[Xen-changelog] [xen-unstable] [IA64] remove unnecessary vtlb_lock

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User awilliam@xxxxxxxxxxx
# Node ID 5389c7b06ccf21856d50d658c5a52bfb190b642c
# Parent  535b466ee1ef431bbb82b0bdea1b3c90a85914b3
[IA64] remove unnecessary vtlb_lock

remove vtlb_lock.
As Tristan pointed out, vtlb_lock is unnecesary.

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
---
 xen/arch/ia64/xen/domain.c    |    1 -
 xen/arch/ia64/xen/faults.c    |    8 ++++----
 xen/arch/ia64/xen/vhpt.c      |   16 ++--------------
 xen/include/asm-ia64/domain.h |    3 ---
 4 files changed, 6 insertions(+), 22 deletions(-)

diff -r 535b466ee1ef -r 5389c7b06ccf xen/arch/ia64/xen/domain.c
--- a/xen/arch/ia64/xen/domain.c        Mon Jun 19 13:06:53 2006 -0600
+++ b/xen/arch/ia64/xen/domain.c        Mon Jun 19 13:13:01 2006 -0600
@@ -306,7 +306,6 @@ int arch_domain_create(struct domain *d)
        // the following will eventually need to be negotiated dynamically
        d->arch.shared_info_va = SHAREDINFO_ADDR;
        d->arch.breakimm = 0x1000;
-       seqlock_init(&d->arch.vtlb_lock);
 
        if (is_idle_domain(d))
            return 0;
diff -r 535b466ee1ef -r 5389c7b06ccf xen/arch/ia64/xen/faults.c
--- a/xen/arch/ia64/xen/faults.c        Mon Jun 19 13:06:53 2006 -0600
+++ b/xen/arch/ia64/xen/faults.c        Mon Jun 19 13:13:01 2006 -0600
@@ -214,8 +214,6 @@ void ia64_do_page_fault (unsigned long a
        // FIXME should validate address here
        unsigned long pteval;
        unsigned long is_data = !((isr >> IA64_ISR_X_BIT) & 1UL);
-       seqlock_t* vtlb_lock = &current->domain->arch.vtlb_lock;
-       unsigned long seq;
        IA64FAULT fault;
 
        if ((isr & IA64_ISR_IR) && handle_lazy_cover(current, regs)) return;
@@ -232,14 +230,16 @@ void ia64_do_page_fault (unsigned long a
        }
 
  again:
-       seq = read_seqbegin(vtlb_lock);
        fault = vcpu_translate(current,address,is_data,&pteval,&itir,&iha);
        if (fault == IA64_NO_FAULT || fault == IA64_USE_TLB) {
                u64 logps;
                struct p2m_entry entry;
                pteval = translate_domain_pte(pteval, address, itir, &logps, 
&entry);
                vcpu_itc_no_srlz(current,is_data?2:1,address,pteval,-1UL,logps);
-               if (read_seqretry(vtlb_lock, seq) || p2m_entry_retry(&entry)) {
+               if ((fault == IA64_USE_TLB && !current->arch.dtlb.pte.p) ||
+                   p2m_entry_retry(&entry)) {
+                       /* dtlb has been purged in-between.  This dtlb was
+                          matching.  Undo the work.  */
                        vcpu_flush_tlb_vhpt_range(address & ((1 << logps) - 1),
                                                  logps);
                        goto again;
diff -r 535b466ee1ef -r 5389c7b06ccf xen/arch/ia64/xen/vhpt.c
--- a/xen/arch/ia64/xen/vhpt.c  Mon Jun 19 13:06:53 2006 -0600
+++ b/xen/arch/ia64/xen/vhpt.c  Mon Jun 19 13:13:01 2006 -0600
@@ -152,9 +152,7 @@ void domain_flush_vtlb_all (void)
 {
        int cpu = smp_processor_id ();
        struct vcpu *v;
-       seqlock_t* vtlb_lock = &current->domain->arch.vtlb_lock;
-
-       write_seqlock(vtlb_lock);
+
        for_each_vcpu (current->domain, v)
                if (v->processor == cpu)
                        vcpu_flush_vtlb_all ();
@@ -163,7 +161,6 @@ void domain_flush_vtlb_all (void)
                                (v->processor,
                                 (void(*)(void *))vcpu_flush_vtlb_all,
                                 NULL,1,1);
-       write_sequnlock(vtlb_lock);
 }
 
 static void cpu_flush_vhpt_range (int cpu, u64 vadr, u64 addr_range)
@@ -190,7 +187,6 @@ void vcpu_flush_tlb_vhpt_range (u64 vadr
 
 void domain_flush_vtlb_range (struct domain *d, u64 vadr, u64 addr_range)
 {
-       seqlock_t* vtlb_lock = &d->arch.vtlb_lock;
        struct vcpu *v;
 
 #if 0
@@ -201,7 +197,6 @@ void domain_flush_vtlb_range (struct dom
        }
 #endif
 
-       write_seqlock(vtlb_lock);
        for_each_vcpu (d, v) {
                /* Purge TC entries.
                   FIXME: clear only if match.  */
@@ -218,7 +213,6 @@ void domain_flush_vtlb_range (struct dom
 
        /* ptc.ga  */
        ia64_global_tlb_purge(vadr,vadr+addr_range,PAGE_SHIFT);
-       write_sequnlock(vtlb_lock);
 }
 
 static void flush_tlb_vhpt_all (struct domain *d)
@@ -230,8 +224,6 @@ static void flush_tlb_vhpt_all (struct d
        local_flush_tlb_all ();
 }
 
-// this is called when a domain is destroyed
-// so that there is no race.
 void domain_flush_destroy (struct domain *d)
 {
        /* Very heavy...  */
@@ -241,10 +233,8 @@ void domain_flush_destroy (struct domain
 
 void flush_tlb_mask(cpumask_t mask)
 {
-    seqlock_t* vtlb_lock = &current->domain->arch.vtlb_lock;
     int cpu;
 
-    write_seqlock(vtlb_lock);
     cpu = smp_processor_id();
     if (cpu_isset (cpu, mask)) {
         cpu_clear(cpu, mask);
@@ -252,13 +242,11 @@ void flush_tlb_mask(cpumask_t mask)
     }
 
     if (cpus_empty(mask))
-        goto out;
+        return;
 
     for_each_cpu_mask (cpu, mask)
         smp_call_function_single
             (cpu, (void (*)(void *))flush_tlb_vhpt_all, NULL, 1, 1);
-out:
-    write_sequnlock(vtlb_lock);
 }
 
 void zero_vhpt_stats(void)
diff -r 535b466ee1ef -r 5389c7b06ccf xen/include/asm-ia64/domain.h
--- a/xen/include/asm-ia64/domain.h     Mon Jun 19 13:06:53 2006 -0600
+++ b/xen/include/asm-ia64/domain.h     Mon Jun 19 13:13:01 2006 -0600
@@ -98,9 +98,6 @@ struct arch_domain {
     void *efi_runtime;
     /* Metaphysical address to fpswa_interface_t in domain firmware memory is 
set. */
     void *fpswa_inf;
-
-    // protect v->itlb, v->dtlb and vhpt
-    seqlock_t   vtlb_lock ____cacheline_aligned_in_smp;
 };
 #define INT_ENABLE_OFFSET(v)             \
     (sizeof(vcpu_info_t) * (v)->vcpu_id + \

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