* [PATCH 00/10] xtensa: support call0 ABI kernel
@ 2021-10-19 5:17 Max Filippov
2021-10-19 5:17 ` [PATCH 01/10] xtensa: move _SimulateUserKernelVectorException out of WindowVectors Max Filippov
` (9 more replies)
0 siblings, 10 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
Hello,
this series adds support for building kernel with call0 ABI. This
extends linux support to xtensa cores without windowed registers option.
call0 ABI kernel still supports windowed ABI userspace on cores with
windowed registers. In this case kernel entry from the userspace saves
active register windows as usual.
Max Filippov (10):
xtensa: move _SimulateUserKernelVectorException out of WindowVectors
xtensa: use a14 instead of a15 in inline assembly
xtensa: don't use a12 in strncpy_user
xtensa: don't use a12 in __xtensa_copy_user in call0 ABI
xtensa: definitions for call0 ABI
xtensa: implement call0 ABI support in assembly
xtensa: use register window specific opcodes only when present
xtensa: only build windowed register support code when needed
xtensa: remove unused variable wmask
xtensa: move section symbols to asm/sections.h
arch/xtensa/boot/boot-elf/bootstrap.S | 2 +
arch/xtensa/boot/boot-redboot/bootstrap.S | 72 ++++----
arch/xtensa/include/asm/asmmacro.h | 65 +++++++
arch/xtensa/include/asm/atomic.h | 26 +--
arch/xtensa/include/asm/cmpxchg.h | 16 +-
arch/xtensa/include/asm/core.h | 11 ++
arch/xtensa/include/asm/processor.h | 32 +++-
arch/xtensa/include/asm/sections.h | 41 ++++
arch/xtensa/include/asm/traps.h | 2 +
arch/xtensa/kernel/align.S | 2 +
arch/xtensa/kernel/entry.S | 216 ++++++++++++++--------
arch/xtensa/kernel/head.S | 24 ++-
arch/xtensa/kernel/mcount.S | 38 +++-
arch/xtensa/kernel/process.c | 27 ++-
arch/xtensa/kernel/setup.c | 102 ++++------
arch/xtensa/kernel/signal.c | 12 +-
arch/xtensa/kernel/traps.c | 6 +-
arch/xtensa/kernel/vectors.S | 55 +++---
arch/xtensa/kernel/vmlinux.lds.S | 12 +-
arch/xtensa/lib/strncpy_user.S | 17 +-
arch/xtensa/lib/usercopy.S | 28 ++-
21 files changed, 541 insertions(+), 265 deletions(-)
create mode 100644 arch/xtensa/include/asm/sections.h
--
2.20.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 01/10] xtensa: move _SimulateUserKernelVectorException out of WindowVectors
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
2021-10-19 5:17 ` [PATCH 02/10] xtensa: use a14 instead of a15 in inline assembly Max Filippov
` (8 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
In configurations without window registers support the section
.WindowVectors.text may never be linked.
_SimulateUserKernelVectorException is a common handler for high priority
interrupts, it does not belong in that section anyway. Move it out of
that section and mark it as __XTENSA_HANDLER so it gets bundled with
other vector helpers.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/kernel/vectors.S | 40 +++++++++++++++++-------------------
1 file changed, 19 insertions(+), 21 deletions(-)
diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S
index 1a7538ccfc5a..0eed5aa82914 100644
--- a/arch/xtensa/kernel/vectors.S
+++ b/arch/xtensa/kernel/vectors.S
@@ -650,6 +650,25 @@ ENTRY(_Level\level\()InterruptVector)
irq_entry_level 5
irq_entry_level 6
+#if XCHAL_EXCM_LEVEL >= 2
+ /*
+ * Continuation of medium priority interrupt dispatch code.
+ * On entry here, a0 contains PS, and EPC2 contains saved a0:
+ */
+ __XTENSA_HANDLER
+ .align 4
+_SimulateUserKernelVectorException:
+ addi a0, a0, (1 << PS_EXCM_BIT)
+#if !XTENSA_FAKE_NMI
+ wsr a0, ps
+#endif
+ bbsi.l a0, PS_UM_BIT, 1f # branch if user mode
+ xsr a0, excsave2 # restore a0
+ j _KernelExceptionVector # simulate kernel vector exception
+1: xsr a0, excsave2 # restore a0
+ j _UserExceptionVector # simulate user vector exception
+#endif
+
/* Window overflow and underflow handlers.
* The handlers must be 64 bytes apart, first starting with the underflow
@@ -680,27 +699,6 @@ ENTRY_ALIGN64(_WindowOverflow4)
ENDPROC(_WindowOverflow4)
-
-#if XCHAL_EXCM_LEVEL >= 2
- /* Not a window vector - but a convenient location
- * (where we know there's space) for continuation of
- * medium priority interrupt dispatch code.
- * On entry here, a0 contains PS, and EPC2 contains saved a0:
- */
- .align 4
-_SimulateUserKernelVectorException:
- addi a0, a0, (1 << PS_EXCM_BIT)
-#if !XTENSA_FAKE_NMI
- wsr a0, ps
-#endif
- bbsi.l a0, PS_UM_BIT, 1f # branch if user mode
- xsr a0, excsave2 # restore a0
- j _KernelExceptionVector # simulate kernel vector exception
-1: xsr a0, excsave2 # restore a0
- j _UserExceptionVector # simulate user vector exception
-#endif
-
-
/* 4-Register Window Underflow Vector (Handler) */
ENTRY_ALIGN64(_WindowUnderflow4)
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 02/10] xtensa: use a14 instead of a15 in inline assembly
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
2021-10-19 5:17 ` [PATCH 01/10] xtensa: move _SimulateUserKernelVectorException out of WindowVectors Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
2021-10-19 5:17 ` [PATCH 03/10] xtensa: don't use a12 in strncpy_user Max Filippov
` (7 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
a15 is a frame pointer in the call0 xtensa ABI, don't use it explicitly
in the inline assembly. Use a14 instead, as it has the same properties
as a15 w.r.t. window overflow.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/include/asm/atomic.h | 26 +++++++++++++-------------
arch/xtensa/include/asm/cmpxchg.h | 16 ++++++++--------
2 files changed, 21 insertions(+), 21 deletions(-)
diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h
index 4361fe4247e3..52da614f953c 100644
--- a/arch/xtensa/include/asm/atomic.h
+++ b/arch/xtensa/include/asm/atomic.h
@@ -25,15 +25,15 @@
*
* Locking interrupts looks like this:
*
- * rsil a15, TOPLEVEL
+ * rsil a14, TOPLEVEL
* <code>
- * wsr a15, PS
+ * wsr a14, PS
* rsync
*
- * Note that a15 is used here because the register allocation
+ * Note that a14 is used here because the register allocation
* done by the compiler is not guaranteed and a window overflow
* may not occur between the rsil and wsr instructions. By using
- * a15 in the rsil, the machine is guaranteed to be in a state
+ * a14 in the rsil, the machine is guaranteed to be in a state
* where no register reference will cause an overflow.
*/
@@ -185,15 +185,15 @@ static inline void arch_atomic_##op(int i, atomic_t * v) \
unsigned int vval; \
\
__asm__ __volatile__( \
- " rsil a15, "__stringify(TOPLEVEL)"\n" \
+ " rsil a14, "__stringify(TOPLEVEL)"\n" \
" l32i %[result], %[mem]\n" \
" " #op " %[result], %[result], %[i]\n" \
" s32i %[result], %[mem]\n" \
- " wsr a15, ps\n" \
+ " wsr a14, ps\n" \
" rsync\n" \
: [result] "=&a" (vval), [mem] "+m" (*v) \
: [i] "a" (i) \
- : "a15", "memory" \
+ : "a14", "memory" \
); \
} \
@@ -203,15 +203,15 @@ static inline int arch_atomic_##op##_return(int i, atomic_t * v) \
unsigned int vval; \
\
__asm__ __volatile__( \
- " rsil a15,"__stringify(TOPLEVEL)"\n" \
+ " rsil a14,"__stringify(TOPLEVEL)"\n" \
" l32i %[result], %[mem]\n" \
" " #op " %[result], %[result], %[i]\n" \
" s32i %[result], %[mem]\n" \
- " wsr a15, ps\n" \
+ " wsr a14, ps\n" \
" rsync\n" \
: [result] "=&a" (vval), [mem] "+m" (*v) \
: [i] "a" (i) \
- : "a15", "memory" \
+ : "a14", "memory" \
); \
\
return vval; \
@@ -223,16 +223,16 @@ static inline int arch_atomic_fetch_##op(int i, atomic_t * v) \
unsigned int tmp, vval; \
\
__asm__ __volatile__( \
- " rsil a15,"__stringify(TOPLEVEL)"\n" \
+ " rsil a14,"__stringify(TOPLEVEL)"\n" \
" l32i %[result], %[mem]\n" \
" " #op " %[tmp], %[result], %[i]\n" \
" s32i %[tmp], %[mem]\n" \
- " wsr a15, ps\n" \
+ " wsr a14, ps\n" \
" rsync\n" \
: [result] "=&a" (vval), [tmp] "=&a" (tmp), \
[mem] "+m" (*v) \
: [i] "a" (i) \
- : "a15", "memory" \
+ : "a14", "memory" \
); \
\
return vval; \
diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h
index 3699e2818efb..eb87810357ad 100644
--- a/arch/xtensa/include/asm/cmpxchg.h
+++ b/arch/xtensa/include/asm/cmpxchg.h
@@ -52,16 +52,16 @@ __cmpxchg_u32(volatile int *p, int old, int new)
return new;
#else
__asm__ __volatile__(
- " rsil a15, "__stringify(TOPLEVEL)"\n"
+ " rsil a14, "__stringify(TOPLEVEL)"\n"
" l32i %[old], %[mem]\n"
" bne %[old], %[cmp], 1f\n"
" s32i %[new], %[mem]\n"
"1:\n"
- " wsr a15, ps\n"
+ " wsr a14, ps\n"
" rsync\n"
: [old] "=&a" (old), [mem] "+m" (*p)
: [cmp] "a" (old), [new] "r" (new)
- : "a15", "memory");
+ : "a14", "memory");
return old;
#endif
}
@@ -116,10 +116,10 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
/*
* xchg_u32
*
- * Note that a15 is used here because the register allocation
+ * Note that a14 is used here because the register allocation
* done by the compiler is not guaranteed and a window overflow
* may not occur between the rsil and wsr instructions. By using
- * a15 in the rsil, the machine is guaranteed to be in a state
+ * a14 in the rsil, the machine is guaranteed to be in a state
* where no register reference will cause an overflow.
