[PATCH 16/16] make vsmp a paravirt client

[Glauber de Oliveira Costa <gcosta@redhat.com>]

This patch makes vsmp a paravirt client. It now uses the whole
infrastructure provided by pvops. When we detect we're running
a vsmp box, we change the irq-related paravirt operations (and so,
it have to happen quite early), and the patching function

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
---
 arch/x86/Kconfig.x86_64    |    3 +-
 arch/x86/kernel/setup_64.c |    3 ++
 arch/x86/kernel/vsmp_64.c  |   72 +++++++++++++++++++++++++++++++++++++++----
 include/asm-x86/setup.h    |    3 +-
 4 files changed, 71 insertions(+), 10 deletions(-)

diff --git a/arch/x86/Kconfig.x86_64 b/arch/x86/Kconfig.x86_64
index 04734dd..544bad5 100644
--- a/arch/x86/Kconfig.x86_64
+++ b/arch/x86/Kconfig.x86_64
@@ -148,15 +148,14 @@ 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"
 	depends on PCI
+	select PARAVIRT
 	 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
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 44a11e3..c522549 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -335,6 +335,9 @@ void __init setup_arch(char **cmdline_p)
 
 	init_memory_mapping(0, (end_pfn_map << PAGE_SHIFT));
 
+#ifdef CONFIG_VSMP
+	vsmp_init();
+#endif
 	dmi_scan_machine();
 
 #ifdef CONFIG_SMP
diff --git a/arch/x86/kernel/vsmp_64.c b/arch/x86/kernel/vsmp_64.c
index 414caf0..547d3b3 100644
--- a/arch/x86/kernel/vsmp_64.c
+++ b/arch/x86/kernel/vsmp_64.c
@@ -8,18 +8,70 @@
  *
  * Ravikiran Thirumalai <kiran@scalemp.com>,
  * Shai Fultheim <shai@scalemp.com>
+ * Paravirt ops integration: Glauber de Oliveira Costa <gcosta@redhat.com>
  */
-
 #include <linux/init.h>
 #include <linux/pci_ids.h>
 #include <linux/pci_regs.h>
 #include <asm/pci-direct.h>
 #include <asm/io.h>
+#include <asm/paravirt.h>
+
+/*
+ * Interrupt control for the VSMP architecture:
+ */
+
+static inline unsigned long vsmp_save_fl(void)
+{
+	unsigned long flags = native_save_fl();
+
+	if (flags & X86_EFLAGS_IF)
+		return X86_EFLAGS_IF;
+	return 0;
+}
 
-static int __init vsmp_init(void)
+static inline void vsmp_restore_fl(unsigned long flags)
+{
+	if (flags & X86_EFLAGS_IF)
+		flags &= ~X86_EFLAGS_AC;
+	if (!(flags & X86_EFLAGS_IF))
+		flags &= X86_EFLAGS_AC;
+	native_restore_fl(flags);
+}
+
+static inline void vsmp_irq_disable(void)
+{
+	unsigned long flags = native_save_fl();
+
+	vsmp_restore_fl((flags & ~X86_EFLAGS_IF));
+}
+
+static inline void vsmp_irq_enable(void)
+{
+	unsigned long flags = native_save_fl();
+
+	vsmp_restore_fl((flags | X86_EFLAGS_IF));
+}
+
+static unsigned __init vsmp_patch(u8 type, u16 clobbers, void *ibuf,
+				  unsigned long addr, unsigned len)
+{
+	switch (type) {
+	case PARAVIRT_PATCH(pv_irq_ops.irq_enable):
+	case PARAVIRT_PATCH(pv_irq_ops.irq_disable):
+	case PARAVIRT_PATCH(pv_irq_ops.save_fl):
+	case PARAVIRT_PATCH(pv_irq_ops.restore_fl):
+		return paravirt_patch_default(type, clobbers, ibuf, addr, len);
+	default:
+		return native_patch(type, clobbers, ibuf, addr, len);
+	}
+
+}
+
+int __init vsmp_init(void)
 {
 	void *address;
-	unsigned int cap, ctl;
+	unsigned int cap, ctl, cfg;
 
 	if (!early_pci_allowed())
 		return 0;
@@ -29,8 +81,16 @@ static int __init vsmp_init(void)
 	    (read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) != PCI_DEVICE_ID_SCALEMP_VSMP_CTL))
 		return 0;
 
+	/* If we are, use the distinguished irq functions */
+	pv_irq_ops.irq_disable = vsmp_irq_disable;
+	pv_irq_ops.irq_enable  = vsmp_irq_enable;
+	pv_irq_ops.save_fl  = vsmp_save_fl;
+	pv_irq_ops.restore_fl  = vsmp_restore_fl;
+	pv_init_ops.patch = vsmp_patch;
+
 	/* set vSMP magic bits to indicate vSMP capable kernel */
-	address = ioremap(read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0), 8);
+	cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
+	address = early_ioremap(cfg, 8);
 	cap = readl(address);
 	ctl = readl(address + 4);
 	printk("vSMP CTL: capabilities:0x%08x  control:0x%08x\n", cap, ctl);
@@ -42,8 +102,6 @@ static int __init vsmp_init(void)
 		printk("vSMP CTL: control set to:0x%08x\n", ctl);
 	}
 
-	iounmap(address);
+	early_iounmap(address, 8);
 	return 0;
 }
-
-core_initcall(vsmp_init);
diff --git a/include/asm-x86/setup.h b/include/asm-x86/setup.h
index 071e054..dd7996c 100644
--- a/include/asm-x86/setup.h
+++ b/include/asm-x86/setup.h
@@ -58,7 +58,8 @@ void __init add_memory_region(unsigned long long start,
 
 extern unsigned long init_pg_tables_end;
 
-
+/* For EM64T-based VSMP machines */
+int vsmp_init(void);
 
 #endif /* __i386__ */
 #endif /* _SETUP */
-- 
1.4.4.2