Re: [PATCH 00/27] sparc32: sunset sun4m and sun4d

From: Kjetil Oftedal
Date: Wed Dec 20 2023 - 09:40:11 EST

On Tue, 19 Dec 2023 at 23:03, Sam Ravnborg via B4 Relay
<devnull+sam.ravnborg.org@xxxxxxxxxx> wrote:
>
> This is the second attempt to sunset sun4m and sun4d.
> See [1] for the inital attempt.
>
> The sun4m and sun4d parts of the kernel have seen no real interest
> for several years now. Last time a few people surfaced, but it was
> either due to a personal project or for nostalgic reasons.
> It is time to let go and drop the parts of sparc32 that in reality
> are not in use.
>
> LEON from Frontgrade Gaisler is the only real user of sparc32,
> and this patchset reduces sparc32 to what is required by LEON.
>
> The defconfig is first adapted to the one used by Gaisler.
> Then the patches removes sun4m and sun4d specific
> implementations such as small drivers, SMP support, IRQ suppor etc.
>
> Removing sun4m and sun4d support allowed removal of the run time
> patching of the code as well as a lot of assembler code.
> The result is a much cleaner assembler code that is easier to
> understand and thus maintain and extend.
>
> So far the code builds but it has seen no run-time testing.
>
> If anyone can tell me how to boot a linux kernel with the leon_genric
> machine with QEMU that would be super as this would be a minimal
> testing that others can reproduce as well.
> I assume QEMU needs a few patches to make it work, but maybe I
> just failed to use the right bootloader.
>
> TODO before this can be applied:
> - Ack from davem - as he is the principal sparc maintainer
> - Tested-by: preferably on a target or QEMU (see above)
> I expect bugs as there are some involved changes!
>
> Ideas for the future
> - Apply the most relevant downstream Gaisler patches
> - The ones introducing CAS should have preference as we then
> can drop the cmpxchg emulation
> - Adjust defconfig to include all Gaisler drivers to make sure they
> see build time coverage
> - Move the leon bits from leon files to the general files
> - Add leon smp support to smp_32.c
> - Add leon irq support to irq_32.c
> - Integrate leom_mm support with srmmu and drop some of the
> function operations that are no longer needed
> - The current sparc32 code assume the bootloader uses the prom
> provided by sun. Maybe migrate over to a more modern device tree
> way of working.
> - Drop some of the homegrown memory allocators and use memblocks
>
> [1]: https://lore.kernel.org/all/20201218184347.2180772-1-sam@xxxxxxxxxxxx/
>
> Sam
>
> ---
> Sam Ravnborg (27):
> sparc32: Update defconfig to LEON SMP
> sparc32: Drop sun4m/sun4d support from head_32.S
> sparc32: Drop floppy support
> sparc32: Drop sun4m specific led driver
> sparc32: Drop sun specific power management drivers
> sparc32: Drop auxio support
> sparc32: Drop run-time patching of ipi trap
> sparc32: Drop patching of interrupt vector
> sparc32: Drop sun4m/sun4d specific irq handling
> sparc32: Drop sun4d/sun4m smp support
> sparc32: Drop pcic support
> sparc32: Drop mbus support
> sparc32: Drop unused function __get_{phys,iospace}
> sparc32: Drop unused mmu models
> sparc32: Drop check for sparc_model
> sparc32: Drop use of sparc_config
> sparc32: Drop run-time patching of ASI instructions
> sparc32: Drop support for 7 register windows
> sparc32: Drop additional sun4d bits
> sparc32: Drop unused prom ranges support
> sparc32: Drop unused iommu support
> sparc32: Drop sun4m irq support
> sparc32: Drop unused trampoline code
> sparc32: Drop config SPARC_LEON
> sparc32: Drop sbus support
> sbus: char: Drop now unused uctrl driver
> fbdev/p9100: Drop now unused driver p9100
>
> arch/sparc/Kconfig | 54 +--
> arch/sparc/configs/sparc32_defconfig | 170 +++----
> arch/sparc/include/asm/asmmacro.h | 22 -
> arch/sparc/include/asm/auxio_32.h | 73 +--
> arch/sparc/include/asm/cpu_type.h | 18 -
> arch/sparc/include/asm/elf_32.h | 2 -
> arch/sparc/include/asm/fb.h | 8 +-
> arch/sparc/include/asm/floppy.h | 2 -
