From: Kefeng Wang <hidden> Date: 2021-06-04 06:58:20
Use setup_initial_init_mm() helper to simplify code.
Note klimit is (unsigned long) _end, with new helper,
will use _end directly.
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Kefeng Wang <redacted>
---
arch/powerpc/kernel/setup-common.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
From: Mike Rapoport <rppt@kernel.org> Date: 2021-06-06 21:29:23
Hello Kefeng,
On Fri, Jun 04, 2021 at 03:06:18PM +0800, Kefeng Wang wrote:
Add setup_initial_init_mm() helper, then use it
to cleanup the text, data and brk setup code.
v2:
- change argument from "char *" to "void *" setup_initial_init_mm()
suggested by Geert Uytterhoeven
- use NULL instead of (void *)0 on h8300 and m68k
- collect ACKs
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-csky@vger.kernel.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-m68k@lists.linux-m68k.org
Cc: openrisc@lists.librecores.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-sh@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Kefeng Wang (15):
mm: add setup_initial_init_mm() helper
arc: convert to setup_initial_init_mm()
arm: convert to setup_initial_init_mm()
arm64: convert to setup_initial_init_mm()
csky: convert to setup_initial_init_mm()
h8300: convert to setup_initial_init_mm()
m68k: convert to setup_initial_init_mm()
nds32: convert to setup_initial_init_mm()
nios2: convert to setup_initial_init_mm()
openrisc: convert to setup_initial_init_mm()
powerpc: convert to setup_initial_init_mm()
riscv: convert to setup_initial_init_mm()
s390: convert to setup_initial_init_mm()
sh: convert to setup_initial_init_mm()
x86: convert to setup_initial_init_mm()
I might be missing something, but AFAIU the init_mm.start_code and other
fields are not used really early so the new setup_initial_init_mm()
function can be called in the generic code outside setup_arch(), e.g in
mm_init().
From: Kefeng Wang <hidden> Date: 2021-06-07 00:56:03
On 2021/6/7 5:29, Mike Rapoport wrote:
Hello Kefeng,
On Fri, Jun 04, 2021 at 03:06:18PM +0800, Kefeng Wang wrote:
quoted
Add setup_initial_init_mm() helper, then use it
to cleanup the text, data and brk setup code.
v2:
- change argument from "char *" to "void *" setup_initial_init_mm()
suggested by Geert Uytterhoeven
- use NULL instead of (void *)0 on h8300 and m68k
- collect ACKs
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-csky@vger.kernel.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-m68k@lists.linux-m68k.org
Cc: openrisc@lists.librecores.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-sh@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Kefeng Wang (15):
mm: add setup_initial_init_mm() helper
arc: convert to setup_initial_init_mm()
arm: convert to setup_initial_init_mm()
arm64: convert to setup_initial_init_mm()
csky: convert to setup_initial_init_mm()
h8300: convert to setup_initial_init_mm()
m68k: convert to setup_initial_init_mm()
nds32: convert to setup_initial_init_mm()
nios2: convert to setup_initial_init_mm()
openrisc: convert to setup_initial_init_mm()
powerpc: convert to setup_initial_init_mm()
riscv: convert to setup_initial_init_mm()
s390: convert to setup_initial_init_mm()
sh: convert to setup_initial_init_mm()
x86: convert to setup_initial_init_mm()
I might be missing something, but AFAIU the init_mm.start_code and other
fields are not used really early so the new setup_initial_init_mm()
function can be called in the generic code outside setup_arch(), e.g in
mm_init().
Hi Mike， each architecture has their own value, not the same, eg m68K and
h8300, also the name of the text/code/brk is different in some arch, so I keep
unchanged.
Hi Kefeng,
Le 07/06/2021 à 02:55, Kefeng Wang a écrit :
On 2021/6/7 5:29, Mike Rapoport wrote:
quoted
Hello Kefeng,
On Fri, Jun 04, 2021 at 03:06:18PM +0800, Kefeng Wang wrote:
quoted
Add setup_initial_init_mm() helper, then use it
to cleanup the text, data and brk setup code.
v2:
- change argument from "char *" to "void *" setup_initial_init_mm()
suggested by Geert Uytterhoeven
- use NULL instead of (void *)0 on h8300 and m68k
- collect ACKs
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-csky@vger.kernel.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-m68k@lists.linux-m68k.org
Cc: openrisc@lists.librecores.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-sh@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Kefeng Wang (15):
mm: add setup_initial_init_mm() helper
arc: convert to setup_initial_init_mm()
arm: convert to setup_initial_init_mm()
arm64: convert to setup_initial_init_mm()
csky: convert to setup_initial_init_mm()
h8300: convert to setup_initial_init_mm()
m68k: convert to setup_initial_init_mm()
nds32: convert to setup_initial_init_mm()
nios2: convert to setup_initial_init_mm()
openrisc: convert to setup_initial_init_mm()
powerpc: convert to setup_initial_init_mm()
riscv: convert to setup_initial_init_mm()
s390: convert to setup_initial_init_mm()
sh: convert to setup_initial_init_mm()
x86: convert to setup_initial_init_mm()
I might be missing something, but AFAIU the init_mm.start_code and other
fields are not used really early so the new setup_initial_init_mm()
function can be called in the generic code outside setup_arch(), e.g in
mm_init().