*/
@@ -157,14 +157,14 @@ static inline unsigned long xchg_u32(volatile int * m, unsigned long val)
#else
unsigned long tmp;
__asm__ __volatile__(
- " rsil a15, "__stringify(TOPLEVEL)"\n"
+ " rsil a14, "__stringify(TOPLEVEL)"\n"
" l32i %[tmp], %[mem]\n"
" s32i %[val], %[mem]\n"
- " wsr a15, ps\n"
+ " wsr a14, ps\n"
" rsync\n"
: [tmp] "=&a" (tmp), [mem] "+m" (*m)
: [val] "a" (val)
- : "a15", "memory");
+ : "a14", "memory");
return tmp;
#endif
}
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 03/10] xtensa: don't use a12 in strncpy_user
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
2021-10-19 5:17 ` [PATCH 01/10] xtensa: move _SimulateUserKernelVectorException out of WindowVectors Max Filippov
2021-10-19 5:17 ` [PATCH 02/10] xtensa: use a14 instead of a15 in inline assembly Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
2021-10-19 5:17 ` [PATCH 04/10] xtensa: don't use a12 in __xtensa_copy_user in call0 ABI Max Filippov
` (6 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
a12 is callee-saved register in xtensa call0 ABI, so a function must not
change it. a10 is not used in this function at all, use it instead of
a12 to avoid saving/restoring it.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/lib/strncpy_user.S | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/arch/xtensa/lib/strncpy_user.S b/arch/xtensa/lib/strncpy_user.S
index 4faf46fe3f38..0731912227d3 100644
--- a/arch/xtensa/lib/strncpy_user.S
+++ b/arch/xtensa/lib/strncpy_user.S
@@ -45,7 +45,6 @@
# a9/ tmp
# a10/ tmp
# a11/ dst
-# a12/ tmp
.text
ENTRY(__strncpy_user)
@@ -61,7 +60,7 @@ ENTRY(__strncpy_user)
bbsi.l a3, 0, .Lsrc1mod2 # if only 8-bit aligned
bbsi.l a3, 1, .Lsrc2mod4 # if only 16-bit aligned
.Lsrcaligned: # return here when src is word-aligned
- srli a12, a4, 2 # number of loop iterations with 4B per loop
+ srli a10, a4, 2 # number of loop iterations with 4B per loop
movi a9, 3
bnone a11, a9, .Laligned
j .Ldstunaligned
@@ -102,11 +101,11 @@ EX(10f) s8i a9, a11, 0 # store byte 0
.byte 0 # (0 mod 4 alignment for LBEG)
.Laligned:
#if XCHAL_HAVE_LOOPS
- loopnez a12, .Loop1done
+ loopnez a10, .Loop1done
#else
- beqz a12, .Loop1done
- slli a12, a12, 2
- add a12, a12, a11 # a12 = end of last 4B chunck
+ beqz a10, .Loop1done
+ slli a10, a10, 2
+ add a10, a10, a11 # a10 = end of last 4B chunck
#endif
.Loop1:
EX(11f) l32i a9, a3, 0 # get word from src
@@ -118,7 +117,7 @@ EX(10f) s32i a9, a11, 0 # store word to dst
bnone a9, a8, .Lz3 # if byte 3 is zero
addi a11, a11, 4 # advance dst pointer
#if !XCHAL_HAVE_LOOPS
- blt a11, a12, .Loop1
+ blt a11, a10, .Loop1
#endif
.Loop1done:
@@ -185,7 +184,7 @@ EX(10f) s8i a9, a11, 2
loopnez a4, .Lunalignedend
#else
beqz a4, .Lunalignedend
- add a12, a11, a4 # a12 = ending address
+ add a10, a11, a4 # a10 = ending address
#endif /* XCHAL_HAVE_LOOPS */
.Lnextbyte:
EX(11f) l8ui a9, a3, 0
@@ -194,7 +193,7 @@ EX(10f) s8i a9, a11, 0
beqz a9, .Lunalignedend
addi a11, a11, 1
#if !XCHAL_HAVE_LOOPS
- blt a11, a12, .Lnextbyte
+ blt a11, a10, .Lnextbyte
#endif
.Lunalignedend:
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 04/10] xtensa: don't use a12 in __xtensa_copy_user in call0 ABI
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
` (2 preceding siblings ...)
2021-10-19 5:17 ` [PATCH 03/10] xtensa: don't use a12 in strncpy_user Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
2021-10-19 5:17 ` [PATCH 05/10] xtensa: definitions for " Max Filippov
` (5 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
a12 is callee-saved register in xtensa call0 ABI, so a function must not
change it. The main unaligned copy loop of __xtensa_copy_user uses all
low-numbered registers, so a register must be spilled to avoid using a12
as a loop counter.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/lib/usercopy.S | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)
diff --git a/arch/xtensa/lib/usercopy.S b/arch/xtensa/lib/usercopy.S
index a0aa4047f94a..16128c094c62 100644
--- a/arch/xtensa/lib/usercopy.S
+++ b/arch/xtensa/lib/usercopy.S
@@ -60,7 +60,12 @@
.text
ENTRY(__xtensa_copy_user)
- abi_entry_default
+#if !XCHAL_HAVE_LOOPS && defined(__XTENSA_CALL0_ABI__)
+#define STACK_SIZE 4
+#else
+#define STACK_SIZE 0
+#endif
+ abi_entry(STACK_SIZE)
# a2/ dst, a3/ src, a4/ len
mov a5, a2 # copy dst so that a2 is return value
mov a11, a4 # preserve original len for error case
@@ -75,7 +80,7 @@ ENTRY(__xtensa_copy_user)
__ssa8 a3 # set shift amount from byte offset
bnez a4, .Lsrcunaligned
movi a2, 0 # return success for len==0
- abi_ret_default
+ abi_ret(STACK_SIZE)
/*
* Destination is unaligned
@@ -127,7 +132,7 @@ EX(10f) s8i a6, a5, 0
#endif /* !XCHAL_HAVE_LOOPS */
.Lbytecopydone:
movi a2, 0 # return success for len bytes copied
- abi_ret_default
+ abi_ret(STACK_SIZE)
/*
* Destination and source are word-aligned.
@@ -187,7 +192,7 @@ EX(10f) l8ui a6, a3, 0
EX(10f) s8i a6, a5, 0
.L5:
movi a2, 0 # return success for len bytes copied
- abi_ret_default
+ abi_ret(STACK_SIZE)
/*
* Destination is aligned, Source is unaligned
@@ -205,8 +210,14 @@ EX(10f) l32i a6, a3, 0 # load first word
loopnez a7, .Loop2done
#else /* !XCHAL_HAVE_LOOPS */
beqz a7, .Loop2done
+#if defined(__XTENSA_CALL0_ABI__)
+ s32i a10, a1, 0
+ slli a10, a7, 4
+ add a10, a10, a3 # a10 = end of last 16B source chunk
+#else
slli a12, a7, 4
add a12, a12, a3 # a12 = end of last 16B source chunk
+#endif
#endif /* !XCHAL_HAVE_LOOPS */
.Loop2:
EX(10f) l32i a7, a3, 4
@@ -224,7 +235,12 @@ EX(10f) s32i a8, a5, 8
EX(10f) s32i a9, a5, 12
addi a5, a5, 16
#if !XCHAL_HAVE_LOOPS
+#if defined(__XTENSA_CALL0_ABI__)
+ blt a3, a10, .Loop2
+ l32i a10, a1, 0
+#else
blt a3, a12, .Loop2
+#endif
#endif /* !XCHAL_HAVE_LOOPS */
.Loop2done:
bbci.l a4, 3, .L12
@@ -264,7 +280,7 @@ EX(10f) l8ui a6, a3, 0
EX(10f) s8i a6, a5, 0
.L15:
movi a2, 0 # return success for len bytes copied
- abi_ret_default
+ abi_ret(STACK_SIZE)
ENDPROC(__xtensa_copy_user)
@@ -281,4 +297,4 @@ ENDPROC(__xtensa_copy_user)
10:
sub a2, a5, a2 /* a2 <-- bytes copied */
sub a2, a11, a2 /* a2 <-- bytes not copied */
- abi_ret_default
+ abi_ret(STACK_SIZE)
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 05/10] xtensa: definitions for call0 ABI
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
` (3 preceding siblings ...)
