Messages in this thread | | | Subject | Re: [PATCH 02/10] irqchip/gic-v3-its: Consolidate LPI_PENDBASE_SZ usage | From | Julien Thierry <> | Date | Mon, 24 Sep 2018 11:55:58 +0100 |
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On 24/09/18 11:54, Suzuki K Poulose wrote: > > > On 24/09/18 11:50, Julien Thierry wrote: >> Hi, >> >> On 24/09/18 11:33, Suzuki K Poulose wrote: >>> Hi Marc, >>> >>> On 21/09/18 20:59, Marc Zyngier wrote: >>>> LPI_PENDING_SZ is always used in conjunction with a max(). Let's >>>> factor this in the definition of the macro, and simplify the rest >>>> of the code. >>>> >>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> >>>> --- >>>> drivers/irqchip/irq-gic-v3-its.c | 12 ++++-------- >>>> 1 file changed, 4 insertions(+), 8 deletions(-) >>>> >>>> diff --git a/drivers/irqchip/irq-gic-v3-its.c >>>> b/drivers/irqchip/irq-gic-v3-its.c >>>> index c2df341ff6fa..ed6aab11e019 100644 >>>> --- a/drivers/irqchip/irq-gic-v3-its.c >>>> +++ b/drivers/irqchip/irq-gic-v3-its.c >>>> @@ -62,7 +62,7 @@ static u32 lpi_id_bits; >>>> */ >>>> #define LPI_NRBITS lpi_id_bits >>>> #define LPI_PROPBASE_SZ ALIGN(BIT(LPI_NRBITS), SZ_64K) >>>> -#define LPI_PENDBASE_SZ ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K) >>>> +#define LPI_PENDBASE_SZ max_t(u32, SZ_64K, >>>> ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K)) >>> >>> minor nit: The ALIGN() already aligns the given value up to the required >>> alignment. So, if the LPI_NRBITS is guaranteed to be non-zero, >>> we could simply drop the max_t(). >>> >> >> Hmmm, Doesn't ALIGN only aligns down? So if "BIT(LPI_NR_BITS) / 8 < >> SZ_64K" (i.e. LPI_NRBITS < 20) The ALIGN(..., SZ_64K) would give 0. > > Isn't it the ALIGN_DOWN(), which aligns it down ? Following the kernel > definitions : > linux/kernel.h -> uapi/linux/kernel.h > ALIGN(x,a) => __ALIGN_KERNEL(x, a) > \ => __ALIGN_KERNEL_MASK(x, (a -1) > \ => (((x + (a - 1)) & ~ (a - 1))
Oh, yes you're right, made the wrong assumption. Your suggestion makes sense. Sorry for the noise.
Thanks,
> > Cheers > Suzuki > > >> >> Thanks, >> >>> Rest looks good to me. >>> >>> Suzuki >>> >>>> #define LPI_PROP_DEFAULT_PRIO 0xa0 >>>> @@ -1924,12 +1924,9 @@ static int its_alloc_collections(struct >>>> its_node *its) >>>> static struct page *its_allocate_pending_table(gfp_t gfp_flags) >>>> { >>>> struct page *pend_page; >>>> - /* >>>> - * The pending pages have to be at least 64kB aligned, >>>> - * hence the 'max(LPI_PENDBASE_SZ, SZ_64K)' below. >>>> - */ >>>> + >>>> pend_page = alloc_pages(gfp_flags | __GFP_ZERO, >>>> - get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K))); >>>> + get_order(LPI_PENDBASE_SZ)); >>>> if (!pend_page) >>>> return NULL; >>>> @@ -1941,8 +1938,7 @@ static struct page >>>> *its_allocate_pending_table(gfp_t gfp_flags) >>>> static void its_free_pending_table(struct page *pt) >>>> { >>>> - free_pages((unsigned long)page_address(pt), >>>> - get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K))); >>>> + free_pages((unsigned long)page_address(pt), >>>> get_order(LPI_PENDBASE_SZ)); >>>> } >>>> static void its_cpu_init_lpis(void) >>>> >>
-- Julien Thierry
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