powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_MASK_FW

This flag was used to support the PHB4 LSIs on P9 DD1 and we have
stopped supporting this CPU when DD2 came out. See skiboot commit:

  https://github.com/open-power/skiboot/commit/0b0d15e3c170Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201210171450.1933725-10-clg@kaod.org

arch/powerpc/include/asm/opal-api.h

@@ -1092,7 +1092,7 @@ enum {
 	OPAL_XIVE_IRQ_STORE_EOI		= 0x00000002,
 	OPAL_XIVE_IRQ_LSI		= 0x00000004,
 	OPAL_XIVE_IRQ_SHIFT_BUG		= 0x00000008, /* P9 DD1.0 workaround */
-	OPAL_XIVE_IRQ_MASK_VIA_FW	= 0x00000010,
+	OPAL_XIVE_IRQ_MASK_VIA_FW	= 0x00000010, /* P9 DD1.0 workaround */
 	OPAL_XIVE_IRQ_EOI_VIA_FW	= 0x00000020,
 };
 

arch/powerpc/include/asm/xive.h

@@ -61,7 +61,7 @@ struct xive_irq_data {
 #define XIVE_IRQ_FLAG_STORE_EOI	0x01
 #define XIVE_IRQ_FLAG_LSI	0x02
 /* #define XIVE_IRQ_FLAG_SHIFT_BUG	0x04 */ /* P9 DD1.0 workaround */
-#define XIVE_IRQ_FLAG_MASK_FW	0x08
+/* #define XIVE_IRQ_FLAG_MASK_FW	0x08 */ /* P9 DD1.0 workaround */
 #define XIVE_IRQ_FLAG_EOI_FW	0x10
 #define XIVE_IRQ_FLAG_H_INT_ESB	0x20
 

arch/powerpc/kvm/book3s_xive.c

@@ -419,37 +419,16 @@ static u8 xive_lock_and_mask(struct kvmppc_xive *xive,
 	/* Get the right irq */
 	kvmppc_xive_select_irq(state, &hw_num, &xd);
 
+	/* Set PQ to 10, return old P and old Q and remember them */
+	val = xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_10);
+	state->old_p = !!(val & 2);
+	state->old_q = !!(val & 1);
+
 	/*
-	 * If the interrupt is marked as needing masking via
-	 * firmware, we do it here. Firmware masking however
-	 * is "lossy", it won't return the old p and q bits
-	 * and won't set the interrupt to a state where it will
-	 * record queued ones. If this is an issue we should do
-	 * lazy masking instead.
-	 *
-	 * For now, we work around this in unmask by forcing
-	 * an interrupt whenever we unmask a non-LSI via FW
-	 * (if ever).
+	 * Synchronize hardware to sensure the queues are updated when
+	 * masking
 	 */
-	if (xd->flags & OPAL_XIVE_IRQ_MASK_VIA_FW) {
-		xive_native_configure_irq(hw_num,
-				kvmppc_xive_vp(xive, state->act_server),
-				MASKED, state->number);
-		/* set old_p so we can track if an H_EOI was done */
-		state->old_p = true;
-		state->old_q = false;
-	} else {
-		/* Set PQ to 10, return old P and old Q and remember them */
-		val = xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_10);
-		state->old_p = !!(val & 2);
-		state->old_q = !!(val & 1);
-
-		/*
-		 * Synchronize hardware to sensure the queues are updated
-		 * when masking
-		 */
-		xive_native_sync_source(hw_num);
-	}
+	xive_native_sync_source(hw_num);
 
 	return old_prio;
 }
@@ -483,23 +462,6 @@ static void xive_finish_unmask(struct kvmppc_xive *xive,
 	/* Get the right irq */
 	kvmppc_xive_select_irq(state, &hw_num, &xd);
 