2021-10-19 5:17 ` [PATCH 04/10] xtensa: don't use a12 in __xtensa_copy_user in call0 ABI Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
2021-10-19 5:17 ` [PATCH 06/10] xtensa: implement call0 ABI support in assembly Max Filippov
` (4 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
Add assembly macros for calls, call arguments, preserved registers,
function entry and return for windowed and call0 ABIs.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/include/asm/asmmacro.h | 65 +++++++++++++++++++++++++++++
arch/xtensa/include/asm/core.h | 11 +++++
arch/xtensa/include/asm/processor.h | 32 +++++++++++---
3 files changed, 102 insertions(+), 6 deletions(-)
diff --git a/arch/xtensa/include/asm/asmmacro.h b/arch/xtensa/include/asm/asmmacro.h
index bfc89e11f469..809c507d1825 100644
--- a/arch/xtensa/include/asm/asmmacro.h
+++ b/arch/xtensa/include/asm/asmmacro.h
@@ -194,6 +194,12 @@
#define XTENSA_STACK_ALIGNMENT 16
#if defined(__XTENSA_WINDOWED_ABI__)
+
+/* Assembly instructions for windowed kernel ABI. */
+#define KABI_W
+/* Assembly instructions for call0 kernel ABI (will be ignored). */
+#define KABI_C0 #
+
#define XTENSA_FRAME_SIZE_RESERVE 16
#define XTENSA_SPILL_STACK_RESERVE 32
@@ -206,8 +212,34 @@
#define abi_ret(frame_size) retw
#define abi_ret_default retw
+ /* direct call */
+#define abi_call call4
+ /* indirect call */
+#define abi_callx callx4
+ /* outgoing call argument registers */
+#define abi_arg0 a6
+#define abi_arg1 a7
+#define abi_arg2 a8
+#define abi_arg3 a9
+#define abi_arg4 a10
+#define abi_arg5 a11
+ /* return value */
+#define abi_rv a6
+ /* registers preserved across call */
+#define abi_saved0 a2
+#define abi_saved1 a3
+
+ /* none of the above */
+#define abi_tmp0 a4
+#define abi_tmp1 a5
+
#elif defined(__XTENSA_CALL0_ABI__)
+/* Assembly instructions for windowed kernel ABI (will be ignored). */
+#define KABI_W #
+/* Assembly instructions for call0 kernel ABI. */
+#define KABI_C0
+
#define XTENSA_SPILL_STACK_RESERVE 0
#define abi_entry(frame_size) __abi_entry (frame_size)
@@ -233,10 +265,43 @@
#define abi_ret_default ret
+ /* direct call */
+#define abi_call call0
+ /* indirect call */
+#define abi_callx callx0
+ /* outgoing call argument registers */
+#define abi_arg0 a2
+#define abi_arg1 a3
+#define abi_arg2 a4
+#define abi_arg3 a5
+#define abi_arg4 a6
+#define abi_arg5 a7
+ /* return value */
+#define abi_rv a2
+ /* registers preserved across call */
+#define abi_saved0 a12
+#define abi_saved1 a13
+
+ /* none of the above */
+#define abi_tmp0 a8
+#define abi_tmp1 a9
+
#else
#error Unsupported Xtensa ABI
#endif
+#if defined(USER_SUPPORT_WINDOWED)
+/* Assembly instructions for windowed user ABI. */
+#define UABI_W
+/* Assembly instructions for call0 user ABI (will be ignored). */
+#define UABI_C0 #
+#else
+/* Assembly instructions for windowed user ABI (will be ignored). */
+#define UABI_W #
+/* Assembly instructions for call0 user ABI. */
+#define UABI_C0
+#endif
+
#define __XTENSA_HANDLER .section ".exception.text", "ax"
#endif /* _XTENSA_ASMMACRO_H */
diff --git a/arch/xtensa/include/asm/core.h b/arch/xtensa/include/asm/core.h
index 5590b0f68837..9138077e567d 100644
--- a/arch/xtensa/include/asm/core.h
+++ b/arch/xtensa/include/asm/core.h
@@ -26,4 +26,15 @@
#define XCHAL_SPANNING_WAY 0
#endif
+#if XCHAL_HAVE_WINDOWED
+#if defined(CONFIG_USER_ABI_DEFAULT) || defined(CONFIG_USER_ABI_CALL0_PROBE)
+/* Whether windowed ABI is supported in userspace. */
+#define USER_SUPPORT_WINDOWED
+#endif
+#if defined(__XTENSA_WINDOWED_ABI__) || defined(USER_SUPPORT_WINDOWED)
+/* Whether windowed ABI is supported either in userspace or in the kernel. */
+#define SUPPORT_WINDOWED
+#endif
+#endif
+
#endif
diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h
index 7f63aca6a0d3..aeec2916030c 100644
--- a/arch/xtensa/include/asm/processor.h
+++ b/arch/xtensa/include/asm/processor.h
@@ -18,12 +18,6 @@
#include <asm/types.h>
#include <asm/regs.h>
-/* Assertions. */
-
-#if (XCHAL_HAVE_WINDOWED != 1)
-# error Linux requires the Xtensa Windowed Registers Option.
-#endif
-
/* Xtensa ABI requires stack alignment to be at least 16 */
#define STACK_ALIGN (XCHAL_DATA_WIDTH > 16 ? XCHAL_DATA_WIDTH : 16)
@@ -105,8 +99,18 @@
#define WSBITS (XCHAL_NUM_AREGS / 4) /* width of WINDOWSTART in bits */
#define WBBITS (XCHAL_NUM_AREGS_LOG2 - 2) /* width of WINDOWBASE in bits */
+#if defined(__XTENSA_WINDOWED_ABI__)
+#define KERNEL_PS_WOE_MASK PS_WOE_MASK
+#elif defined(__XTENSA_CALL0_ABI__)
+#define KERNEL_PS_WOE_MASK 0
+#else
+#error Unsupported xtensa ABI
+#endif
+
#ifndef __ASSEMBLY__
+#if defined(__XTENSA_WINDOWED_ABI__)
+
/* Build a valid return address for the specified call winsize.
* winsize must be 1 (call4), 2 (call8), or 3 (call12)
*/
@@ -117,6 +121,22 @@
*/
#define MAKE_PC_FROM_RA(ra,sp) (((ra) & 0x3fffffff) | ((sp) & 0xc0000000))
+#elif defined(__XTENSA_CALL0_ABI__)
+
+/* Build a valid return address for the specified call winsize.
+ * winsize must be 1 (call4), 2 (call8), or 3 (call12)
+ */
+#define MAKE_RA_FOR_CALL(ra, ws) (ra)
+
+/* Convert return address to a valid pc
+ * Note: We assume that the stack pointer is in the same 1GB ranges as the ra
+ */
+#define MAKE_PC_FROM_RA(ra, sp) (ra)
+
+#else
+#error Unsupported Xtensa ABI
+#endif
+
/* Spill slot location for the register reg in the spill area under the stack
* pointer sp. reg must be in the range [0..4).
*/
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 06/10] xtensa: implement call0 ABI support in assembly
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
` (4 preceding siblings ...)
2021-10-19 5:17 ` [PATCH 05/10] xtensa: definitions for " Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
2021-10-19 5:17 ` [PATCH 07/10] xtensa: use register window specific opcodes only when present Max Filippov
` (3 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
Replace hardcoded register and opcode names with ABI-agnostic macros.
