• Lorenzo Pieralisi's avatar
    ARM64: kernel: make cpu_ops hooks DT agnostic · 819a8826
    Lorenzo Pieralisi authored
    ARM64 CPU operations such as cpu_init and cpu_init_idle take
    a struct device_node pointer as a parameter, which corresponds to
    the device tree node of the logical cpu on which the operation
    has to be applied.
    
    With the advent of ACPI on arm64, where MADT static table entries
    are used to initialize cpus, the device tree node parameter
    in cpu_ops hooks become useless when booting with ACPI, since
    in that case cpu device tree nodes are not present and can not be
    used for cpu initialization.
    
    The current cpu_init hook requires a struct device_node pointer
    parameter because it is called while parsing the device tree to
    initialize CPUs, when the cpu_logical_map (that is used to match
    a cpu node reg property to a device tree node) for a given logical
    cpu id is not set up yet. This means that the cpu_init hook cannot
    rely on the of_get_cpu_node function to retrieve the device tree
    node corresponding to the logical cpu id passed in as parameter,
    so the cpu device tree node must be passed in as a parameter to fix
    this catch-22 dependency cycle.
    
    This patch reshuffles the cpu_logical_map initialization code so
    that the cpu_init cpu_ops hook can safely use the of_get_cpu_node
    function to retrieve the cpu device tree node, removing the need for
    the device tree node pointer parameter.
    
    In the process, the patch removes device tree node parameters
    from all cpu_ops hooks, in preparation for SMP DT/ACPI cpus
    initialization consolidation.
    Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
    Acked-by: default avatarHanjun Guo <hanjun.guo@linaro.org>
    Acked-by: default avatarSudeep Holla <sudeep.holla@arm.com>
    Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
    Tested-by: default avatarHanjun Guo <hanjun.guo@linaro.org>
    Tested-by: Mark Rutland <mark.rutland@arm.com> [DT]
    Cc: Will Deacon <will.deacon@arm.com>
    Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    819a8826
cpu_ops.h 2.79 KB