[CPUFREQ] Longhaul - Disable arbiter CLE266

Please ignore previous message.

This patch is adding support for CPU connected to CLE266
chipset. For older CPU this is only way. For "Powersaver"
processor this way will be used if ACPI C3 isn't supported.

I have tested it. It seems to work exacly like ACPI.
But it is less safe. On CLE266 chipset port 0x22 is
blocking processor access to PCI bus too.
Signed-off-by: Rafa³ Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>

arch/i386/kernel/cpu/cpufreq/longhaul.c

@@ -178,11 +178,17 @@ static void do_powersaver(int cx_address, unsigned int clock_ratio_index)
 	safe_halt();
 	/* Change frequency on next halt or sleep */
 	wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
-	ACPI_FLUSH_CPU_CACHE();
-	/* Invoke C3 */
-	inb(cx_address);
-	/* Dummy op - must do something useless after P_LVL3 read */
-	t = inl(acpi_fadt.xpm_tmr_blk.address);
+	if (port22_en) {
+		ACPI_FLUSH_CPU_CACHE();
+		/* Invoke C1 */
+		halt();
+	} else {
+		ACPI_FLUSH_CPU_CACHE();
+		/* Invoke C3 */
+		inb(cx_address);
+		/* Dummy op - must do something useless after P_LVL3 read */
+		t = inl(acpi_fadt.xpm_tmr_blk.address);
+	}
 
 	/* Disable bus ratio bit */
 	local_irq_disable();
@@ -567,16 +573,23 @@ static acpi_status longhaul_walk_callback(acpi_handle obj_handle,
 static int enable_arbiter_disable(void)
 {
 	struct pci_dev *dev;
+	int reg;
 	u8 pci_cmd;
 
 	/* Find PLE133 host bridge */
+	reg = 0x78;
 	dev = pci_find_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8601_0, NULL);
+	/* Find CLE266 host bridge */
+	if (dev == NULL) {
+		dev = pci_find_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_862X_0, NULL);
+		reg = 0x76;
+	}
 	if (dev != NULL) {
 		/* Enable access to port 0x22 */
-		pci_read_config_byte(dev, 0x78, &pci_cmd);
+		pci_read_config_byte(dev, reg, &pci_cmd);
 		if ( !(pci_cmd & 1<<7) ) {
 			pci_cmd |= 1<<7;
-			pci_write_config_byte(dev, 0x78, pci_cmd);
+			pci_write_config_byte(dev, reg, pci_cmd);
 		}
 		return 1;
 	}
@@ -681,19 +694,29 @@ static int __init longhaul_cpu_init(struct cpufreq_policy *policy)
 		/* Check ACPI support for C3 state */
 		cx = &pr->power.states[ACPI_STATE_C3];
 		if (cx->address == 0 ||
-		   (cx->latency > 1000 && ignore_latency == 0) )
-			goto err_acpi;
+		   (cx->latency > 1000 && ignore_latency == 0) ) {
+			if (enable_arbiter_disable()) {
+				port22_en = 1;
+			} else {
+				goto err_acpi;
+			}
+		}
 
 	} else {
 		/* Check ACPI support for bus master arbiter disable */
 		if (!pr->flags.bm_control) {
-			if (!enable_arbiter_disable()) {
-				printk(KERN_ERR PFX "No ACPI support. No VT8601 host bridge. Aborting.\n");
-				return -ENODEV;
-			} else
+			if (enable_arbiter_disable()) {
 				port22_en = 1;
+			} else {
+				goto err_acpi;
+			}
 		}
 	}
+	if (!port22_en) {
+		printk (KERN_INFO PFX "Using ACPI support.\n");
+	} else {
+		printk (KERN_INFO PFX "Using northbridge support.\n");
+	}
 
 	ret = longhaul_get_ranges();
 	if (ret != 0)
@@ -716,7 +739,7 @@ static int __init longhaul_cpu_init(struct cpufreq_policy *policy)
 	return 0;
 
 err_acpi:
-	printk(KERN_ERR PFX "No ACPI support for CPU frequency changes.\n");
+	printk(KERN_ERR PFX "No ACPI support. No VT8601 or VT8623 northbridge. Aborting.\n");
 	return -ENODEV;
 }