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Re: [PATCH 02/18] x86/boot/reloc: create generic alloc and copy function
From: |
Andrew Cooper |
Subject: |
Re: [PATCH 02/18] x86/boot/reloc: create generic alloc and copy functions |
Date: |
Fri, 30 Jan 2015 18:02:10 +0000 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.3.0 |
On 30/01/15 17:54, Daniel Kiper wrote:
> Create generic alloc and copy functions. We need
> separate tools for memory allocation and copy to
> provide multiboot2 protocol support.
>
> Signed-off-by: Daniel Kiper <address@hidden>
Reviewed-by: Andrew Cooper <address@hidden>
> ---
> xen/arch/x86/boot/reloc.c | 52
> ++++++++++++++++++++++++++++-----------------
> 1 file changed, 33 insertions(+), 19 deletions(-)
>
> diff --git a/xen/arch/x86/boot/reloc.c b/xen/arch/x86/boot/reloc.c
> index 63045c0..f964cda 100644
> --- a/xen/arch/x86/boot/reloc.c
> +++ b/xen/arch/x86/boot/reloc.c
> @@ -33,9 +33,10 @@ asm (
> typedef unsigned int u32;
> #include "../../../include/xen/multiboot.h"
>
> -static void *reloc_mbi_struct(void *old, unsigned int bytes)
> +static u32 alloc_struct(u32 bytes)
> {
> - void *new;
> + u32 s;
> +
> asm(
> " call 1f \n"
> "1: pop %%edx \n"
> @@ -43,50 +44,63 @@ static void *reloc_mbi_struct(void *old, unsigned int
> bytes)
> " sub %1,%0 \n"
> " and $~15,%0 \n"
> " mov %0,alloc-1b(%%edx) \n"
> - " mov %0,%%edi \n"
> - " rep movsb \n"
> - : "=&r" (new), "+c" (bytes), "+S" (old)
> - : : "edx", "edi", "memory");
> - return new;
> + : "=&r" (s) : "r" (bytes) : "edx", "memory");
> +
> + return s;
> +}
> +
> +static u32 copy_struct(u32 src, u32 bytes)
> +{
> + u32 dst, dst_asm;
> +
> + dst = alloc_struct(bytes);
> + dst_asm = dst;
> +
> + asm volatile("rep movsb" : "+S" (src), "+D" (dst_asm), "+c" (bytes) : :
> "memory");
> +
> + return dst;
> }
>
> -static char *reloc_mbi_string(char *old)
> +static u32 copy_string(u32 src)
> {
> char *p;
> - for ( p = old; *p != '\0'; p++ )
> +
> + if ( src == 0 )
> + return 0;
> +
> + for ( p = (char *)src; *p != '\0'; p++ )
> continue;
> - return reloc_mbi_struct(old, p - old + 1);
> +
> + return copy_struct(src, p - (char *)src + 1);
> }
>
> multiboot_info_t *reloc(multiboot_info_t *mbi_old)
> {
> - multiboot_info_t *mbi = reloc_mbi_struct(mbi_old, sizeof(*mbi));
> + multiboot_info_t *mbi = (multiboot_info_t *)copy_struct((u32)mbi_old,
> sizeof(*mbi));
> int i;
>
> if ( mbi->flags & MBI_CMDLINE )
> - mbi->cmdline = (u32)reloc_mbi_string((char *)mbi->cmdline);
> + mbi->cmdline = copy_string(mbi->cmdline);
>
> if ( mbi->flags & MBI_MODULES )
> {
> - module_t *mods = reloc_mbi_struct(
> - (module_t *)mbi->mods_addr, mbi->mods_count * sizeof(module_t));
> + module_t *mods = (module_t *)copy_struct(
> + mbi->mods_addr, mbi->mods_count * sizeof(module_t));
>
> mbi->mods_addr = (u32)mods;
>
> for ( i = 0; i < mbi->mods_count; i++ )
> {
> if ( mods[i].string )
> - mods[i].string = (u32)reloc_mbi_string((char
> *)mods[i].string);
> + mods[i].string = copy_string(mods[i].string);
> }
> }
>
> if ( mbi->flags & MBI_MEMMAP )
> - mbi->mmap_addr = (u32)reloc_mbi_struct(
> - (memory_map_t *)mbi->mmap_addr, mbi->mmap_length);
> + mbi->mmap_addr = copy_struct(mbi->mmap_addr, mbi->mmap_length);
>
> if ( mbi->flags & MBI_LOADERNAME )
> - mbi->boot_loader_name = (u32)reloc_mbi_string(
> - (char *)mbi->boot_loader_name);
> + mbi->boot_loader_name = copy_string(mbi->boot_loader_name);
>
> /* Mask features we don't understand or don't relocate. */
> mbi->flags &= (MBI_MEMLIMITS |
- [PATCH 00/18] x86: multiboot2 protocol support, Daniel Kiper, 2015/01/30
- [PATCH 01/18] x86/boot/reloc: mask out MBI_BOOTDEV from mbi flags, Daniel Kiper, 2015/01/30
- [PATCH 02/18] x86/boot/reloc: create generic alloc and copy functions, Daniel Kiper, 2015/01/30
- Re: [PATCH 02/18] x86/boot/reloc: create generic alloc and copy functions,
Andrew Cooper <=
- [PATCH 03/18] x86/boot: use %ecx instead of %eax, Daniel Kiper, 2015/01/30
- [PATCH 04/18] xen/x86: add multiboot2 protocol support, Daniel Kiper, 2015/01/30
- [PATCH 05/18] efi: split efi_enabled to efi_platform and efi_loader, Daniel Kiper, 2015/01/30
- [PATCH 06/18] x86: remove commented out stale references to efi_enabled, Daniel Kiper, 2015/01/30
- [PATCH 08/18] efi: build xen.gz with EFI code, Daniel Kiper, 2015/01/30
- [PATCH 07/18] efi: run EFI specific code on EFI platform only, Daniel Kiper, 2015/01/30
- [PATCH 12/18] efi: create efi_find_gop_mode(), Daniel Kiper, 2015/01/30
- [PATCH 09/18] efi: create efi_init(), Daniel Kiper, 2015/01/30
- [PATCH 10/18] efi: create efi_console_set_mode(), Daniel Kiper, 2015/01/30