Add register save/restore code where necessary. Conditionalize windowed
only or call0 only code. Add stack initialization matching _switch_to
epilogue to copy_thread.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/boot/boot-redboot/bootstrap.S | 68 +++----
arch/xtensa/kernel/entry.S | 209 ++++++++++++++--------
arch/xtensa/kernel/head.S | 22 +--
arch/xtensa/kernel/mcount.S | 38 +++-
arch/xtensa/kernel/process.c | 27 ++-
5 files changed, 243 insertions(+), 121 deletions(-)
diff --git a/arch/xtensa/boot/boot-redboot/bootstrap.S b/arch/xtensa/boot/boot-redboot/bootstrap.S
index 48ba5a232d94..51e8f3b88e82 100644
--- a/arch/xtensa/boot/boot-redboot/bootstrap.S
+++ b/arch/xtensa/boot/boot-redboot/bootstrap.S
@@ -3,6 +3,7 @@
#include <asm/regs.h>
#include <asm/asmmacro.h>
#include <asm/cacheasm.h>
+#include <asm/processor.h>
/*
* RB-Data: RedBoot data/bss
* P: Boot-Parameters
@@ -36,7 +37,7 @@
.globl __start
/* this must be the first byte of the loader! */
__start:
- entry sp, 32 # we do not intend to return
+ abi_entry(32) # we do not intend to return
_call0 _start
__start_a0:
.align 4
@@ -62,10 +63,12 @@ _start:
wsr a4, windowstart
rsync
- movi a4, 0x00040000
+ movi a4, KERNEL_PS_WOE_MASK
wsr a4, ps
rsync
+KABI_C0 mov abi_saved0, abi_arg0
+
/* copy the loader to its address
* Note: The loader itself is a very small piece, so we assume we
* don't partially overlap. We also assume (even more important)
@@ -168,52 +171,52 @@ _reloc:
movi a3, __image_load
sub a4, a3, a4
- add a8, a0, a4
+ add abi_arg2, a0, a4
# a1 Stack
# a8(a4) Load address of the image
- movi a6, _image_start
- movi a10, _image_end
- movi a7, 0x1000000
- sub a11, a10, a6
- movi a9, complen
- s32i a11, a9, 0
+ movi abi_arg0, _image_start
+ movi abi_arg4, _image_end
+ movi abi_arg1, 0x1000000
+ sub abi_tmp0, abi_arg4, abi_arg0
+ movi abi_arg3, complen
+ s32i abi_tmp0, abi_arg3, 0
movi a0, 0
- # a6 destination
- # a7 maximum size of destination
- # a8 source
- # a9 ptr to length
+ # abi_arg0 destination
+ # abi_arg1 maximum size of destination
+ # abi_arg2 source
+ # abi_arg3 ptr to length
.extern gunzip
- movi a4, gunzip
- beqz a4, 1f
+ movi abi_tmp0, gunzip
+ beqz abi_tmp0, 1f
- callx4 a4
+ abi_callx abi_tmp0
j 2f
- # a6 destination start
- # a7 maximum size of destination
- # a8 source start
- # a9 ptr to length
- # a10 destination end
+ # abi_arg0 destination start
+ # abi_arg1 maximum size of destination
+ # abi_arg2 source start
+ # abi_arg3 ptr to length
+ # abi_arg4 destination end
1:
- l32i a9, a8, 0
- l32i a11, a8, 4
- s32i a9, a6, 0
- s32i a11, a6, 4
- l32i a9, a8, 8
- l32i a11, a8, 12
- s32i a9, a6, 8
- s32i a11, a6, 12
- addi a6, a6, 16
- addi a8, a8, 16
- blt a6, a10, 1b
+ l32i abi_tmp0, abi_arg2, 0
+ l32i abi_tmp1, abi_arg2, 4
+ s32i abi_tmp0, abi_arg0, 0
+ s32i abi_tmp1, abi_arg0, 4
+ l32i abi_tmp0, abi_arg2, 8
+ l32i abi_tmp1, abi_arg2, 12
+ s32i abi_tmp0, abi_arg0, 8
+ s32i abi_tmp1, abi_arg0, 12
+ addi abi_arg0, abi_arg0, 16
+ addi abi_arg2, abi_arg2, 16
+ blt abi_arg0, abi_arg4, 1b
/* jump to the kernel */
@@ -230,6 +233,7 @@ _reloc:
# a2 Boot parameter list
+KABI_C0 mov abi_arg0, abi_saved0
movi a0, _image_start
jx a0
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 647b162f959b..a144b467c3fd 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -158,6 +158,7 @@ _user_exception:
/* Rotate ws so that the current windowbase is at bit0. */
/* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */
+#if defined(USER_SUPPORT_WINDOWED)
rsr a2, windowbase
rsr a3, windowstart
ssr a2
@@ -167,24 +168,33 @@ _user_exception:
src a2, a3, a2
srli a2, a2, 32-WSBITS
s32i a2, a1, PT_WMASK # needed for restoring registers
+#else
+ movi a2, 0
+ movi a3, 1
+ s32i a2, a1, PT_WINDOWBASE
+ s32i a3, a1, PT_WINDOWSTART
+ s32i a3, a1, PT_WMASK
+#endif
/* Save only live registers. */
- _bbsi.l a2, 1, 1f
+UABI_W _bbsi.l a2, 1, 1f
s32i a4, a1, PT_AREG4
s32i a5, a1, PT_AREG5
s32i a6, a1, PT_AREG6
s32i a7, a1, PT_AREG7
- _bbsi.l a2, 2, 1f
+UABI_W _bbsi.l a2, 2, 1f
s32i a8, a1, PT_AREG8
s32i a9, a1, PT_AREG9
s32i a10, a1, PT_AREG10
s32i a11, a1, PT_AREG11
- _bbsi.l a2, 3, 1f
+UABI_W _bbsi.l a2, 3, 1f
s32i a12, a1, PT_AREG12
s32i a13, a1, PT_AREG13
s32i a14, a1, PT_AREG14
s32i a15, a1, PT_AREG15
+
+#if defined(USER_SUPPORT_WINDOWED)
_bnei a2, 1, 1f # only one valid frame?
/* Only one valid frame, skip saving regs. */
@@ -239,7 +249,7 @@ _user_exception:
rsync
/* We are back to the original stack pointer (a1) */
-
+#endif
2: /* Now, jump to the common exception handler. */
j common_exception
@@ -295,6 +305,7 @@ _kernel_exception:
s32i a3, a1, PT_SAR
s32i a2, a1, PT_ICOUNTLEVEL
+#if defined(__XTENSA_WINDOWED_ABI__)
/* Rotate ws so that the current windowbase is at bit0. */
/* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */
@@ -305,27 +316,28 @@ _kernel_exception:
src a2, a3, a2
srli a2, a2, 32-WSBITS
s32i a2, a1, PT_WMASK # needed for kernel_exception_exit
+#endif
/* Save only the live window-frame */
- _bbsi.l a2, 1, 1f
+KABI_W _bbsi.l a2, 1, 1f
s32i a4, a1, PT_AREG4
s32i a5, a1, PT_AREG5
s32i a6, a1, PT_AREG6
s32i a7, a1, PT_AREG7
- _bbsi.l a2, 2, 1f
+KABI_W _bbsi.l a2, 2, 1f
s32i a8, a1, PT_AREG8
s32i a9, a1, PT_AREG9
s32i a10, a1, PT_AREG10
s32i a11, a1, PT_AREG11
- _bbsi.l a2, 3, 1f
+KABI_W _bbsi.l a2, 3, 1f
s32i a12, a1, PT_AREG12
s32i a13, a1, PT_AREG13
s32i a14, a1, PT_AREG14
s32i a15, a1, PT_AREG15
+#ifdef __XTENSA_WINDOWED_ABI__
_bnei a2, 1, 1f
-
/* Copy spill slots of a0 and a1 to imitate movsp
* in order to keep exception stack continuous
*/
@@ -333,6 +345,7 @@ _kernel_exception:
l32i a0, a1, PT_SIZE + 4
s32e a3, a1, -16
s32e a0, a1, -12
+#endif
1:
l32i a0, a1, PT_AREG0 # restore saved a0
wsr a0, depc
@@ -419,16 +432,16 @@ common_exception:
movi a3, LOCKLEVEL
.Lexception:
- movi a0, PS_WOE_MASK
- or a3, a3, a0
+KABI_W movi a0, PS_WOE_MASK
+KABI_W or a3, a3, a0
#else
addi a2, a2, -EXCCAUSE_LEVEL1_INTERRUPT
movi a0, LOCKLEVEL
extui a3, a3, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH
# a3 = PS.INTLEVEL
moveqz a3, a0, a2 # a3 = LOCKLEVEL iff interrupt
- movi a2, PS_WOE_MASK
- or a3, a3, a2
+KABI_W movi a2, PS_WOE_MASK
+KABI_W or a3, a3, a2
rsr a2, exccause
#endif
@@ -461,14 +474,14 @@ common_exception:
*/
rsr a4, excsave1
- mov a6, a1 # pass stack frame
- mov a7, a2 # pass EXCCAUSE
addx4 a4, a2, a4
l32i a4, a4, EXC_TABLE_DEFAULT # load handler
+ mov abi_arg1, a2 # pass EXCCAUSE
+ mov abi_arg0, a1 # pass stack frame
/* Call the second-level handler */
- callx4 a4
+ abi_callx a4
/* Jump here for exception exit */
.global common_exception_return
@@ -482,15 +495,15 @@ common_exception_return:
1:
irq_save a2, a3
#ifdef CONFIG_TRACE_IRQFLAGS
- call4 trace_hardirqs_off
+ abi_call trace_hardirqs_off
#endif
/* Jump if we are returning from kernel exceptions. */
- l32i a3, a1, PT_PS
+ l32i abi_saved1, a1, PT_PS
GET_THREAD_INFO(a2, a1)
l32i a4, a2, TI_FLAGS
- _bbci.l a3, PS_UM_BIT, 6f
+ _bbci.l abi_saved1, PS_UM_BIT, 6f
/* Specific to a user exception exit:
* We need to check some flags for signal handling and rescheduling,
@@ -509,20 +522,20 @@ common_exception_return:
/* Call do_signal() */
#ifdef CONFIG_TRACE_IRQFLAGS
- call4 trace_hardirqs_on
+ abi_call trace_hardirqs_on
#endif
rsil a2, 0
- mov a6, a1
- call4 do_notify_resume # int do_notify_resume(struct pt_regs*)
+ mov abi_arg0, a1
+ abi_call do_notify_resume # int do_notify_resume(struct pt_regs*)
j 1b
3: /* Reschedule */
#ifdef CONFIG_TRACE_IRQFLAGS
- call4 trace_hardirqs_on
+ abi_call trace_hardirqs_on
#endif
rsil a2, 0
- call4 schedule # void schedule (void)
+ abi_call schedule # void schedule (void)
j 1b
#ifdef CONFIG_PREEMPTION
@@ -533,33 +546,33 @@ common_exception_return:
l32i a4, a2, TI_PRE_COUNT
bnez a4, 4f
- call4 preempt_schedule_irq
+ abi_call preempt_schedule_irq
j 4f
#endif
#if XTENSA_FAKE_NMI
.LNMIexit:
- l32i a3, a1, PT_PS
- _bbci.l a3, PS_UM_BIT, 4f
+ l32i abi_saved1, a1, PT_PS
+ _bbci.l abi_saved1, PS_UM_BIT, 4f
#endif
5:
#ifdef CONFIG_HAVE_HW_BREAKPOINT
_bbci.l a4, TIF_DB_DISABLED, 7f
- call4 restore_dbreak
+ abi_call restore_dbreak
7:
#endif
#ifdef CONFIG_DEBUG_TLB_SANITY
l32i a4, a1, PT_DEPC
bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 4f
- call4 check_tlb_sanity
+ abi_call check_tlb_sanity
#endif
6:
4:
#ifdef CONFIG_TRACE_IRQFLAGS
- extui a4, a3, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH
+ extui a4, abi_saved1, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH
bgei a4, LOCKLEVEL, 1f
- call4 trace_hardirqs_on
+ abi_call trace_hardirqs_on
1:
#endif
/* Restore optional registers. */
@@ -572,14 +585,15 @@ common_exception_return:
l32i a2, a1, PT_SCOMPARE1
wsr a2, scompare1
#endif
- wsr a3, ps /* disable interrupts */
+ wsr abi_saved1, ps /* disable interrupts */
- _bbci.l a3, PS_UM_BIT, kernel_exception_exit
+ _bbci.l abi_saved1, PS_UM_BIT, kernel_exception_exit
user_exception_exit:
/* Restore the state of the task and return from the exception. */
+#if defined(USER_SUPPORT_WINDOWED)
/* Switch to the user thread WINDOWBASE. Save SP temporarily in DEPC */
l32i a2, a1, PT_WINDOWBASE
@@ -634,8 +648,10 @@ user_exception_exit:
* frame where we had loaded a2), or at least the lower 4 bits
* (if we have restored WSBITS-1 frames).
