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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Sasha Levin <sashal@kernel.org>,
	benh@kernel.crashing.org, paulus@samba.org,
	linuxppc-dev@lists.ozlabs.org
Subject: [PATCH AUTOSEL 5.10 49/50] powerpc/dcr: Use cmplwi instead of 3-argument cmpli
Date: Tue,  9 Nov 2021 17:21:02 -0500	[thread overview]
Message-ID: <20211109222103.1234885-49-sashal@kernel.org> (raw)
In-Reply-To: <20211109222103.1234885-1-sashal@kernel.org>

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit fef071be57dc43679a32d5b0e6ee176d6f12e9f2 ]

In dcr-low.S we use cmpli with three arguments, instead of four
arguments as defined in the ISA:

	cmpli	cr0,r3,1024

This appears to be a PPC440-ism, looking at the "PPC440x5 CPU Core
User’s Manual" it shows cmpli having no L field, but implied to be 0 due
to the core being 32-bit. It mentions that the ISA defines four
arguments and recommends using cmplwi.

It also corresponds to the old POWER instruction set, which had no L
field there, a reserved bit instead.

dcr-low.S is only built 32-bit, because it is only built when
DCR_NATIVE=y, which is only selected by 40x and 44x. Looking at the
generated code (with gcc/gas) we see cmplwi as expected.

Although gas is happy with the 3-argument version when building for
32-bit, the LLVM assembler is not and errors out with:

  arch/powerpc/sysdev/dcr-low.S:27:10: error: invalid operand for instruction
   cmpli 0,%r3,1024; ...
           ^

Switch to the cmplwi extended opcode, which avoids any confusion when
reading the ISA, fixes the issue with the LLVM assembler, and also means
the code could be built 64-bit in future (though that's very unlikely).

Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
BugLink: https://github.com/ClangBuiltLinux/linux/issues/1419
Link: https://lore.kernel.org/r/20211014024424.528848-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/sysdev/dcr-low.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/sysdev/dcr-low.S b/arch/powerpc/sysdev/dcr-low.S
index efeeb1b885a17..329b9c4ae5429 100644
--- a/arch/powerpc/sysdev/dcr-low.S
+++ b/arch/powerpc/sysdev/dcr-low.S
@@ -11,7 +11,7 @@
 #include <asm/export.h>
 
 #define DCR_ACCESS_PROLOG(table) \
-	cmpli	cr0,r3,1024;	 \
+	cmplwi	cr0,r3,1024;	 \
 	rlwinm  r3,r3,4,18,27;   \
 	lis     r5,table@h;      \
 	ori     r5,r5,table@l;   \
-- 
2.33.0


  parent reply	other threads:[~2021-11-09 22:35 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-09 22:20 [PATCH AUTOSEL 5.10 01/50] arm64: zynqmp: Do not duplicate flash partition label property Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 02/50] arm64: zynqmp: Fix serial compatible string Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 03/50] ARM: dts: sunxi: Fix OPPs node name Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 04/50] arm64: dts: allwinner: h5: Fix GPU thermal zone " Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 05/50] arm64: dts: allwinner: a100: Fix " Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 06/50] staging: wfx: ensure IRQ is ready before enabling it Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 07/50] ARM: dts: NSP: Fix mpcore, mmc node names Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 08/50] scsi: lpfc: Fix list_add() corruption in lpfc_drain_txq() Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 09/50] arm64: dts: rockchip: Disable CDN DP on Pinebook Pro Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 10/50] arm64: dts: hisilicon: fix arm,sp805 compatible string Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 11/50] arm64: dts: rockchip: add Coresight debug range for RK3399 Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 12/50] RDMA/bnxt_re: Check if the vlan is valid before reporting Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 13/50] bus: ti-sysc: Add quirk handling for reinit on context lost Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 14/50] bus: ti-sysc: Use context lost quirks for gpmc Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 15/50] bus: ti-sysc: Use context lost quirk for otg Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 16/50] usb: musb: tusb6010: check return value after calling platform_get_resource() Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 17/50] usb: typec: tipd: Remove WARN_ON in tps6598x_block_read Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 18/50] ARM: dts: ux500: Skomer regulator fixes Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 19/50] staging: rtl8723bs: remove possible deadlock when disconnect (v2) Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 20/50] ARM: BCM53016: Specify switch ports for Meraki MR32 Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 21/50] arm64: dts: qcom: msm8998: Fix CPU/L2 idle state latency and residency Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 22/50] arm64: dts: qcom: ipq6018: Fix qcom,controlled-remotely property Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 23/50] arm64: dts: qcom: msm8916: Add unit name for /soc node Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 24/50] arm64: dts: freescale: fix arm,sp805 compatible string Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 25/50] ASoC: SOF: Intel: hda-dai: fix potential locking issue Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 26/50] clk: imx: imx6ul: Move csi_sel mux to correct base register Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 27/50] ASoC: nau8824: Add DMI quirk mechanism for active-high jack-detect Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 28/50] scsi: advansys: Fix kernel pointer leak Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 29/50] ALSA: intel-dsp-config: add quirk for APL/GLK/TGL devices based on ES8336 codec Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 30/50] ASoC: Intel: sof_sdw: add missing quirk for Dell SKU 0A45 Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 31/50] firmware_loader: fix pre-allocated buf built-in firmware use Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 32/50] cpuidle: tegra: Check whether PMC is ready Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 33/50] ARM: dts: omap: fix gpmc,mux-add-data type Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 34/50] usb: host: ohci-tmio: check return value after calling platform_get_resource() Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 35/50] ARM: dts: ls1021a: move thermal-zones node out of soc/ Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 36/50] ARM: dts: ls1021a-tsn: use generic "jedec,spi-nor" compatible for flash Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 37/50] ALSA: ISA: not for M68K Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 38/50] tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 39/50] MIPS: sni: Fix the build Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 40/50] scsi: scsi_debug: Fix out-of-bound read in resp_readcap16() Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 41/50] scsi: scsi_debug: Fix out-of-bound read in resp_report_tgtpgs() Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 42/50] scsi: target: Fix ordered tag handling Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 43/50] scsi: target: Fix alua_tg_pt_gps_count tracking Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 44/50] iio: imu: st_lsm6dsx: Avoid potential array overflow in st_lsm6dsx_set_odr() Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 45/50] powerpc/5200: dts: fix memory node unit name Sasha Levin
2021-11-09 22:20 ` [PATCH AUTOSEL 5.10 46/50] arm64: dts: qcom: msm8916: Add CPU ACC and SAW/SPM Sasha Levin
2021-11-09 22:21 ` [PATCH AUTOSEL 5.10 47/50] ARM: dts: qcom: fix memory and mdio nodes naming for RB3011 Sasha Levin
2021-11-09 22:21 ` [PATCH AUTOSEL 5.10 48/50] ALSA: gus: fix null pointer dereference on pointer block Sasha Levin
2021-11-09 22:21 ` Sasha Levin [this message]
2021-11-09 22:21 ` [PATCH AUTOSEL 5.10 50/50] powerpc/8xx: Fix Oops with STRICT_KERNEL_RWX without DEBUG_RODATA_TEST Sasha Levin

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