Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=45ed285b54930767937deb0eaf718b1d08c3c475 Commit: 45ed285b54930767937deb0eaf718b1d08c3c475 Parent: fc31b80957a14a60513d953cc67a55519a2b09c7 Author: Paul Mundt <[EMAIL PROTECTED]> AuthorDate: Thu Mar 8 18:12:17 2007 +0900 Committer: Paul Mundt <[EMAIL PROTECTED]> CommitDate: Mon May 7 02:10:51 2007 +0000
sh: speculative execution support for SH7780. SH7780 has a speculative execution mode where it can speculatively perform an instruction fetch for subroutine returns, this allows it to be enabled. There are some various pitfalls associated with this mode, so it's left as depending on CONFIG_EXPERIMENTAL and not enabled by default. Signed-off-by: Paul Mundt <[EMAIL PROTECTED]> --- arch/sh/Kconfig | 10 ++++++++++ arch/sh/kernel/cpu/init.c | 19 +++++++++++++++++++ 2 files changed, 29 insertions(+), 0 deletions(-) diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index 4d16d89..2715834 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -366,6 +366,16 @@ config SH_STORE_QUEUES Selecting this option will enable an in-kernel API for manipulating the store queues integrated in the SH-4 processors. +config SPECULATIVE_EXECUTION + bool "Speculative subroutine return" + depends on CPU_SUBTYPE_SH7780 && EXPERIMENTAL + help + This enables support for a speculative instruction fetch for + subroutine return. There are various pitfalls associated with + this, as outlined in the SH7780 hardware manual. + + If unsure, say N. + config CPU_HAS_INTEVT bool diff --git a/arch/sh/kernel/cpu/init.c b/arch/sh/kernel/cpu/init.c index 726acfc..6451ad6 100644 --- a/arch/sh/kernel/cpu/init.c +++ b/arch/sh/kernel/cpu/init.c @@ -41,6 +41,23 @@ __setup("no" __stringify(x), x##_setup); onchip_setup(fpu); onchip_setup(dsp); +#ifdef CONFIG_SPECULATIVE_EXECUTION +#define CPUOPM 0xff2f0000 +#define CPUOPM_RABD (1 << 5) + +static void __init speculative_execution_init(void) +{ + /* Clear RABD */ + ctrl_outl(ctrl_inl(CPUOPM) & ~CPUOPM_RABD, CPUOPM); + + /* Flush the update */ + (void)ctrl_inl(CPUOPM); + ctrl_barrier(); +} +#else +#define speculative_execution_init() do { } while (0) +#endif + /* * Generic first-level cache init */ @@ -261,4 +278,6 @@ asmlinkage void __init sh_cpu_init(void) */ ubc_wakeup(); #endif + + speculative_execution_init(); } - To unsubscribe from this list: send the line "unsubscribe git-commits-head" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html