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* [PATCH kernel 0/6] powerpc: Build with LLVM_IAS=1
@ 2021-12-21  5:58 ` Alexey Kardashevskiy
  0 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:58 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Alexey Kardashevskiy, llvm, Nick Desaulniers, Alan Modra,
	Nicholas Piggin, Daniel Axtens

This allows compiling the upstream Linux with the upstream llvm with one fix on top;
https://reviews.llvm.org/D115419

This is based on sha1
798527287598 Michael Ellerman "Automatic merge of 'next' into merge (2021-12-14 00:12)".

Please comment. Thanks.



Alan Modra (1):
  powerpc/toc: PowerPC64 future proof kernel toc, revised for lld

Alexey Kardashevskiy (3):
  powerpc/64/asm: Inline BRANCH_TO_C000
  powerpc/mm: Switch obsolete dssall to .long
  powerpc/mm/book3s64/hash: Switch pre 2.06 tlbiel to .long

Daniel Axtens (2):
  powerpc: check for support for -Wa,-m{power4,any}
  powerpc/64/asm: Do not reassign labels

 arch/powerpc/Makefile                   |  9 +++--
 arch/powerpc/include/asm/head-64.h      | 12 +++----
 arch/powerpc/include/asm/ppc-opcode.h   |  4 +++
 arch/powerpc/include/asm/sections.h     | 14 ++++----
 arch/powerpc/kernel/idle.c              |  2 +-
 arch/powerpc/mm/book3s64/hash_native.c  |  4 +--
 arch/powerpc/mm/mmu_context.c           |  2 +-
 arch/powerpc/boot/crt0.S                |  2 +-
 arch/powerpc/boot/zImage.lds.S          |  7 ++--
 arch/powerpc/kernel/exceptions-64s.S    | 47 ++++++++++---------------
 arch/powerpc/kernel/head_64.S           | 20 +++++------
 arch/powerpc/kernel/idle_6xx.S          |  2 +-
 arch/powerpc/kernel/interrupt_64.S      |  2 +-
 arch/powerpc/kernel/l2cr_6xx.S          |  6 ++--
 arch/powerpc/kernel/swsusp_32.S         |  2 +-
 arch/powerpc/kernel/swsusp_asm64.S      |  2 +-
 arch/powerpc/kernel/vmlinux.lds.S       |  8 ++---
 arch/powerpc/platforms/powermac/cache.S |  4 +--
 18 files changed, 69 insertions(+), 80 deletions(-)

-- 
2.30.2


^ permalink raw reply	[flat|nested] 16+ messages in thread
* [PATCH kernel 0/6] powerpc: Build with LLVM_IAS=1
@ 2021-12-21  5:58 ` Alexey Kardashevskiy
  0 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:58 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Segher Boessenkool, Nick Desaulniers, Nicholas Piggin,
	Daniel Axtens, Christophe Leroy, Alan Modra, llvm,
	Alexey Kardashevskiy

This allows compiling the upstream Linux with the upstream llvm with one fix on top;
https://reviews.llvm.org/D115419

This is based on sha1
798527287598 Michael Ellerman "Automatic merge of 'next' into merge (2021-12-14 00:12)".

Please comment. Thanks.



Alan Modra (1):
  powerpc/toc: PowerPC64 future proof kernel toc, revised for lld

Alexey Kardashevskiy (3):
  powerpc/64/asm: Inline BRANCH_TO_C000
  powerpc/mm: Switch obsolete dssall to .long
  powerpc/mm/book3s64/hash: Switch pre 2.06 tlbiel to .long

Daniel Axtens (2):
  powerpc: check for support for -Wa,-m{power4,any}
  powerpc/64/asm: Do not reassign labels

 arch/powerpc/Makefile                   |  9 +++--
 arch/powerpc/include/asm/head-64.h      | 12 +++----
 arch/powerpc/include/asm/ppc-opcode.h   |  4 +++
 arch/powerpc/include/asm/sections.h     | 14 ++++----
 arch/powerpc/kernel/idle.c              |  2 +-
 arch/powerpc/mm/book3s64/hash_native.c  |  4 +--
 arch/powerpc/mm/mmu_context.c           |  2 +-
 arch/powerpc/boot/crt0.S                |  2 +-
 arch/powerpc/boot/zImage.lds.S          |  7 ++--
 arch/powerpc/kernel/exceptions-64s.S    | 47 ++++++++++---------------
 arch/powerpc/kernel/head_64.S           | 20 +++++------
 arch/powerpc/kernel/idle_6xx.S          |  2 +-
 arch/powerpc/kernel/interrupt_64.S      |  2 +-
 arch/powerpc/kernel/l2cr_6xx.S          |  6 ++--
 arch/powerpc/kernel/swsusp_32.S         |  2 +-
 arch/powerpc/kernel/swsusp_asm64.S      |  2 +-
 arch/powerpc/kernel/vmlinux.lds.S       |  8 ++---
 arch/powerpc/platforms/powermac/cache.S |  4 +--
 18 files changed, 69 insertions(+), 80 deletions(-)

-- 
2.30.2


^ permalink raw reply	[flat|nested] 16+ messages in thread
* [PATCH llvm 1/6] powerpc/toc: PowerPC64 future proof kernel toc, revised for lld
  2021-12-21  5:58 ` Alexey Kardashevskiy
@ 2021-12-21  5:58   ` Alexey Kardashevskiy
  -1 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:58 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Alexey Kardashevskiy, llvm, Nick Desaulniers, Alan Modra,
	Nicholas Piggin, Daniel Axtens

From: Alan Modra <amodra@au1.ibm.com>

This patch future-proofs the kernel against linker changes that might
put the toc pointer at some location other than .got+0x8000, by
replacing __toc_start+0x8000 with .TOC. throughout.  If the kernel's
idea of the toc pointer doesn't agree with the linker, bad things
happen.

prom_init.c code relocating its toc is also changed so that a symbolic
__prom_init_toc_start toc-pointer relative address is calculated
rather than assuming that it is always at toc-pointer - 0x8000.  The
length calculations loading values from the toc are also avoided.
It's a little incestuous to do that with unreloc_toc picking up
adjusted values (which is fine in practice, they both adjust by the
same amount if all goes well).

I've also changed the way .got is aligned in vmlinux.lds and
zImage.lds, mostly so that dumping out section info by objdump or
readelf plainly shows the alignment is 256.  This linker script
feature was added 2005-09-27, available in FSF binutils releases from
2.17 onwards.  Should be safe to use in the kernel, I think.

Finally, put *(.got) before the prom_init.o entry which only needs
*(.toc), so that the GOT header goes in the correct place.  I don't
believe this makes any difference for the kernel as it would for
dynamic objects being loaded by ld.so.  That change is just to stop
lusers who blindly copy kernel scripts being led astray.  Of course,
this change needs the prom_init.c changes.

Some notes on .toc and .got.

.toc is a compiler generated section of addresses.  .got is a linker
generated section of addresses, generally built when the linker sees
R_*_*GOT* relocations.  In the case of powerpc64 ld.bfd, there are
multiple generated .got sections, one per input object file.  So you
can somewhat reasonably write in a linker script an input section
statement like *prom_init.o(.got .toc) to mean "the .got and .toc
section for files matching *prom_init.o".  On other architectures that
doesn't make sense, because the linker generally has just one .got
section.  Even on powerpc64, note well that the GOT entries for
prom_init.o may be merged with GOT entries from other objects.  That
means that if prom_init.o references, say, _end via some GOT
relocation, and some other object also references _end via a GOT
relocation, the GOT entry for _end may be in the range
__prom_init_toc_start to __prom_init_toc_end and if the kernel does
something special to GOT/TOC entries in that range then the value of
_end as seen by objects other than prom_init.o will be affected.  On
the other hand the GOT entry for _end may not be in the range
__prom_init_toc_start to __prom_init_toc_end.  Which way it turns out
is deterministic but a detail of linker operation that should not be
relied on.

A feature of ld.bfd is that input .toc (and .got) sections matching
one linker input section statement may be sorted, to put entries used
by small-model code first, near the toc base.  This is why scripts for
powerpc64 normally use *(.got .toc) rather than *(.got) *(.toc), since
the first form allows more freedom to sort.

Another feature of ld.bfd is that indirect addressing sequences using
the GOT/TOC may be edited by the linker to relative addressing.  In
many cases relative addressing would be emitted by gcc for
-mcmodel=medium if you appropriately decorate variable declarations
with non-default visibility.

The original patch is here:
https://lore.kernel.org/linuxppc-dev/20210310034813.GM6042@bubble.grove.modra.org/

Signed-off-by: Alan Modra <amodra@au1.ibm.com>
[aik: removed non-relocatable which is gone in 24d33ac5b8ffb]
[aik: added <=2.24 check]
[aik: because of llvm-as, kernel_toc_addr() uses "mr" instead of global register variable]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/Makefile               |  5 +++--
 arch/powerpc/include/asm/sections.h | 14 +++++++-------
 arch/powerpc/boot/crt0.S            |  2 +-
 arch/powerpc/boot/zImage.lds.S      |  7 ++-----
 arch/powerpc/kernel/head_64.S       |  2 +-
 arch/powerpc/kernel/vmlinux.lds.S   |  8 +++-----
 6 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index e02568f17334..e9aa4e8b07dd 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -445,10 +445,11 @@ PHONY += checkbin
 # Check toolchain versions:
 # - gcc-4.6 is the minimum kernel-wide version so nothing required.
 checkbin:
-	@if test "x${CONFIG_CPU_LITTLE_ENDIAN}" = "xy" \
-	    && $(LD) --version | head -1 | grep ' 2\.24$$' >/dev/null ; then \
+	@if test "x${CONFIG_LD_IS_LLD}" != "xy" -a \
+		"x$(call ld-ifversion, -le, 22400, y)" = "xy" ; then \
 		echo -n '*** binutils 2.24 miscompiles weak symbols ' ; \
 		echo 'in some circumstances.' ; \
+		echo    '*** binutils 2.23 do not define the TOC symbol ' ; \
 		echo -n '*** Please use a different binutils version.' ; \
 		false ; \
 	fi
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index 79cb7a25a5fb..38f79e42bf3c 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -25,16 +25,16 @@ extern char start_virt_trampolines[];
 extern char end_virt_trampolines[];
 #endif
 
