From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757143AbeDXLYh (ORCPT ); Tue, 24 Apr 2018 07:24:37 -0400 Received: from fllnx209.ext.ti.com ([198.47.19.16]:12091 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753057AbeDXLYf (ORCPT ); Tue, 24 Apr 2018 07:24:35 -0400 Subject: Re: [RFC 01/10] PCI: dwc: Add MSI-X callbacks handler To: Gustavo Pimentel , "bhelgaas@google.com" , "lorenzo.pieralisi@arm.com" , "Joao.Pinto@synopsys.com" , "jingoohan1@gmail.com" , "adouglas@cadence.com" , "niklas.cassel@axis.com" , "jesper.nilsson@axis.com" References: <77b7b2687e9618d3f7d1f11c3fc6ecec9a9442ef.1523379766.git.gustavo.pimentel@synopsys.com> <0b7023d9-29c6-0993-07d3-b046d25b67ff@ti.com> <0e8b8ce9-db12-1e11-3eb5-62f3fa686d59@ti.com> <16d237b2-0052-447e-13cb-bc2f15848be4@synopsys.com> CC: "linux-pci@vger.kernel.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" From: Kishon Vijay Abraham I Message-ID: Date: Tue, 24 Apr 2018 16:54:20 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <16d237b2-0052-447e-13cb-bc2f15848be4@synopsys.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tuesday 24 April 2018 03:06 PM, Gustavo Pimentel wrote: > Hi Kishon, > > On 24/04/2018 08:07, Kishon Vijay Abraham I wrote: >> Hi, >> >> On Monday 23 April 2018 03:06 PM, Gustavo Pimentel wrote: >>> Hi Kishon, >>> >>> On 16/04/2018 10:29, Kishon Vijay Abraham I wrote: >>>> Hi Gustavo, >>>> >>>> On Tuesday 10 April 2018 10:44 PM, Gustavo Pimentel wrote: >>>>> Changes the pcie_raise_irq function signature, namely the interrupt_num >>>>> variable type from u8 to u16 to accommodate the MSI-X maximum interrupts >>>>> of 2048. >>>>> >>>>> Implements a PCIe config space capability iterator function to search and >>>>> save the MSI and MSI-X pointers. With this method the code becomes more >>>>> generic and flexible. >>>>> >>>>> Implements MSI-X set/get functions for sysfs interface in order to change >>>>> the EP entries number. >>>>> >>>>> Implements EP MSI-X interface for triggering interruptions. >>>>> >>>>> Signed-off-by: Gustavo Pimentel >>>>> --- >>>>> drivers/pci/dwc/pci-dra7xx.c | 2 +- >>>>> drivers/pci/dwc/pcie-artpec6.c | 2 +- >>>>> drivers/pci/dwc/pcie-designware-ep.c | 145 ++++++++++++++++++++++++++++++++- >>>>> drivers/pci/dwc/pcie-designware-plat.c | 6 +- >>>>> drivers/pci/dwc/pcie-designware.h | 23 +++++- >>>>> 5 files changed, 173 insertions(+), 5 deletions(-) >>>>> >>>>> diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c >>>>> index ed8558d..5265725 100644 >>>>> --- a/drivers/pci/dwc/pci-dra7xx.c >>>>> +++ b/drivers/pci/dwc/pci-dra7xx.c >>>>> @@ -369,7 +369,7 @@ static void dra7xx_pcie_raise_msi_irq(struct dra7xx_pcie *dra7xx, >>>>> } >>>>> >>>>> static int dra7xx_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no, >>>>> - enum pci_epc_irq_type type, u8 interrupt_num) >>>>> + enum pci_epc_irq_type type, u16 interrupt_num) >>>>> { >>>>> struct dw_pcie *pci = to_dw_pcie_from_ep(ep); >>>>> struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci); >>>>> diff --git a/drivers/pci/dwc/pcie-artpec6.c b/drivers/pci/dwc/pcie-artpec6.c >>>>> index e66cede..96dc259 100644 >>>>> --- a/drivers/pci/dwc/pcie-artpec6.c >>>>> +++ b/drivers/pci/dwc/pcie-artpec6.c >>>>> @@ -428,7 +428,7 @@ static void artpec6_pcie_ep_init(struct dw_pcie_ep *ep) >>>>> } >>>>> >>>>> static int artpec6_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no, >>>>> - enum pci_epc_irq_type type, u8 interrupt_num) >>>>> + enum pci_epc_irq_type type, u16 interrupt_num) >>>>> { >>>>> struct dw_pcie *pci = to_dw_pcie_from_ep(ep); >>>>> >>>>> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c >>>>> index 15b22a6..874d4c2 100644 >>>>> --- a/drivers/pci/dwc/pcie-designware-ep.c >>>>> +++ b/drivers/pci/dwc/pcie-designware-ep.c >>>>> @@ -40,6 +40,44 @@ void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar) >>>>> __dw_pcie_ep_reset_bar(pci, bar, 0); >>>>> } >>>>> >>>>> +void dw_pcie_ep_find_cap_addr(struct dw_pcie_ep *ep) >>>>> +{ >>>> >>>> This should be implemented in a generic way similar to pci_find_capability(). >>>> It'll be useful when we try to implement other capabilities as well. >>> >>> Hum, what you suggest? Something implemented on the pci-epf-core? >> >> yeah, Initially thought it could be implemented as a helper function in >> pci-epc-core so that both designware and cadence can use it. > > That would be nice, however I couldn't find out how to access the config space, > through the pci_epf or pci_epc structs. It's just a helper function so it can directly take the base address of the configuration space as argument (in our case, it should be dbi_base). Thanks Kishon > > So, I reworked the functions like this: > > (on pcie-designware-ep.c) > > u8 __dw_pcie_ep_find_next_cap(struct dw_pcie *pci, u8 cap_ptr, > u8 cap) > { > u8 cap_id, next_cap_ptr; > u16 reg; > > reg = dw_pcie_readw_dbi(pci, cap_ptr); > next_cap_ptr = (reg & 0xff00) >> 8; > cap_id = (reg & 0x00ff); > > if (!next_cap_ptr || cap_id > PCI_CAP_ID_MAX) > return 0; > > if (cap_id == cap) > return cap_ptr; > > return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap); > } > > u8 dw_pcie_ep_find_capability(struct dw_pcie *pci, u8 cap) > { > u8 next_cap_ptr; > u16 reg; > > reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST); > next_cap_ptr = (reg & 0x00ff); > > if (!next_cap_ptr) > return 0; > > return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap); > } > > int dw_pcie_ep_init(struct dw_pcie_ep *ep) > { > [...] > ep->msi_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSI); > ep->msix_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSIX); > [...] > } > >> >> But do we really have to find the address like this? since all designware IP's >> will have a particular capability at a fixed address offset, why not follow use >> existing mechanism in dw_pcie_ep_get_msi? > > The capabilities are not fixed to a specific address offset by default they > assume those values, but they can be easily change at design stage. > >> >> Or is it possible for a particular capability to have address offsets for >> different vendors? How is it for cadence? > > Yes, it's possible to have different address offset for different vendors. > >> >> Thanks >> Kishon >> > > Thanks, > Gustavo >