From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f170.google.com ([209.85.192.170]:33663 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932641AbbHJKCa (ORCPT ); Mon, 10 Aug 2015 06:02:30 -0400 Received: by pdrh1 with SMTP id h1so51893188pdr.0 for ; Mon, 10 Aug 2015 03:02:29 -0700 (PDT) Subject: Re: [PATCH v6 15/42] powerpc/powernv: PE oriented during configuration To: Gavin Shan , linuxppc-dev@lists.ozlabs.org References: <1438834307-26960-1-git-send-email-gwshan@linux.vnet.ibm.com> <1438834307-26960-16-git-send-email-gwshan@linux.vnet.ibm.com> Cc: 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 From: Alexey Kardashevskiy Message-ID: <55C876AC.5060205@ozlabs.ru> Date: Mon, 10 Aug 2015 20:02:20 +1000 MIME-Version: 1.0 In-Reply-To: <1438834307-26960-16-git-send-email-gwshan@linux.vnet.ibm.com> Content-Type: text/plain; charset=koi8-r; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: On 08/06/2015 02:11 PM, Gavin Shan wrote: > Several functions used to configure PE take pe_number to indentify > PE instance. As the pe_number is included in PE instance after it > is reserved or allocated. It's convienent for those functions to > return PE instance which includes the required pe_number. This is a description for the half of the patch but this patch also adds a return value to functions which did not have it before and I am not sure you need all of them to return something. It would be cleaner if you added "return" when/where you really need it, not just because it seems that it may be convenient later. > > Signed-off-by: Gavin Shan > --- > arch/powerpc/platforms/powernv/pci-ioda.c | 51 ++++++++++++++++--------------- > arch/powerpc/platforms/powernv/pci.h | 2 +- > 2 files changed, 27 insertions(+), 26 deletions(-) > > diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c > index 3094c61..9f53682 100644 > --- a/arch/powerpc/platforms/powernv/pci-ioda.c > +++ b/arch/powerpc/platforms/powernv/pci-ioda.c > @@ -132,12 +132,12 @@ static inline bool pnv_pci_is_mem_pref_64(unsigned long flags) > (IORESOURCE_MEM_64 | IORESOURCE_PREFETCH)); > } > > -static void pnv_ioda_reserve_pe(struct pnv_phb *phb, int pe_no) > +static struct pnv_ioda_pe *pnv_ioda_reserve_pe(struct pnv_phb *phb, int pe_no) > { > if (!(pe_no >= 0 && pe_no < phb->ioda.total_pe)) { > pr_warn("%s: Invalid PE %d on PHB#%x\n", > __func__, pe_no, phb->hose->global_number); > - return; > + return NULL; > } > > if (test_and_set_bit(pe_no, phb->ioda.pe_alloc)) > @@ -146,9 +146,11 @@ static void pnv_ioda_reserve_pe(struct pnv_phb *phb, int pe_no) > > phb->ioda.pe_array[pe_no].phb = phb; > phb->ioda.pe_array[pe_no].pe_number = pe_no; > + > + return &phb->ioda.pe_array[pe_no]; > } > > -static int pnv_ioda_alloc_pe(struct pnv_phb *phb) > +static struct pnv_ioda_pe *pnv_ioda_alloc_pe(struct pnv_phb *phb) > { > unsigned long pe; > > @@ -156,12 +158,12 @@ static int pnv_ioda_alloc_pe(struct pnv_phb *phb) > pe = find_next_zero_bit(phb->ioda.pe_alloc, > phb->ioda.total_pe, 0); > if (pe >= phb->ioda.total_pe) > - return IODA_INVALID_PE; > + return NULL; > } while(test_and_set_bit(pe, phb->ioda.pe_alloc)); > > phb->ioda.pe_array[pe].phb = phb; > phb->ioda.pe_array[pe].pe_number = pe; > - return pe; > + return &phb->ioda.pe_array[pe]; > } > > static void pnv_ioda_free_pe(struct pnv_phb *phb, int pe) > @@ -334,7 +336,7 @@ static void pnv_ioda_reserve_m64_pe(struct pci_bus *bus, > } > } > > -static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all) > +static struct pnv_ioda_pe *pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all) > { > struct pci_controller *hose = pci_bus_to_host(bus); > struct pnv_phb *phb = hose->private_data; > @@ -344,7 +346,7 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all) > > /* Root bus shouldn't use M64 */ > if (pci_is_root_bus(bus)) > - return IODA_INVALID_PE; > + return NULL; > > /* Allocate bitmap */ > size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long)); > @@ -352,7 +354,7 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all) > if (!pe_alloc) { > pr_warn("%s: Out of memory !