+/*
+ * This assumes the kernel is never compiled -mcmodel=small or
+ * the total .toc is always less than 64k.
+ */
 static inline unsigned long kernel_toc_addr(void)
 {
-	/* Defined by the linker, see vmlinux.lds.S */
-	extern unsigned long __toc_start;
+	unsigned long toc_ptr;
 
-	/*
-	 * The TOC register (r2) points 32kB into the TOC, so that 64kB of
-	 * the TOC can be addressed using a single machine instruction.
-	 */
-	return (unsigned long)(&__toc_start) + 0x8000UL;
+	asm volatile("mr %0, 2" : "=r" (toc_ptr));
+	return toc_ptr;
 }
 
 static inline int overlaps_interrupt_vector_text(unsigned long start,
diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S
index e8f10a599659..feadee18e271 100644
--- a/arch/powerpc/boot/crt0.S
+++ b/arch/powerpc/boot/crt0.S
@@ -28,7 +28,7 @@ p_etext:	.8byte	_etext
 p_bss_start:	.8byte	__bss_start
 p_end:		.8byte	_end
 
-p_toc:		.8byte	__toc_start + 0x8000 - p_base
+p_toc:		.8byte	.TOC. - p_base
 p_dyn:		.8byte	__dynamic_start - p_base
 p_rela:		.8byte	__rela_dyn_start - p_base
 p_prom:		.8byte	0
diff --git a/arch/powerpc/boot/zImage.lds.S b/arch/powerpc/boot/zImage.lds.S
index d6f072865627..d65cd55a6f38 100644
--- a/arch/powerpc/boot/zImage.lds.S
+++ b/arch/powerpc/boot/zImage.lds.S
@@ -36,12 +36,9 @@ SECTIONS
   }
 
 #ifdef CONFIG_PPC64_BOOT_WRAPPER
-  . = ALIGN(256);
-  .got :
+  .got : ALIGN(256)
   {
-    __toc_start = .;
-    *(.got)
-    *(.toc)
+    *(.got .toc)
   }
 #endif
 
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index f17ae2083733..a08c050ff645 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -904,7 +904,7 @@ _GLOBAL(relative_toc)
 	blr
 
 .balign 8
-p_toc:	.8byte	__toc_start + 0x8000 - 0b
+p_toc:	.8byte	.TOC. - 0b
 
 /*
  * This is where the main kernel code starts.
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index dfc3f39d365f..2bcca818136a 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -337,15 +337,13 @@ SECTIONS
 		*(.branch_lt)
 	}
 
-	. = ALIGN(256);
-	.got : AT(ADDR(.got) - LOAD_OFFSET) {
-		__toc_start = .;
+	.got : AT(ADDR(.got) - LOAD_OFFSET) ALIGN(256) {
+		*(.got)
 #ifndef CONFIG_RELOCATABLE
 		__prom_init_toc_start = .;
-		arch/powerpc/kernel/prom_init.o*(.toc .got)
+		arch/powerpc/kernel/prom_init.o*(.toc)
 		__prom_init_toc_end = .;
 #endif
-		*(.got)
 		*(.toc)
 	}
 #endif
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 1/6] powerpc/toc: PowerPC64 future proof kernel toc, revised for lld
@ 2021-12-21  5:58   ` Alexey Kardashevskiy
  0 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:58 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Segher Boessenkool, Nick Desaulniers, Nicholas Piggin,
	Daniel Axtens, Christophe Leroy, Alan Modra, llvm,
	Alexey Kardashevskiy

From: Alan Modra <amodra@au1.ibm.com>

This patch future-proofs the kernel against linker changes that might
put the toc pointer at some location other than .got+0x8000, by
replacing __toc_start+0x8000 with .TOC. throughout.  If the kernel's
idea of the toc pointer doesn't agree with the linker, bad things
happen.

prom_init.c code relocating its toc is also changed so that a symbolic
__prom_init_toc_start toc-pointer relative address is calculated
rather than assuming that it is always at toc-pointer - 0x8000.  The
length calculations loading values from the toc are also avoided.
It's a little incestuous to do that with unreloc_toc picking up
adjusted values (which is fine in practice, they both adjust by the
same amount if all goes well).

I've also changed the way .got is aligned in vmlinux.lds and
zImage.lds, mostly so that dumping out section info by objdump or
readelf plainly shows the alignment is 256.  This linker script
feature was added 2005-09-27, available in FSF binutils releases from
2.17 onwards.  Should be safe to use in the kernel, I think.

Finally, put *(.got) before the prom_init.o entry which only needs
*(.toc), so that the GOT header goes in the correct place.  I don't
believe this makes any difference for the kernel as it would for
dynamic objects being loaded by ld.so.  That change is just to stop
lusers who blindly copy kernel scripts being led astray.  Of course,
this change needs the prom_init.c changes.

Some notes on .toc and .got.

.toc is a compiler generated section of addresses.  .got is a linker
generated section of addresses, generally built when the linker sees
R_*_*GOT* relocations.  In the case of powerpc64 ld.bfd, there are
multiple generated .got sections, one per input object file.  So you
can somewhat reasonably write in a linker script an input section
statement like *prom_init.o(.got .toc) to mean "the .got and .toc
section for files matching *prom_init.o".  On other architectures that
doesn't make sense, because the linker generally has just one .got
section.  Even on powerpc64, note well that the GOT entries for
prom_init.o may be merged with GOT entries from other objects.  That
means that if prom_init.o references, say, _end via some GOT
relocation, and some other object also references _end via a GOT
relocation, the GOT entry for _end may be in the range
__prom_init_toc_start to __prom_init_toc_end and if the kernel does
something special to GOT/TOC entries in that range then the value of
_end as seen by objects other than prom_init.o will be affected.  On
the other hand the GOT entry for _end may not be in the range
__prom_init_toc_start to __prom_init_toc_end.  Which way it turns out
is deterministic but a detail of linker operation that should not be
relied on.

A feature of ld.bfd is that input .toc (and .got) sections matching
one linker input section statement may be sorted, to put entries used
by small-model code first, near the toc base.  This is why scripts for
powerpc64 normally use *(.got .toc) rather than *(.got) *(.toc), since
the first form allows more freedom to sort.

Another feature of ld.bfd is that indirect addressing sequences using
the GOT/TOC may be edited by the linker to relative addressing.  In
many cases relative addressing would be emitted by gcc for
-mcmodel=medium if you appropriately decorate variable declarations
with non-default visibility.

The original patch is here:
https://lore.kernel.org/linuxppc-dev/20210310034813.GM6042@bubble.grove.modra.org/

Signed-off-by: Alan Modra <amodra@au1.ibm.com>
[aik: removed non-relocatable which is gone in 24d33ac5b8ffb]
[aik: added <=2.24 check]
[aik: because of llvm-as, kernel_toc_addr() uses "mr" instead of global register variable]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/Makefile               |  5 +++--
 arch/powerpc/include/asm/sections.h | 14 +++++++-------
 arch/powerpc/boot/crt0.S            |  2 +-
 arch/powerpc/boot/zImage.lds.S      |  7 ++-----
 arch/powerpc/kernel/head_64.S       |  2 +-
 arch/powerpc/kernel/vmlinux.lds.S   |  8 +++-----
 6 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index e02568f17334..e9aa4e8b07dd 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -445,10 +445,11 @@ PHONY += checkbin
 # Check toolchain versions:
 # - gcc-4.6 is the minimum kernel-wide version so nothing required.
 checkbin:
-	@if test "x${CONFIG_CPU_LITTLE_ENDIAN}" = "xy" \
-	    && $(LD) --version | head -1 | grep ' 2\.24$$' >/dev/null ; then \
+	@if test "x${CONFIG_LD_IS_LLD}" != "xy" -a \
+		"x$(call ld-ifversion, -le, 22400, y)" = "xy" ; then \
 		echo -n '*** binutils 2.24 miscompiles weak symbols ' ; \
 		echo 'in some circumstances.' ; \
+		echo    '*** binutils 2.23 do not define the TOC symbol ' ; \
 		echo -n '*** Please use a different binutils version.' ; \
 		false ; \
 	fi
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index 79cb7a25a5fb..38f79e42bf3c 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -25,16 +25,16 @@ extern char start_virt_trampolines[];
 extern char end_virt_trampolines[];
 #endif
 
+/*
+ * This assumes the kernel is never compiled -mcmodel=small or
+ * the total .toc is always less than 64k.
+ */
 static inline unsigned long kernel_toc_addr(void)
 {
-	/* Defined by the linker, see vmlinux.lds.S */
-	extern unsigned long __toc_start;
+	unsigned long toc_ptr;
 
-	/*
-	 * The TOC register (r2) points 32kB into the TOC, so that 64kB of
-	 * the TOC can be addressed using a single machine instruction.
-	 */
-	return (unsigned long)(&__toc_start) + 0x8000UL;
+	asm volatile("mr %0, 2" : "=r" (toc_ptr));
+	return toc_ptr;
 }
 
 static inline int overlaps_interrupt_vector_text(unsigned long start,
diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S
index e8f10a599659..feadee18e271 100644
--- a/arch/powerpc/boot/crt0.S
+++ b/arch/powerpc/boot/crt0.S
@@ -28,7 +28,7 @@ p_etext:	.8byte	_etext
 p_bss_start:	.8byte	__bss_start
 p_end:		.8byte	_end
 
-p_toc:		.8byte	__toc_start + 0x8000 - p_base
+p_toc:		.8byte	.TOC. - p_base
 p_dyn:		.8byte	__dynamic_start - p_base
 p_rela:		.8byte	__rela_dyn_start - p_base
 p_prom:		.8byte	0
diff --git a/arch/powerpc/boot/zImage.lds.S b/arch/powerpc/boot/zImage.lds.S
index d6f072865627..d65cd55a6f38 100644
--- a/arch/powerpc/boot/zImage.lds.S
+++ b/arch/powerpc/boot/zImage.lds.S
@@ -36,12 +36,9 @@ SECTIONS
   }
 
