| From f8e46cd7c3ceb026e77f7ad04656feda70df949c Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 13 May 2022 14:50:28 +0200 |
| Subject: m68k: math-emu: Fix dependencies of math emulation support |
| |
| From: Geert Uytterhoeven <geert@linux-m68k.org> |
| |
| [ Upstream commit ed6bc6bf0a7d75e80eb1df883c09975ebb74e590 ] |
| |
| If CONFIG_M54xx=y, CONFIG_MMU=y, and CONFIG_M68KFPU_EMU=y: |
| |
| {standard input}:272: Error: invalid instruction for this architecture; needs 68000 or higher (68000 [68ec000, 68hc000, 68hc001, 68008, 68302, 68306, 68307, 68322, 68356], 68010, 68020 [68k, 68ec020], 68030 [68ec030], 68040 [68ec040], 68060 [68ec060], cpu32 [68330, 68331, 68332, 68333, 68334, 68336, 68340, 68341, 68349, 68360], fidoa [fido]) -- statement `sub.b %d1,%d3' ignored |
| {standard input}:609: Error: invalid instruction for this architecture; needs 68020 or higher (68020 [68k, 68ec020], 68030 [68ec030], 68040 [68ec040], 68060 [68ec060]) -- statement `bfextu 4(%a1){%d0,#8},%d0' ignored |
| {standard input}:752: Error: operands mismatch -- statement `mulu.l 4(%a0),%d3:%d0' ignored |
| {standard input}:1155: Error: operands mismatch -- statement `divu.l %d0,%d3:%d7' ignored |
| |
| The math emulation support code is intended for 68020 and higher, and |
| uses several instructions or instruction modes not available on coldfire |
| or 68000. |
| |
| Originally, the dependency of M68KFPU_EMU on MMU was fine, as MMU |
| support was only available on 68020 or higher. But this assumption |
| was broken by the introduction of MMU support for M547x and M548x. |
| |
| Drop the dependency on MMU, as the code should work fine on 68020 and up |
| without MMU (which are not yet supported by Linux, though). |
| Add dependencies on M68KCLASSIC (to rule out Coldfire) and FPU (kernel |
| has some type of floating-point support --- be it hardware or software |
| emulated, to rule out anything below 68020). |
| |
| Fixes: 1f7034b9616e6f14 ("m68k: allow ColdFire 547x and 548x CPUs to be built with MMU enabled") |
| Reported-by: kernel test robot <lkp@intel.com> |
| Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> |
| Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> |
| Link: https://lore.kernel.org/r/18c34695b7c95107f60ccca82a4ff252f3edf477.1652446117.git.geert@linux-m68k.org |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| arch/m68k/Kconfig.cpu | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu |
| index d2219f30b78f..2268d19cc915 100644 |
| --- a/arch/m68k/Kconfig.cpu |
| +++ b/arch/m68k/Kconfig.cpu |
| @@ -307,7 +307,7 @@ comment "Processor Specific Options" |
| |
| config M68KFPU_EMU |
| bool "Math emulation support" |
| - depends on MMU |
| + depends on M68KCLASSIC && FPU |
| help |
| At some point in the future, this will cause floating-point math |
| instructions to be emulated by the kernel on machines that lack a |
| -- |
| 2.35.1 |
| |