*/
-
2:
+#else
+ movi a2, 1
+#endif
#if XCHAL_HAVE_THREADPTR
l32i a3, a1, PT_THREADPTR
wur a3, threadptr
@@ -650,6 +666,7 @@ user_exception_exit:
kernel_exception_exit:
+#if defined(__XTENSA_WINDOWED_ABI__)
/* Check if we have to do a movsp.
*
* We only have to do a movsp if the previous window-frame has
@@ -702,6 +719,9 @@ kernel_exception_exit:
*
* Note: We expect a2 to hold PT_WMASK
*/
+#else
+ movi a2, 1
+#endif
common_exception_exit:
@@ -927,7 +947,7 @@ ENTRY(unrecoverable_exception)
wsr a1, windowbase
rsync
- movi a1, PS_WOE_MASK | LOCKLEVEL
+ movi a1, KERNEL_PS_WOE_MASK | LOCKLEVEL
wsr a1, ps
rsync
@@ -935,8 +955,8 @@ ENTRY(unrecoverable_exception)
movi a0, 0
addi a1, a1, PT_REGS_OFFSET
- movi a6, unrecoverable_text
- call4 panic
+ movi abi_arg0, unrecoverable_text
+ abi_call panic
1: j 1b
@@ -1403,12 +1423,12 @@ ENTRY(fast_syscall_spill_registers)
rsr a3, excsave1
l32i a1, a3, EXC_TABLE_KSTK
- movi a4, PS_WOE_MASK | LOCKLEVEL
+ movi a4, KERNEL_PS_WOE_MASK | LOCKLEVEL
wsr a4, ps
rsync
- movi a6, SIGSEGV
- call4 do_exit
+ movi abi_arg0, SIGSEGV
+ abi_call do_exit
/* shouldn't return, so panic */
@@ -1887,57 +1907,77 @@ ENDPROC(fast_store_prohibited)
ENTRY(system_call)
+#if defined(__XTENSA_WINDOWED_ABI__)
abi_entry_default
+#elif defined(__XTENSA_CALL0_ABI__)
+ abi_entry(12)
+
+ s32i a0, sp, 0
+ s32i abi_saved0, sp, 4
+ s32i abi_saved1, sp, 8
+ mov abi_saved0, a2
+#else
+#error Unsupported Xtensa ABI
+#endif
/* regs->syscall = regs->areg[2] */
- l32i a7, a2, PT_AREG2
- s32i a7, a2, PT_SYSCALL
+ l32i a7, abi_saved0, PT_AREG2
+ s32i a7, abi_saved0, PT_SYSCALL
GET_THREAD_INFO(a4, a1)
- l32i a3, a4, TI_FLAGS
+ l32i abi_saved1, a4, TI_FLAGS
movi a4, _TIF_WORK_MASK
- and a3, a3, a4
- beqz a3, 1f
+ and abi_saved1, abi_saved1, a4
+ beqz abi_saved1, 1f
- mov a6, a2
- call4 do_syscall_trace_enter
- beqz a6, .Lsyscall_exit
- l32i a7, a2, PT_SYSCALL
+ mov abi_arg0, abi_saved0
+ abi_call do_syscall_trace_enter
+ beqz abi_rv, .Lsyscall_exit
+ l32i a7, abi_saved0, PT_SYSCALL
1:
/* syscall = sys_call_table[syscall_nr] */
movi a4, sys_call_table
movi a5, __NR_syscalls
- movi a6, -ENOSYS
+ movi abi_rv, -ENOSYS
bgeu a7, a5, 1f
addx4 a4, a7, a4
- l32i a4, a4, 0
+ l32i abi_tmp0, a4, 0
/* Load args: arg0 - arg5 are passed via regs. */
- l32i a6, a2, PT_AREG6
- l32i a7, a2, PT_AREG3
- l32i a8, a2, PT_AREG4
- l32i a9, a2, PT_AREG5
- l32i a10, a2, PT_AREG8
- l32i a11, a2, PT_AREG9
+ l32i abi_arg0, abi_saved0, PT_AREG6
+ l32i abi_arg1, abi_saved0, PT_AREG3
+ l32i abi_arg2, abi_saved0, PT_AREG4
+ l32i abi_arg3, abi_saved0, PT_AREG5
+ l32i abi_arg4, abi_saved0, PT_AREG8
+ l32i abi_arg5, abi_saved0, PT_AREG9
- callx4 a4
+ abi_callx abi_tmp0
1: /* regs->areg[2] = return_value */
- s32i a6, a2, PT_AREG2
- bnez a3, 1f
+ s32i abi_rv, abi_saved0, PT_AREG2
+ bnez abi_saved1, 1f
.Lsyscall_exit:
+#if defined(__XTENSA_WINDOWED_ABI__)
abi_ret_default
+#elif defined(__XTENSA_CALL0_ABI__)
+ l32i a0, sp, 0
+ l32i abi_saved0, sp, 4
+ l32i abi_saved1, sp, 8
+ abi_ret(12)
+#else
+#error Unsupported Xtensa ABI
+#endif
1:
- mov a6, a2
- call4 do_syscall_trace_leave
- abi_ret_default
+ mov abi_arg0, abi_saved0
+ abi_call do_syscall_trace_leave
+ j .Lsyscall_exit
ENDPROC(system_call)
@@ -1988,8 +2028,18 @@ ENDPROC(system_call)
ENTRY(_switch_to)
+#if defined(__XTENSA_WINDOWED_ABI__)
abi_entry(XTENSA_SPILL_STACK_RESERVE)
+#elif defined(__XTENSA_CALL0_ABI__)
+ abi_entry(16)
+ s32i a12, sp, 0
+ s32i a13, sp, 4
+ s32i a14, sp, 8
+ s32i a15, sp, 12
+#else
+#error Unsupported Xtensa ABI
+#endif
mov a11, a3 # and 'next' (a3)
l32i a4, a2, TASK_THREAD_INFO
@@ -2033,7 +2083,9 @@ ENTRY(_switch_to)
/* Flush register file. */
+#if defined(__XTENSA_WINDOWED_ABI__)
spill_registers_kernel
+#endif
/* Set kernel stack (and leave critical section)
* Note: It's save to set it here. The stack will not be overwritten
@@ -2055,34 +2107,43 @@ ENTRY(_switch_to)
wsr a14, ps
rsync
+#if defined(__XTENSA_WINDOWED_ABI__)
abi_ret(XTENSA_SPILL_STACK_RESERVE)
+#elif defined(__XTENSA_CALL0_ABI__)
+ l32i a12, sp, 0
+ l32i a13, sp, 4
+ l32i a14, sp, 8
+ l32i a15, sp, 12
+ abi_ret(16)
+#else
+#error Unsupported Xtensa ABI
+#endif
ENDPROC(_switch_to)
ENTRY(ret_from_fork)
/* void schedule_tail (struct task_struct *prev)
- * Note: prev is still in a6 (return value from fake call4 frame)
+ * Note: prev is still in abi_arg0 (return value from fake call frame)
*/
- call4 schedule_tail
-
- mov a6, a1
- call4 do_syscall_trace_leave
+ abi_call schedule_tail
- j common_exception_return
+ mov abi_arg0, a1
+ abi_call do_syscall_trace_leave
+ j common_exception_return
ENDPROC(ret_from_fork)
/*
* Kernel thread creation helper
- * On entry, set up by copy_thread: a2 = thread_fn, a3 = thread_fn arg
- * left from _switch_to: a6 = prev
+ * On entry, set up by copy_thread: abi_saved0 = thread_fn,
+ * abi_saved1 = thread_fn arg. Left from _switch_to: abi_arg0 = prev
*/
ENTRY(ret_from_kernel_thread)
- call4 schedule_tail
- mov a6, a3
- callx4 a2
- j common_exception_return
+ abi_call schedule_tail
+ mov abi_arg0, abi_saved1
+ abi_callx abi_saved0
+ j common_exception_return
ENDPROC(ret_from_kernel_thread)
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index b9b81e76beea..8972d64e0b86 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -15,6 +15,7 @@
* Kevin Chea
*/
+#include <asm/asmmacro.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/cacheasm.h>
@@ -193,9 +194,10 @@ ENTRY(_startup)
movi a1, start_info
l32i a1, a1, 0
- movi a2, PS_WOE_MASK | LOCKLEVEL
- # WOE=1, INTLEVEL=LOCKLEVEL, UM=0
- wsr a2, ps # (enable reg-windows; progmode stack)
+ /* Disable interrupts. */
+ /* Enable window exceptions if kernel is built with windowed ABI. */
+ movi a2, KERNEL_PS_WOE_MASK | LOCKLEVEL
+ wsr a2, ps
rsync
#ifdef CONFIG_SMP
@@ -267,13 +269,13 @@ ENTRY(_startup)
l32i a1, a1, 0
#endif
- movi a6, 0
- xsr a6, excsave1
+ movi abi_arg0, 0
+ xsr abi_arg0, excsave1
/* init_arch kick-starts the linux kernel */
- call4 init_arch
- call4 start_kernel
+ abi_call init_arch
+ abi_call start_kernel
should_never_return:
j should_never_return
@@ -297,10 +299,10 @@ should_never_return:
s32i a3, a2, 0
memw
- movi a6, 0
- wsr a6, excsave1
+ movi abi_arg0, 0
+ wsr abi_arg0, excsave1
- call4 secondary_start_kernel
+ abi_call secondary_start_kernel
j should_never_return
#endif /* CONFIG_SMP */
diff --git a/arch/xtensa/kernel/mcount.S b/arch/xtensa/kernel/mcount.S
index 5e4619f52858..51daaf4e0b82 100644
--- a/arch/xtensa/kernel/mcount.S
+++ b/arch/xtensa/kernel/mcount.S
@@ -17,11 +17,16 @@
/*
* Entry condition:
*
- * a2: a0 of the caller
+ * a2: a0 of the caller in windowed ABI
+ * a10: a0 of the caller in call0 ABI
+ *
+ * In call0 ABI the function _mcount is called with the special ABI:
+ * its argument is in a10 and all the usual argument registers (a2 - a7)
+ * must be preserved in addition to callee-saved a12 - a15.