-	/*
-	 * See comment in xive_lock_and_mask() concerning masking
-	 * via firmware.
-	 */
-	if (xd->flags & OPAL_XIVE_IRQ_MASK_VIA_FW) {
-		xive_native_configure_irq(hw_num,
-				kvmppc_xive_vp(xive, state->act_server),
-				state->act_priority, state->number);
-		/* If an EOI is needed, do it here */
-		if (!state->old_p)
-			xive_vm_source_eoi(hw_num, xd);
-		/* If this is not an LSI, force a trigger */
-		if (!(xd->flags & OPAL_XIVE_IRQ_LSI))
-			xive_irq_trigger(xd);
-		goto bail;
-	}
-
 	/* Old Q set, set PQ to 11 */
 	if (state->old_q)
 		xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_11);

arch/powerpc/sysdev/xive/common.c

@@ -424,9 +424,7 @@ static void xive_irq_eoi(struct irq_data *d)
 }
 
 /*
- * Helper used to mask and unmask an interrupt source. This
- * is only called for normal interrupts that do not require
- * masking/unmasking via firmware.
+ * Helper used to mask and unmask an interrupt source.
  */
 static void xive_do_source_set_mask(struct xive_irq_data *xd,
 				    bool mask)
@@ -673,20 +671,6 @@ static void xive_irq_unmask(struct irq_data *d)
 
 	pr_devel("xive_irq_unmask: irq %d data @%p\n", d->irq, xd);
 
-	/*
-	 * This is a workaround for PCI LSI problems on P9, for
-	 * these, we call FW to set the mask. The problems might
-	 * be fixed by P9 DD2.0, if that is the case, firmware
-	 * will no longer set that flag.
-	 */
-	if (xd->flags & XIVE_IRQ_FLAG_MASK_FW) {
-		unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
-		xive_ops->configure_irq(hw_irq,
-					get_hard_smp_processor_id(xd->target),
-					xive_irq_priority, d->irq);
-		return;
-	}
-
 	xive_do_source_set_mask(xd, false);
 }
 
@@ -696,20 +680,6 @@ static void xive_irq_mask(struct irq_data *d)
 
 	pr_devel("xive_irq_mask: irq %d data @%p\n", d->irq, xd);
 
-	/*
-	 * This is a workaround for PCI LSI problems on P9, for
-	 * these, we call OPAL to set the mask. The problems might
-	 * be fixed by P9 DD2.0, if that is the case, firmware
-	 * will no longer set that flag.
-	 */
-	if (xd->flags & XIVE_IRQ_FLAG_MASK_FW) {
-		unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
-		xive_ops->configure_irq(hw_irq,
-					get_hard_smp_processor_id(xd->target),
-					0xff, d->irq);
-		return;
-	}
-
 	xive_do_source_set_mask(xd, true);
 }
 
@@ -852,13 +822,6 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state)
 	int rc;
 	u8 pq;
 
-	/*
-	 * We only support this on interrupts that do not require
-	 * firmware calls for masking and unmasking
-	 */
-	if (xd->flags & XIVE_IRQ_FLAG_MASK_FW)
-		return -EIO;
-
 	/*
 	 * This is called by KVM with state non-NULL for enabling
 	 * pass-through or NULL for disabling it
@@ -1304,7 +1267,6 @@ static const struct {
 } xive_irq_flags[] = {
 	{ XIVE_IRQ_FLAG_STORE_EOI, "STORE_EOI" },
 	{ XIVE_IRQ_FLAG_LSI,       "LSI"       },
-	{ XIVE_IRQ_FLAG_MASK_FW,   "MASK_FW"   },
 	{ XIVE_IRQ_FLAG_EOI_FW,    "EOI_FW"    },
 	{ XIVE_IRQ_FLAG_H_INT_ESB, "H_INT_ESB" },
 	{ XIVE_IRQ_FLAG_NO_EOI,    "NO_EOI"    },

arch/powerpc/sysdev/xive/native.c

@@ -64,8 +64,6 @@ int xive_native_populate_irq_data(u32 hw_irq, struct xive_irq_data *data)
 		data->flags |= XIVE_IRQ_FLAG_STORE_EOI;
 	if (opal_flags & OPAL_XIVE_IRQ_LSI)
 		data->flags |= XIVE_IRQ_FLAG_LSI;
-	if (opal_flags & OPAL_XIVE_IRQ_MASK_VIA_FW)
-		data->flags |= XIVE_IRQ_FLAG_MASK_FW;
 	if (opal_flags & OPAL_XIVE_IRQ_EOI_VIA_FW)
 		data->flags |= XIVE_IRQ_FLAG_EOI_FW;
 	data->eoi_page = be64_to_cpu(eoi_page);