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KVM: i8254: drop local copy of mul_u64_u32_div

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A function that does the same as i8254.c's muldiv64 has been added
(for KVM's own use, in fact!) in include/linux/math64.h.  Use it
instead of muldiv64.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2016-03-04 09:28:41 +01:00
parent e23d3fef83
commit 0e4d44151a
1 changed files with 3 additions and 23 deletions
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26
arch/x86/kvm/i8254.c
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@ -51,26 +51,6 @@
#define RW_STATE_WORD0 3
#define RW_STATE_WORD1 4
/* Compute with 96 bit intermediate result: (a*b)/c */
static u64 muldiv64(u64 a, u32 b, u32 c)
{
union {
u64 ll;
struct {
u32 low, high;
} l;
} u, res;
u64 rl, rh;
u.ll = a;
rl = (u64)u.l.low * (u64)b;
rh = (u64)u.l.high * (u64)b;
rh += (rl >> 32);
res.l.high = div64_u64(rh, c);
res.l.low = div64_u64(((mod_64(rh, c) << 32) + (rl & 0xffffffff)), c);
return res.ll;
}
static void pit_set_gate(struct kvm_pit *pit, int channel, u32 val)
{
struct kvm_kpit_channel_state *c = &pit->pit_state.channels[channel];
@ -139,7 +119,7 @@ static int pit_get_count(struct kvm_pit *pit, int channel)
int counter;
t = kpit_elapsed(pit, c, channel);
d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
d = mul_u64_u32_div(t, KVM_PIT_FREQ, NSEC_PER_SEC);
switch (c->mode) {
case 0:
@ -166,7 +146,7 @@ static int pit_get_out(struct kvm_pit *pit, int channel)
int out;
t = kpit_elapsed(pit, c, channel);
d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
d = mul_u64_u32_div(t, KVM_PIT_FREQ, NSEC_PER_SEC);
switch (c->mode) {
default:
@ -338,7 +318,7 @@ static void create_pit_timer(struct kvm_pit *pit, u32 val, int is_period)
ps->flags & KVM_PIT_FLAGS_HPET_LEGACY)
return;
interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ);
interval = mul_u64_u32_div(val, NSEC_PER_SEC, KVM_PIT_FREQ);
pr_debug("create pit timer, interval is %llu nsec\n", interval);