> arch/sparc/include/asm/floppy_32.h | 393 ----------------
> arch/sparc/include/asm/io-unit.h | 59 ---
> arch/sparc/include/asm/io_32.h | 83 ----
> arch/sparc/include/asm/iommu.h | 2 -
> arch/sparc/include/asm/iommu_32.h | 122 -----
> arch/sparc/include/asm/irq_32.h | 2 -
> arch/sparc/include/asm/mbus.h | 97 ----
> arch/sparc/include/asm/mxcc.h | 138 ------
> arch/sparc/include/asm/obio.h | 226 ---------
> arch/sparc/include/asm/oplib_32.h | 11 -
> arch/sparc/include/asm/pcic.h | 130 ------
> arch/sparc/include/asm/pgtable_32.h | 24 -
> arch/sparc/include/asm/pgtsrmmu.h | 33 +-
> arch/sparc/include/asm/ross.h | 192 --------
> arch/sparc/include/asm/sbi.h | 116 -----
> arch/sparc/include/asm/sections.h | 3 -
> arch/sparc/include/asm/swift.h | 107 -----
> arch/sparc/include/asm/switch_to_32.h | 1 -
> arch/sparc/include/asm/timer_32.h | 1 +
> arch/sparc/include/asm/tsunami.h | 65 ---
> arch/sparc/include/asm/turbosparc.h | 126 -----
> arch/sparc/include/asm/viking.h | 255 -----------
> arch/sparc/include/asm/winmacro.h | 11 +-
> arch/sparc/kernel/Makefile | 8 +-
> arch/sparc/kernel/apc.c | 196 --------
> arch/sparc/kernel/auxio_32.c | 139 ------
> arch/sparc/kernel/cpu.c | 1 -
> arch/sparc/kernel/devices.c | 10 +-
> arch/sparc/kernel/entry.S | 413 +----------------
> arch/sparc/kernel/etrap_32.S | 50 +-
> arch/sparc/kernel/head_32.S | 255 +----------
> arch/sparc/kernel/ioport.c | 55 +--
> arch/sparc/kernel/irq.h | 85 +---
> arch/sparc/kernel/irq_32.c | 133 +-----
> arch/sparc/kernel/kernel.h | 53 +--
> arch/sparc/kernel/led.c | 146 ------
> arch/sparc/kernel/leon_kernel.c | 53 +--
> arch/sparc/kernel/leon_pmc.c | 16 +-
> arch/sparc/kernel/leon_smp.c | 3 -
> arch/sparc/kernel/of_device_32.c | 18 +-
> arch/sparc/kernel/pcic.c | 840 ----------------------------------
> arch/sparc/kernel/pmc.c | 100 ----
> arch/sparc/kernel/process_32.c | 10 -
> arch/sparc/kernel/rtrap_32.S | 73 ++-
> arch/sparc/kernel/setup_32.c | 115 -----
> arch/sparc/kernel/smp_32.c | 102 +----
> arch/sparc/kernel/sun4d_irq.c | 519 ---------------------
> arch/sparc/kernel/sun4d_smp.c | 415 -----------------
> arch/sparc/kernel/sun4m_irq.c | 478 -------------------
> arch/sparc/kernel/sun4m_smp.c | 275 -----------
> arch/sparc/kernel/time_32.c | 68 +--
> arch/sparc/kernel/trampoline_32.S | 127 +----
> arch/sparc/kernel/ttable_32.S | 9 +-
> arch/sparc/kernel/vmlinux.lds.S | 5 -
> arch/sparc/kernel/wof.S | 61 +--
> arch/sparc/kernel/wuf.S | 41 +-
> arch/sparc/mm/Makefile | 4 +-
> arch/sparc/mm/hypersparc.S | 414 -----------------
> arch/sparc/mm/io-unit.c | 286 ------------
> arch/sparc/mm/iommu.c | 455 ------------------
> arch/sparc/mm/mm_32.h | 4 -
> arch/sparc/mm/srmmu.c | 836 +--------------------------------
> arch/sparc/mm/srmmu_access.S | 83 ----
> arch/sparc/mm/swift.S | 256 -----------
> arch/sparc/mm/tsunami.S | 132 ------
> arch/sparc/mm/viking.S | 284 ------------
> arch/sparc/prom/Makefile | 1 -
> arch/sparc/prom/init_32.c | 2 -
> arch/sparc/prom/misc_32.c | 2 -
> arch/sparc/prom/ranges.c | 114 -----
> drivers/sbus/char/Kconfig | 8 -
> drivers/sbus/char/Makefile | 1 -
> drivers/sbus/char/uctrl.c | 435 ------------------
> drivers/usb/host/Kconfig | 2 +-
> drivers/usb/host/ehci-hcd.c | 4 +-
> drivers/usb/host/uhci-hcd.c | 2 +-
> drivers/video/fbdev/Kconfig | 10 +-
> drivers/video/fbdev/Makefile | 1 -
> drivers/video/fbdev/p9100.c | 372 ---------------
> sound/sparc/Kconfig | 1 +
> 88 files changed, 318 insertions(+), 10809 deletions(-)
> ---
> base-commit: bee0e7762ad2c6025b9f5245c040fcc36ef2bde8
> change-id: 20231219-sam-sparc32-sunset-v3-4751ea89da2d
>
> Best regards,
> --
> Sam Ravnborg <sam@xxxxxxxxxxxx>
>
>


Hi everyone,

These changes will now effectively make the sparc32 port into a port
that is only really supported by
a rather specific sparc32 implementation delivered by Gaisler. I will
therefore suggest to remove any remaining
references to sparc32 and replaced them with leon, to symbolize the
end of common sparc32 support.


Best regards,
Kjetil Oftedal