From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gavin Shan Subject: Re: [PATCH v6 18/42] powerpc/powernv: Allocate PE# in deasending order Date: Tue, 11 Aug 2015 10:43:39 +1000 Message-ID: <20150811004339.GC18981@gwshan> References: <1438834307-26960-1-git-send-email-gwshan@linux.vnet.ibm.com> <1438834307-26960-19-git-send-email-gwshan@linux.vnet.ibm.com> <55C8B786.1050702@ozlabs.ru> Reply-To: Gavin Shan Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <55C8B786.1050702@ozlabs.ru> Sender: linux-pci-owner@vger.kernel.org To: Alexey Kardashevskiy Cc: Gavin Shan , linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, benh@kernel.crashing.org, mpe@ellerman.id.au, bhelgaas@google.com, grant.likely@linaro.org, robherring2@gmail.com, panto@antoniou-consulting.com List-Id: devicetree@vger.kernel.org On Tue, Aug 11, 2015 at 12:39:02AM +1000, Alexey Kardashevskiy wrote: >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 ;) > Yeah, will correct it. >>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? > On PHB3, the M64 segment is assigned to one PE whose PE number is determined. M64 segment are allocated in ascending order. It's why I would like to allocate PE# in deascending order. >> >>Signed-off-by: Gavin Shan >>--- >> 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)" :) Agree, will change it. > > >> >> return pnv_ioda_init_pe(phb, pe); >> } >> Thanks, Gavin