Re: [RFC/CFT] cmd640 irqlocking fixes

[Alan Cox]

Martin this patch should do the job. It uses the correct pci_config_lock
and it also adds the 2.4 probe safety checks for deciding which pci
modes to use.

--- ../linux-2.5.28/drivers/ide/cmd640.c	Thu Jul 25 10:49:19 2002
+++ drivers/ide/cmd640.c	Thu Jul 25 11:41:27 2002
@@ -216,27 +216,27 @@
 
 /* PCI method 1 access */
 
-static void put_cmd640_reg_pci1 (unsigned short reg, byte val)
+extern spinlock_t pci_config_lock;
+
+static void put_cmd640_reg_pci1 (unsigned short reg, u8 val)
 {
 	unsigned long flags;
-
-	save_flags(flags);
-	cli();
-	outl_p((reg & 0xfc) | cmd640_key, 0xcf8);
+	
+	spin_lock_irqsave(&pci_config_lock, flags);
+	outb_p((reg & 0xfc) | cmd640_key, 0xcf8);
 	outb_p(val, (reg & 3) | 0xcfc);
-	restore_flags(flags);
+	spin_unlock_irqrestore(&pci_config_lock, flags);
 }
 
 static u8 get_cmd640_reg_pci1 (unsigned short reg)
 {
 	u8 b;
 	unsigned long flags;
-
-	save_flags(flags);
-	cli();
-	outl_p((reg & 0xfc) | cmd640_key, 0xcf8);
-	b = inb_p((reg & 3) | 0xcfc);
-	restore_flags(flags);
+	
+	spin_lock_irqsave(&pci_config_lock, flags);
+	outb_p((reg & 0xfc) | cmd640_key, 0xcf8);
+	b=inb_p((reg & 3) | 0xcfc);
+	spin_unlock_irqrestore(&pci_config_lock, flags);
 	return b;
 }
 
@@ -245,26 +245,24 @@
 static void put_cmd640_reg_pci2 (unsigned short reg, u8 val)
 {
 	unsigned long flags;
-
-	save_flags(flags);
-	cli();
+	
+	spin_lock_irqsave(&pci_config_lock, flags);
 	outb_p(0x10, 0xcf8);
 	outb_p(val, cmd640_key + reg);
 	outb_p(0, 0xcf8);
-	restore_flags(flags);
+	spin_unlock_irqrestore(&pci_config_lock, flags);
 }
 
 static u8 get_cmd640_reg_pci2 (unsigned short reg)
 {
 	u8 b;
 	unsigned long flags;
-
-	save_flags(flags);
-	cli();
+	
+	spin_lock_irqsave(&pci_config_lock, flags);
 	outb_p(0x10, 0xcf8);
 	b = inb_p(cmd640_key + reg);
 	outb_p(0, 0xcf8);
-	restore_flags(flags);
+	spin_unlock_irqrestore(&pci_config_lock, flags);
 	return b;
 }
 
@@ -701,9 +699,62 @@
 
 #endif
 
+/**
+ *	pci_conf1	-	check for PCI type 1 configuration
+ *	
+ *	Issues a safe probe sequence for PCI configuration type 1 and
+ *	returns non-zero if conf1 is supported. Takes the pci_config lock
+ */
+ 
+static int pci_conf1(void)
+{
+	u32 tmp;
+	unsigned long flags;
+	
+	spin_lock_irqsave(&pci_config_lock, flags);
+
+	OUT_BYTE(0x01, 0xCFB);
+	tmp = inl(0xCF8);
+	outl(0x80000000, 0xCF8);
+	if (inl(0xCF8) == 0x80000000) {
+		spin_unlock_irqrestore(&pci_config_lock, flags);
+		outl(tmp, 0xCF8);
+		return 1;
+	}
+	outl(tmp, 0xCF8);
+	spin_unlock_irqrestore(&pci_config_lock, flags);
+	return 0;
+}
+
+/**
+ *	pci_conf2	-	check for PCI type 2 configuration
+ *	
+ *	Issues a safe probe sequence for PCI configuration type 2 and
+ *	returns non-zero if conf2 is supported. Takes the pci_config lock.
+ */
+ 
+
+static int pci_conf2(void)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&pci_config_lock, flags);
+	
+	OUT_BYTE(0x00, 0xCFB);
+	OUT_BYTE(0x00, 0xCF8);
+	OUT_BYTE(0x00, 0xCFA);
+	if (IN_BYTE(0xCF8) == 0x00 && IN_BYTE(0xCF8) == 0x00) {
+		spin_unlock_irqrestore(&pci_config_lock, flags);
+		return 1;
+	}
+	spin_unlock_irqrestore(&pci_config_lock, flags);
+	return 0;
+}
+
+
 /*
  * Probe for a cmd640 chipset, and initialize it if found.  Called from ide.c
  */
+ 
 int __init ide_probe_for_cmd640x(void)
 {
 #ifdef CONFIG_BLK_DEV_CMD640_ENHANCED
@@ -718,9 +769,10 @@
 		bus_type = "VLB";
 	} else {
 		cmd640_vlb = 0;
-		if (probe_for_cmd640_pci1())
+		/* Find out what kind of PCI probing is supported */
+		if (pci_conf1() && probe_for_cmd640_pci1())
 			bus_type = "PCI (type1)";
-		else if (probe_for_cmd640_pci2())
+		else if (pci_conf2() && probe_for_cmd640_pci2())
 			bus_type = "PCI (type2)";
 		else
 			return 0;