On 08/06/2015 02:11 PM, Gavin Shan wrote:
The available PE#, represented by a bitmap in the PHB, is allocated
in ascending order.
Available PE# is available exactly because it is not allocated ;)
It conflicts with the fact that M64 segments are
assigned in same order. In order to avoid the conflict, the patch
allocates PE# in descending order.
What kind of conflict?
Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/pci-ioda.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c
b/arch/powerpc/platforms/powernv/pci-ioda.c
index 56b058c..1c950e8 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -161,13 +161,18 @@ static struct pnv_ioda_pe *pnv_ioda_reserve_pe(struct
pnv_phb *phb, int pe_no)
static struct pnv_ioda_pe *pnv_ioda_alloc_pe(struct pnv_phb *phb)
{
unsigned long pe;
+ unsigned long limit = phb->ioda.total_pe_num - 1;
do {
pe = find_next_zero_bit(phb->ioda.pe_alloc,
- phb->ioda.total_pe_num, 0);
- if (pe >= phb->ioda.total_pe_num)
+ phb->ioda.total_pe_num, limit);
+ if (pe < phb->ioda.total_pe_num &&
+ !test_and_set_bit(pe, phb->ioda.pe_alloc))
+ break;
+
+ if (--limit >= phb->ioda.total_pe_num)
return NULL;
- } while(test_and_set_bit(pe, phb->ioda.pe_alloc));
+ } while (1);
Usually, if it is "while(1)", then it is "while(1){}" rather than
"do{}while(1)" :)
return pnv_ioda_init_pe(phb, pe);
}
--
Alexey
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