Hi,
On Tue, 2020-12-15 at 16:47 +0100, Harald Seiler wrote:
> Hi,
>
> this is something I had on my mind for a longer time but never got
> around to actually do until now ... A while back, while working on the
> patchset that led to commit c5635a032a4b ("ARM: imx8m: Don't use the
> addr parameter of reset_cpu()"), I noticed that the `addr` parameter of
> reset_cpu() seems to not actually hold any meaningful value. All
> call-sites in the current tree just pass 0 and the vast majority of
> reset_cpu() implementations actually ignore the parameter.
>
> I dug a bit deeper to find out why this `addr` parameter exists in the
> first place and found out that it's mostly a legacy artifact:
>
> Historically, the reset_cpu() function had this `addr` parameter to
> pass an address of a reset vector location, where the CPU should
> reset to.
>
> The times where this was used are long gone and the only trace it left
> is some (dead) code for the NDS32 arch. The `addr` parameter lived on
> and it looks like it was sometimes used as a way to indicate different
> types of resets (e.g. COLD vs WARM).
>
> Today, however, reset_cpu() is only ever called with `addr` 0 in the
> mainline tree and as such, any code that gives a meaning to the `addr`
> value will only ever follow the `addr == 0` branch. This is probably
> not what the authors intended and as it seems quite unobvious to me,
> I think the best way forward is to remove the `addr` parameter entirely.
>
> This removes any ambiguity in the "contract" of reset_cpu() and thus
> hopefully prevents more code being added which wrongly assumes that the
> parameter can be used for any meaningful purpose. Instead, code which
> wants to properly support multiple reset types needs to be implemented
> as a sysreset driver.
>
>
> I did this API change via a coccinelle patch, see "reset: Remove addr
> parameter from reset_cpu()" for details. I also ran buildman for all
> boards I could, to verify that everything still compiles. One notable
> exception is NDS32 because I couldn't get the compiler to work there ...
I wanted to ask what the current state regarding this patchset is. Is
there anything I should still take care of?
I am a bit worried about it going stale if it stays lying around for too
long and new call-sites get introduced. So far everything is still fine
though, I just applied the patchset to v2021.04-rc3 and ran a worldbuild
- I do not see any builds regressing.
--
Harald
> Regards,
> Harald
>
> Harald Seiler (4):
> nds32: Remove dead reset_cpu() implementation
> board: ns3: Remove superfluous reset logic
> Revert "lpc32xx: cpu: add support for soft reset"
> reset: Remove addr parameter from reset_cpu()
>
> arch/arc/lib/reset.c | 4 ++--
> arch/arm/cpu/arm920t/ep93xx/cpu.c | 2 +-
