]> git.karo-electronics.de Git - linux-beck.git/blobdiff - arch/powerpc/kvm/book3s_hv_rmhandlers.S
KVM: PPC: Book3S HV: Implement dynamic micro-threading on POWER8
[linux-beck.git] / arch / powerpc / kvm / book3s_hv_rmhandlers.S
index ac113b527bf9151add877875ce1b339a90c12b18..db2427db44715eda7858969ccd7d306bb0ad6158 100644 (file)
@@ -128,6 +128,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
        subf    r4, r4, r3
        mtspr   SPRN_DEC, r4
 
+       /* hwthread_req may have got set by cede or no vcpu, so clear it */
+       li      r0, 0
+       stb     r0, HSTATE_HWTHREAD_REQ(r13)
+
        /*
         * For external and machine check interrupts, we need
         * to call the Linux handler to process the interrupt.
@@ -215,7 +219,6 @@ kvm_novcpu_wakeup:
        ld      r5, HSTATE_KVM_VCORE(r13)
        li      r0, 0
        stb     r0, HSTATE_NAPPING(r13)
-       stb     r0, HSTATE_HWTHREAD_REQ(r13)
 
        /* check the wake reason */
        bl      kvmppc_check_wake_reason
@@ -315,10 +318,10 @@ kvm_start_guest:
        cmpdi   r3, 0
        bge     kvm_no_guest
 
-       /* get vcpu pointer, NULL if we have no vcpu to run */
-       ld      r4,HSTATE_KVM_VCPU(r13)
-       cmpdi   r4,0
-       /* if we have no vcpu to run, go back to sleep */
+       /* get vcore pointer, NULL if we have nothing to run */
+       ld      r5,HSTATE_KVM_VCORE(r13)
+       cmpdi   r5,0
+       /* if we have no vcore to run, go back to sleep */
        beq     kvm_no_guest
 
 kvm_secondary_got_guest:
@@ -327,21 +330,42 @@ kvm_secondary_got_guest:
        ld      r6, PACA_DSCR_DEFAULT(r13)
        std     r6, HSTATE_DSCR(r13)
 
-       /* Order load of vcore, ptid etc. after load of vcpu */
+       /* On thread 0 of a subcore, set HDEC to max */
+       lbz     r4, HSTATE_PTID(r13)
+       cmpwi   r4, 0
+       bne     63f
+       lis     r6, 0x7fff
+       ori     r6, r6, 0xffff
+       mtspr   SPRN_HDEC, r6
+       /* and set per-LPAR registers, if doing dynamic micro-threading */
+       ld      r6, HSTATE_SPLIT_MODE(r13)
+       cmpdi   r6, 0
+       beq     63f
+       ld      r0, KVM_SPLIT_RPR(r6)
+       mtspr   SPRN_RPR, r0
+       ld      r0, KVM_SPLIT_PMMAR(r6)
+       mtspr   SPRN_PMMAR, r0
+       ld      r0, KVM_SPLIT_LDBAR(r6)
+       mtspr   SPRN_LDBAR, r0
+       isync
+63:
+       /* Order load of vcpu after load of vcore */
        lwsync
+       ld      r4, HSTATE_KVM_VCPU(r13)
        bl      kvmppc_hv_entry
 
        /* Back from the guest, go back to nap */
-       /* Clear our vcpu pointer so we don't come back in early */
+       /* Clear our vcpu and vcore pointers so we don't come back in early */
        li      r0, 0
+       std     r0, HSTATE_KVM_VCPU(r13)
        /*
-        * Once we clear HSTATE_KVM_VCPU(r13), the code in
+        * Once we clear HSTATE_KVM_VCORE(r13), the code in
         * kvmppc_run_core() is going to assume that all our vcpu
         * state is visible in memory.  This lwsync makes sure
         * that that is true.
         */
        lwsync
-       std     r0, HSTATE_KVM_VCPU(r13)
+       std     r0, HSTATE_KVM_VCORE(r13)
 
 /*
  * At this point we have finished executing in the guest.
@@ -374,16 +398,63 @@ kvm_no_guest:
        b       power7_wakeup_loss
 