 #ifdef CONFIG_PPC64_BOOT_WRAPPER
-  . = ALIGN(256);
-  .got :
+  .got : ALIGN(256)
   {
-    __toc_start = .;
-    *(.got)
-    *(.toc)
+    *(.got .toc)
   }
 #endif
 
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index f17ae2083733..a08c050ff645 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -904,7 +904,7 @@ _GLOBAL(relative_toc)
 	blr
 
 .balign 8
-p_toc:	.8byte	__toc_start + 0x8000 - 0b
+p_toc:	.8byte	.TOC. - 0b
 
 /*
  * This is where the main kernel code starts.
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index dfc3f39d365f..2bcca818136a 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -337,15 +337,13 @@ SECTIONS
 		*(.branch_lt)
 	}
 
-	. = ALIGN(256);
-	.got : AT(ADDR(.got) - LOAD_OFFSET) {
-		__toc_start = .;
+	.got : AT(ADDR(.got) - LOAD_OFFSET) ALIGN(256) {
+		*(.got)
 #ifndef CONFIG_RELOCATABLE
 		__prom_init_toc_start = .;
-		arch/powerpc/kernel/prom_init.o*(.toc .got)
+		arch/powerpc/kernel/prom_init.o*(.toc)
 		__prom_init_toc_end = .;
 #endif
-		*(.got)
 		*(.toc)
 	}
 #endif
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 2/6] powerpc: check for support for -Wa,-m{power4,any}
  2021-12-21  5:58 ` Alexey Kardashevskiy
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  -1 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Segher Boessenkool, Nick Desaulniers, Nicholas Piggin,
	Daniel Axtens, Christophe Leroy, Alan Modra, llvm,
	Alexey Kardashevskiy

From: Daniel Axtens <dja@axtens.net>

LLVM's integrated assembler does not like either -Wa,-mpower4
or -Wa,-many. So just don't pass them if they're not supported.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/Makefile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index e9aa4e8b07dd..5f16ac1583c5 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -245,7 +245,9 @@ cpu-as-$(CONFIG_E500)		+= -Wa,-me500
 # When using '-many -mpower4' gas will first try and find a matching power4
 # mnemonic and failing that it will allow any valid mnemonic that GAS knows
 # about. GCC will pass -many to GAS when assembling, clang does not.
-cpu-as-$(CONFIG_PPC_BOOK3S_64)	+= -Wa,-mpower4 -Wa,-many
+# LLVM IAS doesn't understand either flag: https://github.com/ClangBuiltLinux/linux/issues/675
+# but LLVM IAS only supports ISA >= 2.06 for Book3S 64 anyway...
+cpu-as-$(CONFIG_PPC_BOOK3S_64)	+= $(call as-option,-Wa$(comma)-mpower4) $(call as-option,-Wa$(comma)-many)
 cpu-as-$(CONFIG_PPC_E500MC)	+= $(call as-option,-Wa$(comma)-me500mc)
 
 KBUILD_AFLAGS += $(cpu-as-y)
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 2/6] powerpc: check for support for -Wa,-m{power4,any}
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  0 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Alexey Kardashevskiy, llvm, Nick Desaulniers, Alan Modra,
	Nicholas Piggin, Daniel Axtens

From: Daniel Axtens <dja@axtens.net>

LLVM's integrated assembler does not like either -Wa,-mpower4
or -Wa,-many. So just don't pass them if they're not supported.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/Makefile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index e9aa4e8b07dd..5f16ac1583c5 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -245,7 +245,9 @@ cpu-as-$(CONFIG_E500)		+= -Wa,-me500
 # When using '-many -mpower4' gas will first try and find a matching power4
 # mnemonic and failing that it will allow any valid mnemonic that GAS knows
 # about. GCC will pass -many to GAS when assembling, clang does not.
-cpu-as-$(CONFIG_PPC_BOOK3S_64)	+= -Wa,-mpower4 -Wa,-many
+# LLVM IAS doesn't understand either flag: https://github.com/ClangBuiltLinux/linux/issues/675
+# but LLVM IAS only supports ISA >= 2.06 for Book3S 64 anyway...
+cpu-as-$(CONFIG_PPC_BOOK3S_64)	+= $(call as-option,-Wa$(comma)-mpower4) $(call as-option,-Wa$(comma)-many)
 cpu-as-$(CONFIG_PPC_E500MC)	+= $(call as-option,-Wa$(comma)-me500mc)
 
 KBUILD_AFLAGS += $(cpu-as-y)
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 3/6] powerpc/64/asm: Inline BRANCH_TO_C000
  2021-12-21  5:58 ` Alexey Kardashevskiy
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  -1 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Segher Boessenkool, Nick Desaulniers, Nicholas Piggin,
	Daniel Axtens, Christophe Leroy, Alan Modra, llvm,
	Alexey Kardashevskiy

It is used just once and does not really help with readability, remove it.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/kernel/exceptions-64s.S | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index a30f563bc7a8..83d37678f7cf 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -89,19 +89,6 @@ name:
 	ori	reg,reg,(ABS_ADDR(label))@l;				\
 	addis	reg,reg,(ABS_ADDR(label))@h
 
-/*
- * Branch to label using its 0xC000 address. This results in instruction
- * address suitable for MSR[IR]=0 or 1, which allows relocation to be turned
- * on using mtmsr rather than rfid.
- *
- * This could set the 0xc bits for !RELOCATABLE as an immediate, rather than
- * load KBASE for a slight optimisation.
- */
-#define BRANCH_TO_C000(reg, label)					\
-	__LOAD_FAR_HANDLER(reg, label);					\
-	mtctr	reg;							\
-	bctr
-
 /*
  * Interrupt code generation macros
  */
@@ -962,7 +949,9 @@ TRAMP_REAL_BEGIN(system_reset_idle_wake)
 	/* We are waking up from idle, so may clobber any volatile register */
 	cmpwi	cr1,r5,2
 	bltlr	cr1	/* no state loss, return to idle caller with r3=SRR1 */
-	BRANCH_TO_C000(r12, DOTSYM(idle_return_gpr_loss))
+	__LOAD_FAR_HANDLER(r12, DOTSYM(idle_return_gpr_loss))
+	mtctr	r12
+	bctr
 #endif
 
 #ifdef CONFIG_PPC_PSERIES
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 3/6] powerpc/64/asm: Inline BRANCH_TO_C000
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  0 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Alexey Kardashevskiy, llvm, Nick Desaulniers, Alan Modra,
	Nicholas Piggin, Daniel Axtens

It is used just once and does not really help with readability, remove it.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/kernel/exceptions-64s.S | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index a30f563bc7a8..83d37678f7cf 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -89,19 +89,6 @@ name:
 	ori	reg,reg,(ABS_ADDR(label))@l;				\
 	addis	reg,reg,(ABS_ADDR(label))@h
 
-/*
- * Branch to label using its 0xC000 address. This results in instruction
- * address suitable for MSR[IR]=0 or 1, which allows relocation to be turned
- * on using mtmsr rather than rfid.
- *
- * This could set the 0xc bits for !RELOCATABLE as an immediate, rather than
- * load KBASE for a slight optimisation.
- */
-#define BRANCH_TO_C000(reg, label)					\
-	__LOAD_FAR_HANDLER(reg, label);					\
-	mtctr	reg;							\
-	bctr
-
 /*
  * Interrupt code generation macros
  */
@@ -962,7 +949,9 @@ TRAMP_REAL_BEGIN(system_reset_idle_wake)
 	/* We are waking up from idle, so may clobber any volatile register */
 	cmpwi	cr1,r5,2
 	bltlr	cr1	/* no state loss, return to idle caller with r3=SRR1 */
-	BRANCH_TO_C000(r12, DOTSYM(idle_return_gpr_loss))
+	__LOAD_FAR_HANDLER(r12, DOTSYM(idle_return_gpr_loss))
+	mtctr	r12
+	bctr
 #endif
 
 #ifdef CONFIG_PPC_PSERIES
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 4/6] powerpc/64/asm: Do not reassign labels
  2021-12-21  5:58 ` Alexey Kardashevskiy
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  -1 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Segher Boessenkool, Nick Desaulniers, Nicholas Piggin,
	Daniel Axtens, Christophe Leroy, Alan Modra, llvm,
	Alexey Kardashevskiy

From: Daniel Axtens <dja@axtens.net>

The LLVM integrated assembler really does not like us reassigning things
to the same label:

<instantiation>:7:9: error: invalid reassignment of non-absolute variable 'fs_label'

This happens across a bunch of platforms:
https://github.com/ClangBuiltLinux/linux/issues/1043
https://github.com/ClangBuiltLinux/linux/issues/1008
https://github.com/ClangBuiltLinux/linux/issues/920
https://github.com/ClangBuiltLinux/linux/issues/1050

There is no hope of getting this fixed in LLVM (see
https://github.com/ClangBuiltLinux/linux/issues/1043#issuecomment-641571200
and https://bugs.llvm.org/show_bug.cgi?id=47798#c1 )
so if we want to build with LLVM_IAS, we need to hack
around it ourselves.

For us the big problem comes from this:

\#define USE_FIXED_SECTION(sname)				\
	fs_label = start_##sname;				\
	fs_start = sname##_start;				\
	use_ftsec sname;

\#define USE_TEXT_SECTION()
	fs_label = start_text;					\
	fs_start = text_start;					\
	.text

and in particular fs_label.

This works around it by not setting those 'variables' and requiring
that users of the variables instead track for themselves what section
they are in. This isn't amazing, by any stretch, but it gets us further
in the compilation.

