linux-kernel - Re: n900 in next-20170901

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Message-ID: <20171110061917.GK28152@atomide.com>
Date:   Thu, 9 Nov 2017 22:19:17 -0800
From:   Tony Lindgren <tony@...mide.com>
To:     Joonsoo Kim <iamjoonsoo.kim@....com>
Cc:     Pavel Machek <pavel@....cz>, pali.rohar@...il.com, sre@...nel.org,
        kernel list <linux-kernel@...r.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
        linux-omap@...r.kernel.org, khilman@...nel.org,
        aaro.koskinen@....fi, ivo.g.dimitrov.75@...il.com,
        patrikbachan@...il.com, serge@...lyn.com, abcloriens@...il.com,
        "Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Stephen Rothwell <sfr@...b.auug.org.au>,
        Russell King <linux@...linux.org.uk>
Subject: Re: n900 in next-20170901

* Tony Lindgren <tony@...mide.com> [171110 03:28]:
> * Joonsoo Kim <iamjoonsoo.kim@....com> [171110 00:10]:
> > On Thu, Nov 09, 2017 at 07:08:54AM -0800, Tony Lindgren wrote:
> > > Hmm OK. Does your first patch above now have the initcall issue too?
> > > It boots if I make that also subsys_initcall and then I get:
> > 
> > > [    2.078094] vmalloc_pool_init: DMA: get vmalloc area: d0010000
> > 
> > Yes, first patch has the initcall issue and it's intentional in order
> > to check the theory. I checked following log for this.
> > 
> > - Boot failure
> > SRAM_ADDR: omap_map_sram: P: 0x40208000 - 0x4020f000
> > SRAM_ADDR: omap_map_sram: V: 0xd0050000 - 0xd0057000
> > 
> > - Boot success
> > SRAM_ADDR: omap_map_sram: P: 0x40208000 - 0x4020f000
> > SRAM_ADDR: omap_map_sram: V: 0xd0008000 - 0xd000f000
> > 
> > When failure, virtual address for sram is higher than normal one due
> > to vmalloc area allocation in __dma_alloc_remap(). If it is deferred,
> > virtual address is the same with success case and then the system work.
> > 
> > So, my next theory is that there is n900 specific assumption that sram
> > should have that address. Could you check if any working tree for n900
> > which doesn't have my CMA series work or not with adding
> > "arm/dma: vmalloc area allocation"?
> 
> Oh I see, sorry I was not following you earlier. So you mean that
> by adding the vmalloc_pool_init() initcall the va mapping for SRAM
> changes.
> 
> And yes, save_secure_ram_context seems to be doing some sketchy
> virt to phys calculation with sram_phy_addr_mask. Here's a small
> patch to fix that for your CMA series, maybe you can merge it
> with your series to avoid breaking booting for git bisect.
> 
> Then I'll follow up on cleaning up save_secure_ram_context later.

Here's a better version, the static mapping did not get used.. It
just moved the area so it happened to work. It needs to be set
up as MT_MEMORY_RWX_NONCACHED instead.

Regards,

Tony

8< -------------------
>From tony Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@...mide.com>
Date: Thu, 9 Nov 2017 17:05:34 -0800
Subject: [PATCH] ARM: OMAP2+: Add static SRAM mapping for
 save_secure_ram_context

With the CMA changes from Joonsoo Kim <iamjoonsoo.kim@....com>, it
was noticed that n900 stopped booting. After investigating it turned
out that n900 save_secure_ram_context does some whacky virtual to
physical address translation for the SRAM data address.

Let's fix this for CMA changes by adding a static mapping for SRAM
on omap3. Then we can follow up with a patch to clean up the address
translation in save_secure_ram_context later on.

Debugged-by: Joonsoo Kim <iamjoonsoo.kim@....com>
Signed-off-by: Tony Lindgren <tony@...mide.com>
---
 arch/arm/mach-omap2/io.c    | 6 ++++++
 arch/arm/mach-omap2/iomap.h | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c
--- a/arch/arm/mach-omap2/io.c
+++ b/arch/arm/mach-omap2/io.c
@@ -139,6 +139,12 @@ static struct map_desc omap243x_io_desc[] __initdata = {
 
 #ifdef	CONFIG_ARCH_OMAP3
 static struct map_desc omap34xx_io_desc[] __initdata = {
+	{
+		.virtual	= OMAP34XX_SRAM_VIRT,
+		.pfn		= __phys_to_pfn(OMAP34XX_SRAM_PHYS),
+		.length		= OMAP34XX_SRAM_SIZE,
+		.type		= MT_MEMORY_RWX_NONCACHED
+	},
 	{
 		.virtual	= L3_34XX_VIRT,
 		.pfn		= __phys_to_pfn(L3_34XX_PHYS),
diff --git a/arch/arm/mach-omap2/iomap.h b/arch/arm/mach-omap2/iomap.h
--- a/arch/arm/mach-omap2/iomap.h
+++ b/arch/arm/mach-omap2/iomap.h
@@ -123,6 +123,10 @@
  * VPOM3430 was not working for Int controller
  */
 
+#define OMAP34XX_SRAM_PHYS	0x40200000
+#define OMAP34XX_SRAM_VIRT	0xd0010000
+#define OMAP34XX_SRAM_SIZE	0x10000
+
 #define L4_PER_34XX_PHYS	L4_PER_34XX_BASE
 						/* 0x49000000 --> 0xfb000000 */
 #define L4_PER_34XX_VIRT	(L4_PER_34XX_PHYS + OMAP2_L4_IO_OFFSET)
-- 
2.15.0