diff options
| author | Ralf Baechle <ralf@linux-mips.org> | 2006-04-05 09:45:45 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2006-04-19 04:14:28 +0200 |
| commit | 41c594ab65fc89573af296d192aa5235d09717ab (patch) | |
| tree | 562462512a320f386bdf49eabfbb26bb3ee761fa /arch/mips/kernel/head.S | |
| parent | 2600990e640e3bef29ed89d565864cf16ee83833 (diff) | |
[MIPS] MT: Improved multithreading support.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/head.S')
| -rw-r--r-- | arch/mips/kernel/head.S | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S index 2e9122a4213..bdf6f6eff72 100644 --- a/arch/mips/kernel/head.S +++ b/arch/mips/kernel/head.S @@ -18,6 +18,7 @@ #include <linux/threads.h> #include <asm/asm.h> +#include <asm/asmmacro.h> #include <asm/regdef.h> #include <asm/page.h> #include <asm/mipsregs.h> @@ -82,12 +83,33 @@ */ .macro setup_c0_status set clr .set push +#ifdef CONFIG_MIPS_MT_SMTC + /* + * For SMTC, we need to set privilege and disable interrupts only for + * the current TC, using the TCStatus register. + */ + mfc0 t0, CP0_TCSTATUS + /* Fortunately CU 0 is in the same place in both registers */ + /* Set TCU0, TMX, TKSU (for later inversion) and IXMT */ + li t1, ST0_CU0 | 0x08001c00 + or t0, t1 + /* Clear TKSU, leave IXMT */ + xori t0, 0x00001800 + mtc0 t0, CP0_TCSTATUS + ehb + /* We need to leave the global IE bit set, but clear EXL...*/ + mfc0 t0, CP0_STATUS + or t0, ST0_CU0 | ST0_EXL | ST0_ERL | \set | \clr + xor t0, ST0_EXL | ST0_ERL | \clr + mtc0 t0, CP0_STATUS +#else mfc0 t0, CP0_STATUS or t0, ST0_CU0|\set|0x1f|\clr xor t0, 0x1f|\clr mtc0 t0, CP0_STATUS .set noreorder sll zero,3 # ehb +#endif .set pop .endm @@ -134,6 +156,24 @@ NESTED(kernel_entry, 16, sp) # kernel entry point ARC64_TWIDDLE_PC +#ifdef CONFIG_MIPS_MT_SMTC + /* + * In SMTC kernel, "CLI" is thread-specific, in TCStatus. + * We still need to enable interrupts globally in Status, + * and clear EXL/ERL. + * + * TCContext is used to track interrupt levels under + * service in SMTC kernel. Clear for boot TC before + * allowing any interrupts. + */ + mtc0 zero, CP0_TCCONTEXT + + mfc0 t0, CP0_STATUS + ori t0, t0, 0xff1f + xori t0, t0, 0x001e + mtc0 t0, CP0_STATUS +#endif /* CONFIG_MIPS_MT_SMTC */ + PTR_LA t0, __bss_start # clear .bss LONG_S zero, (t0) PTR_LA t1, __bss_stop - LONGSIZE @@ -166,8 +206,25 @@ NESTED(kernel_entry, 16, sp) # kernel entry point * function after setting up the stack and gp registers. */ NESTED(smp_bootstrap, 16, sp) +#ifdef CONFIG_MIPS_MT_SMTC + /* + * Read-modify-writes of Status must be atomic, and this + * is one case where CLI is invoked without EXL being + * necessarily set. The CLI and setup_c0_status will + * in fact be redundant for all but the first TC of + * each VPE being booted. + */ + DMT 10 # dmt t2 /* t0, t1 are used by CLI and setup_c0_status() */ + jal mips_ihb +#endif /* CONFIG_MIPS_MT_SMTC */ setup_c0_status_sec smp_slave_setup +#ifdef CONFIG_MIPS_MT_SMTC + andi t2, t2, VPECONTROL_TE + beqz t2, 2f + EMT # emt +2: +#endif /* CONFIG_MIPS_MT_SMTC */ j start_secondary END(smp_bootstrap) #endif /* CONFIG_SMP */ |