--- /dev/null
+/*
+ * Copyright 2012 Michael Ellerman, IBM Corporation.
+ * Copyright 2012 Benjamin Herrenschmidt, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kvm_host.h>
+#include <linux/err.h>
+
+#include <asm/kvm_book3s.h>
+#include <asm/kvm_ppc.h>
+#include <asm/hvcall.h>
+#include <asm/xics.h>
+#include <asm/debug.h>
+#include <asm/synch.h>
+#include <asm/ppc-opcode.h>
+
+#include "book3s_xics.h"
+
+#define DEBUG_PASSUP
+
+static inline void rm_writeb(unsigned long paddr, u8 val)
+{
+ __asm__ __volatile__("sync; stbcix %0,0,%1"
+ : : "r" (val), "r" (paddr) : "memory");
+}
+
+static void icp_rm_set_vcpu_irq(struct kvm_vcpu *vcpu,
+ struct kvm_vcpu *this_vcpu)
+{
+ struct kvmppc_icp *this_icp = this_vcpu->arch.icp;
+ unsigned long xics_phys;
+ int cpu;
+
+ /* Mark the target VCPU as having an interrupt pending */
+ vcpu->stat.queue_intr++;
+ set_bit(BOOK3S_IRQPRIO_EXTERNAL_LEVEL, &vcpu->arch.pending_exceptions);
+
+ /* Kick self ? Just set MER and return */
+ if (vcpu == this_vcpu) {
+ mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_MER);
+ return;
+ }
+
+ /* Check if the core is loaded, if not, too hard */
+ cpu = vcpu->cpu;
+ if (cpu < 0 || cpu >= nr_cpu_ids) {
+ this_icp->rm_action |= XICS_RM_KICK_VCPU;
+ this_icp->rm_kick_target = vcpu;
+ return;
+ }
+ /* In SMT cpu will always point to thread 0, we adjust it */
+ cpu += vcpu->arch.ptid;
+
+ /* Not too hard, then poke the target */
+ xics_phys = paca[cpu].kvm_hstate.xics_phys;
+ rm_writeb(xics_phys + XICS_MFRR, IPI_PRIORITY);
+}
+
+static void icp_rm_clr_vcpu_irq(struct kvm_vcpu *vcpu)
+{
+ /* Note: Only called on self ! */
+ clear_bit(BOOK3S_IRQPRIO_EXTERNAL_LEVEL,
+ &vcpu->arch.pending_exceptions);
+ mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~LPCR_MER);
+}
+
+static inline bool icp_rm_try_update(struct kvmppc_icp *icp,
+ union kvmppc_icp_state old,
+ union kvmppc_icp_state new)
+{
+ struct kvm_vcpu *this_vcpu = local_paca->kvm_hstate.kvm_vcpu;
+ bool success;
+
+ /* Calculate new output value */
+ new.out_ee = (new.xisr && (new.pending_pri < new.cppr));
+
+ /* Attempt atomic update */
+ success = cmpxchg64(&icp->state.raw, old.raw, new.raw) == old.raw;
+ if (!success)
+ goto bail;
+
+ /*
+ * Check for output state update
+ *
+ * Note that this is racy since another processor could be updating
+ * the state already. This is why we never clear the interrupt output
+ * here, we only ever set it. The clear only happens prior to doing
+ * an update and only by the processor itself. Currently we do it
+ * in Accept (H_XIRR) and Up_Cppr (H_XPPR).
+ *
+ * We also do not try to figure out whether the EE state has changed,
+ * we unconditionally set it if the new state calls for it. The reason
+ * for that is that we opportunistically remove the pending interrupt
+ * flag when raising CPPR, so we need to set it back here if an
+ * interrupt is still pending.
+ */
+ if (new.out_ee)
+ icp_rm_set_vcpu_irq(icp->vcpu, this_vcpu);
+
+ /* Expose the state change for debug purposes */
+ this_vcpu->arch.icp->rm_dbgstate = new;
+ this_vcpu->arch.icp->rm_dbgtgt = icp->vcpu;
+
+ bail:
+ return success;
+}
+
+static inline int check_too_hard(struct kvmppc_xics *xics,
+ struct kvmppc_icp *icp)
+{
+ return (xics->real_mode_dbg || icp->rm_action) ? H_TOO_HARD : H_SUCCESS;
+}
+
+static void icp_rm_down_cppr(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
+ u8 new_cppr)
+{
+ union kvmppc_icp_state old_state, new_state;
+ bool resend;
+
+ /*
+ * This handles several related states in one operation:
+ *
+ * ICP State: Down_CPPR
+ *
+ * Load CPPR with new value and if the XISR is 0
+ * then check for resends:
+ *
+ * ICP State: Resend
+ *
+ * If MFRR is more favored than CPPR, check for IPIs
+ * and notify ICS of a potential resend. This is done
+ * asynchronously (when used in real mode, we will have
+ * to exit here).
