powerpc/powernv/pci: Rework pnv_opal_pci_msi_eoi()

pnv_opal_pci_msi_eoi() is called from KVM to EOI passthrough interrupts
when in real mode. Adding MSI domain broke the hack using the
'ioda.irq_chip' field to deduce the owning PHB. Fix that by using the
IRQ chip data in the MSI domain.

The 'ioda.irq_chip' field is now unused and could be removed from the
pnv_phb struct.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210701132750.1475580-30-clg@kaod.org

arch/powerpc/include/asm/pnv-pci.h

@@ -33,7 +33,7 @@ int pnv_cxl_alloc_hwirqs(struct pci_dev *dev, int num);
 void pnv_cxl_release_hwirqs(struct pci_dev *dev, int hwirq, int num);
 int pnv_cxl_get_irq_count(struct pci_dev *dev);
 struct device_node *pnv_pci_get_phb_node(struct pci_dev *dev);
-int64_t pnv_opal_pci_msi_eoi(struct irq_chip *chip, unsigned int hw_irq);
+int64_t pnv_opal_pci_msi_eoi(struct irq_data *d);
 bool is_pnv_opal_msi(struct irq_chip *chip);
 
 #ifdef CONFIG_CXL_BASE

arch/powerpc/kvm/book3s_hv_rm_xics.c

@@ -706,6 +706,7 @@ static int ics_rm_eoi(struct kvm_vcpu *vcpu, u32 irq)
 		icp->rm_eoied_irq = irq;
 	}
 
+	/* Handle passthrough interrupts */
 	if (state->host_irq) {
 		++vcpu->stat.pthru_all;
 		if (state->intr_cpu != -1) {
@@ -759,12 +760,12 @@ int xics_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
 
 static unsigned long eoi_rc;
 
-static void icp_eoi(struct irq_chip *c, u32 hwirq, __be32 xirr, bool *again)
+static void icp_eoi(struct irq_data *d, u32 hwirq, __be32 xirr, bool *again)
 {
 	void __iomem *xics_phys;
 	int64_t rc;
 
-	rc = pnv_opal_pci_msi_eoi(c, hwirq);
+	rc = pnv_opal_pci_msi_eoi(d);
 
 	if (rc)
 		eoi_rc = rc;
@@ -872,8 +873,7 @@ long kvmppc_deliver_irq_passthru(struct kvm_vcpu *vcpu,
 		icp_rm_deliver_irq(xics, icp, irq, false);
 
 	/* EOI the interrupt */
-	icp_eoi(irq_desc_get_chip(irq_map->desc), irq_map->r_hwirq, xirr,
-		again);
+	icp_eoi(irq_desc_get_irq_data(irq_map->desc), irq_map->r_hwirq, xirr, again);
 
 	if (check_too_hard(xics, icp) == H_TOO_HARD)
 		return 2;

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -1963,12 +1963,21 @@ void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 	pe->dma_setup_done = true;
 }
 
-int64_t pnv_opal_pci_msi_eoi(struct irq_chip *chip, unsigned int hw_irq)
+/*
+ * Called from KVM in real mode to EOI passthru interrupts. The ICP
+ * EOI is handled directly in KVM in kvmppc_deliver_irq_passthru().
+ *
+ * The IRQ data is mapped in the PCI-MSI domain and the EOI OPAL call
+ * needs an HW IRQ number mapped in the XICS IRQ domain. The HW IRQ
+ * numbers of the in-the-middle MSI domain are vector numbers and it's
+ * good enough for OPAL. Use that.
+ */
+int64_t pnv_opal_pci_msi_eoi(struct irq_data *d)
 {
-	struct pnv_phb *phb = container_of(chip, struct pnv_phb,
-					   ioda.irq_chip);
+	struct pci_controller *hose = irq_data_get_irq_chip_data(d->parent_data);
+	struct pnv_phb *phb = hose->private_data;
 
-	return opal_pci_msi_eoi(phb->opal_id, hw_irq);
+	return opal_pci_msi_eoi(phb->opal_id, d->parent_data->hwirq);
 }
 
 /*