From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8599CCA485 for ; Thu, 21 Jul 2022 08:39:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229779AbiGUIjV (ORCPT ); Thu, 21 Jul 2022 04:39:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229669AbiGUIi5 (ORCPT ); Thu, 21 Jul 2022 04:38:57 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9B8D7E819 for ; Thu, 21 Jul 2022 01:38:53 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id c139so1150032pfc.2 for ; Thu, 21 Jul 2022 01:38:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=xsmhjzXcB2PDTloWeEwW/cdLOTAut/918qYRhypWu3M=; b=FchWfWzxhqkAu8Ppo3Y6LOnpcC1AU316HJgUvx3kgt5KZ+ZAJdRdVWmcSi3BIis/jg RijGdFgc7goatlaaG+K6GwtL1u/UJ7aOEPwnvgkMB6Y8m6ehVibV8sVivYbiPsteGfqL xIf8Aru0Zp9mtrGC5LtBqtW4mKS1f10VulFszeccdsg8bdKb9tlSputJD9MDZ03o7kSW fNSPfTPlA5daR47sW63BISsH85ZYxVVUvhDc7aXIuKYBwZYuaohatY+8P/Xi8Kx7WCk9 cJ9irkAf/+ISFTaZGcUOM8V/5Mj6iK2njOCg5aj0fCSJhAL0GtzPRhRCYxTGFuZvgeIK yVng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=xsmhjzXcB2PDTloWeEwW/cdLOTAut/918qYRhypWu3M=; b=oZGlM/9hLylFzlxC4FBZ9eABdeHbMBpDUvpSqAzcSo1Cz43I/J0Se8ztGLAQBkXyQd xI3TMaS/GRfKi/XhmPVdRBP/hlWUn0OBO+/Tu0QkkHNnNfrDCY0B0Q3rcGYIu7VMQ9zJ rxMVX4Qg0Z6G77FVR5znHQ+AEpKz0uwJaLoEy7+t7CJq0i+KJoQZfrlCVin1OKWnsFgC Ydey692HUe+fcCW8xIPe3zfpZm+IO5jWDTn37g9NhOxbqMiSf8G6MkTTScAHMqzBpXY8 mvT8UEnU0XEwstIGu6rzCjhKa9ZrceY0r0UjFA58n8mDiYSeGS+XVRB6eabTiCS+X2Cs JrgA== X-Gm-Message-State: AJIora+bwhf5jDvXSvdWvgEunAvW2o7FD7W6YO01bWvSKrqfiqB2IewW E4b75JOiYfeba+DFYJBq0YHb X-Google-Smtp-Source: AGRyM1ufUy6be75/2vnSbnWaCywU9r+bSMKoIO+nKlx6h3J4bBZOuxCzVdnU7JWtCWopu8ZSeuKV9Q== X-Received: by 2002:a63:686:0:b0:414:1a88:3b98 with SMTP id 128-20020a630686000000b004141a883b98mr37262278pgg.106.1658392732678; Thu, 21 Jul 2022 01:38:52 -0700 (PDT) Received: from thinkpad ([117.217.186.184]) by smtp.gmail.com with ESMTPSA id l13-20020a170903244d00b0015eab1b097dsm1103816pls.22.2022.07.21.01.38.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Jul 2022 01:38:52 -0700 (PDT) Date: Thu, 21 Jul 2022 14:08:45 +0530 From: Manivannan Sadhasivam To: Bjorn Helgaas Cc: kishon@ti.com, bhelgaas@google.com, robh@kernel.org, lorenzo.pieralisi@arm.com, kw@linux.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Kunihiko Hayashi , Om Prakash Singh , Vidya Sagar Subject: Re: [PATCH] PCI: designware-ep: Move DBI access to init_complete if notifier is used Message-ID: <20220721083845.GA36189@thinkpad> References: <20220719034348.GA4390@thinkpad> <20220719223814.GA1586913@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220719223814.GA1586913@bhelgaas> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 19, 2022 at 05:38:14PM -0500, Bjorn Helgaas wrote: > On Tue, Jul 19, 2022 at 09:13:58AM +0530, Manivannan Sadhasivam wrote: > > On Fri, Jul 15, 2022 at 04:39:58PM -0500, Bjorn Helgaas wrote: > > > On Wed, Mar 30, 2022 at 11:35:15AM +0530, Manivannan Sadhasivam wrote: > > > > For controllers supporting the CORE_INIT notifier, the resources are > > > > supposed to be enabled in the init_complete function. Currently, > > > > these controllers are enabling the resources during probe time due to > > > > the DBI access happens in dw_pcie_ep_init(). > > > > > > > > This creates the dependency with the host PCIe controller since the > > > > resource enablement like PHY