+ *
+ * We do not handle the complete Check_IPI as documented
+ * here. In the PAPR, this state will be used for both
+ * Set_MFRR and Down_CPPR. However, we know that we aren't
+ * changing the MFRR state here so we don't need to handle
+ * the case of an MFRR causing a reject of a pending irq,
+ * this will have been handled when the MFRR was set in the
+ * first place.
+ *
+ * Thus we don't have to handle rejects, only resends.
+ *
+ * When implementing real mode for HV KVM, resend will lead to
+ * a H_TOO_HARD return and the whole transaction will be handled
+ * in virtual mode.
+ */
+ do {
+ old_state = new_state = ACCESS_ONCE(icp->state);
+
+ /* Down_CPPR */
+ new_state.cppr = new_cppr;
+
+ /*
+ * Cut down Resend / Check_IPI / IPI
+ *
+ * The logic is that we cannot have a pending interrupt
+ * trumped by an IPI at this point (see above), so we
+ * know that either the pending interrupt is already an
+ * IPI (in which case we don't care to override it) or
+ * it's either more favored than us or non existent
+ */
+ if (new_state.mfrr < new_cppr &&
+ new_state.mfrr <= new_state.pending_pri) {
+ new_state.pending_pri = new_state.mfrr;
+ new_state.xisr = XICS_IPI;
+ }
+
+ /* Latch/clear resend bit */
+ resend = new_state.need_resend;
+ new_state.need_resend = 0;
+
+ } while (!icp_rm_try_update(icp, old_state, new_state));
+
+ /*
+ * Now handle resend checks. Those are asynchronous to the ICP
+ * state update in HW (ie bus transactions) so we can handle them
+ * separately here as well.
+ */
+ if (resend)
+ icp->rm_action |= XICS_RM_CHECK_RESEND;
+}
+
+
+unsigned long kvmppc_rm_h_xirr(struct kvm_vcpu *vcpu)
+{
+ union kvmppc_icp_state old_state, new_state;
+ struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
+ struct kvmppc_icp *icp = vcpu->arch.icp;
+ u32 xirr;
+
+ if (!xics || !xics->real_mode)
+ return H_TOO_HARD;
+
+ /* First clear the interrupt */
+ icp_rm_clr_vcpu_irq(icp->vcpu);
+
+ /*
+ * ICP State: Accept_Interrupt
+ *
+ * Return the pending interrupt (if any) along with the
+ * current CPPR, then clear the XISR & set CPPR to the
+ * pending priority
+ */
+ do {
+ old_state = new_state = ACCESS_ONCE(icp->state);
+
+ xirr = old_state.xisr | (((u32)old_state.cppr) << 24);
+ if (!old_state.xisr)
+ break;
+ new_state.cppr = new_state.pending_pri;
+ new_state.pending_pri = 0xff;
+ new_state.xisr = 0;
+
+ } while (!icp_rm_try_update(icp, old_state, new_state));
+
+ /* Return the result in GPR4 */
+ vcpu->arch.gpr[4] = xirr;
+
+ return check_too_hard(xics, icp);
+}
+
+int kvmppc_rm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
+ unsigned long mfrr)
+{
+ union kvmppc_icp_state old_state, new_state;
+ struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
+ struct kvmppc_icp *icp, *this_icp = vcpu->arch.icp;
+ u32 reject;
+ bool resend;
+ bool local;
+
+ if (!xics || !xics->real_mode)
+ return H_TOO_HARD;
+
+ local = this_icp->server_num == server;
+ if (local)
+ icp = this_icp;
+ else
+ icp = kvmppc_xics_find_server(vcpu->kvm, server);
+ if (!icp)
+ return H_PARAMETER;
+
+ /*
+ * ICP state: Set_MFRR
+ *
+ * If the CPPR is more favored than the new MFRR, then
+ * nothing needs to be done as there can be no XISR to
+ * reject.
