20060303

1 files changed, 138 insertions, 0 deletions

diff --git a/os/pc/archmp.c b/os/pc/archmp.c
new file mode 100644
index 00000000..fbbda091
--- /dev/null
+++ b/os/pc/archmp.c
@@ -0,0 +1,138 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+
+#include "mp.h"
+
+#define	cpuserver	1
+
+_MP_ *_mp_;
+
+static _MP_*
+mpscan(uchar *addr, int len)
+{
+	uchar *e, *p, sum;
+	int i;
+
+	e = addr+len;
+	for(p = addr; p < e; p += sizeof(_MP_)){
+		if(memcmp(p, "_MP_", 4))
+			continue;
+		sum = 0;
+		for(i = 0; i < sizeof(_MP_); i++)
+			sum += p[i];
+		if(sum == 0)
+			return (_MP_*)p;
+	}
+	return 0;
+}
+
+static _MP_*
+mpsearch(void)
+{
+	uchar *bda;
+	ulong p;
+	_MP_ *mp;
+
+	/*
+	 * Search for the MP Floating Pointer Structure:
+	 * 1) in the first KB of the EBDA;
+	 * 2) in the last KB of system base memory;
+	 * 3) in the BIOS ROM between 0xE0000 and 0xFFFFF.
+	 */
+	bda = KADDR(0x400);
+	if((p = (bda[0x0F]<<8)|bda[0x0E])){
+		if(mp = mpscan(KADDR(p), 1024))
+			return mp;
+	}
+	else{
+		p = ((bda[0x14]<<8)|bda[0x13])*1024;
+		if(mp = mpscan(KADDR(p-1024), 1024))
+			return mp;
+	}
+	return mpscan(KADDR(0xF0000), 0x10000);
+}
+
+static int identify(void);
+
+PCArch archmp = {
+.id=		"_MP_",	
+.ident=		identify,
+.reset=		mpshutdown,
+.intrinit=	mpinit,
+.intrenable=	mpintrenable,
+.fastclock=	i8253read,
+.timerset=	lapictimerset,
+};
+
+static int
+identify(void)
+{
+	PCMP *pcmp;
+	uchar *p, sum;
+	ulong length;
+
+	if(getconf("*nomp"))
+		return 1;
+
+	/*
+	 * Search for an MP configuration table. For now,
+	 * don't accept the default configurations (physaddr == 0).
+	 * Check for correct signature, calculate the checksum and,
+	 * if correct, check the version.
+	 * To do: check extended table checksum.
+	 */
+	if((_mp_ = mpsearch()) == 0 || _mp_->physaddr == 0)
+		return 1;
+
+	pcmp = KADDR(_mp_->physaddr);
+	if(memcmp(pcmp, "PCMP", 4))
+		return 1;
+
+	length = pcmp->length;
+	sum = 0;
+	for(p = (uchar*)pcmp; length; length--)
+		sum += *p++;
+
+	if(sum || (pcmp->version != 1 && pcmp->version != 4))
+		return 1;
+
+	if(cpuserver && m->havetsc)
+		archmp.fastclock = tscticks;
+	return 0;
+}
+
+Lock mpsynclock;
+
+void
+syncclock(void)
+{
+	uvlong x;
+
+	if(arch->fastclock != tscticks)
+		return;
+
+	if(m->machno == 0){
+		wrmsr(0x10, 0);
+		m->tscticks = 0;
+	} else {
+		x = MACHP(0)->tscticks;
+		while(x == MACHP(0)->tscticks)
+			;
+		wrmsr(0x10, MACHP(0)->tscticks);
+		cycles(&m->tscticks);
+	}
+}
+
+uvlong
+tscticks(uvlong *hz)
+{
+	if(hz != nil)
+		*hz = m->cpuhz;
+
+	cycles(&m->tscticks);	/* Uses the rdtsc instruction */
+	return m->tscticks;
+}