depends on host PCIe to be up. For the > > > > standalone endpoint usecase, this would never work. So let's move all DBI > > > > access to init_complete function if CORE_INIT notifier is used. For the > > > > controllers those doesn't support this notifier, this change is a NO-OP. > > > > > > > > Cc: Kunihiko Hayashi > > > > Cc: Om Prakash Singh > > > > Cc: Vidya Sagar > > > > Signed-off-by: Manivannan Sadhasivam > > > > --- > > > > .../pci/controller/dwc/pcie-designware-ep.c | 138 ++++++++++++------ > > > > drivers/pci/controller/dwc/pcie-designware.h | 1 + > > > > 2 files changed, 94 insertions(+), 45 deletions(-) > > > > > > Sorry this got missed. Seems like there are two patches to solve the > > > same problem: > > > > > > 1) This patch, and > > > 2) Vidya's patch (https://lore.kernel.org/linux-pci/20220622040133.31058-1-vidyas@nvidia.com/) > > > > > > I don't know much about dwc or this issue, but if these patches are > > > functionally equivalent, I think Vidya's is a little more attractive > > > because: > > > > > > - It's smaller (49 insertions(+), 39 deletions(-)). > > > > > > - "core_init_notifier" looks like sort of a corner-case feature and > > > Vidya's patch doesn't depend on it so it seems more maintainable. > > > > > > - It's more straightforward to read -- it basically just moves > > > things from dw_pcie_ep_init() to dw_pcie_ep_init_complete(), which > > > is exactly the sort of thing I expect if we're doing something out > > > of order. > > > > I agree that Vidya's patch is simple but as per the feedback from > > Kishon on my previous patch, I had to add some extra logic to make > > sure the move of DBI access doesn't affect the non > > core_init_notifier platforms. > > > > So with my patch, the logic added is essentailly a NO-OP on those. > > Can you include the lore URL for Kishon's feedback? I can't find it. > https://patchwork.kernel.org/project/linux-pci/patch/1630473361-27198-3-git-send-email-hayashi.kunihiko@socionext.com/#24633629 > If we think moving the DBI access is safe on non-core_init_notifier > platforms, I'd like to do it everywhere so they're all the same. I > don't want different behavior just to avoid the risk of theoretical > problems that we think should not happen. > One more issue Kishon pointed out was that, in the patch the endpoint controller is configured after pci_epc_create(). So he raised a concern that if ecp_ops is invoked before the controller gets configured fully, it could result in aborts. While the concern may be true for non-core_init_notifier platforms (I'm not sure though) but I'm certain not for the core_init_notifier ones as the EFP drivers only access EPC ops after dw_pcie_ep_init_complete(). Thanks, Mani > > Thanks, > > Mani > > > > > > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c > > > > index 0eda8236c125..fb2bf4bf5ba0 100644 > > > > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c > > > > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c > > > > @@ -636,6 +636,63 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap) > > > > return 0; > > > > } > > > > > > > > +static int dw_pcie_iatu_config(struct dw_pcie_ep *ep) > > > > +{ > > > > + struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > > > > + struct device *dev = pci->dev; > > > > + void *addr; > > > > + > > > > + dw_pcie_iatu_detect(pci); > > > > + > > > > + ep->ib_window_map = devm_kcalloc(dev, > > > > + BITS_TO_LONGS(pci->num_ib_windows), > > > > + sizeof(long), > > > > + GFP_KERNEL); > > > > + if (!ep->ib_window_map) > > > > + return -ENOMEM; > > > > + > > > > + ep->ob_window_map = devm_kcalloc(dev, > > > > + BITS_TO_LONGS(pci->num_ob_windows), > > > > + sizeof(long), > > > > + GFP_KERNEL); > > > > + if (!ep->ob_window_map) > > > > + return -ENOMEM; > > > > + > > > > + addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t), > > > > + GFP_KERNEL); > > > > + if (!addr) > > > > + return -ENOMEM; > > > > + > > > > + ep->outbound_addr = addr; > > > > + > > > > + return 0; > > > > +} > > > > + > > > > +static int dw_pcie_ep_func_init(struct dw_pcie_ep *ep) > > > > +{ > > > > + struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > > > > + struct dw_pcie_ep_func *ep_func; > > > > + struct pci_epc *epc = ep->epc; > > > > + struct device *dev = pci->dev; > > > > + u8 func_no; > > > > + > > > > + for (func_no = 0; func_no < epc->max_functions; func_no++) { > > > > + ep_func = devm_kzalloc(dev, sizeof(*ep_func), GFP_KERNEL); > > > > + if (!ep_func) > > > > + return -ENOMEM; > > > > + > > > > + ep_func->func_no = func_no; > > > > + ep_func->msi_cap = dw_pcie_ep_find_capability(ep, func_no, > > > > + PCI_CAP_ID_MSI); > > > > + ep_func->msix_cap = dw_pcie_ep_find_capability(ep, func_no, > > > > + PCI_CAP_ID_MSIX); > > > > + > > > > + list_add_tail(&ep_func->list, &ep->func_list); > > > > + } > > > > + > > > > + return 0; > > > > +} > > > > + > > > > int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep) > > > > { > > > > struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > > > > @@ -643,7 +700,22 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep) > > > > unsigned int nbars; > > > > u8 hdr_type; > > > > u32 reg; > > > > - int i; > > > > + int ret, i; > > > > + > > > > + if (ep->core_init_notifier) { > > > > + ret = dw_pcie_iatu_config(ep); > > > > + if (ret) > > > > + return ret; > > > > + } > > > > + > > > > + if (ep->core_init_notifier) { > > > > + ret = dw_pcie_ep_func_init(ep); > > > > + if (ret) > > > > + return ret; > > > > + > > > > + if (ep->ops->ep_init) > > > > + ep->ops->ep_init(ep); > > > > + } > > > > > > > > hdr_type = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE) & > > > > PCI_HEADER_TYPE_MASK; > > > > @@ -677,8 +749,6 @@ EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete); > > > > int dw_pcie_ep_init(struct dw_pcie_ep *ep) > > > > { > > > > int ret; > > > > - void *addr; > > > > - u8 func_no; > > > > struct resource *res; > > > > struct pci_epc *epc; > > > > struct dw_pcie *pci = to_dw_pcie_from_ep(ep); > > > > @@ -686,7 +756,12 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep) > > > > struct platform_device *pdev = to_platform_device(dev); > > > > struct device_node *np = dev->of_node; > > > > const struct pci_epc_features *epc_features; > > > > - struct dw_pcie_ep_func *ep_func; > > > > + > > > > + if (ep->ops->get_features) { > > > > + epc_features = ep->ops->get_features(ep); > > > > + if (epc_features->core_init_notifier) > > > > + ep->core_init_notifier = true; > > > > + } > > > > > > > > INIT_LIST_HEAD(&ep->func_list); > > > > > > > > @@ -708,7 +783,11 