\n", > __func__); > - return IODA_INVALID_PE; > + return NULL; > } > > /* Figure out reserved PE numbers by the PE */ > @@ -365,7 +367,7 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all) > */ > if (bitmap_empty(pe_alloc, phb->ioda.total_pe)) { > kfree(pe_alloc); > - return IODA_INVALID_PE; > + return NULL; > } > > /* > @@ -416,7 +418,7 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all) > } > > kfree(pe_alloc); > - return master_pe->pe_number; > + return master_pe; > } > > static void __init pnv_ioda_parse_m64_window(struct pnv_phb *phb) > @@ -1069,28 +1071,26 @@ static void pnv_ioda_setup_same_PE(struct pci_bus *bus, struct pnv_ioda_pe *pe) > * subordinate PCI devices and buses. The second type of PE is normally > * orgiriated by PCIe-to-PCI bridge or PLX switch downstream ports. > */ > -static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all) > +static struct pnv_ioda_pe *pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all) > { > struct pci_controller *hose = pci_bus_to_host(bus); > struct pnv_phb *phb = hose->private_data; > - struct pnv_ioda_pe *pe; > - int pe_num = IODA_INVALID_PE; > + struct pnv_ioda_pe *pe = NULL; > > /* Check if PE is determined by M64 */ > if (phb->pick_m64_pe) > - pe_num = phb->pick_m64_pe(bus, all); > + pe = phb->pick_m64_pe(bus, all); > > /* The PE number isn't pinned by M64 */ > - if (pe_num == IODA_INVALID_PE) > - pe_num = pnv_ioda_alloc_pe(phb); > + if (!pe) > + pe = pnv_ioda_alloc_pe(phb); > > - if (pe_num == IODA_INVALID_PE) { > - pr_warning("%s: Not enough PE# available for PCI bus %04x:%02x\n", > + if (!pe) { > + pr_warning("%s: No enough PE# for PCI bus %04x:%02x\n", > __func__, pci_domain_nr(bus), bus->number); > - return; > + return NULL; > } > > - pe = &phb->ioda.pe_array[pe_num]; > pe->flags |= (all ? PNV_IODA_PE_BUS_ALL : PNV_IODA_PE_BUS); > pe->pbus = bus; > pe->pdev = NULL; > @@ -1101,17 +1101,16 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all) > > if (all) > pe_info(pe, "Secondary bus %d..%d associated with PE#%d\n", > - bus->busn_res.start, bus->busn_res.end, pe_num); > + bus->busn_res.start, bus->busn_res.end, pe->pe_number); > else > pe_info(pe, "Secondary bus %d associated with PE#%d\n", > - bus->busn_res.start, pe_num); > + bus->busn_res.start, pe->pe_number); > > if (pnv_ioda_configure_pe(phb, pe)) { > /* XXX What do we do here ? */ > - if (pe_num) > - pnv_ioda_free_pe(phb, pe_num); > + pnv_ioda_free_pe(phb, pe->pe_number); > pe->pbus = NULL; > - return; > + return NULL; > } > > /* Associate it with all child devices */ > @@ -1122,6 +1121,8 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all) > > /* Link the PE */ > pnv_ioda_link_pe_by_weight(phb, pe); > + > + return pe; > } > > static void pnv_ioda_setup_PEs(struct pci_bus *bus) > diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h > index 6f8568e..c0bc57f 100644 > --- a/arch/powerpc/platforms/powernv/pci.h > +++ b/arch/powerpc/platforms/powernv/pci.h > @@ -121,7 +121,7 @@ struct pnv_phb { > int (*init_m64)(struct pnv_phb *phb); > void (*reserve_m64_pe)(struct pci_bus *bus, > unsigned long *pe_bitmap, bool all); > - int (*pick_m64_pe)(struct pci_bus *bus, bool all); > + struct pnv_ioda_pe* (*pick_m64_pe)(struct pci_bus *bus, bool all); > int (*get_pe_state)(struct pnv_phb *phb, int pe_no); > void (*freeze_pe)(struct pnv_phb *phb, int pe_no); > int (*unfreeze_pe)(struct pnv_phb *phb, int pe_no, int opt); > -- Alexey