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 X-Spam-Level: X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE643C433DB for ; Thu, 7 Jan 2021 21:18:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9A2323441 for ; Thu, 7 Jan 2021 21:18:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726929AbhAGVSj (ORCPT ); Thu, 7 Jan 2021 16:18:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:33142 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726526AbhAGVSj (ORCPT ); Thu, 7 Jan 2021 16:18:39 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id AB48623441; Thu, 7 Jan 2021 21:17:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610054279; bh=5uoZNAJGLvzV9shzy8WW8XkIqE6H2k9ymeZVJrOtI2U=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=ofjJMoRrimEABG4LRevwmiB41Ps4MRs38jGoi36wqXyh0ztgxlE33oPjaXvjh6rHE wPttEqAFZ6h3AWNUiJa5r5nrUlo62dnEGh0LKEdRdjXqNUQKmv311SKXiQPda9Zag4 GHFQpxrlpVZdPDYB1Cf0nrjsmd0AkSxsZaWguM0rjEsuUVTjNAzsd42SjdCFT4JBqp hfqY8/NR0LbT8qUp2XpGwD7+0QyP8CEwcNseC6wV4Pt6G6ZJcylNgkWKingruevsXr OJAL2+xlCM0KsQwXPKX1b91RGVkW9uimIq56efrdjV3Ntvmqyc6xqlMeOqpIsmKwja Rtol1IwF0trQg== Date: Thu, 7 Jan 2021 15:17:57 -0600 From: Bjorn Helgaas To: Nirmoy Das Cc: bhelgaas@google.com, ckoenig.leichtzumerken@gmail.com, linux-pci@vger.kernel.org, dri-devel@lists.freedesktop.org, devspam@moreofthesa.me.uk, Christian =?iso-8859-1?Q?K=F6nig?= Subject: Re: [PATCH 2/4] PCI: Add pci_rebar_bytes_to_size() Message-ID: <20210107211757.GA1391831@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210107175017.15893-3-nirmoy.das@amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, Jan 07, 2021 at 06:50:15PM +0100, Nirmoy Das wrote: > Users of pci_resize_resource() need a way to calculate bar size > from desired bytes. Add a helper function and export it so that > modular drivers can use it. s/bar/BAR/ > Signed-off-by: Darren Salt > Signed-off-by: Christian König > Signed-off-by: Nirmoy Das Acked-by: Bjorn Helgaas > --- > drivers/pci/pci.c | 2 +- > include/linux/pci.h | 6 ++++++ > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index ef80ed451415..16216186b51c 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -1648,7 +1648,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) > pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); > bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; > res = pdev->resource + bar_idx; > - size = ilog2(resource_size(res)) - 20; > + size = pci_rebar_bytes_to_size(resource_size(res)); > ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; > ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; > pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 9999040cfad9..77fed01523e0 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1226,6 +1226,12 @@ void pci_update_resource(struct pci_dev *dev, int resno); > int __must_check pci_assign_resource(struct pci_dev *dev, int i); > int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align); > void pci_release_resource(struct pci_dev *dev, int resno); > +static inline int pci_rebar_bytes_to_size(u64 bytes) > +{ > + bytes = roundup_pow_of_two(bytes); > + return max(ilog2(bytes), 20) - 20; This isn't returning a "size", is it? It looks like it's returning the log2 of the number of MB the BAR will be, i.e., the encoding used by the Resizable BAR Control register "BAR Size" field. Needs a brief comment to that effect and/or a different function name. > +} > + > u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar); > int __must_check pci_resize_resource(struct pci_dev *dev, int i, int size); > int pci_select_bars(struct pci_dev *dev, unsigned long flags); > -- > 2.29.2 >