target-xtensa: implement MISC SR

The Miscellaneous Special Registers Option provides zero to four scratch
registers within the processor readable and writable by RSR, WSR, and
XSR. These registers are privileged. They may be useful for some
application-specific exception and interrupt processing tasks in the
kernel. The MISC registers are undefined after reset.
See ISA, 4.7.3 for details.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This commit is contained in:
Max Filippov 2012-12-05 07:15:24 +04:00 committed by Blue Swirl
parent 53593e90d1
commit b7909d81f7
3 changed files with 6 additions and 0 deletions

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@ -153,6 +153,7 @@ enum {
ICOUNTLEVEL = 237,
EXCVADDR = 238,
CCOMPARE = 240,
MISC = 244,
};
#define PS_INTLEVEL 0xf

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@ -95,6 +95,7 @@
/* Other, TODO */ \
XCHAL_OPTION(XCHAL_HAVE_WINDOWED, XTENSA_OPTION_WINDOWED_REGISTER) | \
XCHAL_OPTION(XCHAL_HAVE_DEBUG, XTENSA_OPTION_DEBUG) |\
XCHAL_OPTION(XCHAL_NUM_MISC_REGS > 0, XTENSA_OPTION_MISC_SR) | \
XCHAL_OPTION(XCHAL_HAVE_THREADPTR, XTENSA_OPTION_THREAD_POINTER) | \
XCHAL_OPTION(XCHAL_HAVE_PRID, XTENSA_OPTION_PROCESSOR_ID))

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@ -179,6 +179,10 @@ static const XtensaReg sregnames[256] = {
XTENSA_OPTION_TIMER_INTERRUPT),
[CCOMPARE + 2] = XTENSA_REG("CCOMPARE2",
XTENSA_OPTION_TIMER_INTERRUPT),
[MISC] = XTENSA_REG("MISC0", XTENSA_OPTION_MISC_SR),
[MISC + 1] = XTENSA_REG("MISC1", XTENSA_OPTION_MISC_SR),
[MISC + 2] = XTENSA_REG("MISC2", XTENSA_OPTION_MISC_SR),
[MISC + 3] = XTENSA_REG("MISC3", XTENSA_OPTION_MISC_SR),
};
static const XtensaReg uregnames[256] = {