Re: [PATCH 5/6] MIPS: implement architecture dependent 'pci_remap_iospace()'

From: Arnd Bergmann <arnd@arndb.de>
To: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Rob Herring <robh@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Liviu Dudau <Liviu.Dudau@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	gregkh <gregkh@linuxfoundation.org>,
	"open list:BROADCOM NVRAM DRIVER" <linux-mips@vger.kernel.org>,
	linux-pci <linux-pci@vger.kernel.org>,
	linux-staging@lists.linux.dev, neil@brown.name,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 5/6] MIPS: implement architecture dependent 'pci_remap_iospace()'
Date: Sat, 25 Sep 2021 19:32:12 +0200	[thread overview]
Message-ID: <CAK8P3a3SpuioCVBfQpHFGuNQoXG7g8w9VL+V8rYd8Q80Od89HA@mail.gmail.com> (raw)
In-Reply-To: <20210924211139.3477-6-sergio.paracuellos@gmail.com>

On Fri, Sep 24, 2021 at 11:11 PM Sergio Paracuellos
<sergio.paracuellos@gmail.com> wrote:
>
> To make PCI IO work we need to properly virtually map IO cpu physical address
> and set this virtual address as the address of the first PCI IO port which
> is set using function 'set_io_port_base()'.
>
> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>

Acked-by: Arnd Bergmann <arnd@arndb.de>

> +int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
> +{
> +       size_t size = (res->end - res->start) + 1;
> +       unsigned long vaddr = (unsigned long)ioremap(phys_addr, size);
> +
> +       set_io_port_base(vaddr);
> +       return 0;
> +}

It might be good to check that res->start is zero here, otherwise
the io_port_base would be off. That could happen if you ever have more
than one bridge.

        Arnd