: obsolete + +This patch moves the idt, gdt, and segment handling code from machine_kexec.c +to relocate_kernel.S. The main reason behind this move is to avoid code +duplication in the Xen hypervisor. With this patch all code required to kexec +is put on the control page. + +On top of that this patch also counts as a cleanup - I think it is much +nicer to write assembly directly in assembly files than wrap inline assembly +in C functions for no apparent reason. + +Signed-off-by: Magnus Damm <magnus@valinux.co.jp> +Acked-by: jbeulich@novell.com +--- + + Applies to 2.6.19-rc1. + + arch/i386/kernel/machine_kexec.c | 59 ------------------------------------- + arch/i386/kernel/relocate_kernel.S | 58 +++++++++++++++++++++++++++++++++--- + 2 files changed, 53 insertions(+), 64 deletions(-) + +--- a/arch/i386/kernel/machine_kexec.c 2007-08-27 12:09:26.000000000 -0400 ++++ b/arch/i386/kernel/machine_kexec.c 2007-08-27 14:02:11.000000000 -0400 +@@ -29,48 +29,6 @@ static u32 kexec_pmd1[1024] PAGE_ALIGNED + static u32 kexec_pte0[1024] PAGE_ALIGNED; + static u32 kexec_pte1[1024] PAGE_ALIGNED; + +-static void set_idt(void *newidt, __u16 limit) +-{ +- struct Xgt_desc_struct curidt; +- +- /* ia32 supports unaliged loads & stores */ +- curidt.size = limit; +- curidt.address = (unsigned long)newidt; +- +- load_idt(&curidt); +-}; +- +- +-static void set_gdt(void *newgdt, __u16 limit) +-{ +- struct Xgt_desc_struct curgdt; +- +- /* ia32 supports unaligned loads & stores */ +- curgdt.size = limit; +- curgdt.address = (unsigned long)newgdt; +- +- load_gdt(&curgdt); +-}; +- +-static void load_segments(void) +-{ +-#define __STR(X) #X +-#define STR(X) __STR(X) +- +- __asm__ __volatile__ ( +- "\tljmp $"STR(__KERNEL_CS)",$1f\n" +- "\t1:\n" +- "\tmovl $"STR(__KERNEL_DS)",%%eax\n" +- "\tmovl %%eax,%%ds\n" +- "\tmovl %%eax,%%es\n" +- "\tmovl %%eax,%%fs\n" +- "\tmovl %%eax,%%gs\n" +- "\tmovl %%eax,%%ss\n" +- ::: "eax", "memory"); +-#undef STR +-#undef __STR +-} +- + /* + * A architecture hook called to validate the + * proposed image and prepare the control pages +@@ -127,23 +85,6 @@ NORET_TYPE void machine_kexec(struct kim + page_list[PA_PTE_1] = __pa(kexec_pte1); + page_list[VA_PTE_1] = (unsigned long)kexec_pte1; + +- /* The segment registers are funny things, they have both a +- * visible and an invisible part. Whenever the visible part is +- * set to a specific selector, the invisible part is loaded +- * with from a table in memory. At no other time is the +- * descriptor table in memory accessed. +- * +- * I take advantage of this here by force loading the +- * segments, before I zap the gdt with an invalid value. +- */ +- load_segments(); +- /* The gdt & idt are now invalid. +- * If you want to load them you must set up your own idt & gdt. +- */ +- set_gdt(phys_to_virt(0),0); +- set_idt(phys_to_virt(0),0); +- +- /* now call it */ + relocate_kernel((unsigned long)image->head, (unsigned long)page_list, + image->start, cpu_has_pae); + } +--- a/arch/i386/kernel/relocate_kernel.S 2007-08-27 12:09:26.000000000 -0400 ++++ b/arch/i386/kernel/relocate_kernel.S 2007-08-27 14:01:24.000000000 -0400 +@@ -154,14 +154,45 @@ relocate_new_kernel: + movl PTR(PA_PGD)(%ebp), %eax + movl %eax, %cr3 + ++ /* setup idt */ ++ movl %edi, %eax ++ addl $(idt_48 - relocate_kernel), %eax ++ lidtl (%eax) ++ ++ /* setup gdt */ ++ movl %edi, %eax ++ addl $(gdt - relocate_kernel), %eax ++ movl %edi, %esi ++ addl $((gdt_48 - relocate_kernel) + 2), %esi ++ movl %eax, (%esi) ++ ++ movl %edi, %eax ++ addl $(gdt_48 - relocate_kernel), %eax ++ lgdtl (%eax) ++ ++ /* setup data segment registers */ ++ mov $(gdt_ds - gdt), %eax ++ mov %eax, %ds ++ mov %eax, %es ++ mov %eax, %fs ++ mov %eax, %gs ++ mov %eax, %ss ++ + /* setup a new stack at the end of the physical control page */ + lea 4096(%edi), %esp + +- /* jump to identity mapped page */ +- movl %edi, %eax +- addl $(identity_mapped - relocate_kernel), %eax +- pushl %eax +- ret ++ /* load new code segment and jump to identity mapped page */ ++ movl %edi, %esi ++ xorl %eax, %eax ++ pushl %eax ++ pushl %esi ++ pushl %eax ++ movl $(gdt_cs - gdt), %eax ++ pushl %eax ++ movl %edi, %eax ++ addl $(identity_mapped - relocate_kernel),%eax ++ pushl %eax ++ iretl + + identity_mapped: + /* store the start address on the stack */ +@@ -250,3 +281,20 @@ identity_mapped: + xorl %edi, %edi + xorl %ebp, %ebp + ret ++ ++ .align 16 ++gdt: ++ .quad 0x0000000000000000 /* NULL descriptor */ ++gdt_cs: ++ .quad 0x00cf9a000000ffff /* kernel 4GB code at 0x00000000 */ ++gdt_ds: ++ .quad 0x00cf92000000ffff /* kernel 4GB data at 0x00000000 */ ++gdt_end: ++ ++gdt_48: ++ .word gdt_end - gdt - 1 /* limit */ ++ .long 0 /* base - filled in by code above */ ++ ++idt_48: ++ .word 0 /* limit */ ++ .long 0 /* base */ |