[PATCH] x86: Fixed pnp bios limits

PnP BIOS data, code, and 32-bit entry segments all have fixed limits as well;
set them in the GDT rather than adding more code.  It would be nice to add
these fixups to the boot GDT rather than setting the GDT for each CPU; perhaps
I can wiggle this in later, but getting it in before the subsys init looks
tricky.

Also, make some progress on deprecating the ugly Q_SET_SEL macros.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S
index 58d2746670b7..5884469f6bfe 100644
--- a/arch/i386/kernel/head.S
+++ b/arch/i386/kernel/head.S
@@ -504,10 +504,14 @@ ENTRY(cpu_gdt_table)
         .quad 0x0000000000000000        /* 0x80 TSS descriptor */
         .quad 0x0000000000000000        /* 0x88 LDT descriptor */
 
-        /* Segments used for calling PnP BIOS have byte granularity */
-        .quad 0x00409a0000000000        /* 0x90 32-bit code */
-        .quad 0x00009a0000000000        /* 0x98 16-bit code */
-        .quad 0x0000920000000000        /* 0xa0 16-bit data */
+        /*
+         * Segments used for calling PnP BIOS have byte granularity.
+         * They code segments and data segments have fixed 64k limits,
+         * the transfer segment sizes are set at run time.
+         */
+        .quad 0x00409a000000ffff        /* 0x90 32-bit code */
+        .quad 0x00009a000000ffff        /* 0x98 16-bit code */
+        .quad 0x000092000000ffff        /* 0xa0 16-bit data */
         .quad 0x0000920000000000        /* 0xa8 16-bit data */
         .quad 0x0000920000000000        /* 0xb0 16-bit data */