From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932778AbeD0K5E (ORCPT ); Fri, 27 Apr 2018 06:57:04 -0400 Received: from mail-lf0-f65.google.com ([209.85.215.65]:43074 "EHLO mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932415AbeD0K5A (ORCPT ); Fri, 27 Apr 2018 06:57:00 -0400 X-Google-Smtp-Source: AB8JxZqvIffGEsQ9YIB0LguVFkMtL5wz0wQkjgM5MdMcJp2PFmzqaVQvynFQiYWTBH1Ly6wj5HkG5Q== Subject: Re: [PATCH v4 09/15] memory: tegra: Squash tegra20-mc into common tegra-mc driver To: Thierry Reding Cc: Jonathan Hunter , Rob Herring , devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org References: <675f74f82378b5f7d8f61d35e929614a0e156141.1523301400.git.digetx@gmail.com> <20180427093435.GB30388@ulmo> <882f14b8-78c8-95bb-326e-3917c9736faf@gmail.com> <20180427102456.GA17137@ulmo> From: Dmitry Osipenko Openpgp: preference=signencrypt Autocrypt: addr=digetx@gmail.com; prefer-encrypt=mutual; keydata= xsBNBFpX5TwBCADQhg+lBnTunWSPbP5I+rM9q6EKPm5fu2RbqyVAh/W3fRvLyghdb58Yrmjm KpDYUhBIZvAQoFLEL1IPAgJBtmPvemO1XUGPxfYNh/3BlcDFBAgERrI3BfA/6pk7SAFn8u84 p+J1TW4rrPYcusfs44abJrn8CH0GZKt2AZIsGbGQ79O2HHXKHr9V95ZEPWH5AR0UtL6wxg6o O56UNG3rIzSL5getRDQW3yCtjcqM44mz6GPhSE2sxNgqureAbnzvr4/93ndOHtQUXPzzTrYB z/WqLGhPdx5Ouzn0Q0kSVCQiqeExlcQ7i7aKRRrELz/5/IXbCo2O+53twlX8xOps9iMfABEB AAHNIkRtaXRyeSBPc2lwZW5rbyA8ZGlnZXR4QGdtYWlsLmNvbT7CwJQEEwEIAD4WIQSczHcO 3uc4K1eb3yvTNNaPsNRzvAUCWlflPAIbAwUJA8JnAAULCQgHAgYVCgkICwIEFgIDAQIeAQIX gAAKCRDTNNaPsNRzvFjTCACqAh1M9/YPq73/ai5h2ExDquTgJnjegL8KL2yHL3G+XINwzN5E nPI7esoYm+zVWDJbv3UuRqylpookLNSRA01yyvkaMcipB/B128UnqmUiGRqezj9QE20yIauo uHRuwHPE2q+UkfUhRX9iuOaEyQtZDiCa0myMjmRkJ+Z8ZetclEPG8dYZu47w04phuMlu1QAt a0gkZOaMKvXgj21ushALS6nYnvm7HiIPQXfnEXThartatRvFdmbG4PCn0IoICkQBizwJtXrL HEjELIFap0M8krVJlUoZTFaZnaZkGpUDWikeFtAuie2KuIxmVBYPM4X7pM3eP3AVvIPGS7EE UUFuzsBNBFpX5TwBCADFNDou220thijaLLGaQsebWjzc/gPRxMixIpk856MRyRaQin+IbGD6 YskMb5ZSD3nS88LIKNfY4MMH0LwfYztI++ICG2vdFLkbBt78E+LqEa+kZ9072l4W5KO3mWQo +jMfxXbpgGlc7iuEReDgl8iyZ27r51kSW665CYvvu2YJhLqgdj6QM1lN2D1UnhEhkkU+pRAj 1rJVOxdfJaQNQS4+204p3TrURovzNGkN/brqakpNIcqGOAGQqb8F0tuwwuP7ERq/BzDNkbdr qJOrVC/wkHRq1jfabQczWKf8MwYOvivR3HY8d3CpSQxmUXDtdOWfg0XGm1dxYnVfqPjuJaZt ABEBAAHCwHwEGAEIACYWIQSczHcO3uc4K1eb3yvTNNaPsNRzvAUCWlflPAIbDAUJA8JnAAAK CRDTNNaPsNRzvJzuB/9d+sxcwHbO8ZDcgaLX9N+bXFqN9fIRVmBUyWa+qqTSREA4uVAtYcRT lfPE2OQ7aMFxaYPwo+/z5SLpu8HcEhN/FG9uIkfYwK0mdCO0vgvlfvBJm4VHe7C6vyAeEPJQ DKbBvdgeqFqO+PsLkk2sawF/9sontMJ5iFfjNDj4UeAo4VsdlduTBZv5hHFvIbv/p7jKH6OT 90FsgUSVbShh7SH5OzAcgqSy4kxuS1AHizWo6P3f9vei987LZWTyhuEuhJsOfivDsjKIq7qQ c5eR+JJtyLEA0Jt4cQGhpzHtWB0yB3XxXzHVa4QUp00BNVWyiJ/t9JHT4S5mdyLfcKm7ddc9 Message-ID: <103e449b-8ac9-c70b-4d85-638ba4a4a73a@gmail.com> Date: Fri, 27 Apr 2018 13:56:55 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180427102456.GA17137@ulmo> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27.04.2018 13:24, Thierry Reding wrote: > On Fri, Apr 27, 2018 at 01:13:47PM +0300, Dmitry Osipenko wrote: >> On 27.04.2018 12:34, Thierry Reding wrote: >>> On Mon, Apr 09, 2018 at 10:28:31PM +0300, Dmitry Osipenko wrote: >>> [...] >>>> diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c >>> [...] >>>> +#define MC_GART_ERROR_REQ 0x30 >>>> +#define MC_DECERR_EMEM_OTHERS_STATUS 0x58 >>>> +#define MC_SECURITY_VIOLATION_STATUS 0x74 >>> [...] >>>> diff --git a/drivers/memory/tegra/mc.h b/drivers/memory/tegra/mc.h >>> [...] >>>> @@ -21,19 +21,30 @@ >>>> #define MC_INT_INVALID_SMMU_PAGE (1 << 10) >>>> #define MC_INT_ARBITRATION_EMEM (1 << 9) >>>> #define MC_INT_SECURITY_VIOLATION (1 << 8) >>>> +#define MC_INT_INVALID_GART_PAGE (1 << 7) >>>> #define MC_INT_DECERR_EMEM (1 << 6) >>>> >>>> static inline u32 mc_readl(struct tegra_mc *mc, unsigned long offset) >>>> { >>>> + if (mc->regs2 && offset >= 0x24) >>>> + return readl(mc->regs2 + offset - 0x3c); >>> >>> I'm still not sure how this is supposed to work. If we pass in >>> MC_GART_ERROR_REQ as offset into mc_readl(), then the condition above >>> will be true (0x30 >= 0x24) but then the new offset will be computed >>> and we end up with: >>> >>> return readl(mc->regs2 + 0x30 - 0x3c); >>> >>> which means we'll be adding a negative offset (or rather a very large >>> offset because it will wrap around). >> >> Indeed! Thank you for pointing at it again, now I see the issue. It probably >> works because actual registers mapping is aligned to page(?) size and adding the >> large offset with wraparound is equal to subtraction. >> >> That register belongs to the GART and we can't simply move interrupt handling to >> the GART driver because status register is within the MC in device tree. We can >> omit reading of MC_GART_ERROR_REQ and simply report GART page fault for the >> starter and then reorganize drivers by making MC driver MFD and GART its >> sub-device, what do you think? > > Sounds like a good idea. Can you send a fix on top of this that I can > squash into this when applying? Sure. > As for integrating GART with MC, I'd prefer something that doesn't use > MFD but rather does something similar to what we have for the SMMU. I > think that's simpler to do and has less boilerplate. I think it's also > warranted because the MC and GART are very tightly coupled, so an MFD > would be slightly over-engineered, in my opinion. Okay, I'll recap how SMMU is integrated with MC and then come up with something.