[RFC] [PATCH] Scalable phys_cpu_present_map implementation

[RFC] [PATCH] Scalable phys_cpu_present_map implementation

[Russ Weight]

Hi,

	This patch applies to the 2.5.2 kernel.

***	Please refer to my previous e-mail entitled:
***	"[RFC] [PATCH] Scalable CPU bitmasks".

	This patch modifies the phys_cpu_present_map bitmask to
be a "scalable CPU bitmask".  The datatype is changed to cpumap_t,
and all accesses to the bitmask are done through the appropriate
supporting functions.

	Please send comments!

-- 
Russ Weight (rweight@us.ibm.com)
Linux Technology Center


diff -u cpumap/include/asm-i386/smp.h linux/include/asm-i386/smp.h
--- cpumap/include/asm-i386/smp.h	Mon Jan 21 16:28:09 2002
+++ linux/include/asm-i386/smp.h	Mon Jan 21 16:25:32 2002
@@ -8,6 +8,7 @@
 #include <linux/config.h>
 #include <linux/threads.h>
 #include <linux/ptrace.h>
+#include <linux/cpumap.h>
 #endif
 
 #ifdef CONFIG_X86_LOCAL_APIC
@@ -53,7 +54,7 @@
  */
  
 extern void smp_alloc_memory(void);
-extern unsigned long phys_cpu_present_map;
+extern cpumap_t phys_cpu_present_map;
 extern unsigned long cpu_online_map;
 extern volatile unsigned long smp_invalidate_needed;
 extern int pic_mode;
diff -u cpumap/include/asm-i386/mpspec.h linux/include/asm-i386/mpspec.h
--- cpumap/include/asm-i386/mpspec.h	Mon Jan 21 16:28:09 2002
+++ linux/include/asm-i386/mpspec.h	Mon Jan 21 16:25:32 2002
@@ -1,6 +1,8 @@
 #ifndef __ASM_MPSPEC_H
 #define __ASM_MPSPEC_H
 
+#include <linux/cpumap.h>
+
 /*
  * Structure definitions for SMP machines following the
  * Intel Multiprocessing Specification 1.1 and 1.4.
@@ -201,7 +203,7 @@
 extern int mp_bus_id_to_pci_bus [MAX_MP_BUSSES];
 
 extern unsigned int boot_cpu_physical_apicid;
-extern unsigned long phys_cpu_present_map;
+extern cpumap_t phys_cpu_present_map;
 extern int smp_found_config;
 extern void find_smp_config (void);
 extern void get_smp_config (void);
diff -u cpumap/arch/i386/kernel/process.c linux/arch/i386/kernel/process.c
--- cpumap/arch/i386/kernel/process.c	Mon Jan  7 12:55:17 2002
+++ linux/arch/i386/kernel/process.c	Mon Jan 21 16:25:32 2002
@@ -371,7 +371,7 @@
 		   if its not, default to the BSP */
 		if ((reboot_cpu == -1) ||  
 		      (reboot_cpu > (NR_CPUS -1))  || 
-		      !(phys_cpu_present_map & (1<<cpuid))) 
+		      !(cpumap_test_bit(cpuid, phys_cpu_present_map))) 
 			reboot_cpu = boot_cpu_physical_apicid;
 
 		reboot_smp = 0;  /* use this as a flag to only go through this once*/
diff -u cpumap/arch/i386/kernel/io_apic.c linux/arch/i386/kernel/io_apic.c
--- cpumap/arch/i386/kernel/io_apic.c	Tue Nov 13 17:28:41 2001
+++ linux/arch/i386/kernel/io_apic.c	Mon Jan 21 16:25:32 2002
@@ -1006,7 +1006,8 @@
 static void __init setup_ioapic_ids_from_mpc (void)
 {
 	struct IO_APIC_reg_00 reg_00;
-	unsigned long phys_id_present_map = phys_cpu_present_map;
+	unsigned long phys_id_present_map =
+			cpumap_to_ulong(phys_cpu_present_map);
 	int apic;
 	int i;
 	unsigned char old_id;
diff -u cpumap/arch/i386/kernel/smpboot.c linux/arch/i386/kernel/smpboot.c
--- cpumap/arch/i386/kernel/smpboot.c	Mon Jan  7 12:55:17 2002
+++ linux/arch/i386/kernel/smpboot.c	Mon Jan 21 16:25:32 2002
@@ -978,6 +978,9 @@
 void __init smp_boot_cpus(void)
 {
 	int apicid, cpu, bit;
+#ifdef SMP_DEBUG
+	char buf[CPUMAP_BUFSIZE];
+#endif
 
         if (clustered_apic_mode) {
                 /* remap the 1st quad's 256k range for cross-quad I/O */
@@ -1030,7 +1033,9 @@
 #ifndef CONFIG_VISWS
 		io_apic_irqs = 0;
 #endif
-		cpu_online_map = phys_cpu_present_map = 1;
+		cpu_online_map = 1;
+		cpumap_clear_mask(phys_cpu_present_map);
+		cpumap_set_bit(0, phys_cpu_present_map);
 		smp_num_cpus = 1;
 		if (APIC_init_uniprocessor())
 			printk(KERN_NOTICE "Local APIC not detected."
@@ -1044,10 +1049,10 @@
 	 * Makes no sense to do this check in clustered apic mode, so skip it
 	 */
 	if (!clustered_apic_mode && 
-	    !test_bit(boot_cpu_physical_apicid, &phys_cpu_present_map)) {
+	    !cpumap_test_bit(boot_cpu_physical_apicid, phys_cpu_present_map)) {
 		printk("weird, boot CPU (#%d) not listed by the BIOS.\n",
 							boot_cpu_physical_apicid);
-		phys_cpu_present_map |= (1 << hard_smp_processor_id());
+		cpumap_set_bit(hard_smp_processor_id(), phys_cpu_present_map);
 	}
 
 	/*
@@ -1061,7 +1066,9 @@
 #ifndef CONFIG_VISWS
 		io_apic_irqs = 0;
 #endif
-		cpu_online_map = phys_cpu_present_map = 1;
+		cpu_online_map = 1;
+		cpumap_clear_mask(phys_cpu_present_map);
+		cpumap_set_bit(0, phys_cpu_present_map);
 		smp_num_cpus = 1;
 		goto smp_done;
 	}
@@ -1077,7 +1084,9 @@
 #ifndef CONFIG_VISWS
 		io_apic_irqs = 0;
 #endif
-		cpu_online_map = phys_cpu_present_map = 1;
+		cpu_online_map = 1;
+		cpumap_clear_mask(phys_cpu_present_map);
+		cpumap_set_bit(0, phys_cpu_present_map);
 		smp_num_cpus = 1;
 		goto smp_done;
 	}
@@ -1095,7 +1104,8 @@
 	 * bits 0-3 are quad0, 4-7 are quad1, etc. A perverse twist on the 
 	 * clustered apic ID.
 	 */
-	Dprintk("CPU present map: %lx\n", phys_cpu_present_map);
+	Dprintk("CPU present map: %s\n",
+		cpumap_format(phys_cpu_present_map, buf, CPUMAP_BUFSIZE));
 
 	for (bit = 0; bit < NR_CPUS; bit++) {
 		apicid = cpu_present_to_apicid(bit);
@@ -1105,7 +1115,7 @@
 		if (apicid == boot_cpu_apicid)
 			continue;
 
-		if (!(phys_cpu_present_map & (1 << bit)))
+		if (!(cpumap_test_bit(bit, phys_cpu_present_map)))
 			continue;
 		if ((max_cpus >= 0) && (max_cpus <= cpucount+1))
 			continue;
@@ -1116,7 +1126,7 @@
 		 * Make sure we unmap all failed CPUs
 		 */
 		if ((boot_apicid_to_cpu(apicid) == -1) &&
-				(phys_cpu_present_map & (1 << bit)))
+				(cpumap_test_bit(bit, phys_cpu_present_map)))
 			printk("CPU #%d not responding - cannot use it.\n",
 								apicid);
 	}
diff -u cpumap/arch/i386/kernel/apic.c linux/arch/i386/kernel/apic.c
--- cpumap/arch/i386/kernel/apic.c	Mon Jan  7 12:55:17 2002
+++ linux/arch/i386/kernel/apic.c	Mon Jan 21 16:25:32 2002
@@ -279,7 +279,7 @@
 	 * This is meaningless in clustered apic mode, so we skip it.
 	 */
 	if (!clustered_apic_mode && 
-	    !test_bit(GET_APIC_ID(apic_read(APIC_ID)), &phys_cpu_present_map))
+	    !cpumap_test_bit(GET_APIC_ID(apic_read(APIC_ID)), phys_cpu_present_map))
 		BUG();
 
 	/*
@@ -1113,7 +1113,8 @@
 
 	connect_bsp_APIC();
 
-	phys_cpu_present_map = 1;
+	cpumap_clear_mask(phys_cpu_present_map);
+	cpumap_set_bit(0, phys_cpu_present_map);
 	apic_write_around(APIC_ID, boot_cpu_physical_apicid);
 
 	apic_pm_init2();
diff -u cpumap/arch/i386/kernel/mpparse.c linux/arch/i386/kernel/mpparse.c
--- cpumap/arch/i386/kernel/mpparse.c	Fri Nov  9 14:58:18 2001
+++ linux/arch/i386/kernel/mpparse.c	Mon Jan 21 16:25:32 2002
@@ -61,7 +61,7 @@
 static unsigned int num_processors;
 
 /* Bitmask of physically existing CPUs */
-unsigned long phys_cpu_present_map;
+cpumap_t phys_cpu_present_map;
 
 /*
  * Intel MP BIOS table parsing routines:
@@ -224,9 +224,10 @@
 	ver = m->mpc_apicver;
 
 	if (clustered_apic_mode) {
-		phys_cpu_present_map |= (logical_apicid&0xf) << (4*quad);
+		int cpuid = ffs(logical_apicid&0xf) - 1 + (4*quad);
+		cpumap_set_bit(cpuid, phys_cpu_present_map);
 	} else {
-		phys_cpu_present_map |= 1 << m->mpc_apicid;
+		cpumap_set_bit(m->mpc_apicid, phys_cpu_present_map);
 	}
 	/*
 	 * Validate version
@@ -819,7 +820,7 @@
 {
 	smp_found_config = 1;
 
-	phys_cpu_present_map |= 2; /* or in id 1 */
+	cpumap_set_bit(1, phys_cpu_present_map);
 	apic_version[1] |= 0x10; /* integrated APIC */
 	apic_version[0] |= 0x10;