Note that even though users have to keep track of the section, using
a wrong one produces an error with both binutils and llvm which prevents
from using wrong section at the compile time:

llvm error example:

AS      arch/powerpc/kernel/head_64.o
<unknown>:0: error: Cannot represent a difference across sections
make[3]: *** [/home/aik/p/kernels-llvm/llvm/scripts/Makefile.build:388: arch/powerpc/kernel/head_64.o] Error 1

binutils error example:

/home/aik/p/kernels-llvm/llvm/arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
/home/aik/p/kernels-llvm/llvm/arch/powerpc/kernel/exceptions-64s.S:1974: Error: can't resolve `system_call_common' {.text section} - `start_r
eal_vectors' {.head.text.real_vectors section}
make[3]: *** [/home/aik/p/kernels-llvm/llvm/scripts/Makefile.build:388: arch/powerpc/kernel/head_64.o] Error 1

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/include/asm/head-64.h   | 12 +++++------
 arch/powerpc/kernel/exceptions-64s.S | 32 ++++++++++++++--------------
 arch/powerpc/kernel/head_64.S        | 18 ++++++++--------
 arch/powerpc/kernel/interrupt_64.S   |  2 +-
 4 files changed, 31 insertions(+), 33 deletions(-)

diff --git a/arch/powerpc/include/asm/head-64.h b/arch/powerpc/include/asm/head-64.h
index 242204e12993..d73153b0275d 100644
--- a/arch/powerpc/include/asm/head-64.h
+++ b/arch/powerpc/include/asm/head-64.h
@@ -98,13 +98,9 @@ linker_stub_catch:						\
 	. = sname##_len;
 
 #define USE_FIXED_SECTION(sname)				\
-	fs_label = start_##sname;				\
-	fs_start = sname##_start;				\
 	use_ftsec sname;
 
 #define USE_TEXT_SECTION()					\
-	fs_label = start_text;					\
-	fs_start = text_start;					\
 	.text
 
 #define CLOSE_FIXED_SECTION(sname)				\
@@ -161,13 +157,15 @@ end_##sname:
  * - ABS_ADDR is used to find the absolute address of any symbol, from within
  *   a fixed section.
  */
-#define DEFINE_FIXED_SYMBOL(label)				\
-	label##_absolute = (label - fs_label + fs_start)
+// define label as being _in_ sname
+#define DEFINE_FIXED_SYMBOL(label, sname) \
+	label##_absolute = (label - start_ ## sname + sname ## _start)
 
 #define FIXED_SYMBOL_ABS_ADDR(label)				\
 	(label##_absolute)
 
-#define ABS_ADDR(label) (label - fs_label + fs_start)
+// find label from _within_ sname
+#define ABS_ADDR(label, sname) (label - start_ ## sname + sname ## _start)
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 83d37678f7cf..44b70bf535e3 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -48,7 +48,7 @@
 	.balign IFETCH_ALIGN_BYTES;				\
 	.global name;						\
 	_ASM_NOKPROBE_SYMBOL(name);				\
-	DEFINE_FIXED_SYMBOL(name);				\
+	DEFINE_FIXED_SYMBOL(name, text);			\
 name:
 
 #define TRAMP_REAL_BEGIN(name)					\
@@ -76,18 +76,18 @@ name:
 	ld	reg,PACAKBASE(r13);	/* get high part of &label */	\
 	ori	reg,reg,FIXED_SYMBOL_ABS_ADDR(label)
 
-#define __LOAD_HANDLER(reg, label)					\
+#define __LOAD_HANDLER(reg, label, section)					\
 	ld	reg,PACAKBASE(r13);					\
-	ori	reg,reg,(ABS_ADDR(label))@l
+	ori	reg,reg,(ABS_ADDR(label, section))@l
 
 /*
  * Branches from unrelocated code (e.g., interrupts) to labels outside
  * head-y require >64K offsets.
  */
-#define __LOAD_FAR_HANDLER(reg, label)					\
+#define __LOAD_FAR_HANDLER(reg, label, section)					\
 	ld	reg,PACAKBASE(r13);					\
-	ori	reg,reg,(ABS_ADDR(label))@l;				\
-	addis	reg,reg,(ABS_ADDR(label))@h
+	ori	reg,reg,(ABS_ADDR(label, section))@l;				\
+	addis	reg,reg,(ABS_ADDR(label, section))@h
 
 /*
  * Interrupt code generation macros
@@ -363,7 +363,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
  * This switches to virtual mode and sets MSR[RI].
  */
 .macro __GEN_COMMON_ENTRY name
-DEFINE_FIXED_SYMBOL(\name\()_common_real)
+DEFINE_FIXED_SYMBOL(\name\()_common_real, text)
 \name\()_common_real:
 	.if IKVM_REAL
 		KVMTEST \name kvm_interrupt
@@ -386,7 +386,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
 	.endif
 
 	.balign IFETCH_ALIGN_BYTES
-DEFINE_FIXED_SYMBOL(\name\()_common_virt)
+DEFINE_FIXED_SYMBOL(\name\()_common_virt, text)
 \name\()_common_virt:
 	.if IKVM_VIRT
 		KVMTEST \name kvm_interrupt
@@ -400,7 +400,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_virt)
  * want to run in real mode.
  */
 .macro __GEN_REALMODE_COMMON_ENTRY name
-DEFINE_FIXED_SYMBOL(\name\()_common_real)
+DEFINE_FIXED_SYMBOL(\name\()_common_real, text)
 \name\()_common_real:
 	.if IKVM_REAL
 		KVMTEST \name kvm_interrupt
@@ -835,12 +835,12 @@ SOFT_MASK_TABLE(0xc000000000003000, 0xc000000000004000)
 
 #ifdef CONFIG_RELOCATABLE
 TRAMP_VIRT_BEGIN(system_call_vectored_tramp)
-	__LOAD_HANDLER(r10, system_call_vectored_common)
+	__LOAD_HANDLER(r10, system_call_vectored_common, virt_trampolines)
 	mtctr	r10
 	bctr
 
 TRAMP_VIRT_BEGIN(system_call_vectored_sigill_tramp)
-	__LOAD_HANDLER(r10, system_call_vectored_sigill)
+	__LOAD_HANDLER(r10, system_call_vectored_sigill, virt_trampolines)
 	mtctr	r10
 	bctr
 #endif
@@ -949,7 +949,7 @@ TRAMP_REAL_BEGIN(system_reset_idle_wake)
 	/* We are waking up from idle, so may clobber any volatile register */
 	cmpwi	cr1,r5,2
 	bltlr	cr1	/* no state loss, return to idle caller with r3=SRR1 */
-	__LOAD_FAR_HANDLER(r12, DOTSYM(idle_return_gpr_loss))
+	__LOAD_FAR_HANDLER(r12, DOTSYM(idle_return_gpr_loss), real_trampolines)
 	mtctr	r12
 	bctr
 #endif
@@ -1945,12 +1945,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
 	HMT_MEDIUM
 
 	.if ! \virt
-	__LOAD_HANDLER(r10, system_call_common_real)
+	__LOAD_HANDLER(r10, system_call_common_real, real_vectors)
 	mtctr	r10
 	bctr
 	.else
 #ifdef CONFIG_RELOCATABLE
-	__LOAD_HANDLER(r10, system_call_common)
+	__LOAD_HANDLER(r10, system_call_common, virt_vectors)
 	mtctr	r10
 	bctr
 #else
@@ -2004,7 +2004,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
 	 * outside the head section.
 	 */
-	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
+	__LOAD_FAR_HANDLER(r10, kvmppc_hcall, real_trampolines)
 	mtctr   r10
 	bctr
 #else
@@ -3028,7 +3028,7 @@ USE_FIXED_SECTION(virt_trampolines)
 	.align	7
 	.globl	__end_interrupts
 __end_interrupts:
-DEFINE_FIXED_SYMBOL(__end_interrupts)
+DEFINE_FIXED_SYMBOL(__end_interrupts, virt_trampolines)
 
 CLOSE_FIXED_SECTION(real_vectors);
 CLOSE_FIXED_SECTION(real_trampolines);
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index a08c050ff645..5c5181e8d5f1 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -126,7 +126,7 @@ __secondary_hold_acknowledge:
 	. = 0x5c
 	.globl	__run_at_load
 __run_at_load:
-DEFINE_FIXED_SYMBOL(__run_at_load)
+DEFINE_FIXED_SYMBOL(__run_at_load, first_256B)
 	.long	RUN_AT_LOAD_DEFAULT
 #endif
 
@@ -156,7 +156,7 @@ __secondary_hold:
 	/* Tell the master cpu we're here */
 	/* Relocation is off & we are located at an address less */
 	/* than 0x100, so only need to grab low order offset.    */
-	std	r24,(ABS_ADDR(__secondary_hold_acknowledge))(0)
+	std	r24,(ABS_ADDR(__secondary_hold_acknowledge, first_256B))(0)
 	sync
 
 	li	r26,0
@@ -164,7 +164,7 @@ __secondary_hold:
 	tovirt(r26,r26)
 #endif
 	/* All secondary cpus wait here until told to start. */
-100:	ld	r12,(ABS_ADDR(__secondary_hold_spinloop))(r26)
+100:	ld	r12,(ABS_ADDR(__secondary_hold_spinloop, first_256B))(r26)
 	cmpdi	0,r12,0
 	beq	100b
 
@@ -649,15 +649,15 @@ __after_prom_start:
 3:
 #endif
 	/* # bytes of memory to copy */
-	lis	r5,(ABS_ADDR(copy_to_here))@ha
-	addi	r5,r5,(ABS_ADDR(copy_to_here))@l
+	lis	r5,(ABS_ADDR(copy_to_here, text))@ha
+	addi	r5,r5,(ABS_ADDR(copy_to_here, text))@l
 
 	bl	copy_and_flush		/* copy the first n bytes	 */
 					/* this includes the code being	 */
 					/* executed here.		 */
 	/* Jump to the copy of this code that we just made */
-	addis	r8,r3,(ABS_ADDR(4f))@ha
-	addi	r12,r8,(ABS_ADDR(4f))@l
+	addis	r8,r3,(ABS_ADDR(4f, text))@ha
+	addi	r12,r8,(ABS_ADDR(4f, text))@l
 	mtctr	r12
 	bctr
 
