[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 04/57] ARM: GICv3: simplify GICv3 redistributor stride handling
On 08/03/18 12:40, Andre Przywara wrote: Hi, Hi, On 06/03/18 13:49, Julien Grall wrote:On 05/03/18 17:08, Julien Grall wrote:On 05/03/18 16:03, Andre Przywara wrote:Instead of hard coding the architected redistributor stride into the code, lets use a clear #define to the two values for GICv3 and GICv4 and clarify the algorithm to determine the needed stride value. Signed-off-by: Andre Przywara <andre.przywara@xxxxxxxxxx> --- Changelog RFC ... v1: - no changes xen/arch/arm/gic-v3.c | 18 ++++++++++-------- xen/include/asm-arm/gic_v3_defs.h | 5 +++++ 2 files changed, 15 insertions(+), 8 deletions(-) diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c index b1f8a86409..be1787b39a 100644 --- a/xen/arch/arm/gic-v3.c +++ b/xen/arch/arm/gic-v3.c @@ -690,6 +690,15 @@ static int __init gicv3_populate_rdist(void) do { typer = readq_relaxed(ptr + GICR_TYPER); + /* Set the architectural redist size if not overridden by DT. */ + if ( !gicv3.rdist_stride ) + { + if ( typer & GICR_TYPER_VLPIS )Is there anything in the spec promising you that *all* the redistributors will support vLPIs?Answering to myself, Marc pointed out that nothing was promising all redistributors will support vLPIs. This is confirmed by the section 9.7 "Mixing GICv3 and GICv4" in "GICv3 and GICv4 Software Overview" DAI 0492B. So I would prefer to drop that patch and move GICV*_GICR_SIZE definition in patch #5.So I can surely do that, but then we have a definition of GICV*_GICR_SIZE, but still the hardcoded values in the code. So what about I keep this as a patch, but remove the actual code change and just replace it with using the symbol names instead of the "SZ_64K * 2" plus comment? GICV*_GICR_SIZE feels a bit weird to read. More that reading the spec gives the impression that it is possible to have GICv4 without vLPIS (see the description of GICR_TYPER.vLPIS). So I think I would prefer to keep the hardcoding values here. Cheers, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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