[PATCH v1] MIPS: uasm: false warning on use of uasm_i_lui()

From: Jim Quinlan
Date: Fri Aug 07 2020 - 09:53:12 EST


Currently, the example uasm code

uasm_i_lui(p, tmp, 0xa000);

issues a warning at Linux boot when the code is "assembled". This is
because the "lui" instruction is defined by the macro "Ip_u1s2(_lui)" -- I
believe it should be Ip_u1u2(_lui) -- and its definition is associated with
the SIMM macro -- I believe it should be the UIMM macro. The current code
takes a 32bit number and checks that it can be converted to a 16bit signed
immediate. This check fails of course for an immediate such as 0x0000a000.

This is fixed. However, there are two uses of uasm_i_lui() in
UASM_i_LA_mostly() which use 16bit signed immediates in the form of a
sign-extended 32 bit number. Left alone these may now cause a warning when
being processed by build_imm(). These two uses have been modified by first
calling build_simm() on the argument to uasm_i_lui() as to convert it to a
proper 16 bit unsigned integer.

Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
---
arch/mips/include/asm/uasm.h | 2 +-
arch/mips/mm/uasm-micromips.c | 2 +-
arch/mips/mm/uasm-mips.c | 2 +-
arch/mips/mm/uasm.c | 6 +++---
4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/mips/include/asm/uasm.h b/arch/mips/include/asm/uasm.h
index f7effca791a5..7ea1d338570b 100644
--- a/arch/mips/include/asm/uasm.h
+++ b/arch/mips/include/asm/uasm.h
@@ -127,7 +127,7 @@ Ip_u2s3u1(_lh);
Ip_u2s3u1(_lhu);
Ip_u2s3u1(_ll);
Ip_u2s3u1(_lld);
-Ip_u1s2(_lui);
+Ip_u1u2(_lui);
Ip_u2s3u1(_lw);
Ip_u2s3u1(_lwu);
Ip_u3u1u2(_lwx);
diff --git a/arch/mips/mm/uasm-micromips.c b/arch/mips/mm/uasm-micromips.c
index 75ef90486fe6..86ee1499e120 100644
--- a/arch/mips/mm/uasm-micromips.c
+++ b/arch/mips/mm/uasm-micromips.c
@@ -82,7 +82,7 @@ static const struct insn insn_table_MM[insn_invalid] = {
[insn_lh] = {M(mm_lh32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
[insn_ll] = {M(mm_pool32c_op, 0, 0, (mm_ll_func << 1), 0, 0), RS | RT | SIMM},
[insn_lld] = {0, 0},
- [insn_lui] = {M(mm_pool32i_op, mm_lui_op, 0, 0, 0, 0), RS | SIMM},
+ [insn_lui] = {M(mm_pool32i_op, mm_lui_op, 0, 0, 0, 0), RS | UIMM},
[insn_lw] = {M(mm_lw32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
[insn_mfc0] = {M(mm_pool32a_op, 0, 0, 0, mm_mfc0_op, mm_pool32axf_op), RT | RS | RD},
[insn_mfhi] = {M(mm_pool32a_op, 0, 0, 0, mm_mfhi32_op, mm_pool32axf_op), RS},
diff --git a/arch/mips/mm/uasm-mips.c b/arch/mips/mm/uasm-mips.c
index 7154a1d99aad..b45c15111d68 100644
--- a/arch/mips/mm/uasm-mips.c
+++ b/arch/mips/mm/uasm-mips.c
@@ -132,7 +132,7 @@ static const struct insn insn_table[insn_invalid] = {
[insn_ll] = {M6(spec3_op, 0, 0, 0, ll6_op), RS | RT | SIMM9},
[insn_lld] = {M6(spec3_op, 0, 0, 0, lld6_op), RS | RT | SIMM9},
#endif
- [insn_lui] = {M(lui_op, 0, 0, 0, 0, 0), RT | SIMM},
+ [insn_lui] = {M(lui_op, 0, 0, 0, 0, 0), RT | UIMM},
[insn_lw] = {M(lw_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
[insn_lwu] = {M(lwu_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
[insn_lwx] = {M(spec3_op, 0, 0, 0, lwx_op, lx_op), RS | RT | RD},
diff --git a/arch/mips/mm/uasm.c b/arch/mips/mm/uasm.c
index c56f129c9a4b..ca5d47da3bd1 100644
--- a/arch/mips/mm/uasm.c
+++ b/arch/mips/mm/uasm.c
@@ -327,7 +327,7 @@ I_u2s3u1(_lh)
I_u2s3u1(_lhu)
I_u2s3u1(_ll)
I_u2s3u1(_lld)
-I_u1s2(_lui)
+I_u1u2(_lui)
I_u2s3u1(_lw)
I_u2s3u1(_lwu)
I_u1u2u3(_mfc0)
@@ -457,7 +457,7 @@ UASM_EXPORT_SYMBOL(uasm_rel_lo);
void UASM_i_LA_mostly(u32 **buf, unsigned int rs, long addr)
{
if (!uasm_in_compat_space_p(addr)) {
- uasm_i_lui(buf, rs, uasm_rel_highest(addr));
+ uasm_i_lui(buf, rs, build_simm(uasm_rel_highest(addr)));
if (uasm_rel_higher(addr))
uasm_i_daddiu(buf, rs, rs, uasm_rel_higher(addr));
if (uasm_rel_hi(addr)) {
@@ -468,7 +468,7 @@ void UASM_i_LA_mostly(u32 **buf, unsigned int rs, long addr)
} else
uasm_i_dsll32(buf, rs, rs, 0);
} else
- uasm_i_lui(buf, rs, uasm_rel_hi(addr));
+ uasm_i_lui(buf, rs, build_simm(uasm_rel_hi(addr)));
}
UASM_EXPORT_SYMBOL(UASM_i_LA_mostly);

--
2.17.1