@@ -669,8 +669,8 @@ p_end: .8byte _end - copy_to_here
 	 * Now copy the rest of the kernel up to _end, add
 	 * _end - copy_to_here to the copy limit and run again.
 	 */
-	addis   r8,r26,(ABS_ADDR(p_end))@ha
-	ld      r8,(ABS_ADDR(p_end))@l(r8)
+	addis   r8,r26,(ABS_ADDR(p_end, text))@ha
+	ld      r8,(ABS_ADDR(p_end, text))@l(r8)
 	add	r5,r5,r8
 5:	bl	copy_and_flush		/* copy the rest */
 
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
index 2ad223597ca2..d3180139e35a 100644
--- a/arch/powerpc/kernel/interrupt_64.S
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -695,7 +695,7 @@ interrupt_return_macro hsrr
 
 	.globl __end_soft_masked
 __end_soft_masked:
-DEFINE_FIXED_SYMBOL(__end_soft_masked)
+DEFINE_FIXED_SYMBOL(__end_soft_masked, text)
 #endif /* CONFIG_PPC_BOOK3S */
 
 #ifdef CONFIG_PPC_BOOK3S
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 4/6] powerpc/64/asm: Do not reassign labels
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  0 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Alexey Kardashevskiy, llvm, Nick Desaulniers, Alan Modra,
	Nicholas Piggin, Daniel Axtens

From: Daniel Axtens <dja@axtens.net>

The LLVM integrated assembler really does not like us reassigning things
to the same label:

<instantiation>:7:9: error: invalid reassignment of non-absolute variable 'fs_label'

This happens across a bunch of platforms:
https://github.com/ClangBuiltLinux/linux/issues/1043
https://github.com/ClangBuiltLinux/linux/issues/1008
https://github.com/ClangBuiltLinux/linux/issues/920
https://github.com/ClangBuiltLinux/linux/issues/1050

There is no hope of getting this fixed in LLVM (see
https://github.com/ClangBuiltLinux/linux/issues/1043#issuecomment-641571200
and https://bugs.llvm.org/show_bug.cgi?id=47798#c1 )
so if we want to build with LLVM_IAS, we need to hack
around it ourselves.

For us the big problem comes from this:

\#define USE_FIXED_SECTION(sname)				\
	fs_label = start_##sname;				\
	fs_start = sname##_start;				\
	use_ftsec sname;

\#define USE_TEXT_SECTION()
	fs_label = start_text;					\
	fs_start = text_start;					\
	.text

and in particular fs_label.

This works around it by not setting those 'variables' and requiring
that users of the variables instead track for themselves what section
they are in. This isn't amazing, by any stretch, but it gets us further
in the compilation.

Note that even though users have to keep track of the section, using
a wrong one produces an error with both binutils and llvm which prevents
from using wrong section at the compile time:

llvm error example:

AS      arch/powerpc/kernel/head_64.o
<unknown>:0: error: Cannot represent a difference across sections
make[3]: *** [/home/aik/p/kernels-llvm/llvm/scripts/Makefile.build:388: arch/powerpc/kernel/head_64.o] Error 1

binutils error example:

/home/aik/p/kernels-llvm/llvm/arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
/home/aik/p/kernels-llvm/llvm/arch/powerpc/kernel/exceptions-64s.S:1974: Error: can't resolve `system_call_common' {.text section} - `start_r
eal_vectors' {.head.text.real_vectors section}
make[3]: *** [/home/aik/p/kernels-llvm/llvm/scripts/Makefile.build:388: arch/powerpc/kernel/head_64.o] Error 1

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/include/asm/head-64.h   | 12 +++++------
 arch/powerpc/kernel/exceptions-64s.S | 32 ++++++++++++++--------------
 arch/powerpc/kernel/head_64.S        | 18 ++++++++--------
 arch/powerpc/kernel/interrupt_64.S   |  2 +-
 4 files changed, 31 insertions(+), 33 deletions(-)

diff --git a/arch/powerpc/include/asm/head-64.h b/arch/powerpc/include/asm/head-64.h
index 242204e12993..d73153b0275d 100644
--- a/arch/powerpc/include/asm/head-64.h
+++ b/arch/powerpc/include/asm/head-64.h
@@ -98,13 +98,9 @@ linker_stub_catch:						\
 	. = sname##_len;
 
 #define USE_FIXED_SECTION(sname)				\
-	fs_label = start_##sname;				\
-	fs_start = sname##_start;				\
 	use_ftsec sname;
 
 #define USE_TEXT_SECTION()					\
-	fs_label = start_text;					\
-	fs_start = text_start;					\
 	.text
 
 #define CLOSE_FIXED_SECTION(sname)				\
@@ -161,13 +157,15 @@ end_##sname:
  * - ABS_ADDR is used to find the absolute address of any symbol, from within
  *   a fixed section.
  */
-#define DEFINE_FIXED_SYMBOL(label)				\
-	label##_absolute = (label - fs_label + fs_start)
+// define label as being _in_ sname
+#define DEFINE_FIXED_SYMBOL(label, sname) \
+	label##_absolute = (label - start_ ## sname + sname ## _start)
 
 #define FIXED_SYMBOL_ABS_ADDR(label)				\
 	(label##_absolute)
 
-#define ABS_ADDR(label) (label - fs_label + fs_start)
+// find label from _within_ sname
+#define ABS_ADDR(label, sname) (label - start_ ## sname + sname ## _start)
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 83d37678f7cf..44b70bf535e3 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -48,7 +48,7 @@
 	.balign IFETCH_ALIGN_BYTES;				\
 	.global name;						\
 	_ASM_NOKPROBE_SYMBOL(name);				\
-	DEFINE_FIXED_SYMBOL(name);				\
+	DEFINE_FIXED_SYMBOL(name, text);			\
 name:
 
 #define TRAMP_REAL_BEGIN(name)					\
@@ -76,18 +76,18 @@ name:
 	ld	reg,PACAKBASE(r13);	/* get high part of &label */	\
 	ori	reg,reg,FIXED_SYMBOL_ABS_ADDR(label)
 
-#define __LOAD_HANDLER(reg, label)					\
+#define __LOAD_HANDLER(reg, label, section)					\
 	ld	reg,PACAKBASE(r13);					\
-	ori	reg,reg,(ABS_ADDR(label))@l
+	ori	reg,reg,(ABS_ADDR(label, section))@l
 
 /*
  * Branches from unrelocated code (e.g., interrupts) to labels outside
  * head-y require >64K offsets.
  */
-#define __LOAD_FAR_HANDLER(reg, label)					\
+#define __LOAD_FAR_HANDLER(reg, label, section)					\
 	ld	reg,PACAKBASE(r13);					\
-	ori	reg,reg,(ABS_ADDR(label))@l;				\
-	addis	reg,reg,(ABS_ADDR(label))@h
+	ori	reg,reg,(ABS_ADDR(label, section))@l;				\
+	addis	reg,reg,(ABS_ADDR(label, section))@h
 
 /*
  * Interrupt code generation macros
@@ -363,7 +363,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
  * This switches to virtual mode and sets MSR[RI].
  */
 .macro __GEN_COMMON_ENTRY name
-DEFINE_FIXED_SYMBOL(\name\()_common_real)
+DEFINE_FIXED_SYMBOL(\name\()_common_real, text)
 \name\()_common_real:
 	.if IKVM_REAL
 		KVMTEST \name kvm_interrupt
@@ -386,7 +386,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
 	.endif
 
 	.balign IFETCH_ALIGN_BYTES
-DEFINE_FIXED_SYMBOL(\name\()_common_virt)
+DEFINE_FIXED_SYMBOL(\name\()_common_virt, text)
 \name\()_common_virt:
 	.if IKVM_VIRT
 		KVMTEST \name kvm_interrupt
@@ -400,7 +400,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_virt)
  * want to run in real mode.
  */
 .macro __GEN_REALMODE_COMMON_ENTRY name
-DEFINE_FIXED_SYMBOL(\name\()_common_real)
+DEFINE_FIXED_SYMBOL(\name\()_common_real, text)
 \name\()_common_real:
 	.if IKVM_REAL
 		KVMTEST \name kvm_interrupt
@@ -835,12 +835,12 @@ SOFT_MASK_TABLE(0xc000000000003000, 0xc000000000004000)
 
 #ifdef CONFIG_RELOCATABLE
 TRAMP_VIRT_BEGIN(system_call_vectored_tramp)
-	__LOAD_HANDLER(r10, system_call_vectored_common)
+	__LOAD_HANDLER(r10, system_call_vectored_common, virt_trampolines)
 	mtctr	r10
 	bctr
 
 TRAMP_VIRT_BEGIN(system_call_vectored_sigill_tramp)
-	__LOAD_HANDLER(r10, system_call_vectored_sigill)
+	__LOAD_HANDLER(r10, system_call_vectored_sigill, virt_trampolines)
 	mtctr	r10
 	bctr
 #endif
@@ -949,7 +949,7 @@ TRAMP_REAL_BEGIN(system_reset_idle_wake)
 	/* We are waking up from idle, so may clobber any volatile register */
 	cmpwi	cr1,r5,2
 	bltlr	cr1	/* no state loss, return to idle caller with r3=SRR1 */
-	__LOAD_FAR_HANDLER(r12, DOTSYM(idle_return_gpr_loss))
+	__LOAD_FAR_HANDLER(r12, DOTSYM(idle_return_gpr_loss), real_trampolines)
 	mtctr	r12
 	bctr
 #endif
@@ -1945,12 +1945,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
 	HMT_MEDIUM
 
 	.if ! \virt
-	__LOAD_HANDLER(r10, system_call_common_real)
+	__LOAD_HANDLER(r10, system_call_common_real, real_vectors)
 	mtctr	r10
 	bctr
 	.else
 #ifdef CONFIG_RELOCATABLE
-	__LOAD_HANDLER(r10, system_call_common)
+	__LOAD_HANDLER(r10, system_call_common, virt_vectors)
 	mtctr	r10
 	bctr
 #else
@@ -2004,7 +2004,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
 	 * outside the head section.
 	 */
-	__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
+	__LOAD_FAR_HANDLER(r10, kvmppc_hcall, real_trampolines)
 	mtctr   r10
 	bctr
 #else
@@ -3028,7 +3028,7 @@ USE_FIXED_SECTION(virt_trampolines)
 	.align	7
 	.globl	__end_interrupts
 __end_interrupts:
-DEFINE_FIXED_SYMBOL(__end_interrupts)
+DEFINE_FIXED_SYMBOL(__end_interrupts, virt_trampolines)
 
 CLOSE_FIXED_SECTION(real_vectors);
 CLOSE_FIXED_SECTION(real_trampolines);
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index a08c050ff645..5c5181e8d5f1 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -126,7 +126,7 @@ __secondary_hold_acknowledge:
 	. = 0x5c
 	.globl	__run_at_load
 __run_at_load:
-DEFINE_FIXED_SYMBOL(__run_at_load)
+DEFINE_FIXED_SYMBOL(__run_at_load, first_256B)
 	.long	RUN_AT_LOAD_DEFAULT
 #endif
 
@@ -156,7 +156,7 @@ __secondary_hold:
 	/* Tell the master cpu we're here */
 	/* Relocation is off & we are located at an address less */
 	/* than 0x100, so only need to grab low order offset.    */
-	std	r24,(ABS_ADDR(__secondary_hold_acknowledge))(0)
+	std	r24,(ABS_ADDR(__secondary_hold_acknowledge, first_256B))(0)
 	sync
 
 	li	r26,0
@@ -164,7 +164,7 @@ __secondary_hold:
 	tovirt(r26,r26)
 #endif
 	/* All secondary cpus wait here until told to start. */
-100:	ld	r12,(ABS_ADDR(__secondary_hold_spinloop))(r26)
+100:	ld	r12,(ABS_ADDR(__secondary_hold_spinloop, first_256B))(r26)
 	cmpdi	0,r12,0
 	beq	100b
 
@@ -649,15 +649,15 @@ __after_prom_start:
 3:
 #endif
 	/* # bytes of memory to copy */
-	lis	r5,(ABS_ADDR(copy_to_here))@ha
-	addi	r5,r5,(ABS_ADDR(copy_to_here))@l
+	lis	r5,(ABS_ADDR(copy_to_here, text))@ha
+	addi	r5,r5,(ABS_ADDR(copy_to_here, text))@l
 
 	bl	copy_and_flush		/* copy the first n bytes	 */
 					/* this includes the code being	 */
 					/* executed here.		 */
 	/* Jump to the copy of this code that we just made */
-	addis	r8,r3,(ABS_ADDR(4f))@ha
-	addi	r12,r8,(ABS_ADDR(4f))@l
+	addis	r8,r3,(ABS_ADDR(4f, text))@ha
+	addi	r12,r8,(ABS_ADDR(4f, text))@l
 	mtctr	r12
 	bctr
 
@@ -669,8 +669,8 @@ p_end: .8byte _end - copy_to_here
 	 * Now copy the rest of the kernel up to _end, add
 	 * _end - copy_to_here to the copy limit and run again.
 	 */
-	addis   r8,r26,(ABS_ADDR(p_end))@ha
-	ld      r8,(ABS_ADDR(p_end))@l(r8)
+	addis   r8,r26,(ABS_ADDR(p_end, text))@ha
+	ld      r8,(ABS_ADDR(p_end, text))@l(r8)
 	add	r5,r5,r8
 5:	bl	copy_and_flush		/* copy the rest */
 
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
index 2ad223597ca2..d3180139e35a 100644
--- a/arch/powerpc/kernel/interrupt_64.S
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -695,7 +695,7 @@ interrupt_return_macro hsrr
 
 	.globl __end_soft_masked
 __end_soft_masked:
-DEFINE_FIXED_SYMBOL(__end_soft_masked)
+DEFINE_FIXED_SYMBOL(__end_soft_masked, text)
 #endif /* CONFIG_PPC_BOOK3S */
 
 #ifdef CONFIG_PPC_BOOK3S
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 5/6] powerpc/mm: Switch obsolete dssall to .long
  2021-12-21  5:58 ` Alexey Kardashevskiy
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  -1 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Segher Boessenkool, Nick Desaulniers, Nicholas Piggin,
	Daniel Axtens, Christophe Leroy, Alan Modra, llvm,
	Alexey Kardashevskiy

The dssall ("Data Stream Stop All") instruction is obsolete altogether
with other Data Cache Instructions since ISA 2.03 (year 2006).

LLVM IAS does not support it but PPC970 seems to be using it.
This switches dssall to .long as there is no much point in fixing LLVM.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/include/asm/ppc-opcode.h   | 2 ++
 arch/powerpc/kernel/idle.c              | 2 +-
 arch/powerpc/mm/mmu_context.c           | 2 +-
 arch/powerpc/kernel/idle_6xx.S          | 2 +-
 arch/powerpc/kernel/l2cr_6xx.S          | 6 +++---
 arch/powerpc/kernel/swsusp_32.S         | 2 +-
 arch/powerpc/kernel/swsusp_asm64.S      | 2 +-
 arch/powerpc/platforms/powermac/cache.S | 4 ++--
 8 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index f50213e2a3e0..9fe3223e7820 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -249,6 +249,7 @@
 #define PPC_INST_COPY			0x7c20060c
 #define PPC_INST_DCBA			0x7c0005ec
 #define PPC_INST_DCBA_MASK		0xfc0007fe
+#define PPC_INST_DSSALL			0x7e00066c
 #define PPC_INST_ISEL			0x7c00001e
 #define PPC_INST_ISEL_MASK		0xfc00003e
 #define PPC_INST_LSWI			0x7c0004aa
@@ -577,6 +578,7 @@
 #define	PPC_DCBZL(a, b)		stringify_in_c(.long PPC_RAW_DCBZL(a, b))
 #define	PPC_DIVDE(t, a, b)	stringify_in_c(.long PPC_RAW_DIVDE(t, a, b))
 #define	PPC_DIVDEU(t, a, b)	stringify_in_c(.long PPC_RAW_DIVDEU(t, a, b))
+#define PPC_DSSALL		stringify_in_c(.long PPC_INST_DSSALL)
 #define PPC_LQARX(t, a, b, eh)	stringify_in_c(.long PPC_RAW_LQARX(t, a, b, eh))
 #define PPC_STQCX(t, a, b)	stringify_in_c(.long PPC_RAW_STQCX(t, a, b))
 #define PPC_MADDHD(t, a, b, c)	stringify_in_c(.long PPC_RAW_MADDHD(t, a, b, c))
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
index 1f835539fda4..4ad79eb638c6 100644
--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -82,7 +82,7 @@ void power4_idle(void)
 		return;
 
 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		asm volatile("DSSALL ; sync" ::: "memory");
+		asm volatile(PPC_DSSALL " ; sync" ::: "memory");
 
 	power4_idle_nap();
 
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index 735c36f26388..1fb9c99f8679 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -90,7 +90,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 	 * context
 	 */
 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		asm volatile ("dssall");
+		asm volatile (PPC_DSSALL);
 
 	if (!new_on_cpu)
 		membarrier_arch_switch_mm(prev, next, tsk);
diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 13cad9297d82..3c097356366b 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -129,7 +129,7 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFCLR(CPU_FTR_NO_DPM)
 	mtspr	SPRN_HID0,r4
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	lwz	r8,TI_LOCAL_FLAGS(r2)	/* set napping bit */
diff --git a/arch/powerpc/kernel/l2cr_6xx.S b/arch/powerpc/kernel/l2cr_6xx.S
index 225511d73bef..f2e03ed423d0 100644
--- a/arch/powerpc/kernel/l2cr_6xx.S
+++ b/arch/powerpc/kernel/l2cr_6xx.S
@@ -96,7 +96,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_L2CR)
 
 	/* Stop DST streams */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 
@@ -292,7 +292,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_L3CR)
 	isync
 
 	/* Stop DST streams */
-	DSSALL
+	PPC_DSSALL
 	sync
 
 	/* Get the current enable bit of the L3CR into r4 */
@@ -401,7 +401,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_L3CR)
 _GLOBAL(__flush_disable_L1)
 	/* Stop pending alitvec streams and memory accesses */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
  	sync
 
diff --git a/arch/powerpc/kernel/swsusp_32.S b/arch/powerpc/kernel/swsusp_32.S
index f73f4d72fea4..e0cbd63007f2 100644
--- a/arch/powerpc/kernel/swsusp_32.S
+++ b/arch/powerpc/kernel/swsusp_32.S
@@ -181,7 +181,7 @@ _GLOBAL(swsusp_arch_resume)
 #ifdef CONFIG_ALTIVEC
 	/* Stop pending alitvec streams and memory accesses */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif
  	sync
diff --git a/arch/powerpc/kernel/swsusp_asm64.S b/arch/powerpc/kernel/swsusp_asm64.S
index 96bb20715aa9..9f1903c7f540 100644
--- a/arch/powerpc/kernel/swsusp_asm64.S
+++ b/arch/powerpc/kernel/swsusp_asm64.S
@@ -141,7 +141,7 @@ END_FW_FTR_SECTION_IFCLR(FW_FEATURE_LPAR)
 _GLOBAL(swsusp_arch_resume)
 	/* Stop pending alitvec streams and memory accesses */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	sync
 
diff --git a/arch/powerpc/platforms/powermac/cache.S b/arch/powerpc/platforms/powermac/cache.S
index ced225415486..b8ae56e9f414 100644
--- a/arch/powerpc/platforms/powermac/cache.S
+++ b/arch/powerpc/platforms/powermac/cache.S
@@ -48,7 +48,7 @@ flush_disable_75x:
 
 	/* Stop DST streams */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 
@@ -197,7 +197,7 @@ flush_disable_745x:
 	isync
 
 	/* Stop prefetch streams */
-	DSSALL
+	PPC_DSSALL
 	sync
 
 	/* Disable L2 prefetching */
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 5/6] powerpc/mm: Switch obsolete dssall to .long
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  0 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Alexey Kardashevskiy, llvm, Nick Desaulniers, Alan Modra,
	Nicholas Piggin, Daniel Axtens

The dssall ("Data Stream Stop All") instruction is obsolete altogether
with other Data Cache Instructions since ISA 2.03 (year 2006).

