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 6259CC433F5 for ; Fri, 4 Feb 2022 15:12:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359599AbiBDPMc (ORCPT ); Fri, 4 Feb 2022 10:12:32 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:60822 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359596AbiBDPMa (ORCPT ); Fri, 4 Feb 2022 10:12:30 -0500 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 9C05E61132 for ; Fri, 4 Feb 2022 15:12:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 78BD3C004E1; Fri, 4 Feb 2022 15:12:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643987550; bh=rvvwcqpr5WCBgFzc3z360qu5rbDLAccigRdzUjm0a2c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=C/GMxvSjpshvlGSovANszs9R8r6NcZ31Qzpl49eZPSMd8HDrBD3zNK9+IyTbDauGi Xsn6Bw67kDeU7cVqVKyWYcHe8wSz7qR/ss0eP6IElcJRt48PuIX6WzJEOi7ooy8CDr hyj7mqpgfG4DmulYva5E9iADaeN1kUf9X0MDHEGg= Date: Fri, 4 Feb 2022 16:12:27 +0100 From: Greg KH To: Jorgen Hansen Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, pv-drivers@vmware.com, Vishnu Dasa Subject: Re: [PATCH v2 2/8] VMCI: dma dg: add MMIO access to registers Message-ID: References: <20220203131237.3380-1-jhansen@vmware.com> <20220203131237.3380-3-jhansen@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220203131237.3380-3-jhansen@vmware.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 03, 2022 at 05:12:31AM -0800, Jorgen Hansen wrote: > Detect the support for MMIO access through examination of the length > of the region requested in BAR1. If it is 256KB, the VMCI device > supports MMIO access to registers. > > If MMIO access is supported, map the area of the region used for > MMIO access (64KB size at offset 128KB). > > Add wrapper functions for accessing 32 bit register accesses through > either MMIO or IO ports based on device configuration. > > Sending and receiving datagrams through iowrite8_rep/ioread8_rep is > left unchanged for now, and will be addressed in a later change. > > Reviewed-by: Vishnu Dasa > Signed-off-by: Jorgen Hansen > --- > drivers/misc/vmw_vmci/vmci_guest.c | 68 ++++++++++++++++++++++-------- > include/linux/vmw_vmci_defs.h | 12 ++++++ > 2 files changed, 62 insertions(+), 18 deletions(-) > > diff --git a/drivers/misc/vmw_vmci/vmci_guest.c b/drivers/misc/vmw_vmci/vmci_guest.c > index 1018dc77269d..38ee7ed32ab9 100644 > --- a/drivers/misc/vmw_vmci/vmci_guest.c > +++ b/drivers/misc/vmw_vmci/vmci_guest.c > @@ -45,6 +45,7 @@ static u32 vm_context_id = VMCI_INVALID_ID; > struct vmci_guest_device { > struct device *dev; /* PCI device we are attached to */ > void __iomem *iobase; > + void __iomem *mmio_base; > > bool exclusive_vectors; > > @@ -89,6 +90,21 @@ u32 vmci_get_vm_context_id(void) > return vm_context_id; > } > > +static unsigned int vmci_read_reg(struct vmci_guest_device *dev, u32 reg) > +{ > + if (dev->mmio_base != NULL) > + return readl(dev->mmio_base + reg); > + return ioread32(dev->iobase + reg); > +} > + > +static void vmci_write_reg(struct vmci_guest_device *dev, u32 val, u32 reg) > +{ > + if (dev->mmio_base != NULL) > + writel(val, dev->mmio_base + reg); > + else > + iowrite32(val, dev->iobase + reg); > +} > + > /* > * VM to hypervisor call mechanism. We use the standard VMware naming > * convention since shared code is calling this function as well. > @@ -116,7 +132,7 @@ int vmci_send_datagram(struct vmci_datagram *dg) > if (vmci_dev_g) { > iowrite8_rep(vmci_dev_g->iobase + VMCI_DATA_OUT_ADDR, > dg, VMCI_DG_SIZE(dg)); > - result = ioread32(vmci_dev_g->iobase + VMCI_RESULT_LOW_ADDR); > + result = vmci_read_reg(vmci_dev_g, VMCI_RESULT_LOW_ADDR); > } else { > result = VMCI_ERROR_UNAVAILABLE; > } > @@ -384,7 +400,7 @@ static irqreturn_t vmci_interrupt(int irq, void *_dev) > unsigned int icr; > > /* Acknowledge interrupt and determine what needs doing. */ > - icr = ioread32(dev->iobase + VMCI_ICR_ADDR); > + icr = vmci_read_reg(dev, VMCI_ICR_ADDR); > if (icr == 0 || icr == ~0) > return IRQ_NONE; > > @@ -429,7 +445,8 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, > const struct pci_device_id *id) > { > struct vmci_guest_device *vmci_dev; > - void __iomem *iobase; > + void __iomem *iobase = NULL; > + void __iomem *mmio_base = NULL; > unsigned int capabilities; > unsigned int caps_in_use; > unsigned long cmd; > @@ -445,16 +462,32 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, > return error; > } > > - error = pcim_iomap_regions(pdev, 1 << 0, KBUILD_MODNAME); > - if (error) { > - dev_err(&pdev->dev, "Failed to reserve/map IO regions\n"); > - return error; > + /* > + * The VMCI device with mmio access to registers requests 256KB > + * for BAR1. If present, driver will use new VMCI device > + * functionality for register access and datagram send/recv. > + */ > + > + if (pci_resource_len(pdev, 1) == VMCI_WITH_MMIO_ACCESS_BAR_SIZE) { > + dev_info(&pdev->dev, "MMIO register access is available\n"); > + mmio_base = pci_iomap_range(pdev, 1, VMCI_MMIO_ACCESS_OFFSET, > + VMCI_MMIO_ACCESS_SIZE); > + /* If the map fails, we fall back to IOIO access. */ > + if (!mmio_base) > + dev_warn(&pdev->dev, "Failed to map MMIO register access\n"); > } > > - iobase = pcim_iomap_table(pdev)[0]; > + if (!mmio_base) { > + error = pcim_iomap_regions(pdev, BIT(0), KBUILD_MODNAME); > + if (error) { > + dev_err(&pdev->dev, "Failed to reserve/map IO regions\n"); > + return error; > + } > + iobase = pcim_iomap_table(pdev)[0]; > + } > > - dev_info(&pdev->dev, "Found VMCI PCI device at %#lx, irq %u\n", > - (unsigned long)iobase, pdev->irq); > + dev_info(&pdev->dev, "Found VMCI PCI device at %#lx, %#lx, irq %u\n", > + (unsigned long)iobase, (unsigned long)mmio_base, pdev->irq); Why are you printing iomem addresses to userspace? Are you sure that is ok? Who is going to use it? thanks, greg k-h