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[IA64] Multiple outstanding ptc.g instruction support

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According to SDM2.2, Itanium supports multiple outstanding ptc.g instructions.
But current kernel function ia64_global_tlb_purge() uses a spinlock to serialize
ptc.g instructions issued by multiple processors. This serialization might have
scalability issue on a big SMP machine where many processors could purge TLB
in parallel.

The patch fixes this problem by issuing multiple ptc.g instructions in
ia64_global_tlb_purge(). It also adds support for the "PALO" table to get
a platform view of the max number of outstanding ptc.g instructions (which
may be different from the processor view found from PAL_VM_SUMMARY).

PALO specification can be found at: http://www.dig64.org/home/DIG64_PALO_R1_0.pdf

spinaphore implementation by Matthew Wilcox.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Fenghua Yu
2008-04-04 11:05:59 -07:00
committed by Tony Luck
parent e315c121a8
commit 2046b94e7c
5 changed files with 178 additions and 17 deletions
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46
arch/ia64/kernel/efi.c
View File

@@ -37,6 +37,7 @@
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/mca.h>
#include <asm/tlbflush.h>
#define EFI_DEBUG 0
@@ -403,6 +404,41 @@ efi_get_pal_addr (void)
return NULL;
}
static u8 __init palo_checksum(u8 *buffer, u32 length)
{
u8 sum = 0;
u8 *end = buffer + length;
while (buffer < end)
sum = (u8) (sum + *(buffer++));
return sum;
}
/*
* Parse and handle PALO table which is published at:
* http://www.dig64.org/home/DIG64_PALO_R1_0.pdf
*/
static void __init handle_palo(unsigned long palo_phys)
{
struct palo_table *palo = __va(palo_phys);
u8 checksum;
if (strncmp(palo->signature, PALO_SIG, sizeof(PALO_SIG) - 1)) {
printk(KERN_INFO "PALO signature incorrect.\n");
return;
}
checksum = palo_checksum((u8 *)palo, palo->length);
if (checksum) {
printk(KERN_INFO "PALO checksum incorrect.\n");
return;
}
setup_ptcg_sem(palo->max_tlb_purges, 1);
}
void
efi_map_pal_code (void)
{
@@ -432,6 +468,7 @@ efi_init (void)
u64 efi_desc_size;
char *cp, vendor[100] = "unknown";
int i;
unsigned long palo_phys;
/*
* It's too early to be able to use the standard kernel command line
@@ -496,6 +533,8 @@ efi_init (void)
efi.hcdp = EFI_INVALID_TABLE_ADDR;
efi.uga = EFI_INVALID_TABLE_ADDR;
palo_phys = EFI_INVALID_TABLE_ADDR;
for (i = 0; i < (int) efi.systab->nr_tables; i++) {
if (efi_guidcmp(config_tables[i].guid, MPS_TABLE_GUID) == 0) {
efi.mps = config_tables[i].table;
@@ -515,10 +554,17 @@ efi_init (void)
} else if (efi_guidcmp(config_tables[i].guid, HCDP_TABLE_GUID) == 0) {
efi.hcdp = config_tables[i].table;
printk(" HCDP=0x%lx", config_tables[i].table);
} else if (efi_guidcmp(config_tables[i].guid,
PROCESSOR_ABSTRACTION_LAYER_OVERWRITE_GUID) == 0) {
palo_phys = config_tables[i].table;
printk(" PALO=0x%lx", config_tables[i].table);
}
}
printk("\n");
if (palo_phys != EFI_INVALID_TABLE_ADDR)
handle_palo(palo_phys);
runtime = __va(efi.systab->runtime);
efi.get_time = phys_get_time;
efi.set_time = phys_set_time;