*/
ENTRY(_mcount)
-
+#if defined(__XTENSA_WINDOWED_ABI__)
abi_entry_default
movi a4, ftrace_trace_function
@@ -42,7 +47,36 @@ ENTRY(_mcount)
callx4 a4
abi_ret_default
+#elif defined(__XTENSA_CALL0_ABI__)
+ abi_entry_default
+
+ movi a9, ftrace_trace_function
+ l32i a9, a9, 0
+ movi a11, ftrace_stub
+ bne a9, a11, 1f
+ abi_ret_default
+1: abi_entry(28)
+ s32i a0, sp, 0
+ s32i a2, sp, 4
+ s32i a3, sp, 8
+ s32i a4, sp, 12
+ s32i a5, sp, 16
+ s32i a6, sp, 20
+ s32i a7, sp, 24
+ addi a2, a10, -MCOUNT_INSN_SIZE
+ callx0 a9
+ l32i a0, sp, 0
+ l32i a2, sp, 4
+ l32i a3, sp, 8
+ l32i a4, sp, 12
+ l32i a5, sp, 16
+ l32i a6, sp, 20
+ l32i a7, sp, 24
+ abi_ret(28)
+#else
+#error Unsupported Xtensa ABI
+#endif
ENDPROC(_mcount)
ENTRY(ftrace_stub)
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 060165340612..de6eb9ddea44 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -211,11 +211,18 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
struct thread_info *ti;
#endif
+#if defined(__XTENSA_WINDOWED_ABI__)
/* Create a call4 dummy-frame: a0 = 0, a1 = childregs. */
SPILL_SLOT(childregs, 1) = (unsigned long)childregs;
SPILL_SLOT(childregs, 0) = 0;
p->thread.sp = (unsigned long)childregs;
+#elif defined(__XTENSA_CALL0_ABI__)
+ /* Reserve 16 bytes for the _switch_to stack frame. */
+ p->thread.sp = (unsigned long)childregs - 16;
+#else
+#error Unsupported Xtensa ABI
+#endif
if (!(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
struct pt_regs *regs = current_pt_regs();
@@ -272,11 +279,25 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
p->thread.ra = MAKE_RA_FOR_CALL(
(unsigned long)ret_from_kernel_thread, 1);
- /* pass parameters to ret_from_kernel_thread:
- * a2 = thread_fn, a3 = thread_fn arg
+ /* pass parameters to ret_from_kernel_thread: */
+#if defined(__XTENSA_WINDOWED_ABI__)
+ /*
+ * a2 = thread_fn, a3 = thread_fn arg.
+ * Window underflow will load registers from the
+ * spill slots on the stack on return from _switch_to.
*/
- SPILL_SLOT(childregs, 3) = thread_fn_arg;
SPILL_SLOT(childregs, 2) = usp_thread_fn;
+ SPILL_SLOT(childregs, 3) = thread_fn_arg;
+#elif defined(__XTENSA_CALL0_ABI__)
+ /*
+ * a12 = thread_fn, a13 = thread_fn arg.
+ * _switch_to epilogue will load registers from the stack.
+ */
+ ((unsigned long *)p->thread.sp)[0] = usp_thread_fn;
+ ((unsigned long *)p->thread.sp)[1] = thread_fn_arg;
+#else
+#error Unsupported Xtensa ABI
+#endif
/* Childregs are only used when we're going to userspace
* in which case start_thread will set them up.
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 07/10] xtensa: use register window specific opcodes only when present
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
` (5 preceding siblings ...)
2021-10-19 5:17 ` [PATCH 06/10] xtensa: implement call0 ABI support in assembly Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
2021-10-19 5:17 ` [PATCH 08/10] xtensa: only build windowed register support code when needed Max Filippov
` (2 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
xtensa core may be configured without register windows support, don't
use register window specific opcodes in that case. Use window register
specific opcodes to initialize hardware or reset core to a known state
regardless of the chosen ABI.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/boot/boot-elf/bootstrap.S | 2 ++
arch/xtensa/boot/boot-redboot/bootstrap.S | 4 ++--
arch/xtensa/kernel/align.S | 2 ++
arch/xtensa/kernel/entry.S | 2 ++
arch/xtensa/kernel/head.S | 2 ++
5 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/xtensa/boot/boot-elf/bootstrap.S b/arch/xtensa/boot/boot-elf/bootstrap.S
index 99e98c9bae41..2dd28931d699 100644
--- a/arch/xtensa/boot/boot-elf/bootstrap.S
+++ b/arch/xtensa/boot/boot-elf/bootstrap.S
@@ -42,12 +42,14 @@ _bootparam:
.align 4
_SetupMMU:
+#if XCHAL_HAVE_WINDOWED
movi a0, 0
wsr a0, windowbase
rsync
movi a0, 1
wsr a0, windowstart
rsync
+#endif
movi a0, 0x1F
wsr a0, ps
rsync
diff --git a/arch/xtensa/boot/boot-redboot/bootstrap.S b/arch/xtensa/boot/boot-redboot/bootstrap.S
index 51e8f3b88e82..3ed94ad35000 100644
--- a/arch/xtensa/boot/boot-redboot/bootstrap.S
+++ b/arch/xtensa/boot/boot-redboot/bootstrap.S
@@ -56,13 +56,13 @@ _start:
movi a4, 1
wsr a4, ps
rsync
-
+#if XCHAL_HAVE_WINDOWED
rsr a5, windowbase
ssl a5
sll a4, a4
wsr a4, windowstart
rsync
-
+#endif
movi a4, KERNEL_PS_WOE_MASK
wsr a4, ps
rsync
diff --git a/arch/xtensa/kernel/align.S b/arch/xtensa/kernel/align.S
index 9301452e521e..d062c732ef18 100644
--- a/arch/xtensa/kernel/align.S
+++ b/arch/xtensa/kernel/align.S
@@ -58,7 +58,9 @@
* BE shift left / mask 0 0 X X
*/
+#if XCHAL_HAVE_WINDOWED
#define UNALIGNED_USER_EXCEPTION
+#endif
#if XCHAL_HAVE_BE
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index a144b467c3fd..8029ce24af92 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -940,12 +940,14 @@ unrecoverable_text:
ENTRY(unrecoverable_exception)
+#if XCHAL_HAVE_WINDOWED
movi a0, 1
movi a1, 0
wsr a0, windowstart
wsr a1, windowbase
rsync
+#endif
movi a1, KERNEL_PS_WOE_MASK | LOCKLEVEL
wsr a1, ps
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index 8972d64e0b86..8484294bc623 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -67,11 +67,13 @@ _SetupOCD:
* xt-gdb to single step via DEBUG exceptions received directly
* by ocd.
*/
+#if XCHAL_HAVE_WINDOWED
movi a1, 1
movi a0, 0
wsr a1, windowstart
wsr a0, windowbase
rsync
+#endif
movi a1, LOCKLEVEL
wsr a1, ps
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 08/10] xtensa: only build windowed register support code when needed
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
` (6 preceding siblings ...)