 53:    HMT_LOW
-       ld      r4, HSTATE_KVM_VCPU(r13)
-       cmpdi   r4, 0
+       ld      r5, HSTATE_KVM_VCORE(r13)
+       cmpdi   r5, 0
+       bne     60f
+       ld      r3, HSTATE_SPLIT_MODE(r13)
+       cmpdi   r3, 0
+       beq     kvm_no_guest
+       lbz     r0, KVM_SPLIT_DO_NAP(r3)
+       cmpwi   r0, 0
        beq     kvm_no_guest
        HMT_MEDIUM
+       b       kvm_unsplit_nap
+60:    HMT_MEDIUM
        b       kvm_secondary_got_guest
 
 54:    li      r0, KVM_HWTHREAD_IN_KVM
        stb     r0, HSTATE_HWTHREAD_STATE(r13)
        b       kvm_no_guest
 
+/*
+ * Here the primary thread is trying to return the core to
+ * whole-core mode, so we need to nap.
+ */
+kvm_unsplit_nap:
+       /* clear any pending message */
+BEGIN_FTR_SECTION
+       lis     r6, (PPC_DBELL_SERVER << (63-36))@h
+       PPC_MSGCLR(6)
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+       /* Set kvm_split_mode.napped[tid] = 1 */
+       ld      r3, HSTATE_SPLIT_MODE(r13)
+       li      r0, 1
+       lhz     r4, PACAPACAINDEX(r13)
+       clrldi  r4, r4, 61      /* micro-threading => P8 => 8 threads/core */
+       addi    r4, r4, KVM_SPLIT_NAPPED
+       stbx    r0, r3, r4
+       /* Check the do_nap flag again after setting napped[] */
+       sync
+       lbz     r0, KVM_SPLIT_DO_NAP(r3)
+       cmpwi   r0, 0
+       beq     57f
+       li      r3, (LPCR_PECEDH | LPCR_PECE0) >> 4
+       mfspr   r4, SPRN_LPCR
+       rlwimi  r4, r3, 4, (LPCR_PECEDP | LPCR_PECEDH | LPCR_PECE0 | LPCR_PECE1)
+       mtspr   SPRN_LPCR, r4
+       isync
+       std     r0, HSTATE_SCRATCH0(r13)
+       ptesync
+       ld      r0, HSTATE_SCRATCH0(r13)
+1:     cmpd    r0, r0
+       bne     1b
+       nap
+       b       .
+
+57:    li      r0, 0
+       stbx    r0, r3, r4
+       b       kvm_no_guest
+
 /******************************************************************************
  *                                                                            *
  *                               Entry code                                   *
@@ -854,7 +925,10 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
        cmpwi   r0, 0
        bne     21f
        HMT_LOW
-20:    lbz     r0, VCORE_IN_GUEST(r5)
+20:    lwz     r3, VCORE_ENTRY_EXIT(r5)
+       cmpwi   r3, 0x100
+       bge     no_switch_exit
+       lbz     r0, VCORE_IN_GUEST(r5)
        cmpwi   r0, 0
        beq     20b
        HMT_MEDIUM
@@ -985,9 +1059,13 @@ secondary_too_late:
 #endif
 11:    b       kvmhv_switch_to_host
 
+no_switch_exit:
+       HMT_MEDIUM
+       li      r12, 0
+       b       12f
 hdec_soon:
        li      r12, BOOK3S_INTERRUPT_HV_DECREMENTER
-       stw     r12, VCPU_TRAP(r4)
+12:    stw     r12, VCPU_TRAP(r4)
        mr      r9, r4
 #ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
        addi    r3, r4, VCPU_TB_RMEXIT
@@ -1545,12 +1623,17 @@ kvmhv_switch_to_host:
 
        /* Primary thread waits for all the secondaries to exit guest */
 15:    lwz     r3,VCORE_ENTRY_EXIT(r5)
-       srwi    r0,r3,8
+       rlwinm  r0,r3,32-8,0xff
        clrldi  r3,r3,56
        cmpw    r3,r0
        bne     15b
        isync
 
+       /* Did we actually switch to the guest at all? */
+       lbz     r6, VCORE_IN_GUEST(r5)
+       cmpwi   r6, 0
+       beq     19f
+
        /* Primary thread switches back to host partition */
        ld      r6,KVM_HOST_SDR1(r4)
        lwz     r7,KVM_HOST_LPID(r4)
@@ -1594,7 +1677,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 18:
        /* Signal secondary CPUs to continue */
        stb     r0,VCORE_IN_GUEST(r5)
-       lis     r8,0x7fff               /* MAX_INT@h */
+19:    lis     r8,0x7fff               /* MAX_INT@h */
        mtspr   SPRN_HDEC,r8
 
 16:    ld      r8,KVM_HOST_LPCR(r4)