• Gautham R. Shenoy's avatar
    powerpc: powernv: Framework to show the correct clock in /proc/cpuinfo · 2299d03a
    Gautham R. Shenoy authored
    Currently, the code in setup-common.c for powerpc assumes that all
    clock rates are same in a smp system. This value is cached in the
    variable named ppc_proc_freq and is the value that is reported in
    /proc/cpuinfo.
    
    However on the PowerNV platform, the clock rate is same only across
    the threads of the same core. Hence the value that is reported in
    /proc/cpuinfo is incorrect on PowerNV platforms. We need a better way
    to query and report the correct value of the processor clock in
    /proc/cpuinfo.
    
    The patch achieves this by creating a machdep_call named
    get_proc_freq() which is expected to returns the frequency in Hz. The
    code in show_cpuinfo() can invoke this method to display the correct
    clock rate on platforms that have implemented this method. On the
    other powerpc platforms it can use the value cached in ppc_proc_freq.
    Signed-off-by: default avatarGautham R. Shenoy <ego@linux.vnet.ibm.com>
    Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
    2299d03a
setup-common.c 18.1 KB