| Message ID | 20220913183129.14184-1-ovpanait@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | Tom Rini |
| Headers | show |
| Series | [v2,1/4] common/board_f: remove XTRN_DECLARE_GLOBAL_DATA_PTR dead code | expand |
On Tue, 13 Sept 2022 at 12:31, Ovidiu Panait <ovpanait@gmail.com> wrote: > > The XTRN_DECLARE_GLOBAL_DATA_PTR declarations in ppc code are permanently > commented out, so there are no users for this macro: > #if 1 > #define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r2") > #else /* We could use plain global data, but the resulting code is bigger */ > #define XTRN_DECLARE_GLOBAL_DATA_PTR extern > #define DECLARE_GLOBAL_DATA_PTR XTRN_DECLARE_GLOBAL_DATA_PTR \ > gd_t *gd > #endif > > Remove all references to this macro, but add a documentation note regarding > the possibility of using plain global data for the GD pointer. > > Signed-off-by: Ovidiu Panait <ovpanait@gmail.com> > --- > > Changes in v2: > - update global data documentation with the info provided by Wolfgang > > arch/powerpc/include/asm/global_data.h | 6 ------ > common/board_f.c | 11 ----------- > doc/develop/global_data.rst | 5 +++++ > 3 files changed, 5 insertions(+), 17 deletions(-) Reviewed-by: Simon Glass <sjg@chromium.org>
On Tue, Sep 13, 2022 at 09:31:26PM +0300, Ovidiu Panait wrote: > The XTRN_DECLARE_GLOBAL_DATA_PTR declarations in ppc code are permanently > commented out, so there are no users for this macro: > #if 1 > #define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r2") > #else /* We could use plain global data, but the resulting code is bigger */ > #define XTRN_DECLARE_GLOBAL_DATA_PTR extern > #define DECLARE_GLOBAL_DATA_PTR XTRN_DECLARE_GLOBAL_DATA_PTR \ > gd_t *gd > #endif > > Remove all references to this macro, but add a documentation note regarding > the possibility of using plain global data for the GD pointer. > > Signed-off-by: Ovidiu Panait <ovpanait@gmail.com> Reviewed-by: Tom Rini <trini@konsulko.com>
On Tue, Sep 13, 2022 at 09:31:26PM +0300, Ovidiu Panait wrote: > The XTRN_DECLARE_GLOBAL_DATA_PTR declarations in ppc code are permanently > commented out, so there are no users for this macro: > #if 1 > #define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r2") > #else /* We could use plain global data, but the resulting code is bigger */ > #define XTRN_DECLARE_GLOBAL_DATA_PTR extern > #define DECLARE_GLOBAL_DATA_PTR XTRN_DECLARE_GLOBAL_DATA_PTR \ > gd_t *gd > #endif > > Remove all references to this macro, but add a documentation note regarding > the possibility of using plain global data for the GD pointer. > > Signed-off-by: Ovidiu Panait <ovpanait@gmail.com> > Reviewed-by: Simon Glass <sjg@chromium.org> > Reviewed-by: Tom Rini <trini@konsulko.com> Applied to u-boot/master, thanks!
diff --git a/arch/powerpc/include/asm/global_data.h b/arch/powerpc/include/asm/global_data.h index 6709e692e6..6ed21c781f 100644 --- a/arch/powerpc/include/asm/global_data.h +++ b/arch/powerpc/include/asm/global_data.h @@ -92,12 +92,6 @@ struct arch_global_data { #include <asm-generic/global_data.h> -#if 1 #define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r2") -#else /* We could use plain global data, but the resulting code is bigger */ -#define XTRN_DECLARE_GLOBAL_DATA_PTR extern -#define DECLARE_GLOBAL_DATA_PTR XTRN_DECLARE_GLOBAL_DATA_PTR \ - gd_t *gd -#endif #endif /* __ASM_GBL_DATA_H */ diff --git a/common/board_f.c b/common/board_f.c index 18e2246733..f4238d4c90 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -57,18 +57,7 @@ #include <dm/root.h> #include <linux/errno.h> -/* - * Pointer to initial global data area - * - * Here we initialize it if needed. - */ -#ifdef XTRN_DECLARE_GLOBAL_DATA_PTR -#undef XTRN_DECLARE_GLOBAL_DATA_PTR -#define XTRN_DECLARE_GLOBAL_DATA_PTR /* empty = allocate here */ -DECLARE_GLOBAL_DATA_PTR = (gd_t *)(CONFIG_SYS_INIT_GD_ADDR); -#else DECLARE_GLOBAL_DATA_PTR; -#endif /* * TODO(sjg@chromium.org): IMO this code should be diff --git a/doc/develop/global_data.rst b/doc/develop/global_data.rst index 2ac893de49..d143f27eed 100644 --- a/doc/develop/global_data.rst +++ b/doc/develop/global_data.rst @@ -36,6 +36,11 @@ On most architectures the global data pointer is stored in a register. The sandbox, x86_64, and Xtensa are notable exceptions. +Current implementation uses a register for the GD pointer because this results +in smaller code. However, using plain global data for the GD pointer would be +possible too (and simpler, as it does not require the reservation of a specific +register for it), but the resulting code is bigger. + Clang for ARM does not support assigning a global register. When using Clang gd is defined as an inline function using assembly code. This adds a few bytes to the code size.
The XTRN_DECLARE_GLOBAL_DATA_PTR declarations in ppc code are permanently commented out, so there are no users for this macro: #if 1 #define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r2") #else /* We could use plain global data, but the resulting code is bigger */ #define XTRN_DECLARE_GLOBAL_DATA_PTR extern #define DECLARE_GLOBAL_DATA_PTR XTRN_DECLARE_GLOBAL_DATA_PTR \ gd_t *gd #endif Remove all references to this macro, but add a documentation note regarding the possibility of using plain global data for the GD pointer. Signed-off-by: Ovidiu Panait <ovpanait@gmail.com> --- Changes in v2: - update global data documentation with the info provided by Wolfgang arch/powerpc/include/asm/global_data.h | 6 ------ common/board_f.c | 11 ----------- doc/develop/global_data.rst | 5 +++++ 3 files changed, 5 insertions(+), 17 deletions(-)