LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Andi Kleen <ak@suse.de>
Cc: ying.huang@intel.com, mingo@elte.hu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [8/8] RFC: Fix some EFI problems
Date: Tue, 12 Feb 2008 21:04:06 +0100 (CET)	[thread overview]
Message-ID: <alpine.LFD.1.00.0802122043460.12988@apollo.tec.linutronix.de> (raw)
In-Reply-To: <20080211093436.EAFB11B41CE@basil.firstfloor.org>

On Mon, 11 Feb 2008, Andi Kleen wrote:

> >From code review the EFI memory map handling has a couple of problems:
> 
> - The test for _WB memory was reversed so it would set cache able memory
> to uncached
> - It would always set a wrong uninitialized zero address to uncached
> (so I suspect it always set the first few pages in phys memory to uncached,
> that is why it may have gone unnoticed) 
> - It would call set_memory_x() on a fixmap address that it doesn't
> handle correct.
> - Some other problems I commented in the code (but was unable to solve
> for now) 
> 
> I changed the ioremaps to set the correct caching attributes
> and also corrected the ordering so it looks roughly correct now.

The only effective change is:

-               if (md->attribute & EFI_MEMORY_WB)
+               if (!(md->attribute & EFI_MEMORY_WB))

I appreciate that you noticed the reverse logic, which I messed up
when I fixed up rejects.

I pulled this out as it is a real fix. The rest of this patch is just
turning code in circles for nothing, simply because it is functionally
completely irrelevant whether does simply:

        if ((end >> PAGE_SHIFT) <= max_pfn_mapped)
                va = __va(md->phys_addr);
        else
                va = efi_ioremap(md->phys_addr, size);

       if (!(md->attribute & EFI_MEMORY_WB))
                set_memory_uc(md->virt_addr, size);
or

       if ((end >> PAGE_SHIFT) <= max_pfn_mapped) {
                va = __va(md->phys_addr);

                if (!(md->attribute & EFI_MEMORY_WB))
                        set_memory_uc(md->virt_addr, size);
       } else
                va = efi_ioremap(md->phys_addr, size,
                                 !!(md->attribute & EFI_MEMORY_WB));

And you just copied the real bug in that logic as well:

          set_memory_uc(md->virt_addr, size);
------------------------^^^^^^^^

which is initialized a couple of lines down.

	md->virt_addr = (u64) (unsigned long) va;

The reordering/optimizing needs to be a separate patch.

Please keep bugfixes and other changes separate.
 
> +		/* RED-PEN does not handle overlapped areas */

Can you please use CHECKME/FIXME which is used everywhere else. No need to
invent an extra marker.

Thanks,

	tglx

  reply	other threads:[~2008-02-12 20:04 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-11  9:34 [PATCH] [0/8] Various kernel mapping bug fixes Andi Kleen
2008-02-11  9:34 ` [PATCH] [1/8] CPA: Fix gbpages support in try_preserve_lage_page Andi Kleen
2008-02-11  9:45   ` Thomas Gleixner
2008-02-11 10:12     ` Ingo Molnar
2008-02-11 11:01       ` Andi Kleen
2008-02-11  9:34 ` [PATCH] [2/8] CPA: Flush the caches when setting pages not present Andi Kleen
2008-02-11 11:00   ` Ingo Molnar
2008-02-11 12:26     ` Andi Kleen
2008-02-11  9:34 ` [PATCH] [3/8] CPA: Test the correct mapping alias on x86-64 Andi Kleen
2008-02-11 11:49   ` Ingo Molnar
2008-02-11  9:34 ` [PATCH] [4/8] CPA: Fix set_memory_x for ioremap Andi Kleen
2008-02-11 12:27   ` Ingo Molnar
2008-02-11 12:45     ` Andi Kleen
2008-02-11  9:34 ` [PATCH] [5/8] Fix logic error in 64bit memory hotadd Andi Kleen
2008-02-11 12:46   ` Ingo Molnar
2008-02-11 13:05     ` Andi Kleen
2008-02-11 13:33       ` Ingo Molnar
2008-02-11 13:44         ` Andi Kleen
2008-02-12 10:35       ` Yasunori Goto
2008-02-12 11:20         ` Andi Kleen
2008-02-11  9:34 ` [PATCH] [6/8] Account overlapped mappings in end_pfn_map Andi Kleen
2008-02-11 13:08   ` Ingo Molnar
2008-02-11 13:27     ` Andi Kleen
2008-02-11 13:55       ` Ingo Molnar
2008-02-11 14:16       ` Peter Zijlstra
2008-02-11 14:24         ` Andi Kleen
2008-02-11 14:41           ` Sam Ravnborg
2008-02-11 15:12   ` Arjan van de Ven
2008-02-11  9:34 ` [PATCH] [7/8] Implement true end_pfn_mapped for 32bit Andi Kleen
2008-02-12 19:39   ` Thomas Gleixner
2008-02-12 19:49     ` Andi Kleen
2008-02-12 20:25       ` Thomas Gleixner
2008-02-11  9:34 ` [PATCH] [8/8] RFC: Fix some EFI problems Andi Kleen
2008-02-12 20:04   ` Thomas Gleixner [this message]
2008-02-12 20:23     ` Andi Kleen
2008-02-12 20:48       ` Thomas Gleixner
2008-02-13 11:05         ` Andi Kleen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.LFD.1.00.0802122043460.12988@apollo.tec.linutronix.de \
    --to=tglx@linutronix.de \
    --cc=ak@suse.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=ying.huang@intel.com \
    --subject='Re: [PATCH] [8/8] RFC: Fix some EFI problems' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).