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 41F98C433EF for ; Tue, 19 Jul 2022 22:38:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234242AbiGSWiV (ORCPT ); Tue, 19 Jul 2022 18:38:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231350AbiGSWiU (ORCPT ); Tue, 19 Jul 2022 18:38:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E51F51A35; Tue, 19 Jul 2022 15:38:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 886D961B5C; Tue, 19 Jul 2022 22:38:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99823C341C6; Tue, 19 Jul 2022 22:38:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1658270295; bh=obJWTUw1NA9T0L+goOsAOuGwnxuMngwTRG7icA6zQrc=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=Ml9Qpw4VQoX87l5mNYTggCGEDulmZxeAIK7yh+05xACyn6kgm/aaLLcmVqFbbnvLt FUOF5hWDgm5q1xGTb2+TDzlnFFleJbCIiWH6YSButttJJ7YJ0Sr91M1UCOS33jq0cf SusMSohFcooS/HK2/MSoPZAGLNFJ0IARe3JV6y35kCNparzuXcSUGbh/chHIGXZOaq swowGfgv0P2Zl+BI5gWfrkDfdO1shasw8woFJVDyr04A9ZsPIJ41/yq433uTqzPZwB vjsxsfop3arof5NZQfVZYPbFe+fxyzx2sRUkHizmxBPy+gtadNQu8sPaIpOEyE/pud bJXLAiqtxVEog== Date: Tue, 19 Jul 2022 17:38:14 -0500 From: Bjorn Helgaas To: Manivannan Sadhasivam 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: <20220719223814.GA1586913@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220719034348.GA4390@thinkpad> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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. 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. > 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