Merge commit '5bc66170dc486556a1e36fd384463536573f4b82' into x86/urgent

From Borislav Petkov <bp@amd64.org>:

Below is a RAS fix which reverts the addition of a sysfs attribute
which we agreed is not needed, post-factum. And this should go in now
because that sysfs attribute is going to end up in 3.7 otherwise and
thus exposed to userspace; removing it then would be a lot harder.

This is done as a merge rather than a simple patch/cherry-pick since
the baseline for this patch was not in the previous x86/urgent.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 42 insertions, 9 deletions

diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 3ae2ced4a874..b1581527a236 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -342,6 +342,47 @@ const struct irq_domain_ops ioapic_irq_domain_ops = {
 	.xlate = ioapic_xlate,
 };
 
+static void dt_add_ioapic_domain(unsigned int ioapic_num,
+		struct device_node *np)
+{
+	struct irq_domain *id;
+	struct mp_ioapic_gsi *gsi_cfg;
+	int ret;
+	int num;
+
+	gsi_cfg = mp_ioapic_gsi_routing(ioapic_num);
+	num = gsi_cfg->gsi_end - gsi_cfg->gsi_base + 1;
+
+	id = irq_domain_add_linear(np, num, &ioapic_irq_domain_ops,
+			(void *)ioapic_num);
+	BUG_ON(!id);
+	if (gsi_cfg->gsi_base == 0) {
+		/*
+		 * The first NR_IRQS_LEGACY irq descs are allocated in
+		 * early_irq_init() and need just a mapping. The
+		 * remaining irqs need both. All of them are preallocated
+		 * and assigned so we can keep the 1:1 mapping which the ioapic
+		 * is having.
+		 */
+		ret = irq_domain_associate_many(id, 0, 0, NR_IRQS_LEGACY);
+		if (ret)
+			pr_err("Error mapping legacy IRQs: %d\n", ret);
+
+		if (num > NR_IRQS_LEGACY) {
+			ret = irq_create_strict_mappings(id, NR_IRQS_LEGACY,
+					NR_IRQS_LEGACY, num - NR_IRQS_LEGACY);
+			if (ret)
+				pr_err("Error creating mapping for the "
+						"remaining IRQs: %d\n", ret);
+		}
+		irq_set_default_host(id);
+	} else {
+		ret = irq_create_strict_mappings(id, gsi_cfg->gsi_base, 0, num);
+		if (ret)
+			pr_err("Error creating IRQ mapping: %d\n", ret);
+	}
+}
+
 static void __init ioapic_add_ofnode(struct device_node *np)
 {
 	struct resource r;
@@ -356,15 +397,7 @@ static void __init ioapic_add_ofnode(struct device_node *np)
 
 	for (i = 0; i < nr_ioapics; i++) {
 		if (r.start == mpc_ioapic_addr(i)) {
-			struct irq_domain *id;
-			struct mp_ioapic_gsi *gsi_cfg;
-
-			gsi_cfg = mp_ioapic_gsi_routing(i);
-
-			id = irq_domain_add_legacy(np, 32, gsi_cfg->gsi_base, 0,
-						   &ioapic_irq_domain_ops,
-						   (void*)i);
-			BUG_ON(!id);
+			dt_add_ioapic_domain(i, np);
 			return;
 		}
 	}