[Skiboot] [PATCH 2/2] hw/phb4: Use read/write_reg in assert_perst

Stewart Smith stewart at linux.ibm.com
Mon Jun 3 12:07:46 AEST 2019

"Oliver O'Halloran" <oohall at gmail.com> writes:
> While the PHB is fenced we can't use the MMIO interface to access PHB
> registers. While processing a complete reset we inject a PHB fence to
> isolate the PHB from the rest of the system because the PHB won't
> respond to MMIOs from the rest of the system while being reset.
> We assert PERST after the fence has been erected which requires us to
> use the XSCOM indirect interface to access the PHB registers rather than
> the MMIO interface. Previously we did that when asserting PERST in the
> CRESET path. However in b8b4c79d4419 ("hw/phb4: Factor out PERST
> control"). This was re-written to use the raw in_be64() accessor. This
> means that CRESET would not be asserted in the reset path. On some
> Mellanox cards this would prevent them from re-loading their firmware
> when the system was fast-reset.
> This patch fixes the problem by replacing the raw {in|out}_be64()
> accessors with the phb4_{read|write}_reg() functions.
> Reported-by: Carol L Soto <clsoto at us.ibm.com>
> Fixes: b8b4c79d4419 ("hw/phb4: Factor out PERST control")
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
> ---
>  hw/phb4.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Merged to master as of 771497098efded8d3a2c0688bab1c1d48d093443

Stewart Smith
OPAL Architect, IBM.

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