Re: [coreboot] Multiboot bugfix #2 (coreboot-v3)

[Jordan Crouse]

On 28/09/08 00:13 +0200, Robert Millan wrote:
> Hi,
>
> I noticed that free regions provided by search_global_resources() don't have
> the reserved regions substracted from them.  This patch introduces a check
> to weed them out, splitting when necessary.
>
> The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
>   how) you may access your data; but nobody's threatening your freedom: we
>   still allow you to remove your data and not access it at all."
> Signed-off-by: Robert Millan

Acked-by: Jordan Crouse
> Index: arch/x86/multiboot.c
>
> --- arch/x86/multiboot.c	(revision 870)
> +++ arch/x86/multiboot.c	(working copy)
> @@ -25,42 +25,83 @@
>
> static struct multiboot_mmap_entry *mb_mem;
>
> -static void build_mb_mem_range(void *gp, struct device *dev, struct resource *res)
> +static struct {
> u64 addr;
> u64 len;
>
> +} reserved_mem[2];
>
> +static void build_mb_mem_range_nooverlap(u64 addr, u64 len)
>  {
> mb_mem->addr = res->base;
> mb_mem->len = res->size;
> int i;
> for (i = 0; i < sizeof(reserved_mem) / sizeof(reserved_mem[0]); i++) {
> /* free region fully contained in reserved region, abort */
> if (addr >= reserved_mem[i].addr && addr + len <= reserved_mem[i].addr + reserved_mem[i].len)
> 	return;
> /* reserved region splits free region */
> if (addr < reserved_mem[i].addr && addr + len > reserved_mem[i].addr + reserved_mem[i].len) {
> 	build_mb_mem_range_nooverlap(addr, reserved_mem[i].addr - addr);
> 	build_mb_mem_range_nooverlap(reserved_mem[i].addr + reserved_mem[i].len, (addr + len) - (reserved_mem[i].addr + reserved_mem[i].len));
> 	return;
> }
> /* left overlap */
> if (addr < reserved_mem[i].addr + reserved_mem[i].len && addr + len > reserved_mem[i].addr + reserved_mem[i].len) {
> 	len += addr;
> 	addr = reserved_mem[i].addr + reserved_mem[i].len;
> 	len -= addr;
> 	/* len += addr - old_addr */
> 	continue;
> }
> /* right overlap */
> if (addr < reserved_mem[i].addr && addr + len > reserved_mem[i].addr) {
> 	len = reserved_mem[i].addr - addr;
> 	continue;
> }
> /* none of the above, just add it */
> }
> mb_mem->addr = addr;
> mb_mem->len = len;
> mb_mem->type = 1;
> mb_mem->size = sizeof(*mb_mem) - sizeof(mb_mem->size);
> mb_mem++;
>
> }
>
> +static void build_mb_mem_range(void *gp, struct device *dev, struct resource *res)
> +{
> build_mb_mem_range_nooverlap(res->base, res->size);
>
> +}
>
> unsigned long write_multiboot_info(
>    unsigned long low_table_start, unsigned long low_table_end,
>    unsigned long rom_table_start, unsigned long rom_table_end)
>  {
> struct multiboot_info *mbi = rom_table_end;
>
> struct multiboot_info *mbi;
>
> int i;
>
> mbi = rom_table_end;
> memset(mbi, 0, sizeof(*mbi));
> rom_table_end += sizeof(*mbi);
>
> mbi->mmap_addr = (u32) rom_table_end;
> mb_mem = rom_table_end;
>
> /* reserved regions */
>
> reserved_mem[0].addr = low_table_start;
>
> reserved_mem[0].len = low_table_end - low_table_start;
>
> reserved_mem[1].addr = rom_table_start;
>
> reserved_mem[1].len = rom_table_end - rom_table_start;
>
> for (i = 0; i < sizeof(reserved_mem) / sizeof(reserved_mem[0]); i++) {
> mb_mem->addr = reserved_mem[i].addr;
> mb_mem->len = reserved_mem[i].len;
> mb_mem->type = 2;
> mb_mem->size = sizeof(*mb_mem) - sizeof(mb_mem->size);
> mb_mem++;
>
> }
>
> /* free regions */
>  search_global_resources( IORESOURCE_MEM | IORESOURCE_CACHEABLE,
>   IORESOURCE_MEM | IORESOURCE_CACHEABLE, build_mb_mem_range, NULL);
> /* reserved regions */
> mb_mem->addr = low_table_start;
> mb_mem->len = low_table_end - low_table_start;
> mb_mem->type = 2;
> mb_mem->size = sizeof(*mb_mem) - sizeof(mb_mem->size);
> mb_mem++;
> mb_mem->addr = rom_table_start;
> mb_mem->len = rom_table_end - rom_table_start;
> mb_mem->type = 2;
> mb_mem->size = sizeof(*mb_mem) - sizeof(mb_mem->size);
> mb_mem++;
> mbi->mmap_length = ((u32) mb_mem) - mbi->mmap_addr;
>  mbi->flags |= MB_INFO_MEM_MAP;
>