From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752696AbeDRFqa (ORCPT ); Wed, 18 Apr 2018 01:46:30 -0400 Received: from mga14.intel.com ([192.55.52.115]:50747 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752086AbeDRFq3 (ORCPT ); Wed, 18 Apr 2018 01:46:29 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,464,1517904000"; d="scan'208";a="47837412" From: Jani Nikula To: Souptick Joarder , Matthew Wilcox Cc: rodrigo.vivi@intel.com, linux-kernel@vger.kernel.org, joonas.lahtinen@linux.intel.com, intel-gfx@lists.freedesktop.org, airlied@linux.ie, dri-devel@lists.freedesktop.org Subject: Re: [PATCH] gpu: drm: i915: Change return type to vm_fault_t In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20180417151127.GA31655@jordon-HP-15-Notebook-PC> <87h8o9g8be.fsf@intel.com> <20180417161557.GA3603@bombadil.infradead.org> Date: Wed, 18 Apr 2018 08:46:44 +0300 Message-ID: <871sfdxe0r.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 17 Apr 2018, Souptick Joarder wrote: > On 17-Apr-2018 9:45 PM, "Matthew Wilcox" wrote: >> >> On Tue, Apr 17, 2018 at 09:14:32PM +0530, Souptick Joarder wrote: >> > Not exactly. The plan for these patches is to introduce new vm_fault_t > type >> > in vm_operations_struct fault handlers. It's now available in 4.17-rc1. > We will >> > push all the required drivers/filesystem changes through different > maintainers >> > to linus tree. Once everything is converted into vm_fault_t type then > Changing >> > it from a signed to an unsigned int causes GCC to warn about an > assignment >> > from an incompatible type -- int foo(void) is incompatible with >> > unsigned int foo(void). >> > >> > Please refer 1c8f422059ae ("mm: change return type to vm_fault_t") in > 4.17-rc1. >> >> I think this patch would be clearer if you did >> >> - int ret; >> + int err; >> + vm_fault_t ret; >> >> Then it would be clearer to the maintainer that you're splitting apart the >> VM_FAULT and errno codes. >> >> Sorry for not catching this during initial review. > > Ok, I will make required changes and send v2. Sorry, even I missed this :) I'm afraid Daniel is closer to the truth. My bad, sorry for the noise. BR, Jani. >> >> > On Tue, Apr 17, 2018 at 8:59 PM, Jani Nikula >> > wrote: >> > > On Tue, 17 Apr 2018, Souptick Joarder wrote: >> > >> Use new return type vm_fault_t for fault handler. For >> > >> now, this is just documenting that the function returns >> > >> a VM_FAULT value rather than an errno. Once all instances >> > >> are converted, vm_fault_t will become a distinct type. >> > >> >> > >> Reference id -> 1c8f422059ae ("mm: change return type to >> > >> vm_fault_t") >> > >> >> > >> Signed-off-by: Souptick Joarder >> > >> --- >> > >> drivers/gpu/drm/i915/i915_drv.h | 3 ++- >> > >> drivers/gpu/drm/i915/i915_gem.c | 15 ++++++++------- >> > >> 2 files changed, 10 insertions(+), 8 deletions(-) >> > >> >> > >> diff --git a/drivers/gpu/drm/i915/i915_drv.h > b/drivers/gpu/drm/i915/i915_drv.h >> > >> index a42deeb..95b0d50 100644 >> > >> --- a/drivers/gpu/drm/i915/i915_drv.h >> > >> +++ b/drivers/gpu/drm/i915/i915_drv.h >> > >> @@ -51,6 +51,7 @@ >> > >> #include >> > >> #include >> > >> #include >> > >> +#include >> > >> >> > >> #include "i915_params.h" >> > >> #include "i915_reg.h" >> > >> @@ -3363,7 +3364,7 @@ int i915_gem_wait_for_idle(struct > drm_i915_private *dev_priv, >> > >> unsigned int flags); >> > >> int __must_check i915_gem_suspend(struct drm_i915_private > *dev_priv); >> > >> void i915_gem_resume(struct drm_i915_private *dev_priv); >> > >> -int i915_gem_fault(struct vm_fault *vmf); >> > >> +vm_fault_t i915_gem_fault(struct vm_fault *vmf); >> > >> int i915_gem_object_wait(struct drm_i915_gem_object *obj, >> > >> unsigned int flags, >> > >> long timeout, >> > >> diff --git a/drivers/gpu/drm/i915/i915_gem.c > b/drivers/gpu/drm/i915/i915_gem.c >> > >> index dd89abd..bdac690 100644 >> > >> --- a/drivers/gpu/drm/i915/i915_gem.c >> > >> +++ b/drivers/gpu/drm/i915/i915_gem.c >> > >> @@ -1882,7 +1882,7 @@ int i915_gem_mmap_gtt_version(void) >> > >> * The current feature set supported by i915_gem_fault() and thus > GTT mmaps >> > >> * is exposed via I915_PARAM_MMAP_GTT_VERSION (see > i915_gem_mmap_gtt_version). >> > >> */ >> > >> -int i915_gem_fault(struct vm_fault *vmf) >> > >> +vm_fault_t i915_gem_fault(struct vm_fault *vmf) >> > >> { >> > >> #define MIN_CHUNK_PAGES ((1 << 20) >> PAGE_SHIFT) /* 1 MiB */ >> > >> struct vm_area_struct *area = vmf->vma; >> > >> @@ -1895,6 +1895,7 @@ int i915_gem_fault(struct vm_fault *vmf) >> > >> pgoff_t page_offset; >> > >> unsigned int flags; >> > >> int ret; >> > >> + vm_fault_t retval; >> > > >> > > What's the point of changing the name? An unnecessary change. >> > > >> > > BR, >> > > Jani. >> > > >> > >> >> > >> /* We don't use vmf->pgoff since that has the fake offset */ >> > >> page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT; >> > >> @@ -2000,7 +2001,7 @@ int i915_gem_fault(struct vm_fault *vmf) >> > >> * and so needs to be reported. >> > >> */ >> > >> if (!i915_terminally_wedged(&dev_priv->gpu_error)) { >> > >> - ret = VM_FAULT_SIGBUS; >> > >> + retval = VM_FAULT_SIGBUS; >> > >> break; >> > >> } >> > >> case -EAGAIN: >> > >> @@ -2017,21 +2018,21 @@ int i915_gem_fault(struct vm_fault *vmf) >> > >> * EBUSY is ok: this just means that another thread >> > >> * already did the job. >> > >> */ >> > >> - ret = VM_FAULT_NOPAGE; >> > >> + retval = VM_FAULT_NOPAGE; >> > >> break; >> > >> case -ENOMEM: >> > >> - ret = VM_FAULT_OOM; >> > >> + retval = VM_FAULT_OOM; >> > >> break; >> > >> case -ENOSPC: >> > >> case -EFAULT: >> > >> - ret = VM_FAULT_SIGBUS; >> > >> + retval = VM_FAULT_SIGBUS; >> > >> break; >> > >> default: >> > >> WARN_ONCE(ret, "unhandled error in i915_gem_fault: > %i\n", ret); >> > >> - ret = VM_FAULT_SIGBUS; >> > >> + retval = VM_FAULT_SIGBUS; >> > >> break; >> > >> } >> > >> - return ret; >> > >> + return retval; >> > >> } >> > >> >> > >> static void __i915_gem_object_release_mmap(struct > drm_i915_gem_object *obj) >> > >> -- >> > >> 1.9.1 >> > >> >> > > >> > > -- >> > > Jani Nikula, Intel Open Source Technology Center -- Jani Nikula, Intel Open Source Technology Center