luck/tmp_suning_uos_patched
1
0
Fork 1
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[IA64] Multiple outstanding ptc.g instruction support

Browse Source 
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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

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;

6
arch/ia64/kernel/setup.c
View File

@ -59,6 +59,7 @@
#include <asm/setup.h>
#include <asm/smp.h>
#include <asm/system.h>
#include <asm/tlbflush.h>
#include <asm/unistd.h>
#include <asm/hpsim.h>
@ -946,9 +947,10 @@ cpu_init (void)
#endif
/* set ia64_ctx.max_rid to the maximum RID that is supported by all CPUs: */
if (ia64_pal_vm_summary(NULL, &vmi) == 0)
if (ia64_pal_vm_summary(NULL, &vmi) == 0) {
max_ctx = (1U << (vmi.pal_vm_info_2_s.rid_size - 3)) - 1;
else {
setup_ptcg_sem(vmi.pal_vm_info_2_s.max_purges, 0);
} else {
printk(KERN_WARNING "cpu_init: PAL VM summary failed, assuming 18 RID bits\n");
max_ctx = (1U << 15) - 1; /* use architected minimum */
}

125
arch/ia64/mm/tlb.c
View File

@ -11,6 +11,9 @@
* Rohit Seth <rohit.seth@intel.com>
* Ken Chen <kenneth.w.chen@intel.com>
* Christophe de Dinechin <ddd@hp.com>: Avoid ptc.e on memory allocation
* Copyright (C) 2007 Intel Corp
* Fenghua Yu <fenghua.yu@intel.com>
* Add multiple ptc.g/ptc.ga instruction support in global tlb purge.
*/
#include <linux/module.h>
#include <linux/init.h>
@ -26,6 +29,7 @@
#include <asm/pal.h>
#include <asm/tlbflush.h>
#include <asm/dma.h>
#include <asm/sal.h>
static struct {
unsigned long mask; /* mask of supported purge page-sizes */
@ -84,14 +88,104 @@ wrap_mmu_context (struct mm_struct *mm)
local_flush_tlb_all();
}
/*
* Implement "spinaphores" ... like counting semaphores, but they
* spin instead of sleeping. If there are ever any other users for
* this primitive it can be moved up to a spinaphore.h header.
*/
struct spinaphore {
atomic_t cur;
};
static inline void spinaphore_init(struct spinaphore *ss, int val)
{
atomic_set(&ss->cur, val);
}
static inline void down_spin(struct spinaphore *ss)
{
while (unlikely(!atomic_add_unless(&ss->cur, -1, 0)))
while (atomic_read(&ss->cur) == 0)
cpu_relax();
}
static inline void up_spin(struct spinaphore *ss)
{
atomic_add(1, &ss->cur);
}
static struct spinaphore ptcg_sem;
static u16 nptcg = 1;
static int need_ptcg_sem = 1;
static int toolatetochangeptcgsem = 0;
/*
* Maximum number of simultaneous ptc.g purges in the system can
* be defined by PAL_VM_SUMMARY (in which case we should take
* the smallest value for any cpu in the system) or by the PAL
* override table (in which case we should ignore the value from
* PAL_VM_SUMMARY).
*
* Complicating the logic here is the fact that num_possible_cpus()
* isn't fully setup until we start bringing cpus online.
*/
void
setup_ptcg_sem(int max_purges, int from_palo)
{
static int have_palo;
static int firstcpu = 1;
if (toolatetochangeptcgsem) {
BUG_ON(max_purges < nptcg);
return;
}
if (from_palo) {
have_palo = 1;
/* In PALO max_purges == 0 really means it! */
if (max_purges == 0)
panic("Whoa! Platform does not support global TLB purges.\n");
nptcg = max_purges;
if (nptcg == PALO_MAX_TLB_PURGES) {
need_ptcg_sem = 0;
return;
}
goto resetsema;
}
if (have_palo) {
if (nptcg != PALO_MAX_TLB_PURGES)
need_ptcg_sem = (num_possible_cpus() > nptcg);
return;
}
/* In PAL_VM_SUMMARY max_purges == 0 actually means 1 */
if (max_purges == 0) max_purges = 1;
if (firstcpu) {
nptcg = max_purges;
firstcpu = 0;
}
if (max_purges < nptcg)
nptcg = max_purges;
if (nptcg == PAL_MAX_PURGES) {
need_ptcg_sem = 0;
return;
} else
need_ptcg_sem = (num_possible_cpus() > nptcg);
resetsema:
spinaphore_init(&ptcg_sem, max_purges);
}
void
ia64_global_tlb_purge (struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned long nbits)
{
static DEFINE_SPINLOCK(ptcg_lock);
struct mm_struct *active_mm = current->active_mm;
toolatetochangeptcgsem = 1;
if (mm != active_mm) {
/* Restore region IDs for mm */
if (mm && active_mm) {
@ -102,19 +196,20 @@ ia64_global_tlb_purge (struct mm_struct *mm, unsigned long start,
}
}
/* HW requires global serialization of ptc.ga. */
spin_lock(&ptcg_lock);
{
do {
/*
* Flush ALAT entries also.
*/
ia64_ptcga(start, (nbits<<2));
ia64_srlz_i();
start += (1UL << nbits);
} while (start < end);
}
spin_unlock(&ptcg_lock);
if (need_ptcg_sem)
down_spin(&ptcg_sem);
do {
/*
* Flush ALAT entries also.
*/
ia64_ptcga(start, (nbits << 2));
ia64_srlz_i();
start += (1UL << nbits);
} while (start < end);
if (need_ptcg_sem)
up_spin(&ptcg_sem);
if (mm != active_mm) {
activate_context(active_mm);

17
include/asm-ia64/sal.h
View File

@ -296,6 +296,9 @@ enum {
EFI_GUID(0xe429faf8, 0x3cb7, 0x11d4, 0xbc, 0xa7, 0x0, 0x80, 0xc7, 0x3c, 0x88, 0x81)
#define SAL_PLAT_BUS_ERR_SECT_GUID \
EFI_GUID(0xe429faf9, 0x3cb7, 0x11d4, 0xbc, 0xa7, 0x0, 0x80, 0xc7, 0x3c, 0x88, 0x81)
#define PROCESSOR_ABSTRACTION_LAYER_OVERWRITE_GUID \
EFI_GUID(0x6cb0a200, 0x893a, 0x11da, 0x96, 0xd2, 0x0, 0x10, 0x83, 0xff, \
0xca, 0x4d)
#define MAX_CACHE_ERRORS 6
#define MAX_TLB_ERRORS 6
@ -879,6 +882,20 @@ extern void ia64_jump_to_sal(struct sal_to_os_boot *);
extern void ia64_sal_handler_init(void *entry_point, void *gpval);
#define PALO_MAX_TLB_PURGES 0xFFFF
#define PALO_SIG "PALO"
struct palo_table {
u8 signature[4]; /* Should be "PALO" */
u32 length;
u8 minor_revision;
u8 major_revision;
u8 checksum;
u8 reserved1[5];
u16 max_tlb_purges;
u8 reserved2[6];
};
#endif /* __ASSEMBLY__ */
#endif /* _ASM_IA64_SAL_H */

1
include/asm-ia64/tlbflush.h
View File

@ -17,6 +17,7 @@
* Now for some TLB flushing routines. This is the kind of stuff that
* can be very expensive, so try to avoid them whenever possible.
*/
extern void setup_ptcg_sem(int max_purges, int from_palo);
/*
* Flush everything (kernel mapping may also have changed due to