> arch/arm/cpu/arm920t/imx/timer.c | 2 +-
> arch/arm/cpu/arm926ejs/armada100/timer.c | 2 +-
> arch/arm/cpu/arm926ejs/mx25/reset.c | 2 +-
> arch/arm/cpu/arm926ejs/mx27/reset.c | 2 +-
> arch/arm/cpu/arm926ejs/mxs/mxs.c | 4 ++--
> arch/arm/cpu/arm926ejs/spear/reset.c | 2 +-
> arch/arm/cpu/arm946es/cpu.c | 2 +-
> arch/arm/cpu/armv7/bcm281xx/reset.c | 2 +-
> arch/arm/cpu/armv7/bcmcygnus/reset.c | 2 +-
> arch/arm/cpu/armv7/bcmnsp/reset.c | 2 +-
> arch/arm/cpu/armv7/ls102xa/cpu.c | 2 +-
> arch/arm/cpu/armv7/s5p4418/cpu.c | 2 +-
> arch/arm/cpu/armv7/stv0991/reset.c | 2 +-
> arch/arm/cpu/armv7m/cpu.c | 2 +-
> arch/arm/cpu/armv8/fsl-layerscape/cpu.c | 4 ++--
> arch/arm/cpu/armv8/s32v234/generic.c | 2 +-
> arch/arm/cpu/pxa/pxa2xx.c | 4 ++--
> arch/arm/cpu/sa1100/cpu.c | 2 +-
> arch/arm/lib/interrupts.c | 2 +-
> arch/arm/lib/interrupts_m.c | 2 +-
> arch/arm/lib/reset.c | 2 +-
> arch/arm/mach-at91/arm920t/reset.c | 2 +-
> arch/arm/mach-at91/arm926ejs/reset.c | 2 +-
> arch/arm/mach-at91/armv7/reset.c | 2 +-
> arch/arm/mach-bcm283x/reset.c | 2 +-
> arch/arm/mach-davinci/reset.c | 2 +-
> arch/arm/mach-exynos/soc.c | 2 +-
> arch/arm/mach-imx/imx8m/soc.c | 2 +-
> arch/arm/mach-imx/mx7ulp/soc.c | 2 +-
> arch/arm/mach-k3/common.c | 2 +-
> arch/arm/mach-keystone/ddr3.c | 4 ++--
> arch/arm/mach-keystone/init.c | 2 +-
> arch/arm/mach-kirkwood/cpu.c | 2 +-
> arch/arm/mach-lpc32xx/cpu.c | 23 +++++-------------
> arch/arm/mach-mediatek/mt7622/init.c | 2 +-
> arch/arm/mach-mediatek/mt8512/init.c | 2 +-
> arch/arm/mach-mediatek/mt8516/init.c | 2 +-
> arch/arm/mach-mediatek/mt8518/init.c | 2 +-
> arch/arm/mach-meson/board-common.c | 4 ++--
> arch/arm/mach-mvebu/armada3700/cpu.c | 2 +-
> arch/arm/mach-mvebu/armada8k/cpu.c | 2 +-
> arch/arm/mach-mvebu/cpu.c | 2 +-
> arch/arm/mach-octeontx/cpu.c | 2 +-
> arch/arm/mach-octeontx2/cpu.c | 2 +-
> arch/arm/mach-omap2/omap5/hwinit.c | 2 +-
> arch/arm/mach-omap2/reset.c | 2 +-
> arch/arm/mach-orion5x/cpu.c | 2 +-
> arch/arm/mach-owl/soc.c | 2 +-
> .../mach-socfpga/include/mach/reset_manager.h | 2 +-
> arch/arm/mach-sunxi/board.c | 2 +-
> arch/arm/mach-tegra/cmd_enterrcm.c | 2 +-
> arch/arm/mach-tegra/pmc.c | 2 +-
> arch/arm/mach-uniphier/arm32/psci.c | 2 +-
> arch/arm/mach-uniphier/reset.c | 2 +-
> arch/arm/mach-zynq/cpu.c | 2 +-
> arch/arm/mach-zynqmp-r5/cpu.c | 2 +-
> arch/nds32/cpu/n1213/ag101/cpu.c | 2 +-
> arch/nds32/cpu/n1213/start.S | 22 -----------------
> arch/nds32/lib/interrupts.c | 2 +-
> arch/sandbox/cpu/sdl.c | 4 ++--
> arch/sh/cpu/sh4/cpu.c | 2 +-
> arch/sh/cpu/sh4/watchdog.c | 2 +-
> arch/x86/cpu/ivybridge/cpu.c | 2 +-
> board/BuR/brppt2/board.c | 2 +-
> board/abilis/tb100/tb100.c | 2 +-
> .../imx8qm_rom7720_a1/imx8qm_rom7720_a1.c | 2 +-
> board/armltd/total_compute/total_compute.c | 2 +-
> board/armltd/vexpress/vexpress_common.c | 2 +-
