| Message ID | 20180521073912.13510-1-andr2000@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 21/05/18 09:39, Oleksandr Andrushchenko wrote: > From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> > > 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 <oleksandr_andrushchenko@epam.com> > --- > 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? > } > > 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? Juergen
On 05/23/2018 12:19 PM, Juergen Gross wrote: > On 21/05/18 09:39, Oleksandr Andrushchenko wrote: >> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> >> >> 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 <oleksandr_andrushchenko@epam.com> >> --- >> 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
On 23/05/18 12:00, Oleksandr Andrushchenko wrote: > On 05/23/2018 12:19 PM, Juergen Gross wrote: >> On 21/05/18 09:39, Oleksandr Andrushchenko wrote: >>> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> >>> >>> 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 >>> <oleksandr_andrushchenko@epam.com> >>> --- >>> 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 :( Okay, but this means the compiler should do the necessary cast when you drop the cast to phys_addr_t in xen_page_to_vaddr(), as the cast to uintptr_t is already producing an unsigned integer value which can easily be promoted to more bits, right? Juergen
On 05/23/2018 02:06 PM, Juergen Gross wrote: > On 23/05/18 12:00, Oleksandr Andrushchenko wrote: >> On 05/23/2018 12:19 PM, Juergen Gross wrote: >>> On 21/05/18 09:39, Oleksandr Andrushchenko wrote: >>>> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> >>>> >>>> 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 >>>> <oleksandr_andrushchenko@epam.com> >>>> --- >>>> 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 :( > Okay, but this means the compiler should do the necessary cast when > you drop the cast to phys_addr_t in xen_page_to_vaddr(), as the cast > to uintptr_t is already producing an unsigned integer value which can > easily be promoted to more bits, right? Right, so I can safely use: #define xen_page_to_vaddr(page) \ - ((phys_addr_t)(uintptr_t)pfn_to_kaddr(page_to_xen_pfn(page))) + ((uintptr_t)pfn_to_kaddr(page_to_xen_pfn(page))) > > Juergen Thank you for your time and comments, Oleksandr
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; } 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))) static int backend_unmap(struct xen_drm_front_shbuf *buf) {