similar to: [PATCH 7/12] gdt-accessor

Add an accessor function for getting the per-CPU gdt. Callee must already have the CPU. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-rc1/include/asm-i386/desc.h =================================================================== --- linux-2.6.14-rc1.orig/include/asm-i386/desc.h 2005-09-20 14:49:10.000000000 -0700 +++ linux-2.6.14-rc1/include/asm-i386/desc.h

Add an accessor function for getting the per-CPU gdt. Callee must already have the CPU. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-rc1/include/asm-i386/desc.h =================================================================== --- linux-2.6.14-rc1.orig/include/asm-i386/desc.h 2005-09-20 14:49:10.000000000 -0700 +++ linux-2.6.14-rc1/include/asm-i386/desc.h

Add an accessor function for getting the per-CPU gdt. Callee must already have the CPU. Patch-base: 2.6.13-rc5-mm1 Patch-keys: i386 desc xen Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/desc.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/desc.h 2005-08-09 20:17:21.000000000 -0700 +++

Add an accessor function for getting the per-CPU gdt. Callee must already have the CPU. Patch-base: 2.6.13-rc5-mm1 Patch-keys: i386 desc xen Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/desc.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/desc.h 2005-08-09 20:17:21.000000000 -0700 +++

Found some stray descriptor table accessors that had non-optimal assembler constraints. Use "q" to get word, high and low byte access without forcing a specific register constraint. Add desc as a memory output operand. Also, get_base was completely unused. Deprecate it. The function get_limit is also unused, but I did not deprecate it; it could be used in arch/i386/mm/fault.c.

Found some stray descriptor table accessors that had non-optimal assembler constraints. Use "q" to get word, high and low byte access without forcing a specific register constraint. Add desc as a memory output operand. Also, get_base was completely unused. Deprecate it. The function get_limit is also unused, but I did not deprecate it; it could be used in arch/i386/mm/fault.c.

Found some stray descriptor table accessors that had non-optimal assembler constraints. Use "q" to get word, high and low byte access without forcing a specific register constraint. Add desc as a memory output operand. Also, get_base was completely unused. Deprecate it. The function get_limit is also unused, but I did not deprecate it; it could be used in arch/i386/mm/fault.c.

Found some stray descriptor table accessors that had non-optimal assembler constraints. Use "q" to get word, high and low byte access without forcing a specific register constraint. Add desc as a memory output operand. Also, get_base was completely unused. Deprecate it. The function get_limit is also unused, but I did not deprecate it; it could be used in arch/i386/mm/fault.c.

APM BIOSes have many bugs regarding proper representation of the appropriate segment limits for calling the BIOS. By default, APM_RELAX_SEGMENTS is always turned on to support running the APM BIOS on these buggy machines. Keeping 64k limits poses very little danger to the kernel, because the pages where the APM BIOS is located will always be in low physical memory BIOS areas, which should

APM BIOSes have many bugs regarding proper representation of the appropriate segment limits for calling the BIOS. By default, APM_RELAX_SEGMENTS is always turned on to support running the APM BIOS on these buggy machines. Keeping 64k limits poses very little danger to the kernel, because the pages where the APM BIOS is located will always be in low physical memory BIOS areas, which should

APM BIOS code has a protective wrapper that runs it only on CPU zero. Thus, no need to set APM BIOS segments in the GDT for other CPUs. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/arch/i386/kernel/apm.c =================================================================== --- linux-2.6.14-zach-work.orig/arch/i386/kernel/apm.c 2005-11-07 10:17:45.000000000

APM BIOS code has a protective wrapper that runs it only on CPU zero. Thus, no need to set APM BIOS segments in the GDT for other CPUs. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/arch/i386/kernel/apm.c =================================================================== --- linux-2.6.14-zach-work.orig/arch/i386/kernel/apm.c 2005-11-07 10:17:45.000000000

Since APM BIOS segment limits are now fixed, set them in head.S GDT and don't use the complicated _set_limit() macro expansion. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/arch/i386/kernel/head.S =================================================================== --- linux-2.6.14-zach-work.orig/arch/i386/kernel/head.S 2005-11-04 15:46:11.000000000 -0800

Since APM BIOS segment limits are now fixed, set them in head.S GDT and don't use the complicated _set_limit() macro expansion. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/arch/i386/kernel/head.S =================================================================== --- linux-2.6.14-zach-work.orig/arch/i386/kernel/head.S 2005-11-04 15:46:11.000000000 -0800

Ancient inline assembler that manipulates descriptor tables is unreadable and has no type checking. Doing this in C actually generates better code, saves code space, and improves readability. The fact that you must cast descriptors to (char *) for the inline assembler to work properly caused me no end of grief working on these patches. Note that GCC does not generate rotations to utilize

Ancient inline assembler that manipulates descriptor tables is unreadable and has no type checking. Doing this in C actually generates better code, saves code space, and improves readability. The fact that you must cast descriptors to (char *) for the inline assembler to work properly caused me no end of grief working on these patches. Note that GCC does not generate rotations to utilize

Both the APM BIOS and PnP BIOS code use a segment hack to simulate real mode selector 0x40 (which points to the BIOS data area at 0x00400 in real mode). Several broken BIOSen use selector 0x40 as if they were running in real mode, which we make work by faking up selector 0x40 in the GDT to point to physical memory starting at 0x400. We limit the access to the remainder of this physical page

Both the APM BIOS and PnP BIOS code use a segment hack to simulate real mode selector 0x40 (which points to the BIOS data area at 0x00400 in real mode). Several broken BIOSen use selector 0x40 as if they were running in real mode, which we make work by faking up selector 0x40 in the GDT to point to physical memory starting at 0x400. We limit the access to the remainder of this physical page

Andrew Morton's fix for PnP BIOS. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-rc1/drivers/pnp/pnpbios/bioscalls.c =================================================================== --- linux-2.6.14-rc1.orig/drivers/pnp/pnpbios/bioscalls.c 2005-08-28 16:41:01.000000000 -0700 +++ linux-2.6.14-rc1/drivers/pnp/pnpbios/bioscalls.c 2005-09-28 13:13:42.000000000 -0700

Andrew Morton's fix for PnP BIOS. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-rc1/drivers/pnp/pnpbios/bioscalls.c =================================================================== --- linux-2.6.14-rc1.orig/drivers/pnp/pnpbios/bioscalls.c 2005-08-28 16:41:01.000000000 -0700 +++ linux-2.6.14-rc1/drivers/pnp/pnpbios/bioscalls.c 2005-09-28 13:13:42.000000000 -0700