From 60e9114c621095285314cc530016d7930b327f34 Mon Sep 17 00:00:00 2001 From: Felix Held Date: Thu, 21 Oct 2021 02:03:04 +0200 Subject: [PATCH] include/device: ensure valid link/bus is passed to mp_cpu_bus_init When a chipset or mainboard devicetree doesn't have any LAPIC devices in its CPU cluster, not only the LAPIC device, but also the link/bus between the CPU cluster device and the LAPIC devices will be missing and the CPU cluster's dev->link_list will be NULL. This patch handles this case in the common code like commit 3c0ecd57c174b7391c66d22406effe18ce570cac (soc/intel/common/cpu: Handle non-zero BSP APIC ID in init_cpus) and commit ba936ce5db819d5ecb34e83a998b2390ecbdc4b9 (soc/intel/denverton_ns: Ensure CPU device has a valid link) already did in the common Intel SoC and the Denverton code. With this change all CPUs and SoC that use the common mp_cpu_bus_init as init function in the CPU cluster's device operations struct won't require having at least one LAPIC device in the chipset or mainboard device tree. Signed-off-by: Felix Held Change-Id: Ib0d85de5cafb6390b8fbd512186899d6a815e972 Reviewed-on: https://review.coreboot.org/c/coreboot/+/58508 Tested-by: build bot (Jenkins) Reviewed-by: Raul Rangel --- src/include/device/device.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/src/include/device/device.h b/src/include/device/device.h index 6bd6e0e551..8610e0a4c6 100644 --- a/src/include/device/device.h +++ b/src/include/device/device.h @@ -228,6 +228,17 @@ void set_cpu_topology(struct device *cpu, unsigned int node, void mp_init_cpus(DEVTREE_CONST struct bus *cpu_bus); static inline void mp_cpu_bus_init(struct device *dev) { + /* + * When no LAPIC device is specified in the devietree inside the CPU cluster device, + * neither a LAPIC device nor the link/bus between the CPU cluster and the LAPIC device + * will be present in the static device tree and the link_list struct element of the + * CPU cluster device will be NULL. In this case add one link, so that the + * alloc_find_dev calls in init_bsp and allocate_cpu_devices will be able to add a + * LAPIC device for the BSP and the APs on this link/bus. + */ + if (!dev->link_list) + add_more_links(dev, 1); + mp_init_cpus(dev->link_list); }