[PATCH] x86_64: Inclusion of ScaleMP vSMP architecture patches - vsmp_arch

Introduce vSMP arch to the kernel.

This patch:
1. Adds CONFIG_X86_VSMP
2. Adds machine specific macros for local_irq_disabled, local_irq_enabled
and irqs_disabled
3. Writes to the vSMP CTL device to indicate kernel compiled with CONFIG_VSMP

Signed-off-by: Ravikiran Thirumalai <[e-mail]>
Signed-off-by: Shai Fultheim <[e-mail]>
Signed-off-by: Andi Kleen <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/x86_64/Kconfig

···
 menu "Processor type and features"
 
 choice
+	prompt "Subarchitecture Type"
+	default X86_PC
+
+config X86_PC
+	bool "PC-compatible"
+	help
+	  Choose this option if your computer is a standard PC or compatible.
+
+config X86_VSMP
+	bool "Support for ScaleMP vSMP"
+	 help
+	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
+	  supposed to run on these EM64T-based machines.  Only choose this option
+	  if you have one of these machines.
+
+endchoice
+
+choice
 	prompt "Processor family"
 	default MK8
 

arch/x86_64/kernel/Makefile

···
 obj-$(CONFIG_SWIOTLB)		+= pci-swiotlb.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_X86_PM_TIMER)	+= pmtimer.o
+obj-$(CONFIG_X86_VSMP)		+= vsmp.o
 
 obj-$(CONFIG_MODULES)		+= module.o
 

arch/x86_64/kernel/vsmp.c

···
+/*
+ * vSMPowered(tm) systems specific initialization
+ * Copyright (C) 2005 ScaleMP Inc.
+ *
+ * Use of this code is subject to the terms and conditions of the
+ * GNU general public license version 2. See "COPYING" or
+ * http://www.gnu.org/licenses/gpl.html
+ *
+ * Ravikiran Thirumalai <[e-mail]>,
+ * Shai Fultheim <[e-mail]>
+ */
+
+#include <linux/init.h>
+#include <linux/pci_ids.h>
+#include <linux/pci_regs.h>
+#include <asm/pci-direct.h>
+
+static int __init vsmp_init(void)
+{
+	void *address;
+	unsigned int cap, ctl;
+
+	/* Check if we are running on a ScaleMP vSMP box */
+	if ((read_pci_config_16(0, 0x1f, 0, PCI_VENDOR_ID) != PCI_VENDOR_ID_SCALEMP) ||
+	    (read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) != PCI_DEVICE_ID_SCALEMP_VSMP_CTL))
+		return 0;
+
+	/* set vSMP magic bits to indicate vSMP capable kernel */
+	address = ioremap(read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0), 8);
+	cap = readl(address);
+	ctl = readl(address + 4);
+	printk("vSMP CTL: capabilities:0x%08x  control:0x%08x\n", cap, ctl);
+	if (cap & ctl & (1 << 4)) {
+		/* Turn on vSMP IRQ fastpath handling (see system.h) */
+		ctl &= ~(1 << 4);
+		writel(ctl, address + 4);
+		ctl = readl(address + 4);
+		printk("vSMP CTL: control set to:0x%08x\n", ctl);
+	}
+
+	iounmap(address);
+	return 0;
+}
+
+core_initcall(vsmp_init);

include/asm-x86_64/system.h

···
 /* interrupt control.. */
 #define local_save_flags(x)	do { warn_if_not_ulong(x); __asm__ __volatile__("# save_flags \n\t pushfq ; popq %q0":"=g" (x): /* no input */ :"memory"); } while (0)
 #define local_irq_restore(x) 	__asm__ __volatile__("# restore_flags \n\t pushq %0 ; popfq": /* no output */ :"g" (x):"memory", "cc")
+
+#ifdef CONFIG_X86_VSMP
+/* Interrupt control for VSMP  architecture */
+#define local_irq_disable()	do { unsigned long flags; local_save_flags(flags); local_irq_restore((flags & ~(1 << 9)) | (1 << 18)); } while (0)
+#define local_irq_enable()	do { unsigned long flags; local_save_flags(flags); local_irq_restore((flags | (1 << 9)) & ~(1 << 18)); } while (0)
+
+#define irqs_disabled()					\
+({							\
+	unsigned long flags;				\
+	local_save_flags(flags);			\
+	(flags & (1<<18)) || !(flags & (1<<9));		\
+})
+
+/* For spinlocks etc */
+#define local_irq_save(x)	do { local_save_flags(x); local_irq_restore((x & ~(1 << 9)) | (1 << 18)); } while (0)
+#else  /* CONFIG_X86_VSMP */
 #define local_irq_disable() 	__asm__ __volatile__("cli": : :"memory")
 #define local_irq_enable()	__asm__ __volatile__("sti": : :"memory")
+
 /* used in the idle loop; sti takes one instruction cycle to complete */
 #define safe_halt()		__asm__ __volatile__("sti; hlt": : :"memory")
 /* used when interrupts are already enabled or to shutdown the processor */
···
 
 /* For spinlocks etc */
 #define local_irq_save(x) 	do { warn_if_not_ulong(x); __asm__ __volatile__("# local_irq_save \n\t pushfq ; popq %0 ; cli":"=g" (x): /* no input */ :"memory"); } while (0)
+#endif
 
 void cpu_idle_wait(void);
 

include/linux/pci_ids.h

···
 #define PCI_DEVICE_ID_INTEL_IXP2800	0x9004
 #define PCI_DEVICE_ID_INTEL_S21152BB	0xb152
 
+#define PCI_VENDOR_ID_SCALEMP		0x8686
+#define PCI_DEVICE_ID_SCALEMP_VSMP_CTL	0x1010
+
 #define PCI_VENDOR_ID_COMPUTONE		0x8e0e
 #define PCI_DEVICE_ID_COMPUTONE_IP2EX	0x0291
 #define PCI_DEVICE_ID_COMPUTONE_PG	0x0302