# HG changeset patch
# User gingold@virtu10
# Node ID 780e422b936818fbc91a458f1e7632d2ded48332
# Parent  ae93d70e8df7247494b580043db156d4d298fd36
Implement fast hypercall for physdevop eoi.

Eoi is a very frequent hypercall which has only one argument passed through
a structure.  To avoid the xencomm overhead, a new hypercall is created
and the argument is passed by value.

Signed-off-by: Tristan Gingold <tristan.gingold@xxxxxxxx>

diff -r ae93d70e8df7 -r 780e422b9368 linux-2.6-xen-sparse/include/asm-ia64/hypercall.h
--- a/linux-2.6-xen-sparse/include/asm-ia64/hypercall.h	Thu Sep 28 10:39:00 2006 +0200
+++ b/linux-2.6-xen-sparse/include/asm-ia64/hypercall.h	Thu Sep 28 11:06:30 2006 +0200
@@ -259,6 +259,19 @@ xencomm_arch_hypercall_hvm_op(int cmd, v
 	return _hypercall2(unsigned long, hvm_op, cmd, arg);
 }
 
+static inline int
+HYPERVISOR_physdev_op(
+    int cmd, void *arg)
+{
+	switch (cmd) {
+	case PHYSDEVOP_eoi:
+		return _hypercall1(int, ia64_fast_eoi,
+				   ((struct physdev_eoi *)arg)->irq);
+	default:
+		return xencomm_hypercall_physdev_op(cmd, arg);
+	}
+}
+
 extern fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs);
 static inline void exit_idle(void) {}
 #define do_IRQ(irq, regs) ({			\
@@ -377,7 +390,6 @@ HYPERVISOR_add_physmap(unsigned long gpf
 #define HYPERVISOR_multicall xencomm_mini_hypercall_multicall
 #define HYPERVISOR_xen_version xencomm_mini_hypercall_xen_version
 #define HYPERVISOR_console_io xencomm_mini_hypercall_console_io
-#define HYPERVISOR_physdev_op xencomm_mini_hypercall_physdev_op
 #define HYPERVISOR_hvm_op xencomm_mini_hypercall_hvm_op
 #ifdef CONFIG_VMX_GUEST
 #define HYPERVISOR_memory_op 0
@@ -391,7 +403,6 @@ HYPERVISOR_add_physmap(unsigned long gpf
 #define HYPERVISOR_multicall xencomm_hypercall_multicall
 #define HYPERVISOR_xen_version xencomm_hypercall_xen_version
 #define HYPERVISOR_console_io xencomm_hypercall_console_io
-#define HYPERVISOR_physdev_op xencomm_hypercall_physdev_op
 #define HYPERVISOR_hvm_op xencomm_hypercall_hvm_op
 #define HYPERVISOR_memory_op xencomm_hypercall_memory_op
 #endif
diff -r ae93d70e8df7 -r 780e422b9368 xen/arch/ia64/xen/hypercall.c
--- a/xen/arch/ia64/xen/hypercall.c	Thu Sep 28 10:39:00 2006 +0200
+++ b/xen/arch/ia64/xen/hypercall.c	Thu Sep 28 11:06:30 2006 +0200
@@ -120,6 +120,20 @@ xen_hypercall (struct pt_regs *regs)
 	} else
 		regs->r8 = -ENOSYS;
 	
+	return IA64_NO_FAULT;
+}
+
+static IA64FAULT
+xen_fast_hypercall (struct pt_regs *regs)
+{
+	uint32_t cmd = (uint32_t)regs->r2;
+	switch (cmd) {
+	case __HYPERVISOR_ia64_fast_eoi:
+	    regs->r8 = pirq_guest_eoi(current->domain, regs->r14);
+	    break;
+	default:
+	    regs->r8 = -ENOSYS;
+	}
 	return IA64_NO_FAULT;
 }
 
@@ -187,8 +201,8 @@ fw_hypercall_fpswa (struct vcpu *v)
 	return PSCBX(v, fpswa_ret);
 }
 
-static IA64FAULT
-fw_hypercall (struct pt_regs *regs)
+IA64FAULT
+ia64_hypercall (struct pt_regs *regs)
 {
 	struct vcpu *v = current;
 	struct sal_ret_values x;
@@ -199,6 +213,12 @@ fw_hypercall (struct pt_regs *regs)
 
 	perfc_incra(fw_hypercall, index >> 8);
 	switch (index) {
+	    case FW_HYPERCALL_XEN:
+	        return xen_hypercall (regs);
+
+	    case FW_HYPERCALL_XEN_FAST:
+	        return xen_fast_hypercall (regs);
+
 	    case FW_HYPERCALL_PAL_CALL:
 		//printf("*** PAL hypercall: index=%d\n",regs->r28);
 		//FIXME: This should call a C routine
@@ -287,17 +307,6 @@ fw_hypercall (struct pt_regs *regs)
 	return IA64_NO_FAULT;
 }
 
-IA64FAULT
-ia64_hypercall (struct pt_regs *regs)
-{
-	unsigned long index = regs->r2;
-
-	if (index >= FW_HYPERCALL_FIRST_ARCH)
-	    return fw_hypercall (regs);
-	else
-	    return xen_hypercall (regs);
-}
-
 unsigned long hypercall_create_continuation(
 	unsigned int op, const char *format, ...)
 {
diff -r ae93d70e8df7 -r 780e422b9368 xen/include/asm-ia64/dom_fw.h
--- a/xen/include/asm-ia64/dom_fw.h	Thu Sep 28 10:39:00 2006 +0200
+++ b/xen/include/asm-ia64/dom_fw.h	Thu Sep 28 11:06:30 2006 +0200
@@ -38,6 +38,13 @@
    The high part is the class (xen/pal/sal/efi).  */
 #define FW_HYPERCALL_NUM_MASK_HIGH	~0xffUL
 #define FW_HYPERCALL_NUM_MASK_LOW	 0xffUL
+
+/* Xen hypercalls are 0-63.  */
+#define FW_HYPERCALL_XEN		0x0000UL
+
+/* Define some faster and lighter hypercalls.
+   See definitions in arch-ia64.h */
+#define FW_HYPERCALL_XEN_FAST		0x0200UL
 
 /*
  * PAL can be called in physical or virtual mode simply by
diff -r ae93d70e8df7 -r 780e422b9368 xen/include/public/arch-ia64.h
--- a/xen/include/public/arch-ia64.h	Thu Sep 28 10:39:00 2006 +0200
+++ b/xen/include/public/arch-ia64.h	Thu Sep 28 11:06:30 2006 +0200
@@ -432,6 +432,9 @@ struct xen_ia64_boot_param {
 #define HYPERPRIVOP_GET_PSR		0x19
 #define HYPERPRIVOP_MAX			0x19
 
+/* Fast and light hypercalls.  */
+#define __HYPERVISOR_ia64_fast_eoi	0x0200
+
 /* Xencomm macros.  */
 #define XENCOMM_INLINE_MASK 0xf800000000000000UL
 #define XENCOMM_INLINE_FLAG 0x8000000000000000UL