psi: Add DT option to disable LPC interrupts

Some sim models have the LPC interrupts stuck asserted on secondary
chips so we add a device-tree option that makes us set the policy
for these to "Linux" instead of "OPAL".

Since they aren't referenced in the device-tree this will de-facto
prevent them from being enabled

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/hw/psi.c b/hw/psi.c
index 17e83a5..503e1ce 100644
--- a/hw/psi.c
+++ b/hw/psi.c
@@ -521,6 +521,9 @@ static uint64_t psi_p8_irq_attributes(struct irq_source *is, uint32_t isn)
 	uint32_t idx = isn - psi->interrupt;
 	uint64_t attr;
 
+	if (psi->no_lpc_irqs && idx == P8_IRQ_PSI_LPC)
+		return IRQ_ATTR_TARGET_LINUX;
+
 	if (idx == P8_IRQ_PSI_EXTERNAL &&
 	    psi_ext_irq_policy == EXTERNAL_IRQ_POLICY_LINUX)
 		return IRQ_ATTR_TARGET_LINUX;
@@ -586,8 +589,23 @@ static void psihb_p9_interrupt(struct irq_source *is, uint32_t isn)
 }
 
 static uint64_t psi_p9_irq_attributes(struct irq_source *is __unused,
-				      uint32_t isn __unused)
+				      uint32_t isn)
 {
+	struct psi *psi = is->data;
+	unsigned int idx = isn & 0xf;
+
+	/* If LPC interrupts are disabled, route them to Linux
+	 * (who will not request them since they aren't referenced
+	 * in the device tree)
+	 */
+	if (psi->no_lpc_irqs &&
+	    (idx == P9_PSI_IRQ_LPC_SIRQ0 ||
+	     idx == P9_PSI_IRQ_LPC_SIRQ1 ||
+	     idx == P9_PSI_IRQ_LPC_SIRQ2 ||
+	     idx == P9_PSI_IRQ_LPC_SIRQ3 ||
+	     idx == P9_PSI_IRQ_LPCHC))
+		return IRQ_ATTR_TARGET_LINUX;
+
 	/* XXX For now, all go to OPAL, this will change */
 	return IRQ_ATTR_TARGET_OPAL | IRQ_ATTR_TARGET_FREQUENT;
 }
@@ -1002,6 +1020,9 @@ static bool psi_init_psihb(struct dt_node *psihb)
 	}
 	chip->psi = psi;
 
+	if (dt_has_node_property(psihb, "no-lpc-interrupts", NULL))
+		psi->no_lpc_irqs = true;
+
 	psi_activate_phb(psi);
 	psi_init_interrupts(psi);
 	psi_create_mm_dtnode(psi);