LLVM IAS does not support it but PPC970 seems to be using it.
This switches dssall to .long as there is no much point in fixing LLVM.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/include/asm/ppc-opcode.h   | 2 ++
 arch/powerpc/kernel/idle.c              | 2 +-
 arch/powerpc/mm/mmu_context.c           | 2 +-
 arch/powerpc/kernel/idle_6xx.S          | 2 +-
 arch/powerpc/kernel/l2cr_6xx.S          | 6 +++---
 arch/powerpc/kernel/swsusp_32.S         | 2 +-
 arch/powerpc/kernel/swsusp_asm64.S      | 2 +-
 arch/powerpc/platforms/powermac/cache.S | 4 ++--
 8 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index f50213e2a3e0..9fe3223e7820 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -249,6 +249,7 @@
 #define PPC_INST_COPY			0x7c20060c
 #define PPC_INST_DCBA			0x7c0005ec
 #define PPC_INST_DCBA_MASK		0xfc0007fe
+#define PPC_INST_DSSALL			0x7e00066c
 #define PPC_INST_ISEL			0x7c00001e
 #define PPC_INST_ISEL_MASK		0xfc00003e
 #define PPC_INST_LSWI			0x7c0004aa
@@ -577,6 +578,7 @@
 #define	PPC_DCBZL(a, b)		stringify_in_c(.long PPC_RAW_DCBZL(a, b))
 #define	PPC_DIVDE(t, a, b)	stringify_in_c(.long PPC_RAW_DIVDE(t, a, b))
 #define	PPC_DIVDEU(t, a, b)	stringify_in_c(.long PPC_RAW_DIVDEU(t, a, b))
+#define PPC_DSSALL		stringify_in_c(.long PPC_INST_DSSALL)
 #define PPC_LQARX(t, a, b, eh)	stringify_in_c(.long PPC_RAW_LQARX(t, a, b, eh))
 #define PPC_STQCX(t, a, b)	stringify_in_c(.long PPC_RAW_STQCX(t, a, b))
 #define PPC_MADDHD(t, a, b, c)	stringify_in_c(.long PPC_RAW_MADDHD(t, a, b, c))
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
index 1f835539fda4..4ad79eb638c6 100644
--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -82,7 +82,7 @@ void power4_idle(void)
 		return;
 
 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		asm volatile("DSSALL ; sync" ::: "memory");
+		asm volatile(PPC_DSSALL " ; sync" ::: "memory");
 
 	power4_idle_nap();
 
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index 735c36f26388..1fb9c99f8679 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -90,7 +90,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 	 * context
 	 */
 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		asm volatile ("dssall");
+		asm volatile (PPC_DSSALL);
 
 	if (!new_on_cpu)
 		membarrier_arch_switch_mm(prev, next, tsk);
diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 13cad9297d82..3c097356366b 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -129,7 +129,7 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFCLR(CPU_FTR_NO_DPM)
 	mtspr	SPRN_HID0,r4
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	lwz	r8,TI_LOCAL_FLAGS(r2)	/* set napping bit */
diff --git a/arch/powerpc/kernel/l2cr_6xx.S b/arch/powerpc/kernel/l2cr_6xx.S
index 225511d73bef..f2e03ed423d0 100644
--- a/arch/powerpc/kernel/l2cr_6xx.S
+++ b/arch/powerpc/kernel/l2cr_6xx.S
@@ -96,7 +96,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_L2CR)
 
 	/* Stop DST streams */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 
@@ -292,7 +292,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_L3CR)
 	isync
 
 	/* Stop DST streams */
-	DSSALL
+	PPC_DSSALL
 	sync
 
 	/* Get the current enable bit of the L3CR into r4 */
@@ -401,7 +401,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_L3CR)
 _GLOBAL(__flush_disable_L1)
 	/* Stop pending alitvec streams and memory accesses */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
  	sync
 
diff --git a/arch/powerpc/kernel/swsusp_32.S b/arch/powerpc/kernel/swsusp_32.S
index f73f4d72fea4..e0cbd63007f2 100644
--- a/arch/powerpc/kernel/swsusp_32.S
+++ b/arch/powerpc/kernel/swsusp_32.S
@@ -181,7 +181,7 @@ _GLOBAL(swsusp_arch_resume)
 #ifdef CONFIG_ALTIVEC
 	/* Stop pending alitvec streams and memory accesses */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif
  	sync
diff --git a/arch/powerpc/kernel/swsusp_asm64.S b/arch/powerpc/kernel/swsusp_asm64.S
index 96bb20715aa9..9f1903c7f540 100644
--- a/arch/powerpc/kernel/swsusp_asm64.S
+++ b/arch/powerpc/kernel/swsusp_asm64.S
@@ -141,7 +141,7 @@ END_FW_FTR_SECTION_IFCLR(FW_FEATURE_LPAR)
 _GLOBAL(swsusp_arch_resume)
 	/* Stop pending alitvec streams and memory accesses */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	sync
 
diff --git a/arch/powerpc/platforms/powermac/cache.S b/arch/powerpc/platforms/powermac/cache.S
index ced225415486..b8ae56e9f414 100644
--- a/arch/powerpc/platforms/powermac/cache.S
+++ b/arch/powerpc/platforms/powermac/cache.S
@@ -48,7 +48,7 @@ flush_disable_75x:
 
 	/* Stop DST streams */
 BEGIN_FTR_SECTION
-	DSSALL
+	PPC_DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 
@@ -197,7 +197,7 @@ flush_disable_745x:
 	isync
 
 	/* Stop prefetch streams */
-	DSSALL
+	PPC_DSSALL
 	sync
 
 	/* Disable L2 prefetching */
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 6/6] powerpc/mm/book3s64/hash: Switch pre 2.06 tlbiel to .long
  2021-12-21  5:58 ` Alexey Kardashevskiy
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  -1 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Segher Boessenkool, Nick Desaulniers, Nicholas Piggin,
	Daniel Axtens, Christophe Leroy, Alan Modra, llvm,
	Alexey Kardashevskiy

The llvm integrated assembler does not recognise the ISA 2.05 tlbiel
version. Work around it by switching to .long when an old arch level
detected.

Signed-off-by: Daniel Axtens <dja@axtens.net>
[aik: did "Eventually do this more smartly"]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/include/asm/ppc-opcode.h  | 2 ++
 arch/powerpc/mm/book3s64/hash_native.c | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 9fe3223e7820..efad07081cc0 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -394,6 +394,7 @@
 	(0x7c000264 | ___PPC_RB(rb) | ___PPC_RS(rs) | ___PPC_RIC(ric) | ___PPC_PRS(prs) | ___PPC_R(r))
 #define PPC_RAW_TLBIEL(rb, rs, ric, prs, r) \
 	(0x7c000224 | ___PPC_RB(rb) | ___PPC_RS(rs) | ___PPC_RIC(ric) | ___PPC_PRS(prs) | ___PPC_R(r))
+#define PPC_RAW_TLBIEL_v205(rb, l)	(0x7c000224 | ___PPC_RB(rb) | (l << 21))
 #define PPC_RAW_TLBSRX_DOT(a, b)	(0x7c0006a5 | __PPC_RA0(a) | __PPC_RB(b))
 #define PPC_RAW_TLBIVAX(a, b)		(0x7c000624 | __PPC_RA0(a) | __PPC_RB(b))
 #define PPC_RAW_ERATWE(s, a, w)		(0x7c0001a6 | __PPC_RS(s) | __PPC_RA(a) | __PPC_WS(w))
@@ -606,6 +607,7 @@
 				stringify_in_c(.long PPC_RAW_TLBIE_5(rb, rs, ric, prs, r))
 #define	PPC_TLBIEL(rb,rs,ric,prs,r) \
 				stringify_in_c(.long PPC_RAW_TLBIEL(rb, rs, ric, prs, r))
+#define PPC_TLBIEL_v205(rb, l)	stringify_in_c(.long PPC_RAW_TLBIEL_v205(rb, l))
 #define PPC_TLBSRX_DOT(a, b)	stringify_in_c(.long PPC_RAW_TLBSRX_DOT(a, b))
 #define PPC_TLBIVAX(a, b)	stringify_in_c(.long PPC_RAW_TLBIVAX(a, b))
 
diff --git a/arch/powerpc/mm/book3s64/hash_native.c b/arch/powerpc/mm/book3s64/hash_native.c
index d2a320828c0b..623a7b7ab38b 100644
--- a/arch/powerpc/mm/book3s64/hash_native.c
+++ b/arch/powerpc/mm/book3s64/hash_native.c
@@ -163,7 +163,7 @@ static inline void __tlbiel(unsigned long vpn, int psize, int apsize, int ssize)
 		va |= ssize << 8;
 		sllp = get_sllp_encoding(apsize);
 		va |= sllp << 5;
-		asm volatile(ASM_FTR_IFSET("tlbiel %0", "tlbiel %0,0", %1)
+		asm volatile(ASM_FTR_IFSET("tlbiel %0", PPC_TLBIEL_v205(%0, 0), %1)
 			     : : "r" (va), "i" (CPU_FTR_ARCH_206)
 			     : "memory");
 		break;
@@ -182,7 +182,7 @@ static inline void __tlbiel(unsigned long vpn, int psize, int apsize, int ssize)
 		 */
 		va |= (vpn & 0xfe);
 		va |= 1; /* L */
-		asm volatile(ASM_FTR_IFSET("tlbiel %0", "tlbiel %0,1", %1)
+		asm volatile(ASM_FTR_IFSET("tlbiel %0", PPC_TLBIEL_v205(%0, 1), %1)
 			     : : "r" (va), "i" (CPU_FTR_ARCH_206)
 			     : "memory");
 		break;
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* [PATCH llvm 6/6] powerpc/mm/book3s64/hash: Switch pre 2.06 tlbiel to .long
@ 2021-12-21  5:59   ` Alexey Kardashevskiy
  0 siblings, 0 replies; 16+ messages in thread
From: Alexey Kardashevskiy @ 2021-12-21  5:59 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Alexey Kardashevskiy, llvm, Nick Desaulniers, Alan Modra,
	Nicholas Piggin, Daniel Axtens

The llvm integrated assembler does not recognise the ISA 2.05 tlbiel
version. Work around it by switching to .long when an old arch level
detected.