+ *
+ * If the CPPR is less favored, then we might be replacing
+ * an interrupt, and thus need to possibly reject it as in
+ *
+ * ICP state: Check_IPI
+ */
+ do {
+ old_state = new_state = ACCESS_ONCE(icp->state);
+
+ /* Set_MFRR */
+ new_state.mfrr = mfrr;
+
+ /* Check_IPI */
+ reject = 0;
+ resend = false;
+ if (mfrr < new_state.cppr) {
+ /* Reject a pending interrupt if not an IPI */
+ if (mfrr <= new_state.pending_pri)
+ reject = new_state.xisr;
+ new_state.pending_pri = mfrr;
+ new_state.xisr = XICS_IPI;
+ }
+
+ if (mfrr > old_state.mfrr && mfrr > new_state.cppr) {
+ resend = new_state.need_resend;
+ new_state.need_resend = 0;
+ }
+ } while (!icp_rm_try_update(icp, old_state, new_state));
+
+ /* Pass rejects to virtual mode */
+ if (reject && reject != XICS_IPI) {
+ this_icp->rm_action |= XICS_RM_REJECT;
+ this_icp->rm_reject = reject;
+ }
+
+ /* Pass resends to virtual mode */
+ if (resend)
+ this_icp->rm_action |= XICS_RM_CHECK_RESEND;
+
+ return check_too_hard(xics, this_icp);
+}
+
+int kvmppc_rm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
+{
+ union kvmppc_icp_state old_state, new_state;
+ struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
+ struct kvmppc_icp *icp = vcpu->arch.icp;
+ u32 reject;
+
+ if (!xics || !xics->real_mode)
+ return H_TOO_HARD;
+
+ /*
+ * ICP State: Set_CPPR
+ *
+ * We can safely compare the new value with the current
+ * value outside of the transaction as the CPPR is only
+ * ever changed by the processor on itself
+ */
+ if (cppr > icp->state.cppr) {
+ icp_rm_down_cppr(xics, icp, cppr);
+ goto bail;
+ } else if (cppr == icp->state.cppr)
+ return H_SUCCESS;
+
+ /*
+ * ICP State: Up_CPPR
+ *
+ * The processor is raising its priority, this can result
+ * in a rejection of a pending interrupt:
+ *
+ * ICP State: Reject_Current
+ *
+ * We can remove EE from the current processor, the update
+ * transaction will set it again if needed
+ */
+ icp_rm_clr_vcpu_irq(icp->vcpu);
+
+ do {
+ old_state = new_state = ACCESS_ONCE(icp->state);
+
+ reject = 0;
+ new_state.cppr = cppr;
+
+ if (cppr <= new_state.pending_pri) {
+ reject = new_state.xisr;
+ new_state.xisr = 0;
+ new_state.pending_pri = 0xff;
+ }
+
+ } while (!icp_rm_try_update(icp, old_state, new_state));
+
+ /* Pass rejects to virtual mode */
+ if (reject && reject != XICS_IPI) {
+ icp->rm_action |= XICS_RM_REJECT;
+ icp->rm_reject = reject;
+ }
+ bail:
+ return check_too_hard(xics, icp);
+}
+
+int kvmppc_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
+{
+ struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
+ struct kvmppc_icp *icp = vcpu->arch.icp;
+ struct kvmppc_ics *ics;
+ struct ics_irq_state *state;
+ u32 irq = xirr & 0x00ffffff;
+ u16 src;
+
+ if (!xics || !xics->real_mode)
+ return H_TOO_HARD;
+
+ /*
+ * ICP State: EOI
+ *
+ * Note: If EOI is incorrectly used by SW to lower the CPPR
+ * value (ie more favored), we do not check for rejection of
+ * a pending interrupt, this is a SW error and PAPR sepcifies
+ * that we don't have to deal with it.
+ *
+ * The sending of an EOI to the ICS is handled after the
+ * CPPR update
+ *
+ * ICP State: Down_CPPR which we handle
+ * in a separate function as it's shared with H_CPPR.
+ */
+ icp_rm_down_cppr(xics, icp, xirr >> 24);
+
+ /* IPIs have no EOI */
+ if (irq == XICS_IPI)
+ goto bail;
+ /*
+ * EOI handling: If the interrupt is still asserted, we need to
+ * resend it. We can take a lockless "peek" at the ICS state here.
