From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Thompson Subject: Re: [PATCH v3.18-rc3] drm: msm: Allow exported dma-bufs to be mapped Date: Tue, 11 Nov 2014 14:28:49 +0000 Message-ID: <54621D21.2000100@linaro.org> References: <1415639805-17477-1-git-send-email-daniel.thompson@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail-wi0-f178.google.com (mail-wi0-f178.google.com [209.85.212.178]) by gabe.freedesktop.org (Postfix) with ESMTP id 107996E5D0 for ; Tue, 11 Nov 2014 06:28:57 -0800 (PST) Received: by mail-wi0-f178.google.com with SMTP id bs8so1771279wib.17 for ; Tue, 11 Nov 2014 06:28:56 -0800 (PST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Rob Clark Cc: linaro-kernel@lists.linaro.org, "patches@linaro.org" , Linux Kernel Mailing List , "dri-devel@lists.freedesktop.org" , Benjamin Gaignard List-Id: dri-devel@lists.freedesktop.org T24gMTAvMTEvMTQgMTc6MzYsIFJvYiBDbGFyayB3cm90ZToKPiBPbiBNb24sIE5vdiAxMCwgMjAx NCBhdCAxMjoxNiBQTSwgRGFuaWVsIFRob21wc29uCj4gPGRhbmllbC50aG9tcHNvbkBsaW5hcm8u b3JnPiB3cm90ZToKPj4gZGlmZiAtLWdpdCBhL2RyaXZlcnMvZ3B1L2RybS9tc20vbXNtX2dlbV9w cmltZS5jIGIvZHJpdmVycy9ncHUvZHJtL21zbS9tc21fZ2VtX3ByaW1lLmMKPj4gaW5kZXggYWQ3 NzJmZTM2MTE1Li40ZTRmYTU4MjhkNWQgMTAwNjQ0Cj4+IC0tLSBhL2RyaXZlcnMvZ3B1L2RybS9t c20vbXNtX2dlbV9wcmltZS5jCj4+ICsrKyBiL2RyaXZlcnMvZ3B1L2RybS9tc20vbXNtX2dlbV9w cmltZS5jCj4+IEBAIC0yMCw2ICsyMCwxNCBAQAo+Pgo+PiAgI2luY2x1ZGUgPGxpbnV4L2RtYS1i dWYuaD4KPj4KPj4gK3N0cnVjdCBkbWFfYnVmICptc21fZ2VtX3ByaW1lX2V4cG9ydChzdHJ1Y3Qg ZHJtX2RldmljZSAqZGV2LAo+PiArICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg c3RydWN0IGRybV9nZW1fb2JqZWN0ICpvYmosIGludCBmbGFncykKPj4gK3sKPj4gKyAgICAgICAv KiB3ZSB3YW50IHRvIGJlIGFibGUgdG8gd3JpdGUgaW4gbW1hcHBlZCBidWZmZXIgKi8KPj4gKyAg ICAgICBmbGFncyB8PSBPX1JEV1I7Cj4+ICsgICAgICAgcmV0dXJuIGRybV9nZW1fcHJpbWVfZXhw b3J0KGRldiwgb2JqLCBmbGFncyk7Cj4+ICt9Cj4+ICsKPiAKPiBzZWVtcyBsaWtlIHRoaXMgcHJv YmFibHkgc2hvdWxkIGJlIGRvbmUgbW9yZSBjZW50cmFsbHkuLiAgYW5kIGluIGZhY3QsCj4gbWln aHQgYmUgYmV0dGVyIHRvIGhhdmUgc29tZXRoaW5nIGxpa2UgdGhpcyBpbgo+IGRybV9wcmltZV9o YW5kbGVfdG9fZmRfaW9jdGw6Cj4gCj4gICAgIC8qIGNoZWNrIGZsYWdzIGFyZSB2YWxpZCAqLwo+ IC0gICAgaWYgKGFyZ3MtPmZsYWdzICYgfkRSTV9DTE9FWEVDKQo+ICsgICAgaWYgKGFyZ3MtPmZs YWdzICYgfihEUk1fQ0xPRVhFQyB8IE9fUkRXUikpCj4gICAgICAgIHJldHVybiAtRUlOVkFMOwo+ IAo+IHNvIGV4cG9ydGVyIGNhbiBzcGVjaWZ5IHdoZXRoZXIgdG8gYWxsb3cgbW1hcCBvciBub3Qu CgpUaGF0IG1ha2VzIHNlbnNlIEknbGwgdHJ5IHRoaXMuCgpEbyB3ZSBuZWVkIHRvIHdyYXAgT19S RFdSIGluIHRoZSBzYW1lIHdheSB3ZSB3cmFwIE9fQ0xPRVhFQz8gKEkgZG9uJ3QKcmVhbGx5IHVu ZGVyc3RhbmQgd2h5IERSTV9DTE9FWEVDIGV4aXN0czsgZXZlbiB0aGUgcGF0Y2ggZGVzY3JpcHRp b24KZnJvbSB3aGVuIHRoZSBzeW1ib2wgd2FzIGludHJvZHVjZWQgbmFtZXMgaXQgT19DTE9FWEVD KS4KCkFsc28gdGhlICJmbGFncyB8PSBPX1JEV1IiIGFwcHJvYWNoIGlzIGNvcGllZCBmcm9tIHRo ZSBzdGkgZHJpdmVyLiBJJ2xsCnNoYXJlIGEgcGF0Y2ggdG8gcmVtb3ZlIGl0IGJ1dCB0aGF0IHdp