Signed-off-by: Daniel Axtens <dja@axtens.net>
[aik: did "Eventually do this more smartly"]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/include/asm/ppc-opcode.h  | 2 ++
 arch/powerpc/mm/book3s64/hash_native.c | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 9fe3223e7820..efad07081cc0 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -394,6 +394,7 @@
 	(0x7c000264 | ___PPC_RB(rb) | ___PPC_RS(rs) | ___PPC_RIC(ric) | ___PPC_PRS(prs) | ___PPC_R(r))
 #define PPC_RAW_TLBIEL(rb, rs, ric, prs, r) \
 	(0x7c000224 | ___PPC_RB(rb) | ___PPC_RS(rs) | ___PPC_RIC(ric) | ___PPC_PRS(prs) | ___PPC_R(r))
+#define PPC_RAW_TLBIEL_v205(rb, l)	(0x7c000224 | ___PPC_RB(rb) | (l << 21))
 #define PPC_RAW_TLBSRX_DOT(a, b)	(0x7c0006a5 | __PPC_RA0(a) | __PPC_RB(b))
 #define PPC_RAW_TLBIVAX(a, b)		(0x7c000624 | __PPC_RA0(a) | __PPC_RB(b))
 #define PPC_RAW_ERATWE(s, a, w)		(0x7c0001a6 | __PPC_RS(s) | __PPC_RA(a) | __PPC_WS(w))
@@ -606,6 +607,7 @@
 				stringify_in_c(.long PPC_RAW_TLBIE_5(rb, rs, ric, prs, r))
 #define	PPC_TLBIEL(rb,rs,ric,prs,r) \
 				stringify_in_c(.long PPC_RAW_TLBIEL(rb, rs, ric, prs, r))
+#define PPC_TLBIEL_v205(rb, l)	stringify_in_c(.long PPC_RAW_TLBIEL_v205(rb, l))
 #define PPC_TLBSRX_DOT(a, b)	stringify_in_c(.long PPC_RAW_TLBSRX_DOT(a, b))
 #define PPC_TLBIVAX(a, b)	stringify_in_c(.long PPC_RAW_TLBIVAX(a, b))
 
diff --git a/arch/powerpc/mm/book3s64/hash_native.c b/arch/powerpc/mm/book3s64/hash_native.c
index d2a320828c0b..623a7b7ab38b 100644
--- a/arch/powerpc/mm/book3s64/hash_native.c
+++ b/arch/powerpc/mm/book3s64/hash_native.c
@@ -163,7 +163,7 @@ static inline void __tlbiel(unsigned long vpn, int psize, int apsize, int ssize)
 		va |= ssize << 8;
 		sllp = get_sllp_encoding(apsize);
 		va |= sllp << 5;
-		asm volatile(ASM_FTR_IFSET("tlbiel %0", "tlbiel %0,0", %1)
+		asm volatile(ASM_FTR_IFSET("tlbiel %0", PPC_TLBIEL_v205(%0, 0), %1)
 			     : : "r" (va), "i" (CPU_FTR_ARCH_206)
 			     : "memory");
 		break;
@@ -182,7 +182,7 @@ static inline void __tlbiel(unsigned long vpn, int psize, int apsize, int ssize)
 		 */
 		va |= (vpn & 0xfe);
 		va |= 1; /* L */
-		asm volatile(ASM_FTR_IFSET("tlbiel %0", "tlbiel %0,1", %1)
+		asm volatile(ASM_FTR_IFSET("tlbiel %0", PPC_TLBIEL_v205(%0, 1), %1)
 			     : : "r" (va), "i" (CPU_FTR_ARCH_206)
 			     : "memory");
 		break;
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 16+ messages in thread
* Re: [PATCH kernel 0/6] powerpc: Build with LLVM_IAS=1
  2021-12-21  5:58 ` Alexey Kardashevskiy
@ 2021-12-26 21:52   ` Michael Ellerman
  -1 siblings, 0 replies; 16+ messages in thread
From: Michael Ellerman @ 2021-12-26 21:52 UTC (permalink / raw)
  To: Alexey Kardashevskiy, linuxppc-dev
  Cc: llvm, Nick Desaulniers, Alan Modra, Nicholas Piggin, Daniel Axtens

On Tue, 21 Dec 2021 16:58:58 +1100, Alexey Kardashevskiy wrote:
> This allows compiling the upstream Linux with the upstream llvm with one fix on top;
> https://reviews.llvm.org/D115419
> 
> This is based on sha1
> 798527287598 Michael Ellerman "Automatic merge of 'next' into merge (2021-12-14 00:12)".
> 
> Please comment. Thanks.
> 
> [...]

Applied to powerpc/next.

[1/6] powerpc/toc: PowerPC64 future proof kernel toc, revised for lld
      https://git.kernel.org/powerpc/c/a3ad84da076009c94969fa97f604257667e2980f
[2/6] powerpc: check for support for -Wa,-m{power4,any}
      https://git.kernel.org/powerpc/c/f5140cab448e4819ca6f158cb4130352f73c92e4
[3/6] powerpc/64/asm: Inline BRANCH_TO_C000
      https://git.kernel.org/powerpc/c/fd983957971632088908c646116383402f04084b
[4/6] powerpc/64/asm: Do not reassign labels
      https://git.kernel.org/powerpc/c/d72c4a36d7ab560127885473a310ece28988b604
[5/6] powerpc/mm: Switch obsolete dssall to .long
      https://git.kernel.org/powerpc/c/d51f86cfd8e378d4907958db77da3074f6dce3ba
[6/6] powerpc/mm/book3s64/hash: Switch pre 2.06 tlbiel to .long
      https://git.kernel.org/powerpc/c/62479e6e26ef18f00e2e540c0e30156254533a43

cheers

^ permalink raw reply	[flat|nested] 16+ messages in thread
* Re: [PATCH kernel 0/6] powerpc: Build with LLVM_IAS=1
@ 2021-12-26 21:52   ` Michael Ellerman
  0 siblings, 0 replies; 16+ messages in thread
From: Michael Ellerman @ 2021-12-26 21:52 UTC (permalink / raw)
  To: Alexey Kardashevskiy, linuxppc-dev
  Cc: Segher Boessenkool, Christophe Leroy, Nick Desaulniers, llvm,
	Alan Modra, Nicholas Piggin, Daniel Axtens

On Tue, 21 Dec 2021 16:58:58 +1100, Alexey Kardashevskiy wrote:
> This allows compiling the upstream Linux with the upstream llvm with one fix on top;
> https://reviews.llvm.org/D115419
> 
> This is based on sha1
> 798527287598 Michael Ellerman "Automatic merge of 'next' into merge (2021-12-14 00:12)".
> 
> Please comment. Thanks.
> 
> [...]

Applied to powerpc/next.

[1/6] powerpc/toc: PowerPC64 future proof kernel toc, revised for lld
      https://git.kernel.org/powerpc/c/a3ad84da076009c94969fa97f604257667e2980f
[2/6] powerpc: check for support for -Wa,-m{power4,any}
      https://git.kernel.org/powerpc/c/f5140cab448e4819ca6f158cb4130352f73c92e4
[3/6] powerpc/64/asm: Inline BRANCH_TO_C000
      https://git.kernel.org/powerpc/c/fd983957971632088908c646116383402f04084b
[4/6] powerpc/64/asm: Do not reassign labels
      https://git.kernel.org/powerpc/c/d72c4a36d7ab560127885473a310ece28988b604
[5/6] powerpc/mm: Switch obsolete dssall to .long
      https://git.kernel.org/powerpc/c/d51f86cfd8e378d4907958db77da3074f6dce3ba
[6/6] powerpc/mm/book3s64/hash: Switch pre 2.06 tlbiel to .long
      https://git.kernel.org/powerpc/c/62479e6e26ef18f00e2e540c0e30156254533a43

cheers

^ permalink raw reply	[flat|nested] 16+ messages in thread
end of thread, other threads:[~2021-12-26 22:02 UTC | newest]

Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-12-21  5:58 [PATCH kernel 0/6] powerpc: Build with LLVM_IAS=1 Alexey Kardashevskiy
2021-12-21  5:58 ` Alexey Kardashevskiy
2021-12-21  5:58 ` [PATCH llvm 1/6] powerpc/toc: PowerPC64 future proof kernel toc, revised for lld Alexey Kardashevskiy
2021-12-21  5:58   ` Alexey Kardashevskiy
2021-12-21  5:59 ` [PATCH llvm 2/6] powerpc: check for support for -Wa,-m{power4,any} Alexey Kardashevskiy
2021-12-21  5:59   ` Alexey Kardashevskiy
2021-12-21  5:59 ` [PATCH llvm 3/6] powerpc/64/asm: Inline BRANCH_TO_C000 Alexey Kardashevskiy
2021-12-21  5:59   ` Alexey Kardashevskiy
2021-12-21  5:59 ` [PATCH llvm 4/6] powerpc/64/asm: Do not reassign labels Alexey Kardashevskiy
2021-12-21  5:59   ` Alexey Kardashevskiy
2021-12-21  5:59 ` [PATCH llvm 5/6] powerpc/mm: Switch obsolete dssall to .long Alexey Kardashevskiy
2021-12-21  5:59   ` Alexey Kardashevskiy
2021-12-21  5:59 ` [PATCH llvm 6/6] powerpc/mm/book3s64/hash: Switch pre 2.06 tlbiel " Alexey Kardashevskiy
2021-12-21  5:59   ` Alexey Kardashevskiy
2021-12-26 21:52 ` [PATCH kernel 0/6] powerpc: Build with LLVM_IAS=1 Michael Ellerman
2021-12-26 21:52   ` Michael Ellerman

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