Hi Mike， each architecture has their own value, not the same, eg m68K and
h8300, also the name of the text/code/brk is different in some arch, so I keep
unchanged.
What you could do is to define a __weak function that architectures can override and call that function from mm_init() as suggested by Mike,
Something like:
void __weak setup_initial_init_mm(void)
{
init_mm.start_code = (unsigned long)_stext;
init_mm.end_code = (unsigned long)_etext;
init_mm.end_data = (unsigned long)_edata;
init_mm.brk = (unsigned long)_end;
}
Then only the few architecture that are different would override it.
I see a few archictectures are usigne PAGE_OFFSET to set .start_code, but it is likely that this is equivalent to _stext.
Christophe
From: Kefeng Wang <hidden> Date: 2021-06-07 08:30:47
On 2021/6/7 13:48, Christophe Leroy wrote:
Hi Kefeng,
Le 07/06/2021 à 02:55, Kefeng Wang a écrit :
quoted
On 2021/6/7 5:29, Mike Rapoport wrote:
quoted
Hello Kefeng,
On Fri, Jun 04, 2021 at 03:06:18PM +0800, Kefeng Wang wrote:
quoted
Add setup_initial_init_mm() helper, then use it
to cleanup the text, data and brk setup code.
v2:
- change argument from "char *" to "void *" setup_initial_init_mm()
suggested by Geert Uytterhoeven
- use NULL instead of (void *)0 on h8300 and m68k
- collect ACKs
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-csky@vger.kernel.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-m68k@lists.linux-m68k.org
Cc: openrisc@lists.librecores.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-sh@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Kefeng Wang (15):
mm: add setup_initial_init_mm() helper
arc: convert to setup_initial_init_mm()
arm: convert to setup_initial_init_mm()
arm64: convert to setup_initial_init_mm()
csky: convert to setup_initial_init_mm()
h8300: convert to setup_initial_init_mm()
m68k: convert to setup_initial_init_mm()
nds32: convert to setup_initial_init_mm()
nios2: convert to setup_initial_init_mm()
openrisc: convert to setup_initial_init_mm()
powerpc: convert to setup_initial_init_mm()
riscv: convert to setup_initial_init_mm()
s390: convert to setup_initial_init_mm()
sh: convert to setup_initial_init_mm()
x86: convert to setup_initial_init_mm()
I might be missing something, but AFAIU the init_mm.start_code and other
fields are not used really early so the new setup_initial_init_mm()
function can be called in the generic code outside setup_arch(), e.g in
mm_init().
Hi Mike， each architecture has their own value, not the same, eg m68K and
h8300, also the name of the text/code/brk is different in some arch, so I keep
unchanged.
What you could do is to define a __weak function that architectures can override and call that function from mm_init() as suggested by Mike,
Something like:
void __weak setup_initial_init_mm(void)
{
init_mm.start_code = (unsigned long)_stext;
init_mm.end_code = (unsigned long)_etext;
init_mm.end_data = (unsigned long)_edata;
init_mm.brk = (unsigned long)_end;
}
Then only the few architecture that are different would override it.
I see a few archictectures are usigne PAGE_OFFSET to set .start_code, but it is likely that this is equivalent to _stext.
Yes, the __weak function is option, but the change is only covered 14 archs, there are 7 other archs（alpha hexagon ia64
microblaze mips sparc um xtensa）without related setup code. Also like x86, it has own brk , maybe there are some
other different in some arch, so I think let's keep unchanged for now, thanks.
From: "Russell King (Oracle)" <linux@armlinux.org.uk> Date: 2021-06-07 09:31:37
On Mon, Jun 07, 2021 at 07:48:54AM +0200, Christophe Leroy wrote:
Hi Kefeng,
What you could do is to define a __weak function that architectures can
override and call that function from mm_init() as suggested by Mike,
The problem with weak functions is that they bloat the kernel. Each
time a weak function is overriden, it becomes dead unreachable code
within the kernel image.
At some point we're probabily going to have to enable -ffunction-sections
to (hopefully) allow the dead code to be discarded.
--
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