ia64/pv_ops/xen: define xen pv_cpu_ops.

define xen pv_cpu_ops which implementes xen paravirtualized
privileged instructions.

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 114 insertions, 0 deletions

diff --git a/arch/ia64/xen/xen_pv_ops.c b/arch/ia64/xen/xen_pv_ops.c
index fc9d599b62a..c236f04ffad 100644
--- a/arch/ia64/xen/xen_pv_ops.c
+++ b/arch/ia64/xen/xen_pv_ops.c
@@ -163,6 +163,119 @@ static const struct pv_init_ops xen_init_ops __initdata = {
 };
 
 /***************************************************************************
+ * pv_cpu_ops
+ * intrinsics hooks.
+ */
+
+static void xen_setreg(int regnum, unsigned long val)
+{
+        switch (regnum) {
+        case _IA64_REG_AR_KR0 ... _IA64_REG_AR_KR7:
+                xen_set_kr(regnum - _IA64_REG_AR_KR0, val);
+                break;
+#ifdef CONFIG_IA32_SUPPORT
+        case _IA64_REG_AR_EFLAG:
+                xen_set_eflag(val);
+                break;
+#endif
+        case _IA64_REG_CR_TPR:
+                xen_set_tpr(val);
+                break;
+        case _IA64_REG_CR_ITM:
+                xen_set_itm(val);
+                break;
+        case _IA64_REG_CR_EOI:
+                xen_eoi(val);
+                break;
+        default:
+                ia64_native_setreg_func(regnum, val);
+                break;
+        }
+}
+
+static unsigned long xen_getreg(int regnum)
+{
+        unsigned long res;
+
+        switch (regnum) {
+        case _IA64_REG_PSR:
+                res = xen_get_psr();
+                break;
+#ifdef CONFIG_IA32_SUPPORT
+        case _IA64_REG_AR_EFLAG:
+                res = xen_get_eflag();
+                break;
+#endif
+        case _IA64_REG_CR_IVR:
+                res = xen_get_ivr();
+                break;
+        case _IA64_REG_CR_TPR:
+                res = xen_get_tpr();
+                break;
+        default:
+                res = ia64_native_getreg_func(regnum);
+                break;
+        }
+        return res;
+}
+
+/* turning on interrupts is a bit more complicated.. write to the
+ * memory-mapped virtual psr.i bit first (to avoid race condition),
+ * then if any interrupts were pending, we have to execute a hyperprivop
+ * to ensure the pending interrupt gets delivered; else we're done! */
+static void
+xen_ssm_i(void)
+{
+        int old = xen_get_virtual_psr_i();
+        xen_set_virtual_psr_i(1);
+        barrier();
+        if (!old && xen_get_virtual_pend())
+                xen_hyper_ssm_i();
+}
+
+/* turning off interrupts can be paravirtualized simply by writing
+ * to a memory-mapped virtual psr.i bit (implemented as a 16-bit bool) */
+static void
+xen_rsm_i(void)
+{
+        xen_set_virtual_psr_i(0);
+        barrier();
+}
+
+static unsigned long
+xen_get_psr_i(void)
+{
+        return xen_get_virtual_psr_i() ? IA64_PSR_I : 0;
+}
+
+static void
+xen_intrin_local_irq_restore(unsigned long mask)
+{
+        if (mask & IA64_PSR_I)
+                xen_ssm_i();
+        else
+                xen_rsm_i();
+}
+
+static const struct pv_cpu_ops xen_cpu_ops __initdata = {
+        .fc             = xen_fc,
+        .thash          = xen_thash,
+        .get_cpuid      = xen_get_cpuid,
+        .get_pmd        = xen_get_pmd,
+        .getreg         = xen_getreg,
+        .setreg         = xen_setreg,
+        .ptcga          = xen_ptcga,
+        .get_rr         = xen_get_rr,
+        .set_rr         = xen_set_rr,
+        .set_rr0_to_rr4 = xen_set_rr0_to_rr4,
+        .ssm_i          = xen_ssm_i,
+        .rsm_i          = xen_rsm_i,
+        .get_psr_i      = xen_get_psr_i,
+        .intrin_local_irq_restore
+                        = xen_intrin_local_irq_restore,
+};
+
+/***************************************************************************
  * pv_ops initialization
  */
 
@@ -172,4 +285,5 @@ xen_setup_pv_ops(void)
         xen_info_init();
         pv_info = xen_info;
         pv_init_ops = xen_init_ops;
+        pv_cpu_ops = xen_cpu_ops;
 }