| Message ID | 1435673643-31676-2-git-send-email-rric@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 30/06/15 15:14, Robert Richter wrote: > From: Robert Richter <rrichter@cavium.com> > > No need to read the typer register in the loop. Values do not change. > > Signed-off-by: Robert Richter <rrichter@cavium.com> > --- > drivers/irqchip/irq-gic-v3-its.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index 1b7e155869f6..c5ce21277920 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -803,6 +803,8 @@ static int its_alloc_tables(struct its_node *its) > int psz = SZ_64K; > u64 shr = GITS_BASER_InnerShareable; > u64 cache = GITS_BASER_WaWb; > + u64 typer = readq_relaxed(its->base + GITS_TYPER); > + u32 ids = GITS_TYPER_DEVBITS(typer); > > for (i = 0; i < GITS_BASER_NR_REGS; i++) { > u64 val = readq_relaxed(its->base + GITS_BASER + i * 8); > @@ -825,9 +827,6 @@ static int its_alloc_tables(struct its_node *its) > * For other tables, only allocate a single page. > */ > if (type == GITS_BASER_TYPE_DEVICE) { > - u64 typer = readq_relaxed(its->base + GITS_TYPER); > - u32 ids = GITS_TYPER_DEVBITS(typer); > - > /* > * 'order' was initialized earlier to the default page > * granule of the the ITS. We can't have an allocation > The TYPER value certainly don't change, but there is also only one device table per ITS instance, so we only read it once. What do we gain here? Thanks, M.
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 1b7e155869f6..c5ce21277920 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -803,6 +803,8 @@ static int its_alloc_tables(struct its_node *its) int psz = SZ_64K; u64 shr = GITS_BASER_InnerShareable; u64 cache = GITS_BASER_WaWb; + u64 typer = readq_relaxed(its->base + GITS_TYPER); + u32 ids = GITS_TYPER_DEVBITS(typer); for (i = 0; i < GITS_BASER_NR_REGS; i++) { u64 val = readq_relaxed(its->base + GITS_BASER + i * 8); @@ -825,9 +827,6 @@ static int its_alloc_tables(struct its_node *its) * For other tables, only allocate a single page. */ if (type == GITS_BASER_TYPE_DEVICE) { - u64 typer = readq_relaxed(its->base + GITS_TYPER); - u32 ids = GITS_TYPER_DEVBITS(typer); - /* * 'order' was initialized earlier to the default page * granule of the the ITS. We can't have an allocation