bGwgZGVmaW5pdGVseSBuZWVkcyBCZW5qYW1pbidzIGFjawpiZWNhdXNlIGl0IHdpbGwgc3RvcCBz b21lIHVzZXJzcGFjZXMgd29ya2luZyBjb3JyZWN0bHkgKGhvd2V2ZXIgSQpzdXNwZWN0IHRoYXQg QmVuamFtaW4gbWF5IGJlIHRoZSBvbmx5IHBlcnNvbiBjdXJyZW50bHkgd2l0aCBzdWNoIGEKdXNl cnNwYWNlIGFuZCB0aGF0IGhlIGNhbiBiZSBwZXJzdWFkZWQgbm90IHRvIGNhbGwgaXQgYSByZWdy ZXNzaW9uKS4KCgpEYW5pZWwuCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRldmVsQGxpc3RzLmZyZWVkZXNr dG9wLm9yZwpodHRwOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJp LWRldmVsCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751747AbaKKO3A (ORCPT ); Tue, 11 Nov 2014 09:29:00 -0500 Received: from mail-wi0-f182.google.com ([209.85.212.182]:55636 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750980AbaKKO25 (ORCPT ); Tue, 11 Nov 2014 09:28:57 -0500 Message-ID: <54621D21.2000100@linaro.org> Date: Tue, 11 Nov 2014 14:28:49 +0000 From: Daniel Thompson User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Rob Clark CC: David Airlie , "dri-devel@lists.freedesktop.org" , Benjamin Gaignard , Linux Kernel Mailing List , "patches@linaro.org" , linaro-kernel@lists.linaro.org, John Stultz , Sumit Semwal Subject: Re: [PATCH v3.18-rc3] drm: msm: Allow exported dma-bufs to be mapped References: <1415639805-17477-1-git-send-email-daniel.thompson@linaro.org> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/11/14 17:36, Rob Clark wrote: > On Mon, Nov 10, 2014 at 12:16 PM, Daniel Thompson > wrote: >> diff --git a/drivers/gpu/drm/msm/msm_gem_prime.c b/drivers/gpu/drm/msm/msm_gem_prime.c >> index ad772fe36115..4e4fa5828d5d 100644 >> --- a/drivers/gpu/drm/msm/msm_gem_prime.c >> +++ b/drivers/gpu/drm/msm/msm_gem_prime.c >> @@ -20,6 +20,14 @@ >> >> #include >> >> +struct dma_buf *msm_gem_prime_export(struct drm_device *dev, >> + struct drm_gem_object *obj, int flags) >> +{ >> + /* we want to be able to write in mmapped buffer */ >> + flags |= O_RDWR; >> + return drm_gem_prime_export(dev, obj, flags); >> +} >> + > > seems like this probably should be done more centrally.. and in fact, > might be better to have something like this in > drm_prime_handle_to_fd_ioctl: > > /* check flags are valid */ > - if (args->flags & ~DRM_CLOEXEC) > + if (args->flags & ~(DRM_CLOEXEC | O_RDWR)) > return -EINVAL; > > so exporter can specify whether to allow mmap or not. That makes sense I'll try this. Do we need to wrap O_RDWR in the same way we wrap O_CLOEXEC? (I don't really understand why DRM_CLOEXEC exists; even the patch description from when the symbol was introduced names it O_CLOEXEC). Also the "flags |= O_RDWR" approach is copied from the sti driver. I'll share a patch to remove it but that will definitely needs Benjamin's ack because it will stop some userspaces working correctly (however I suspect that Benjamin may be the only person currently with such a userspace and that he can be persuaded not to call it a regression). Daniel.