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| author | Marc Gauthier <marc@tensilica.com> | 2013-01-05 04:57:17 +0400 |
|---|---|---|
| committer | Chris Zankel <chris@zankel.net> | 2013-02-24 07:12:52 +0400 |
| commit | 2d1c645cc50b8f5a718b24bad9eb3931e7105d12 (patch) | |
| tree | c385e5064cee10f79b9c359ddd99bd5d1b9f838a /arch/xtensa/kernel/entry.S | |
| parent | d0b73b488c55df905ea8faaad079f8535629ed26 (diff) | |
| download | linux-2d1c645cc50b8f5a718b24bad9eb3931e7105d12.tar.xz | |
xtensa: dispatch medium-priority interrupts
Add support for dispatching medium-priority interrupts, that is,
interrupts of priority levels 2 to EXCM_LEVEL. IRQ handling may be
preempted by higher priority IRQ.
Signed-off-by: Marc Gauthier <marc@tensilica.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
Diffstat (limited to 'arch/xtensa/kernel/entry.S')
| -rw-r--r-- | arch/xtensa/kernel/entry.S | 55 |
1 files changed, 44 insertions, 11 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 3777fec85e7c..0ace2acbbad0 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -7,7 +7,7 @@ * License. See the file "COPYING" in the main directory of this archive * for more details. * - * Copyright (C) 2004-2007 by Tensilica Inc. + * Copyright (C) 2004 - 2008 by Tensilica Inc. * * Chris Zankel <chris@zankel.net> * @@ -349,15 +349,16 @@ common_exception: * so we can allow exceptions and interrupts (*) again. * Set PS(EXCM = 0, UM = 0, RING = 0, OWB = 0, WOE = 1, INTLEVEL = X) * - * (*) We only allow interrupts if PS.INTLEVEL was not set to 1 before - * (interrupts disabled) and if this exception is not an interrupt. + * (*) We only allow interrupts of higher priority than current IRQ */ rsr a3, ps addi a0, a0, -4 movi a2, 1 - extui a3, a3, 0, 1 # a3 = PS.INTLEVEL[0] - moveqz a3, a2, a0 # a3 = 1 iff interrupt exception + extui a3, a3, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH + # a3 = PS.INTLEVEL + movnez a2, a3, a3 # a2 = 1: level-1, > 1: high priority + moveqz a3, a2, a0 # a3 = IRQ level iff interrupt movi a2, 1 << PS_WOE_BIT or a3, a3, a2 rsr a0, exccause @@ -641,19 +642,51 @@ common_exception_exit: l32i a0, a1, PT_DEPC l32i a3, a1, PT_AREG3 + _bltui a0, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f + + wsr a0, depc l32i a2, a1, PT_AREG2 - _bgeui a0, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f + l32i a0, a1, PT_AREG0 + l32i a1, a1, PT_AREG1 + rfde +1: /* Restore a0...a3 and return */ + rsr a0, ps + extui a2, a0, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH + movi a0, 2f + slli a2, a2, 4 + add a0, a2, a0 + l32i a2, a1, PT_AREG2 + jx a0 + + .macro irq_exit_level level + .align 16 + .if XCHAL_EXCM_LEVEL >= \level + l32i a0, a1, PT_PC + wsr a0, epc\level l32i a0, a1, PT_AREG0 l32i a1, a1, PT_AREG1 - rfe + rfi \level + .endif + .endm -1: wsr a0, depc + .align 16 +2: l32i a0, a1, PT_AREG0 l32i a1, a1, PT_AREG1 - rfde + rfe + + .align 16 + /* no rfi for level-1 irq, handled by rfe above*/ + nop + + irq_exit_level 2 + irq_exit_level 3 + irq_exit_level 4 + irq_exit_level 5 + irq_exit_level 6 ENDPROC(kernel_exception) @@ -753,7 +786,7 @@ ENTRY(unrecoverable_exception) wsr a1, windowbase rsync - movi a1, (1 << PS_WOE_BIT) | 1 + movi a1, (1 << PS_WOE_BIT) | LOCKLEVEL wsr a1, ps rsync @@ -1474,7 +1507,7 @@ ENTRY(_spill_registers) l32i a1, a3, EXC_TABLE_KSTK wsr a3, excsave1 - movi a4, (1 << PS_WOE_BIT) | 1 + movi a4, (1 << PS_WOE_BIT) | LOCKLEVEL wsr a4, ps rsync |