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep) > > > > } > > > > } > > > > > > > > - dw_pcie_iatu_detect(pci); > > > > + if (!ep->core_init_notifier) { > > > > + ret = dw_pcie_iatu_config(ep); > > > > + if (ret) > > > > + return ret; > > > > + } > > > > > > > > res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space"); > > > > if (!res) > > > > @@ -717,26 +796,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep) > > > > ep->phys_base = res->start; > > > > ep->addr_size = resource_size(res); > > > > > > > > - ep->ib_window_map = devm_kcalloc(dev, > > > > - BITS_TO_LONGS(pci->num_ib_windows), > > > > - sizeof(long), > > > > - GFP_KERNEL); > > > > - if (!ep->ib_window_map) > > > > - return -ENOMEM; > > > > - > > > > - ep->ob_window_map = devm_kcalloc(dev, > > > > - BITS_TO_LONGS(pci->num_ob_windows), > > > > - sizeof(long), > > > > - GFP_KERNEL); > > > > - if (!ep->ob_window_map) > > > > - return -ENOMEM; > > > > - > > > > - addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t), > > > > - GFP_KERNEL); > > > > - if (!addr) > > > > - return -ENOMEM; > > > > - ep->outbound_addr = addr; > > > > - > > > > if (pci->link_gen < 1) > > > > pci->link_gen = of_pci_get_max_link_speed(np); > > > > > > > > @@ -753,23 +812,15 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep) > > > > if (ret < 0) > > > > epc->max_functions = 1; > > > > > > > > - for (func_no = 0; func_no < epc->max_functions; func_no++) { > > > > - ep_func = devm_kzalloc(dev, sizeof(*ep_func), GFP_KERNEL); > > > > - if (!ep_func) > > > > - return -ENOMEM; > > > > - > > > > - ep_func->func_no = func_no; > > > > - ep_func->msi_cap = dw_pcie_ep_find_capability(ep, func_no, > > > > - PCI_CAP_ID_MSI); > > > > - ep_func->msix_cap = dw_pcie_ep_find_capability(ep, func_no, > > > > - PCI_CAP_ID_MSIX); > > > > + if (!ep->core_init_notifier) { > > > > + ret = dw_pcie_ep_func_init(ep); > > > > + if (ret) > > > > + return ret; > > > > > > > > - list_add_tail(&ep_func->list, &ep->func_list); > > > > + if (ep->ops->ep_init) > > > > + ep->ops->ep_init(ep); > > > > } > > > > > > > > - if (ep->ops->ep_init) > > > > - ep->ops->ep_init(ep); > > > > - > > > > ret = pci_epc_mem_init(epc, ep->phys_base, ep->addr_size, > > > > ep->page_size); > > > > if (ret < 0) { > > > > @@ -784,12 +835,9 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep) > > > > return -ENOMEM; > > > > } > > > > > > > > - if (ep->ops->get_features) { > > > > - epc_features = ep->ops->get_features(ep); > > > > - if (epc_features->core_init_notifier) > > > > - return 0; > > > > - } > > > > + if (!ep->core_init_notifier) > > > > + return dw_pcie_ep_init_complete(ep); > > > > > > > > - return dw_pcie_ep_init_complete(ep); > > > > + return 0; > > > > } > > > > EXPORT_SYMBOL_GPL(dw_pcie_ep_init); > > > > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h > > > > index 7d6e9b7576be..aadb14159df7 100644 > > > > --- a/drivers/pci/controller/dwc/pcie-designware.h > > > > +++ b/drivers/pci/controller/dwc/pcie-designware.h > > > > @@ -242,6 +242,7 @@ struct dw_pcie_ep { > > > > void __iomem *msi_mem; > > > > phys_addr_t msi_mem_phys; > > > > struct pci_epf_bar *epf_bar[PCI_STD_NUM_BARS]; > > > > + bool core_init_notifier; > > > > }; > > > > > > > > struct dw_pcie_ops { > > > > -- > > > > 2.25.1 > > > > > > > > -- > > மணிவண்ணன் சதாசிவம் -- மணிவண்ணன் சதாசிவம்