Re: [RFC v2 3/7] firmware: port built-in section to linker table

From: "Luis R. Rodriguez" <mcgrof@kernel.org>
To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: David Woodhouse <dwmw2@infradead.org>,
	"Luis R. Rodriguez" <mcgrof@kernel.org>,
	hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com,
	bp@alien8.de, x86@kernel.org, linux-kernel@vger.kernel.org,
	luto@amacapital.net, boris.ostrovsky@oracle.com,
	rusty@rustcorp.com.au, david.vrabel@citrix.com,
	konrad.wilk@oracle.com, mcb30@ipxe.org, jgross@suse.com,
	ming.lei@canonical.com, gregkh@linuxfoundation.org,
	arnd@arndb.de, linux-arch@vger.kernel.org,
	linux@arm.linux.org.uk, benh@kernel.crashing.org,
	jbaron@akamai.com, ananth@in.ibm.com,
	anil.s.keshavamurthy@intel.com, davem@davemloft.net,
	masami.hiramatsu.pt@hitachi.com,
	andriy.shevchenko@linux.intel.com, xen-devel@lists.xensource.com
Subject: Re: [RFC v2 3/7] firmware: port built-in section to linker table
Date: Tue, 1 Mar 2016 18:54:53 +0100	[thread overview]
Message-ID: <20160301175453.GE25240@wotan.suse.de> (raw)
In-Reply-To: <1456848624.2369.9.camel@HansenPartnership.com>

On Tue, Mar 01, 2016 at 08:10:24AM -0800, James Bottomley wrote:
> On Mon, 2016-02-29 at 10:12 +0000, David Woodhouse wrote:
> > On Fri, 2016-02-19 at 05:45 -0800, Luis R. Rodriguez wrote:
> > > This ports built-in firmware to use linker tables,
> > > this replaces the custom section solution with a
> > > generic solution.
> > > 
> > > This also demos the use of the .rodata (SECTION_RO)
> > > linker tables.
> > > 
> > > Tested with 0 built-in firmware, 1 and 2 built-in
> > > firmwares successfully.
> > 
> > I think we'd do better to rip this support out entirely. It just 
> > isn't needed; firmware can live in an initramfs and don't even need 
> > *any* actual running userspace support to load it from there these 
> > days, do we?
> 
> We have lots of SCSI drivers with built in firmware.  The obvious
> examples are 53c700, aic7xxx and aic79xx.  For them, we actually have
> the firmware compilers in tree.  The firmware model they use just isn't
> amenable to the firmware loader: they're not monolithic blobs, it's a
> set of firmware scripts we use to handle particular operations before
> giving control back to the host, so the firmware and the driver are
> very much symbiotic.

I'm in the process of doing some other cleanups with the firmware_class
stuff so that odd requirements get supported but clean interfaces are
also not hampered by these odd requirements, so I'll take a look at
this later. If you have other oddball firmware requirements please
let me know so I can also keep in mind.

> On the other hand, I don't think any of them uses firmware sections, so
> it's not an argument for not ripping out this type.

Thanks for confirming. I'll rip this out.

  Luis