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MFC revision 1.679:

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Disallow the legacy USB circuit to generate an SMI# via an ICH
  register (MacBooks only).
  This allows MacBooks to boot in SMP mode without any trick and
  solves the timer problems with HZ=1000.

Approved by:	     re (kensmith), njl (mentor)
This commit is contained in:
Rui Paulo 2007-12-19 21:08:33 +00:00
parent edc309ced3
commit 6536499f7d
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/releng/6.3/; revision=174793
1 changed files with 25 additions and 0 deletions
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25
sys/amd64/amd64/machdep.c
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@ -154,6 +154,10 @@ SYSINIT(cpu, SI_SUB_CPU, SI_ORDER_FIRST, cpu_startup, NULL)
extern vm_offset_t ksym_start, ksym_end;
#endif
/* Intel ICH registers */
#define ICH_PMBASE 0x400
#define ICH_SMI_EN ICH_PMBASE + 0x30
int _udatasel, _ucodesel, _ucode32sel;
int cold = 1;
@ -185,6 +189,27 @@ static void
cpu_startup(dummy)
void *dummy;
{
char *sysenv;
/*
* On MacBooks, we need to disallow the legacy USB circuit to
* generate an SMI# because this can cause several problems,
* namely: incorrect CPU frequency detection and failure to
* start the APs.
* We do this by disabling a bit in the SMI_EN (SMI Control and
* Enable register) of the Intel ICH LPC Interface Bridge.
*/
sysenv = getenv("smbios.system.product");
if (sysenv != NULL) {
if (strncmp(sysenv, "MacBook", 7) == 0) {
if (bootverbose)
printf("Disabling LEGACY_USB_EN bit on "
"Intel ICH.\n");
outl(ICH_SMI_EN, inl(ICH_SMI_EN) & ~0x8);
}
freeenv(sysenv);
}
/*
* Good {morning,afternoon,evening,night}.
*/