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Message-ID: <3abf071d12de5b69e146665dfb57386e3b0ddfe0.camel@redhat.com>
Subject: Re: [PATCH v5 RESEND 2/5] lib: move pci_iomap.c to drivers/pci/
From: Philipp Stanner <pstanner@redhat.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>, Arnd Bergmann <arnd@arndb.de>, 
 Johannes Berg <johannes@sipsolutions.net>, Randy Dunlap
 <rdunlap@infradead.org>, NeilBrown <neilb@suse.de>,  John Sanpe
 <sanpeqf@gmail.com>, Kent Overstreet <kent.overstreet@gmail.com>, Niklas
 Schnelle <schnelle@linux.ibm.com>, Dave Jiang <dave.jiang@intel.com>,
 Uladzislau Koshchanka <koshchanka@gmail.com>, "Masami Hiramatsu (Google)"
 <mhiramat@kernel.org>, David Gow <davidgow@google.com>, Kees Cook
 <keescook@chromium.org>, Rae Moar <rmoar@google.com>, Geert Uytterhoeven
 <geert@linux-m68k.org>, "wuqiang.matt" <wuqiang.matt@bytedance.com>, Yury
 Norov <yury.norov@gmail.com>, Jason Baron <jbaron@akamai.com>, Thomas
 Gleixner <tglx@linutronix.de>, Marco Elver <elver@google.com>, Andrew
 Morton <akpm@linux-foundation.org>, Ben Dooks <ben.dooks@codethink.co.uk>,
 dakr@redhat.com, linux-kernel@vger.kernel.org,  linux-pci@vger.kernel.org,
 linux-arch@vger.kernel.org, stable@vger.kernel.org
Date: Thu, 25 Jan 2024 15:54:51 +0100
In-Reply-To: <20240123202022.GA325908@bhelgaas>
References: <20240123202022.GA325908@bhelgaas>
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On Tue, 2024-01-23 at 14:20 -0600, Bjorn Helgaas wrote:
> On Thu, Jan 11, 2024 at 09:55:37AM +0100, Philipp Stanner wrote:
> > This file is guarded by an #ifdef CONFIG_PCI. It, consequently,
> > does not
> > belong to lib/ because it is not generic infrastructure.
> >=20
> > Move the file to drivers/pci/ and implement the necessary changes
> > to
> > Makefiles and Kconfigs.
> > ...
>=20
> > --- a/drivers/pci/Kconfig
> > +++ b/drivers/pci/Kconfig
> > @@ -13,6 +13,11 @@ config FORCE_PCI
> > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0select HAVE_PCI
> > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0select PCI
> > =C2=A0
> > +# select this to provide a generic PCI iomap,
> > +# without PCI itself having to be defined
> > +config GENERIC_PCI_IOMAP
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0bool
>=20
> > --- a/lib/pci_iomap.c
> > +++ b/drivers/pci/iomap.c
> > @@ -9,7 +9,6 @@
> > =C2=A0
> > =C2=A0#include <linux/export.h>
> > =C2=A0
> > -#ifdef CONFIG_PCI
>=20
> IIUC, in the case where CONFIG_GENERIC_PCI_IOMAP=3Dy but CONFIG_PCI was
> not set, pci_iomap.c was compiled but produced no code because the
> entire file was wrapped with this #ifdef.
>=20
> But after this patch, it looks like pci_iomap_range(),
> pci_iomap_wc_range(), etc., *will* be compiled?
>=20
> Is that what you intend, or did I miss something?

They *will* be compiled when BOTH, CONFIG_PCI and
CONFIG_GENERIC_PCI_IOMAP have been set. It's a bit hard to see that in
the patch's diff. Here, look closely:

--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -14,6 +14,7 @@ ifdef CONFIG_PCI   <-----------
 obj-$(CONFIG_PROC_FS)		+=3D proc.o
 obj-$(CONFIG_SYSFS)		+=3D slot.o
 obj-$(CONFIG_ACPI)		+=3D pci-acpi.o
+obj-$(CONFIG_GENERIC_PCI_IOMAP) +=3D iomap.o  <------------
 endif

So if I am not mistaken it behaves 100% as it did before

I prefered Makefile-logic over even more C Preprocessor to implement
that. The preprocessor has caused us so much trouble... :(

P.


>=20
> Bjorn
>=20