From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932293AbeEWKAw (ORCPT ); Wed, 23 May 2018 06:00:52 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35123 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932180AbeEWKAv (ORCPT ); Wed, 23 May 2018 06:00:51 -0400 X-Google-Smtp-Source: AB8JxZqzn1RNsOGj0cK5wtnsSUEWxE/gVQHXro36kXX03+a3zXp3N3VaoUrmFB+ga0WTF3o96D74Og== Subject: Re: [PATCH] drm/xen-front: fix pointer casts To: Juergen Gross , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, daniel.vetter@intel.com, boris.ostrovsky@oracle.com Cc: Oleksandr Andrushchenko References: <20180521073912.13510-1-andr2000@gmail.com> From: Oleksandr Andrushchenko Message-ID: Date: Wed, 23 May 2018 13:00:48 +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: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/23/2018 12:19 PM, Juergen Gross wrote: > On 21/05/18 09:39, Oleksandr Andrushchenko wrote: >> From: Oleksandr Andrushchenko >> >> Building for a 32-bit target results in warnings from casting >> between a 32-bit pointer and a 64-bit integer. Fix the warnings >> by casting those pointers to uintptr_t first. >> >> Signed-off-by: Oleksandr Andrushchenko >> --- >> drivers/gpu/drm/xen/xen_drm_front.h | 4 ++-- >> drivers/gpu/drm/xen/xen_drm_front_shbuf.c | 2 +- >> 2 files changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/xen/xen_drm_front.h b/drivers/gpu/drm/xen/xen_drm_front.h >> index 2c2479b571ae..8e15dbebc4ba 100644 >> --- a/drivers/gpu/drm/xen/xen_drm_front.h >> +++ b/drivers/gpu/drm/xen/xen_drm_front.h >> @@ -126,12 +126,12 @@ struct xen_drm_front_drm_info { >> >> static inline u64 xen_drm_front_fb_to_cookie(struct drm_framebuffer *fb) >> { >> - return (u64)fb; >> + return (u64)(uintptr_t)fb; > Do you really still need the cast to u64? Indeed, I can remove (u64) now, thank you > >> } >> >> static inline u64 xen_drm_front_dbuf_to_cookie(struct drm_gem_object *gem_obj) >> { >> - return (u64)gem_obj; >> + return (u64)(uintptr_t)gem_obj; >> } >> >> int xen_drm_front_mode_set(struct xen_drm_front_drm_pipeline *pipeline, >> diff --git a/drivers/gpu/drm/xen/xen_drm_front_shbuf.c b/drivers/gpu/drm/xen/xen_drm_front_shbuf.c >> index 8099cb343ae3..47fc93847765 100644 >> --- a/drivers/gpu/drm/xen/xen_drm_front_shbuf.c >> +++ b/drivers/gpu/drm/xen/xen_drm_front_shbuf.c >> @@ -122,7 +122,7 @@ static void guest_calc_num_grefs(struct xen_drm_front_shbuf *buf) >> } >> >> #define xen_page_to_vaddr(page) \ >> - ((phys_addr_t)pfn_to_kaddr(page_to_xen_pfn(page))) >> + ((phys_addr_t)(uintptr_t)pfn_to_kaddr(page_to_xen_pfn(page))) > phys_addr_t for a virtual address? This is because the resulting value is then passed to gnttab_set_map_op/ gnttab_set_unmap_op which expects host address to be passed as phys_addr_t addr :( Please see [1], [2]: regardless of the fact that xen_page_to_vaddr does produce host address I have to convert it to phys_addr_t then to pass to [1] and [2]. Please also see [3], [4], [5] which either cast to phys_addr_t or unsigned long or u64. > > Juergen [1] https://elixir.bootlin.com/linux/v4.17-rc6/source/include/xen/grant_table.h#L147 [2] https://elixir.bootlin.com/linux/v4.17-rc6/source/include/xen/grant_table.h#L163 [3] https://elixir.bootlin.com/linux/v4.17-rc6/source/drivers/block/xen-blkback/blkback.c#L845 [4] https://elixir.bootlin.com/linux/v4.17-rc6/source/drivers/net/xen-netback/netback.c#L334 [5] https://elixir.bootlin.com/linux/v4.17-rc6/source/drivers/xen/xenbus/xenbus_client.c#L478