iommu/amd: Add early maps for ioapic and hpet

This is needed in a later patch were ioapic_map and hpet_map
entries are created before the slab allocator is initialized
(and thus add_special_device() can't be used).
Reviewed-by: NShuah Khan <shuahkhan@gmail.com>
Signed-off-by: NJoerg Roedel <joro@8bytes.org>

drivers/iommu/amd_iommu_init.c

@@ -213,6 +213,13 @@ enum iommu_init_state {
 	IOMMU_INIT_ERROR,
 };
 
+/* Early ioapic and hpet maps from kernel command line */
+#define EARLY_MAP_SIZE		4
+static struct devid_map __initdata early_ioapic_map[EARLY_MAP_SIZE];
+static struct devid_map __initdata early_hpet_map[EARLY_MAP_SIZE];
+static int __initdata early_ioapic_map_size;
+static int __initdata early_hpet_map_size;
+
 static enum iommu_init_state init_state = IOMMU_START_STATE;
 
 static int amd_iommu_enable_interrupts(void);
@@ -738,6 +745,31 @@ static int __init add_special_device(u8 type, u8 id, u16 devid, bool cmd_line)
 	return 0;
 }
 
+static int __init add_early_maps(void)
+{
+	int i, ret;
+
+	for (i = 0; i < early_ioapic_map_size; ++i) {
+		ret = add_special_device(IVHD_SPECIAL_IOAPIC,
+					 early_ioapic_map[i].id,
+					 early_ioapic_map[i].devid,
+					 early_ioapic_map[i].cmd_line);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < early_hpet_map_size; ++i) {
+		ret = add_special_device(IVHD_SPECIAL_HPET,
+					 early_hpet_map[i].id,
+					 early_hpet_map[i].devid,
+					 early_hpet_map[i].cmd_line);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 /*
  * Reads the device exclusion range from ACPI and initializes the IOMMU with
  * it
@@ -774,6 +806,12 @@ static int __init init_iommu_from_acpi(struct amd_iommu *iommu,
 	u32 dev_i, ext_flags = 0;
 	bool alias = false;
 	struct ivhd_entry *e;
+	int ret;
+
+
+	ret = add_early_maps();
+	if (ret)
+		return ret;
 
 	/*
 	 * First save the recommended feature enable bits from ACPI