Merge tag 'iwlwifi-next-for-kalle-2014-12-30' of https://git.kernel.org/pub/scm/linux...

[cascardo/linux.git] / arch / powerpc / kvm / book3s_hv_builtin.c

diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 1786bf8..1f083ff 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -12,11 +12,11 @@
 #include <linux/export.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
-#include <linux/bootmem.h>
 #include <linux/init.h>
 #include <linux/memblock.h>
 #include <linux/sizes.h>
 #include <linux/cma.h>
+#include <linux/bitops.h>
 
 #include <asm/cputable.h>
 #include <asm/kvm_ppc.h>
@@ -63,7 +63,7 @@ EXPORT_SYMBOL_GPL(kvm_release_hpt);
  * kvm_cma_reserve() - reserve area for kvm hash pagetable
  *
  * This function reserves memory from early allocator. It should be
- * called by arch specific code once the early allocator (memblock or bootmem)
+ * called by arch specific code once the memblock allocator
  * has been activated and all other subsystems have already allocated/reserved
  * memory.
  */
@@ -96,6 +96,37 @@ void __init kvm_cma_reserve(void)
        }
 }
 
+/*
+ * Real-mode H_CONFER implementation.
+ * We check if we are the only vcpu out of this virtual core
+ * still running in the guest and not ceded.  If so, we pop up
+ * to the virtual-mode implementation; if not, just return to
+ * the guest.
+ */
+long int kvmppc_rm_h_confer(struct kvm_vcpu *vcpu, int target,
+                           unsigned int yield_count)
+{
+       struct kvmppc_vcore *vc = vcpu->arch.vcore;
+       int threads_running;
+       int threads_ceded;
+       int threads_conferring;
+       u64 stop = get_tb() + 10 * tb_ticks_per_usec;
+       int rv = H_SUCCESS; /* => don't yield */
+
+       set_bit(vcpu->arch.ptid, &vc->conferring_threads);
+       while ((get_tb() < stop) && (VCORE_EXIT_COUNT(vc) == 0)) {
+               threads_running = VCORE_ENTRY_COUNT(vc);
+               threads_ceded = hweight32(vc->napping_threads);
+               threads_conferring = hweight32(vc->conferring_threads);
+               if (threads_ceded + threads_conferring >= threads_running) {
+                       rv = H_TOO_HARD; /* => do yield */
+                       break;
+               }
+       }
+       clear_bit(vcpu->arch.ptid, &vc->conferring_threads);
+       return rv;
+}
+
 /*
  * When running HV mode KVM we need to block certain operations while KVM VMs
  * exist in the system. We use a counter of VMs to track this.