2021-10-19 5:17 ` [PATCH 07/10] xtensa: use register window specific opcodes only when present Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
2021-10-19 5:17 ` [PATCH 09/10] xtensa: remove unused variable wmask Max Filippov
2021-10-19 5:17 ` [PATCH 10/10] xtensa: move section symbols to asm/sections.h Max Filippov
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
There's no need in window overflow/underflow/alloca exception handlers
or window spill code when neither kernel nor userspace support windowed
registers. Don't build or link it.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/include/asm/traps.h | 2 ++
arch/xtensa/kernel/entry.S | 5 ++++-
arch/xtensa/kernel/setup.c | 2 ++
arch/xtensa/kernel/signal.c | 12 ++++++++++--
arch/xtensa/kernel/traps.c | 2 ++
arch/xtensa/kernel/vectors.S | 15 +++++++++++++++
arch/xtensa/kernel/vmlinux.lds.S | 12 ++++++++++--
7 files changed, 45 insertions(+), 5 deletions(-)
diff --git a/arch/xtensa/include/asm/traps.h b/arch/xtensa/include/asm/traps.h
index f720a57d0a5b..6fa47cd8e02d 100644
--- a/arch/xtensa/include/asm/traps.h
+++ b/arch/xtensa/include/asm/traps.h
@@ -56,6 +56,7 @@ void secondary_trap_init(void);
static inline void spill_registers(void)
{
+#if defined(__XTENSA_WINDOWED_ABI__)
#if XCHAL_NUM_AREGS > 16
__asm__ __volatile__ (
" call8 1f\n"
@@ -96,6 +97,7 @@ static inline void spill_registers(void)
" mov a12, a12\n"
: : : "memory");
#endif
+#endif
}
struct debug_table {
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 8029ce24af92..99ab3c1a3387 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -969,6 +969,7 @@ ENDPROC(unrecoverable_exception)
__XTENSA_HANDLER
.literal_position
+#ifdef SUPPORT_WINDOWED
/*
* Fast-handler for alloca exceptions
*
@@ -1032,6 +1033,7 @@ ENTRY(fast_alloca)
8: j _WindowUnderflow8
4: j _WindowUnderflow4
ENDPROC(fast_alloca)
+#endif
#ifdef CONFIG_USER_ABI_CALL0_PROBE
/*
@@ -1228,7 +1230,8 @@ ENDPROC(fast_syscall_xtensa)
* Note: We assume the stack pointer is EXC_TABLE_KSTK in the fixup handler.
*/
-#ifdef CONFIG_FAST_SYSCALL_SPILL_REGISTERS
+#if defined(CONFIG_FAST_SYSCALL_SPILL_REGISTERS) && \
+ defined(USER_SUPPORT_WINDOWED)
ENTRY(fast_syscall_spill_registers)
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index ed184106e4cf..3638fb98a1ab 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -349,8 +349,10 @@ void __init setup_arch(char **cmdline_p)
#endif
#ifdef CONFIG_VECTORS_ADDR
+#ifdef SUPPORT_WINDOWED
mem_reserve(__pa(&_WindowVectors_text_start),
__pa(&_WindowVectors_text_end));
+#endif
mem_reserve(__pa(&_DebugInterruptVector_text_start),
__pa(&_DebugInterruptVector_text_end));
diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c
index c4d77dbfb61a..f6c949895b3e 100644
--- a/arch/xtensa/kernel/signal.c
+++ b/arch/xtensa/kernel/signal.c
@@ -45,12 +45,13 @@ struct rt_sigframe
unsigned int window[4];
};
-/*
+#if defined(USER_SUPPORT_WINDOWED)
+/*
* Flush register windows stored in pt_regs to stack.
* Returns 1 for errors.
*/
-int
+static int
flush_window_regs_user(struct pt_regs *regs)
{
const unsigned long ws = regs->windowstart;
@@ -121,6 +122,13 @@ flush_window_regs_user(struct pt_regs *regs)
errout:
return err;
}
+#else
+static int
+flush_window_regs_user(struct pt_regs *regs)
+{
+ return 0;
+}
+#endif
/*
* Note: We don't copy double exception 'regs', we have to finish double exc.
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 874b6efc6fb3..4418438b13e6 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -97,7 +97,9 @@ static dispatch_init_table_t __initdata dispatch_init_table[] = {
/* EXCCAUSE_INSTRUCTION_FETCH unhandled */
/* EXCCAUSE_LOAD_STORE_ERROR unhandled*/
{ EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt },
+#ifdef SUPPORT_WINDOWED
{ EXCCAUSE_ALLOCA, USER|KRNL, fast_alloca },
+#endif
/* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */
/* EXCCAUSE_PRIVILEGED unhandled */
#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S
index 0eed5aa82914..407ece204e7c 100644
--- a/arch/xtensa/kernel/vectors.S
+++ b/arch/xtensa/kernel/vectors.S
@@ -226,6 +226,7 @@ ENTRY(_DoubleExceptionVector)
xsr a0, depc # get DEPC, save a0
+#ifdef SUPPORT_WINDOWED
movi a2, WINDOW_VECTORS_VADDR
_bltu a0, a2, .Lfixup
addi a2, a2, WINDOW_VECTORS_SIZE
@@ -275,6 +276,10 @@ _DoubleExceptionVector_WindowUnderflow:
l32i a0, a0, EXC_TABLE_FAST_USER
jx a0
+#else
+ j .Lfixup
+#endif
+
/*
* We only allow the ITLB miss exception if we are in kernel space.
* All other exceptions are unexpected and thus unrecoverable!
@@ -343,6 +348,7 @@ _DoubleExceptionVector_WindowUnderflow:
l32i a0, a0, EXC_TABLE_FAST_USER
jx a0
+#ifdef SUPPORT_WINDOWED
/*
* Restart window OVERFLOW exception.
* Currently:
@@ -475,9 +481,12 @@ _DoubleExceptionVector_handle_exception:
rsr a0, depc
rotw -3
j 1b
+#endif
ENDPROC(_DoubleExceptionVector)
+#ifdef SUPPORT_WINDOWED
+
/*
* Fixup handler for TLB miss in double exception handler for window owerflow.
* We get here with windowbase set to the window that was being spilled and
@@ -590,6 +599,8 @@ ENTRY(window_overflow_restore_a0_fixup)
ENDPROC(window_overflow_restore_a0_fixup)
+#endif
+
/*
* Debug interrupt vector
*
@@ -687,6 +698,8 @@ _SimulateUserKernelVectorException:
.section .WindowVectors.text, "ax"
+#ifdef SUPPORT_WINDOWED
+
/* 4-Register Window Overflow Vector (Handler) */
ENTRY_ALIGN64(_WindowOverflow4)
@@ -787,4 +800,6 @@ ENTRY_ALIGN64(_WindowUnderflow12)
ENDPROC(_WindowUnderflow12)
+#endif
+
.text
diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S
index d23a6e38f062..eee270a039a4 100644
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -94,7 +94,9 @@ SECTIONS
. = ALIGN(PAGE_SIZE);
_vecbase = .;
+#ifdef SUPPORT_WINDOWED
SECTION_VECTOR2 (.WindowVectors.text, WINDOW_VECTORS_VADDR)
+#endif
#if XCHAL_EXCM_LEVEL >= 2
SECTION_VECTOR2 (.Level2InterruptVector.text, INTLEVEL2_VECTOR_VADDR)
#endif
@@ -166,8 +168,10 @@ SECTIONS
__boot_reloc_table_start = ABSOLUTE(.);
#if !MERGED_VECTORS
+#ifdef SUPPORT_WINDOWED
RELOCATE_ENTRY(_WindowVectors_text,
.WindowVectors.text);
+#endif
#if XCHAL_EXCM_LEVEL >= 2
RELOCATE_ENTRY(_Level2InterruptVector_text,
.Level2InterruptVector.text);
@@ -229,14 +233,18 @@ SECTIONS
#if !MERGED_VECTORS
/* The vectors are relocated to the real position at startup time */
+#ifdef SUPPORT_WINDOWED
SECTION_VECTOR4 (_WindowVectors_text,
.WindowVectors.text,
WINDOW_VECTORS_VADDR,
- .dummy)
+ LAST)
+#undef LAST
+#define LAST .WindowVectors.text
+#endif
SECTION_VECTOR4 (_DebugInterruptVector_text,
.DebugInterruptVector.text,
DEBUG_VECTOR_VADDR,
- .WindowVectors.text)
+ LAST)
#undef LAST
#define LAST .DebugInterruptVector.text
#if XCHAL_EXCM_LEVEL >= 2
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 09/10] xtensa: remove unused variable wmask
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
` (7 preceding siblings ...)
2021-10-19 5:17 ` [PATCH 08/10] xtensa: only build windowed register support code when needed Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
2021-10-19 5:17 ` [PATCH 10/10] xtensa: move section symbols to asm/sections.h Max Filippov
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
After a cleanup the function show_regs doesn't use variable wmask but
still computes it. Drop it.
Fixes: 8d7e8240e66c ("[XTENSA] Clean up elf-gregset.")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/kernel/traps.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 4418438b13e6..35a7d47f28cf 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -464,12 +464,10 @@ void secondary_trap_init(void)
void show_regs(struct pt_regs * regs)
{
- int i, wmask;
+ int i;
show_regs_print_info(KERN_DEFAULT);
- wmask = regs->wmask & ~1;
-
for (i = 0; i < 16; i++) {
if ((i % 8) == 0)
pr_info("a%02d:", i);
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 10/10] xtensa: move section symbols to asm/sections.h
2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
` (8 preceding siblings ...)
2021-10-19 5:17 ` [PATCH 09/10] xtensa: remove unused variable wmask Max Filippov
@ 2021-10-19 5:17 ` Max Filippov
9 siblings, 0 replies; 11+ messages in thread
From: Max Filippov @ 2021-10-19 5:17 UTC (permalink / raw)
To: linux-xtensa; +Cc: Chris Zankel, linux-kernel, Max Filippov
Introduce asm/sections.h and move section declarations to this header
from setup.c. Assign section symbols char array type uniformly and drop
address operator from section symbol references in code.
