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/18c34695b7c95107f60ccca82a4ff252f3edf477.165244611... 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 21f00349af52..b2fd1e2fbd89 100644 --- a/arch/m68k/Kconfig.cpu +++ b/arch/m68k/Kconfig.cpu @@ -308,7 +308,7 @@ 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