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authorZachary Amsden <zach@vmware.com>2006-01-06 00:11:47 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-06 08:33:33 -0800
commit7c4cb60e5b97677424e95baee9c29df54b26e6ba (patch)
treea2ad6e6104e153d15bc4bfbb67f74b0e05fea03c /drivers
parent599a6e8ca4ff7f453f847217ecc2718d68e3b0f6 (diff)
downloadop-kernel-dev-7c4cb60e5b97677424e95baee9c29df54b26e6ba.zip
op-kernel-dev-7c4cb60e5b97677424e95baee9c29df54b26e6ba.tar.gz
[PATCH] x86: GDT alignment fix
Make GDT page aligned and page padded to support running inside of a hypervisor. This prevents false sharing of the GDT page with other hot data, which is not allowed in Xen, and causes performance problems in VMware. Rather than go back to the old method of statically allocating the GDT (which wastes unneded space for non-present CPUs), the GDT for APs is allocated dynamically. Signed-off-by: Zachary Amsden <zach@vmware.com> Cc: "Seth, Rohit" <rohit.seth@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/pnp/pnpbios/bioscalls.c22
1 files changed, 13 insertions, 9 deletions
diff --git a/drivers/pnp/pnpbios/bioscalls.c b/drivers/pnp/pnpbios/bioscalls.c
index 6b7583f..7cb476e 100644
--- a/drivers/pnp/pnpbios/bioscalls.c
+++ b/drivers/pnp/pnpbios/bioscalls.c
@@ -69,14 +69,16 @@ __asm__(
#define Q_SET_SEL(cpu, selname, address, size) \
do { \
-set_base(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], __va((u32)(address))); \
-set_limit(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], size); \
+struct desc_struct *gdt = get_cpu_gdt_table((cpu)); \
+set_base(gdt[(selname) >> 3], __va((u32)(address))); \
+set_limit(gdt[(selname) >> 3], size); \
} while(0)
#define Q2_SET_SEL(cpu, selname, address, size) \
do { \
-set_base(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], (u32)(address)); \
-set_limit(per_cpu(cpu_gdt_table,cpu)[(selname) >> 3], size); \
+struct desc_struct *gdt = get_cpu_gdt_table((cpu)); \
+set_base(gdt[(selname) >> 3], (u32)(address)); \
+set_limit(gdt[(selname) >> 3], size); \
} while(0)
static struct desc_struct bad_bios_desc = { 0, 0x00409200 };
@@ -115,8 +117,8 @@ static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3,
return PNP_FUNCTION_NOT_SUPPORTED;
cpu = get_cpu();
- save_desc_40 = per_cpu(cpu_gdt_table,cpu)[0x40 / 8];
- per_cpu(cpu_gdt_table,cpu)[0x40 / 8] = bad_bios_desc;
+ save_desc_40 = get_cpu_gdt_table(cpu)[0x40 / 8];
+ get_cpu_gdt_table(cpu)[0x40 / 8] = bad_bios_desc;
/* On some boxes IRQ's during PnP BIOS calls are deadly. */
spin_lock_irqsave(&pnp_bios_lock, flags);
@@ -158,7 +160,7 @@ static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3,
);
spin_unlock_irqrestore(&pnp_bios_lock, flags);
- per_cpu(cpu_gdt_table,cpu)[0x40 / 8] = save_desc_40;
+ get_cpu_gdt_table(cpu)[0x40 / 8] = save_desc_40;
put_cpu();
/* If we get here and this is set then the PnP BIOS faulted on us. */
@@ -535,8 +537,10 @@ void pnpbios_calls_init(union pnp_bios_install_struct *header)
set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
_set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
- for(i=0; i < NR_CPUS; i++)
- {
+ for (i = 0; i < NR_CPUS; i++) {
+ struct desc_struct *gdt = get_cpu_gdt_table(i);
+ if (!gdt)
+ continue;
Q2_SET_SEL(i, PNP_CS32, &pnp_bios_callfunc, 64 * 1024);
Q_SET_SEL(i, PNP_CS16, header->fields.pm16cseg, 64 * 1024);
Q_SET_SEL(i, PNP_DS, header->fields.pm16dseg, 64 * 1024);
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