diff options
Diffstat (limited to 'arch/xtensa/kernel/vectors.S')
| -rw-r--r-- | arch/xtensa/kernel/vectors.S | 57 |
1 files changed, 56 insertions, 1 deletions
diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S index 68df35f66ce..82109b42e24 100644 --- a/arch/xtensa/kernel/vectors.S +++ b/arch/xtensa/kernel/vectors.S @@ -10,7 +10,7 @@ * Public License. See the file "COPYING" in the main directory of * this archive for more details. * - * Copyright (C) 2005 Tensilica, Inc. + * Copyright (C) 2005 - 2008 Tensilica, Inc. * * Chris Zankel <chris@zankel.net> * @@ -366,6 +366,41 @@ ENTRY(_DebugInterruptVector) ENDPROC(_DebugInterruptVector) + +/* + * Medium priority level interrupt vectors + * + * Each takes less than 16 (0x10) bytes, no literals, by placing + * the extra 8 bytes that would otherwise be required in the window + * vectors area where there is space. With relocatable vectors, + * all vectors are within ~ 4 kB range of each other, so we can + * simply jump (J) to another vector without having to use JX. + * + * common_exception code gets current IRQ level in PS.INTLEVEL + * and preserves it for the IRQ handling time. + */ + + .macro irq_entry_level level + + .if XCHAL_EXCM_LEVEL >= \level + .section .Level\level\()InterruptVector.text, "ax" +ENTRY(_Level\level\()InterruptVector) + wsr a0, epc1 + rsr a0, epc\level + xsr a0, epc1 + # branch to user or kernel vector + j _SimulateUserKernelVectorException + .endif + + .endm + + irq_entry_level 2 + irq_entry_level 3 + irq_entry_level 4 + irq_entry_level 5 + irq_entry_level 6 + + /* Window overflow and underflow handlers. * The handlers must be 64 bytes apart, first starting with the underflow * handlers underflow-4 to underflow-12, then the overflow handlers @@ -396,6 +431,26 @@ ENTRY_ALIGN64(_WindowOverflow4) ENDPROC(_WindowOverflow4) +#if XCHAL_EXCM_LEVEL >= 2 + /* Not a window vector - but a convenient location + * (where we know there's space) for continuation of + * medium priority interrupt dispatch code. + * On entry here, a0 contains PS, and EPC2 contains saved a0: + */ + .align 4 +_SimulateUserKernelVectorException: + wsr a0, excsave2 + movi a0, 4 # LEVEL1_INTERRUPT cause + wsr a0, exccause + rsr a0, ps + bbsi.l a0, PS_UM_BIT, 1f # branch if user mode + rsr a0, excsave2 # restore a0 + j _KernelExceptionVector # simulate kernel vector exception +1: rsr a0, excsave2 # restore a0 + j _UserExceptionVector # simulate user vector exception +#endif + + /* 4-Register Window Underflow Vector (Handler) */ ENTRY_ALIGN64(_WindowUnderflow4) |