lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[POWERPC] Add support for FP emulation for the e300c2 core

Browse Source 
The e300c2 has no FPU.  Its MSR[FP] is grounded to zero.  If an attempt
is made to execute a floating point instruction (including floating-point
load, store, or move instructions), the e300c2 takes a floating-point
unavailable interrupt.

This patch adds support for FP emulation on the e300c2 by declaring a
new CPU_FTR_FP_TAKES_FPUNAVAIL, where FP unavail interrupts are
intercepted and redirected to the ProgramCheck exception path for
correct emulation handling.

(If we run out of CPU_FTR bits we could look to reclaim this bit by adding
support to test the cpu_user_features for PPC_FEATURE_HAS_FPU instead)

It adds a nop to the exception path for 32-bit processors with a FPU.

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This commit is contained in:
Kim Phillips
2006-12-08 02:43:30 -06:00
committed by Kumar Gala
parent c99767974e
commit aa42c69c67
5 changed files with 19 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
include/asm-powerpc/cputable.h
View File

@ -126,6 +126,7 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
#define CPU_FTR_NODSISRALIGN ASM_CONST(0x0000000000100000)
#define CPU_FTR_PPC_LE ASM_CONST(0x0000000000200000)
#define CPU_FTR_REAL_LE ASM_CONST(0x0000000000400000)
#define CPU_FTR_FPU_UNAVAILABLE ASM_CONST(0x0000000000800000)
/*
* Add the 64-bit processor unique features in the top half of the word;
@ -295,6 +296,9 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
#define CPU_FTRS_E300 (CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_MAYBE_CAN_DOZE | \
CPU_FTR_USE_TB | CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_HAS_HIGH_BATS | \
CPU_FTR_COMMON)
#define CPU_FTRS_E300C2 (CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_MAYBE_CAN_DOZE | \
CPU_FTR_USE_TB | CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_HAS_HIGH_BATS | \
CPU_FTR_COMMON | CPU_FTR_FPU_UNAVAILABLE)
#define CPU_FTRS_CLASSIC32 (CPU_FTR_COMMON | CPU_FTR_SPLIT_ID_CACHE | \
CPU_FTR_USE_TB | CPU_FTR_HPTE_TABLE)
#define CPU_FTRS_8XX (CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_USE_TB)
@ -364,7 +368,8 @@ enum {
CPU_FTRS_7450_21 | CPU_FTRS_7450_23 | CPU_FTRS_7455_1 |
CPU_FTRS_7455_20 | CPU_FTRS_7455 | CPU_FTRS_7447_10 |
CPU_FTRS_7447 | CPU_FTRS_7447A | CPU_FTRS_82XX |
CPU_FTRS_G2_LE | CPU_FTRS_E300 | CPU_FTRS_CLASSIC32 |
CPU_FTRS_G2_LE | CPU_FTRS_E300 | CPU_FTRS_E300C2 |
CPU_FTRS_CLASSIC32 |
#else
CPU_FTRS_GENERIC_32 |
#endif
@ -403,7 +408,8 @@ enum {
CPU_FTRS_7450_21 & CPU_FTRS_7450_23 & CPU_FTRS_7455_1 &
CPU_FTRS_7455_20 & CPU_FTRS_7455 & CPU_FTRS_7447_10 &
CPU_FTRS_7447 & CPU_FTRS_7447A & CPU_FTRS_82XX &
CPU_FTRS_G2_LE & CPU_FTRS_E300 & CPU_FTRS_CLASSIC32 &
CPU_FTRS_G2_LE & CPU_FTRS_E300 & CPU_FTRS_E300C2 &
CPU_FTRS_CLASSIC32 &
#else
CPU_FTRS_GENERIC_32 &
#endif