i386/85655: [patch] expose cpu info for i386 systems

[Ben Thomas]

>Number:         85655
>Category:       i386
>Synopsis:       [patch] expose cpu info for i386 systems
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Fri Sep 02 18:00:36 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Ben Thomas
>Release:        FreeBSD 5.4-RELEASE i386
>Organization:
Virtual Iron Software
>Environment:
System: FreeBSD bthomas4.katana-technology.com 5.4-RELEASE FreeBSD 5.4-RELEASE #10: Sun Aug 28 13:48:00 EDT 2005 ben at bthomas4.katana-technology.com:/usr/obj/usr/home/ben/BSD/RELENG_5_4_0_RELEASE/src/sys/BEN i386


>Description:

This change makes some slight modifications:

- add "packed" attribute to the cpu_info structure to make it a bit smaller
- add the hyperthread index to the structure
- expose the entire structure via a machdep sysctl (I probably should have
  also added an .h file for the user/kernel to agree on the structure format)


This patch is against the 5_4_0_RELEASE code

>How-To-Repeat:
>Fix:

--- mp_machdep.c-DIFF begins here ---
--- /usr/src.original/sys/i386/i386/mp_machdep.c	Sun May  1 01:38:13 2005
+++ /usr/src/sys/i386/i386/mp_machdep.c	Fri Aug 12 17:29:11 2005
@@ -202,9 +202,12 @@
 	int	cpu_present:1;
 	int	cpu_bsp:1;
 	int	cpu_disabled:1;
-} static cpu_info[MAXCPU];
+	unsigned char	cpu_htt;
+} __attribute__((packed)) static cpu_info[MAXCPU];
 static int cpu_apic_ids[MAXCPU];
 
+SYSCTL_OPAQUE(_machdep, OID_AUTO, cpu_info, CTLFLAG_RD, &cpu_info, sizeof(cpu_info), "S,cpu_info", "CPU Information");
+
 /* Holds pending bitmap based IPIs per CPU */
 static volatile u_int cpu_ipi_pending[MAXCPU];
 
@@ -284,7 +287,8 @@
 void
 cpu_add(u_int apic_id, char boot_cpu)
 {
-
+	int	cores;
+	
 	if (apic_id >= MAXCPU) {
 		printf("SMP: CPU %d exceeds maximum CPU %d, ignoring\n",
 		    apic_id, MAXCPU - 1);
@@ -304,7 +308,12 @@
 	if (bootverbose)
 		printf("SMP: Added CPU %d (%s)\n", apic_id, boot_cpu ? "BSP" :
 		    "AP");
-	
+	if ((cpu_feature & CPUID_HTT) == 0)
+	  cores = 1;
+	else
+	  cores = (cpu_procinfo & CPUID_HTT_CORES) >> 16;
+	  
+	cpu_info[apic_id].cpu_htt = apic_id % cores;	
 }
 
 void
--- mp_machdep.c-DIFF ends here ---
>Release-Note:
>Audit-Trail:
>Unformatted: