Re: [PATCH V3 0/2] x86/microcode/amd: early loading fixes

[Jacob Shin <jacob.shin@amd.com>]

On Thu, Jun 20, 2013 at 12:30:53PM +0200, Ingo Molnar wrote:
> 
> * Jacob Shin <jacob.shin@amd.com> wrote:
> 
> > On Fri, Jun 07, 2013 at 09:22:18PM -0500, Jacob Shin wrote:
> > > This patchset addreses two problems with early loading on AMD.
> > > 
> > > First, feedback from Yinghai that find_ucode_in_initrd() should be
> > > marked __init:
> > >   https://lkml.org/lkml/2013/6/4/695
> > > 
> > > And second, feedback from Henrique that Intel early loading supports
> > > multiple microcode firmware concatenated together, whereas the current
> > > AMD implementation lacks this support:
> > >   https://lkml.org/lkml/2013/5/31/4
> > > 
> > > V3:
> > > * style fix -- reduce multiple if statements into a single one
> > 
> > Hi hpa or Yinghai, just wondering if you had the chance to look at this
> > V3 yet.
> 
> It appears Peter applied v2 to tip:x86/microcode two days before you sent 
> v3 - please send any changes in v3 as delta patches.

I actually recieved the tip-bot email <https://lkml.org/lkml/2013/6/12/468>
couple of days after sending out the above message, so I assumed that
V3 was committed in.

I should have read the tip-bot message thoroughly and noticed
it. Sorry about that. Here is the delta patch:

---8<---

>From 1445587da716b306f39feef46fb7150f292060c7 Mon Sep 17 00:00:00 2001
From: Jacob Shin <jacob.shin@amd.com>
Date: Thu, 20 Jun 2013 09:52:50 -0500
Subject: [PATCH] x86, microcode, amd: another early loading fixup

commit cd1c32ca969ebfd65e61312c988223bb14f09c2e is an early premature
rendition of the patch. Augment it with this delta patch to:
  * correctly mark offset and size of the matching bin file
  * use __pa instead of __pa_nodebug during AP load
  * check for !initrd_start before using it
---
 arch/x86/kernel/microcode_amd_early.c |   40 ++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/microcode_amd_early.c b/arch/x86/kernel/microcode_amd_early.c
index 4c593c2..1ac6e9a 100644
--- a/arch/x86/kernel/microcode_amd_early.c
+++ b/arch/x86/kernel/microcode_amd_early.c
@@ -143,13 +143,17 @@ static void __cpuinit apply_ucode_in_initrd(void *ucode, size_t size)
 			left  -= offset;
 		}
 
-		offset = data - (u8 *)ucode;
+		/* mark where the next microcode container file starts */
+		offset    = data - (u8 *)ucode;
 		*uoffset += offset;
 		*usize   -= offset;
+		ucode     = data;
 	}
 
-	if (!eq_id)
+	if (!eq_id) {
+		*usize = 0;
 		return;
+	}
 
 	/* find ucode and update if needed */
 
@@ -166,15 +170,21 @@ static void __cpuinit apply_ucode_in_initrd(void *ucode, size_t size)
 		mc = (struct microcode_amd *)(data + SECTION_HDR_SIZE);
 		if (eq_id == mc->hdr.processor_rev_id && rev < mc->hdr.patch_id)
 			if (__apply_microcode_amd(mc) == 0) {
-				if (!(*new_rev))
-					*new_rev = mc->hdr.patch_id;
-				break;
+				rev = mc->hdr.patch_id;
+				*new_rev = rev;
 			}
 
 		offset  = header[1] + SECTION_HDR_SIZE;
 		data   += offset;
 		left   -= offset;
 	}
+
+	/* mark where this microcode container file ends */
+	offset  = *usize - (data - (u8 *)ucode);
+	*usize -= offset;
+
+	if (!(*new_rev))
+		*usize = 0;
 }
 
 void __init load_ucode_amd_bsp(void)
@@ -204,19 +214,20 @@ void __cpuinit load_ucode_amd_ap(void)
 	size_t *usize;
 	void *ucode;
 
-	mc = (struct microcode_amd *)__pa_nodebug(amd_bsp_mpb);
+	mc = (struct microcode_amd *)__pa(amd_bsp_mpb);
 	if (mc->hdr.patch_id && mc->hdr.processor_rev_id) {
 		__apply_microcode_amd(mc);
 		return;
 	}
 
-	initrd  = (unsigned long *)__pa_nodebug(&initrd_start);
-	uoffset = (unsigned long *)__pa_nodebug(&ucode_offset);
-	usize   = (size_t *)__pa_nodebug(&ucode_size);
-	if (!*usize)
+	initrd  = (unsigned long *)__pa(&initrd_start);
+	uoffset = (unsigned long *)__pa(&ucode_offset);
+	usize   = (size_t *)__pa(&ucode_size);
+
+	if (!*usize || !*initrd)
 		return;
 
-	ucode = (void *)((unsigned long)__pa_nodebug(*initrd) + *uoffset);
+	ucode = (void *)((unsigned long)__pa(*initrd) + *uoffset);
 	apply_ucode_in_initrd(ucode, *usize);
 }
 
@@ -250,7 +261,7 @@ void __cpuinit load_ucode_amd_ap(void)
 	if (cpu && !ucode_loaded) {
 		void *ucode;
 
-		if (!ucode_size)
+		if (!ucode_size || !initrd_start)
 			return;
 
 		ucode = (void *)(initrd_start + ucode_offset);
@@ -278,10 +289,7 @@ int __init save_microcode_in_initrd_amd(void)
 		pr_info("microcode: updated early to new patch_level=0x%08x\n",
 			ucode_new_rev);
 
-	if (ucode_loaded)
-		return 0;
-
-	if (!ucode_size)
+	if (ucode_loaded || !ucode_size || !initrd_start)
 		return 0;
 
 	ucode = (void *)(initrd_start + ucode_offset);
-- 
1.7.9.5