powerpc/math-emu: Allow math-emu to be used for HW FPU

(Including 64-bit ones)

This allow SW emulation by the kernel of optional instructions
such as fsqrt which aren't implemented on some processors, and
thus fixes some Fedora 19 issues such as Anaconda since the
compiler is set to generate those by default on 64-bit.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c33e3ad2c8fd..e3009abc7f75 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -298,7 +298,7 @@ config HUGETLB_PAGE_SIZE_VARIABLE
 
 config MATH_EMULATION
         bool "Math emulation"
-        depends on 4xx || 8xx || E200 || PPC_MPC832x || E500
+        depends on 4xx || 8xx || PPC_MPC832x || BOOKE
         ---help---
           Some PowerPC chips designed for embedded applications do not have
           a floating-point unit and therefore do not implement the
@@ -307,6 +307,10 @@ config MATH_EMULATION
           unit, which will allow programs that use floating-point
           instructions to run.
 
+          This is also useful to emulate missing (optional) instructions
+          such as fsqrt on cores that do have an FPU but do not implement
+          them (such as Freescale BookE).
+
 config PPC_TRANSACTIONAL_MEM
        bool "Transactional Memory support for POWERPC"
        depends on PPC_BOOK3S_64