+ *
+ * "Message" interrupts will never have "asserted" set
+ */
+ ics = kvmppc_xics_find_ics(xics, irq, &src);
+ if (!ics)
+ goto bail;
+ state = &ics->irq_state[src];
+
+ /* Still asserted, resend it, we make it look like a reject */
+ if (state->asserted) {
+ icp->rm_action |= XICS_RM_REJECT;
+ icp->rm_reject = irq;
+ }
+ bail:
+ return check_too_hard(xics, icp);
+}
#define XICS_DBG(fmt...) trace_printk(fmt)
#endif
+#define ENABLE_REALMODE true
+#define DEBUG_REALMODE false
+
/*
* LOCKING
* =======
* in Accept (H_XIRR) and Up_Cppr (H_XPPR).
*
* We also do not try to figure out whether the EE state has changed,
- * we unconditionally set it if the new state calls for it for the
- * same reason.
+ * we unconditionally set it if the new state calls for it. The reason
+ * for that is that we opportunistically remove the pending interrupt
+ * flag when raising CPPR, so we need to set it back here if an
+ * interrupt is still pending.
*/
if (new.out_ee) {
kvmppc_book3s_queue_irqprio(icp->vcpu,
icp_check_resend(xics, icp);
}
-static noinline unsigned long h_xirr(struct kvm_vcpu *vcpu)
+static noinline unsigned long kvmppc_h_xirr(struct kvm_vcpu *vcpu)
{
union kvmppc_icp_state old_state, new_state;
struct kvmppc_icp *icp = vcpu->arch.icp;
return xirr;
}
-static noinline int h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
- unsigned long mfrr)
+static noinline int kvmppc_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
+ unsigned long mfrr)
{
union kvmppc_icp_state old_state, new_state;
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
return H_SUCCESS;
}
-static noinline void h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
+static noinline void kvmppc_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
{
union kvmppc_icp_state old_state, new_state;
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
icp_deliver_irq(xics, icp, reject);
}
-static noinline int h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
+static noinline int kvmppc_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
{
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp = vcpu->arch.icp;
return H_SUCCESS;
}
+static noinline int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall)
+{
+ struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
+ struct kvmppc_icp *icp = vcpu->arch.icp;
+
+ XICS_DBG("XICS_RM: H_%x completing, act: %x state: %lx tgt: %p\n",
+ hcall, icp->rm_action, icp->rm_dbgstate.raw, icp->rm_dbgtgt);
+
+ if (icp->rm_action & XICS_RM_KICK_VCPU)
+ kvmppc_fast_vcpu_kick(icp->rm_kick_target);
+ if (icp->rm_action & XICS_RM_CHECK_RESEND)
+ icp_check_resend(xics, icp);
+ if (icp->rm_action & XICS_RM_REJECT)
+ icp_deliver_irq(xics, icp, icp->rm_reject);
+
+ icp->rm_action = 0;
+
+ return H_SUCCESS;
+}
+
int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
{
+ struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
unsigned long res;
int rc = H_SUCCESS;
/* Check if we have an ICP */
- if (!vcpu->arch.icp || !vcpu->kvm->arch.xics)
+ if (!xics || !vcpu->arch.icp)
return H_HARDWARE;
+ /* Check for real mode returning too hard */
+ if (xics->real_mode)
+ return kvmppc_xics_rm_complete(vcpu, req);
+
switch (req) {
case H_XIRR:
- res = h_xirr(vcpu);
+ res = kvmppc_h_xirr(vcpu);
kvmppc_set_gpr(vcpu, 4, res);
break;
case H_CPPR:
- h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
+ kvmppc_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
break;
case H_EOI:
- rc = h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
+ rc = kvmppc_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
break;
case H_IPI:
- rc = h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
- kvmppc_get_gpr(vcpu, 5));
+ rc = kvmppc_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
+ kvmppc_get_gpr(vcpu, 5));
break;
}
xics_debugfs_init(xics);
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+ if (cpu_has_feature(CPU_FTR_ARCH_206)) {
+ /* Enable real mode support */
+ xics->real_mode = ENABLE_REALMODE;
+ xics->real_mode_dbg = DEBUG_REALMODE;
+ }
+#endif /* CONFIG_KVM_BOOK3S_64_HV */
+
return 0;
}
projects / platform / kernel / linux-rpi.git / commitdiff