Sort headers in setup.c while at it.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/include/asm/sections.h | 41 ++++++++++++
arch/xtensa/kernel/setup.c | 100 +++++++++--------------------
2 files changed, 70 insertions(+), 71 deletions(-)
create mode 100644 arch/xtensa/include/asm/sections.h
diff --git a/arch/xtensa/include/asm/sections.h b/arch/xtensa/include/asm/sections.h
new file mode 100644
index 000000000000..a8c42d08e281
--- /dev/null
+++ b/arch/xtensa/include/asm/sections.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _XTENSA_SECTIONS_H
+#define _XTENSA_SECTIONS_H
+
+#include <asm-generic/sections.h>
+
+#ifdef CONFIG_VECTORS_ADDR
+extern char _WindowVectors_text_start[];
+extern char _WindowVectors_text_end[];
+extern char _DebugInterruptVector_text_start[];
+extern char _DebugInterruptVector_text_end[];
+extern char _KernelExceptionVector_text_start[];
+extern char _KernelExceptionVector_text_end[];
+extern char _UserExceptionVector_text_start[];
+extern char _UserExceptionVector_text_end[];
+extern char _DoubleExceptionVector_text_start[];
+extern char _DoubleExceptionVector_text_end[];
+extern char _exception_text_start[];
+extern char _exception_text_end[];
+extern char _Level2InterruptVector_text_start[];
+extern char _Level2InterruptVector_text_end[];
+extern char _Level3InterruptVector_text_start[];
+extern char _Level3InterruptVector_text_end[];
+extern char _Level4InterruptVector_text_start[];
+extern char _Level4InterruptVector_text_end[];
+extern char _Level5InterruptVector_text_start[];
+extern char _Level5InterruptVector_text_end[];
+extern char _Level6InterruptVector_text_start[];
+extern char _Level6InterruptVector_text_end[];
+#endif
+#ifdef CONFIG_SMP
+extern char _SecondaryResetVector_text_start[];
+extern char _SecondaryResetVector_text_end[];
+#endif
+#ifdef CONFIG_XIP_KERNEL
+extern char _xip_start[];
+extern char _xip_end[];
+#endif
+
+#endif
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index 3638fb98a1ab..c9fc39883ea9 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -37,14 +37,15 @@
#include <asm/bootparam.h>
#include <asm/kasan.h>
#include <asm/mmu_context.h>
-#include <asm/processor.h>
-#include <asm/timex.h>
-#include <asm/platform.h>
#include <asm/page.h>
-#include <asm/setup.h>
#include <asm/param.h>
+#include <asm/platform.h>
+#include <asm/processor.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
#include <asm/smp.h>
#include <asm/sysmem.h>
+#include <asm/timex.h>
#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
struct screen_info screen_info = {
@@ -271,49 +272,6 @@ void __init init_arch(bp_tag_t *bp_start)
* Initialize system. Setup memory and reserve regions.
*/
-extern char _end[];
-extern char _stext[];
-extern char _WindowVectors_text_start;
-extern char _WindowVectors_text_end;
-extern char _DebugInterruptVector_text_start;
-extern char _DebugInterruptVector_text_end;
-extern char _KernelExceptionVector_text_start;
-extern char _KernelExceptionVector_text_end;
-extern char _UserExceptionVector_text_start;
-extern char _UserExceptionVector_text_end;
-extern char _DoubleExceptionVector_text_start;
-extern char _DoubleExceptionVector_text_end;
-extern char _exception_text_start;
-extern char _exception_text_end;
-#if XCHAL_EXCM_LEVEL >= 2
-extern char _Level2InterruptVector_text_start;
-extern char _Level2InterruptVector_text_end;
-#endif
-#if XCHAL_EXCM_LEVEL >= 3
-extern char _Level3InterruptVector_text_start;
-extern char _Level3InterruptVector_text_end;
-#endif
-#if XCHAL_EXCM_LEVEL >= 4
-extern char _Level4InterruptVector_text_start;
-extern char _Level4InterruptVector_text_end;
-#endif
-#if XCHAL_EXCM_LEVEL >= 5
-extern char _Level5InterruptVector_text_start;
-extern char _Level5InterruptVector_text_end;
-#endif
-#if XCHAL_EXCM_LEVEL >= 6
-extern char _Level6InterruptVector_text_start;
-extern char _Level6InterruptVector_text_end;
-#endif
-#ifdef CONFIG_SMP
-extern char _SecondaryResetVector_text_start;
-extern char _SecondaryResetVector_text_end;
-#endif
-#ifdef CONFIG_XIP_KERNEL
-extern char _xip_start[];
-extern char _xip_end[];
-#endif
-
static inline int __init_memblock mem_reserve(unsigned long start,
unsigned long end)
{
@@ -350,50 +308,50 @@ void __init setup_arch(char **cmdline_p)
#ifdef CONFIG_VECTORS_ADDR
#ifdef SUPPORT_WINDOWED
- mem_reserve(__pa(&_WindowVectors_text_start),
- __pa(&_WindowVectors_text_end));
+ mem_reserve(__pa(_WindowVectors_text_start),
+ __pa(_WindowVectors_text_end));
#endif
- mem_reserve(__pa(&_DebugInterruptVector_text_start),
- __pa(&_DebugInterruptVector_text_end));
+ mem_reserve(__pa(_DebugInterruptVector_text_start),
+ __pa(_DebugInterruptVector_text_end));
- mem_reserve(__pa(&_KernelExceptionVector_text_start),
- __pa(&_KernelExceptionVector_text_end));
+ mem_reserve(__pa(_KernelExceptionVector_text_start),
+ __pa(_KernelExceptionVector_text_end));
- mem_reserve(__pa(&_UserExceptionVector_text_start),
- __pa(&_UserExceptionVector_text_end));
+ mem_reserve(__pa(_UserExceptionVector_text_start),
+ __pa(_UserExceptionVector_text_end));
- mem_reserve(__pa(&_DoubleExceptionVector_text_start),
- __pa(&_DoubleExceptionVector_text_end));
+ mem_reserve(__pa(_DoubleExceptionVector_text_start),
+ __pa(_DoubleExceptionVector_text_end));
- mem_reserve(__pa(&_exception_text_start),
- __pa(&_exception_text_end));
+ mem_reserve(__pa(_exception_text_start),
+ __pa(_exception_text_end));
#if XCHAL_EXCM_LEVEL >= 2
- mem_reserve(__pa(&_Level2InterruptVector_text_start),
- __pa(&_Level2InterruptVector_text_end));
+ mem_reserve(__pa(_Level2InterruptVector_text_start),
+ __pa(_Level2InterruptVector_text_end));
#endif
#if XCHAL_EXCM_LEVEL >= 3
- mem_reserve(__pa(&_Level3InterruptVector_text_start),
- __pa(&_Level3InterruptVector_text_end));
+ mem_reserve(__pa(_Level3InterruptVector_text_start),
+ __pa(_Level3InterruptVector_text_end));
#endif
#if XCHAL_EXCM_LEVEL >= 4
- mem_reserve(__pa(&_Level4InterruptVector_text_start),
- __pa(&_Level4InterruptVector_text_end));
+ mem_reserve(__pa(_Level4InterruptVector_text_start),
+ __pa(_Level4InterruptVector_text_end));
#endif
#if XCHAL_EXCM_LEVEL >= 5
- mem_reserve(__pa(&_Level5InterruptVector_text_start),
- __pa(&_Level5InterruptVector_text_end));
+ mem_reserve(__pa(_Level5InterruptVector_text_start),
+ __pa(_Level5InterruptVector_text_end));
#endif
#if XCHAL_EXCM_LEVEL >= 6
- mem_reserve(__pa(&_Level6InterruptVector_text_start),
- __pa(&_Level6InterruptVector_text_end));
+ mem_reserve(__pa(_Level6InterruptVector_text_start),
+ __pa(_Level6InterruptVector_text_end));
#endif
#endif /* CONFIG_VECTORS_ADDR */
#ifdef CONFIG_SMP
- mem_reserve(__pa(&_SecondaryResetVector_text_start),
- __pa(&_SecondaryResetVector_text_end));
+ mem_reserve(__pa(_SecondaryResetVector_text_start),
+ __pa(_SecondaryResetVector_text_end));
#endif
parse_early_param();
bootmem_init();
--
2.20.1
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2021-10-19 5:17 [PATCH 00/10] xtensa: support call0 ABI kernel Max Filippov
2021-10-19 5:17 ` [PATCH 01/10] xtensa: move _SimulateUserKernelVectorException out of WindowVectors Max Filippov
2021-10-19 5:17 ` [PATCH 02/10] xtensa: use a14 instead of a15 in inline assembly Max Filippov
2021-10-19 5:17 ` [PATCH 03/10] xtensa: don't use a12 in strncpy_user Max Filippov
2021-10-19 5:17 ` [PATCH 04/10] xtensa: don't use a12 in __xtensa_copy_user in call0 ABI Max Filippov
2021-10-19 5:17 ` [PATCH 05/10] xtensa: definitions for " Max Filippov
2021-10-19 5:17 ` [PATCH 06/10] xtensa: implement call0 ABI support in assembly Max Filippov
2021-10-19 5:17 ` [PATCH 07/10] xtensa: use register window specific opcodes only when present Max Filippov
2021-10-19 5:17 ` [PATCH 08/10] xtensa: only build windowed register support code when needed Max Filippov
2021-10-19 5:17 ` [PATCH 09/10] xtensa: remove unused variable wmask Max Filippov
2021-10-19 5:17 ` [PATCH 10/10] xtensa: move section symbols to asm/sections.h Max Filippov
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