> board/armltd/vexpress64/vexpress64.c | 2 +-
> .../armadillo-800eva/armadillo-800eva.c | 2 +-
> board/beacon/beacon-rzg2m/beacon-rzg2m.c | 2 +-
> board/bosch/shc/board.c | 2 +-
> board/broadcom/bcmns2/northstar2.c | 2 +-
> board/broadcom/bcmns3/ns3.c | 24 +++----------------
> board/broadcom/bcmstb/bcmstb.c | 2 +-
> board/cavium/thunderx/thunderx.c | 2 +-
> board/compulab/cm_t335/spl.c | 2 +-
> board/cortina/presidio-asic/presidio.c | 2 +-
> board/freescale/imx8qm_mek/imx8qm_mek.c | 2 +-
> board/freescale/imx8qxp_mek/imx8qxp_mek.c | 2 +-
> board/freescale/mx6memcal/spl.c | 2 +-
> board/ge/b1x5v2/spl.c | 2 +-
> board/highbank/highbank.c | 2 +-
> board/hisilicon/hikey/hikey.c | 2 +-
> board/hisilicon/hikey960/hikey960.c | 2 +-
> board/hisilicon/poplar/poplar.c | 2 +-
> board/kmc/kzm9g/kzm9g.c | 2 +-
> board/liebherr/display5/spl.c | 2 +-
> board/phytium/durian/durian.c | 2 +-
> .../dragonboard410c/dragonboard410c.c | 2 +-
> .../dragonboard820c/dragonboard820c.c | 2 +-
> board/renesas/alt/alt.c | 2 +-
> board/renesas/alt/alt_spl.c | 2 +-
> board/renesas/blanche/blanche.c | 2 +-
> board/renesas/condor/condor.c | 2 +-
> board/renesas/draak/draak.c | 2 +-
> board/renesas/eagle/eagle.c | 2 +-
> board/renesas/ebisu/ebisu.c | 2 +-
> board/renesas/gose/gose.c | 2 +-
> board/renesas/gose/gose_spl.c | 2 +-
> board/renesas/grpeach/grpeach.c | 2 +-
> board/renesas/koelsch/koelsch.c | 2 +-
> board/renesas/koelsch/koelsch_spl.c | 2 +-
> board/renesas/lager/lager.c | 2 +-
> board/renesas/lager/lager_spl.c | 2 +-
> board/renesas/porter/porter.c | 2 +-
> board/renesas/porter/porter_spl.c | 2 +-
> board/renesas/rcar-common/gen3-spl.c | 2 +-
> board/renesas/salvator-x/salvator-x.c | 2 +-
> board/renesas/silk/silk.c | 2 +-
> board/renesas/silk/silk_spl.c | 2 +-
> board/renesas/stout/cpld.c | 2 +-
> board/renesas/stout/stout_spl.c | 2 +-
> board/siemens/capricorn/board.c | 2 +-
> board/synopsys/emsdp/emsdp.c | 2 +-
> board/synopsys/iot_devkit/iot_devkit.c | 2 +-
> board/technexion/pico-imx6ul/spl.c | 2 +-
> board/technexion/pico-imx7d/spl.c | 2 +-
> board/toradex/apalis-imx8/apalis-imx8.c | 2 +-
> board/toradex/apalis-imx8x/apalis-imx8x.c | 2 +-
> board/toradex/apalis_imx6/apalis_imx6.c | 2 +-
> board/toradex/colibri-imx8x/colibri-imx8x.c | 2 +-
> board/toradex/colibri_imx6/colibri_imx6.c | 2 +-
> board/toradex/colibri_imx7/colibri_imx7.c | 2 +-
> board/xen/xenguest_arm64/xenguest_arm64.c | 2 +-
> board/xilinx/versal/board.c | 2 +-
> board/xilinx/zynqmp/zynqmp.c | 2 +-
> cmd/tpm_test.c | 2 +-
> drivers/sysreset/sysreset-uclass.c | 2 +-
> drivers/watchdog/imx_watchdog.c | 2 +-
> drivers/watchdog/ulp_wdog.c | 2 +-
> include/cpu_func.h | 4 ++--
> include/sysreset.h | 2 +-
> 135 files changed, 149 insertions(+), 200 deletions(-)
>
