From 2046b94e7c4fce92eb8165c2c36c6478f4927178 Mon Sep 17 00:00:00 2001 From: Fenghua Yu Date: Fri, 4 Apr 2008 11:05:59 -0700 Subject: [IA64] Multiple outstanding ptc.g instruction support 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 Signed-off-by: Tony Luck --- arch/ia64/kernel/efi.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'arch/ia64/kernel/efi.c') diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c index 728d7247a1a6..003cd09b0732 100644 --- a/arch/ia64/kernel/efi.c +++ b/arch/ia64/kernel/efi.c @@ -37,6 +37,7 @@ #include #include #include +#include #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; -- cgit v1.2.3-59-g8ed1b