From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Slxeb-0001KF-DK for barebox@lists.infradead.org; Tue, 03 Jul 2012 07:36:12 +0000 Date: Tue, 3 Jul 2012 09:36:05 +0200 From: Sascha Hauer Message-ID: <20120703073605.GT2698@pengutronix.de> References: <1341249753-5480-1-git-send-email-steve@scheftech.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1341249753-5480-1-git-send-email-steve@scheftech.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] Avoid SDRAM access crash To: steve@scheftech.com Cc: barebox@lists.infradead.org Hi Steve, On Mon, Jul 02, 2012 at 01:22:33PM -0400, steve@scheftech.com wrote: > From: Steve Schefter > > When remapping the SDRAM with the MMU enabled, we need to ensure > that the translation tables are not still in cache before > invalidating the TLB. Failure to do so will result in the following > crash approximately 50% of the time: > > booting kernel from /dev/nand0.kernel.bb > Image Name: Linux-3.3.0PD12.0.0 > OS: Linux > Architecture: ARM > Type: Kernel Image > Compression: uncompressed > Data Size: 3384824 Bytes = 3.2 MB > Load Address: 80008000 > Entry Point: 80008000 > unable to handle paging request at address 0x80028000 > pc : [<8f01f280>] lr : [<8f005330>] > sp : 8cfff9b0 ip : 0000003f fp : 00000000 > r10: 00001000 r9 : 00000000 r8 : 8d2a8f70 > r7 : 8f043818 r6 : 0033a5f8 r5 : 8f04381c r4 : 00001000 > r3 : 80028000 r2 : 00000fff r1 : 8d2a8f71 r0 : 80028000 > Flags: nzCv IRQs off FIQs off Mode SVC_32 > [<8f01f280>] (memcpy+0x18/0x20) from [<8f005330>] (uimage_sdram_flush+0x90/0xb8) > [<8f005330>] (uimage_sdram_flush+0x90/0xb8) from [<8f0053a4>] (uncompress_copy+0x4c/0x74) I wonder why this has never hit me. On what hardware did you see this? Does the following patch solve your problem aswell? 8<---------------------------------------------------- ARM mmu: flush page tables in arm_mmu_remap_sdram() Signed-off-by: Sascha Hauer --- arch/arm/cpu/mmu.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm/cpu/mmu.c b/arch/arm/cpu/mmu.c index 55b07a4..607f357 100644 --- a/arch/arm/cpu/mmu.c +++ b/arch/arm/cpu/mmu.c @@ -147,7 +147,7 @@ static int arm_mmu_remap_sdram(struct memory_bank *bank) if ((phys & (SZ_1M - 1)) || (bank->size & (SZ_1M - 1))) return -EINVAL; - ptes = memalign(0x400, num_ptes * sizeof(u32)); + ptes = memalign(PAGE_SIZE, num_ptes * sizeof(u32)); debug("ptes: 0x%p ttb_start: 0x%08lx ttb_end: 0x%08lx\n", ptes, ttb_start, ttb_end); @@ -165,6 +165,9 @@ static int arm_mmu_remap_sdram(struct memory_bank *bank) pte += 256; } + dma_flush_range((unsigned long)ttb, (unsigned long)ttb + 0x4000); + dma_flush_range((unsigned long)ptes, num_ptes * sizeof(u32)); + tlb_invalidate(); return 0; -- 1.7.10 -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox