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MIPS: MT: Remove SMTC support

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Nobody is maintaining SMTC anymore and there also seems to be no userbase.
Which is a pity - the SMTC technology primarily developed by Kevin D.
Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT
ASE's power and elegance.

Based on Markos Chandras <Markos.Chandras@imgtec.com> patch
https://patchwork.linux-mips.org/patch/6719/ which while very similar did
no longer apply cleanly when I tried to merge it plus some additional
post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to
merge once upon a time.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle
2014-05-23 16:29:44 +02:00
parent 8b2e62cc34
commit b633648c5a
64 changed files with 72 additions and 4097 deletions
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133
arch/mips/include/asm/mipsregs.h
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@@ -1014,19 +1014,8 @@ do { \
#define write_c0_compare3(val) __write_32bit_c0_register($11, 7, val)
#define read_c0_status() __read_32bit_c0_register($12, 0)
#ifdef CONFIG_MIPS_MT_SMTC
#define write_c0_status(val) \
do { \
__write_32bit_c0_register($12, 0, val); \
__ehb(); \
} while (0)
#else
/*
* Legacy non-SMTC code, which may be hazardous
* but which might not support EHB
*/
#define write_c0_status(val) __write_32bit_c0_register($12, 0, val)
#endif /* CONFIG_MIPS_MT_SMTC */
#define read_c0_cause() __read_32bit_c0_register($13, 0)
#define write_c0_cause(val) __write_32bit_c0_register($13, 0, val)
@@ -1750,11 +1739,6 @@ static inline void tlb_write_random(void)
/*
* Manipulate bits in a c0 register.
*/
#ifndef CONFIG_MIPS_MT_SMTC
/*
* SMTC Linux requires shutting-down microthread scheduling
* during CP0 register read-modify-write sequences.
*/
#define __BUILD_SET_C0(name) \
static inline unsigned int \
set_c0_##name(unsigned int set) \
@@ -1793,121 +1777,6 @@ change_c0_##name(unsigned int change, unsigned int val) \
return res; \
}
#else /* SMTC versions that manage MT scheduling */
#include <linux/irqflags.h>
/*
* This is a duplicate of dmt() in mipsmtregs.h to avoid problems with
* header file recursion.
*/
static inline unsigned int __dmt(void)
{
int res;
__asm__ __volatile__(
" .set push \n"
" .set mips32r2 \n"
" .set noat \n"
" .word 0x41610BC1 # dmt $1 \n"
" ehb \n"
" move %0, $1 \n"
" .set pop \n"
: "=r" (res));
instruction_hazard();
return res;
}
#define __VPECONTROL_TE_SHIFT 15
#define __VPECONTROL_TE (1UL << __VPECONTROL_TE_SHIFT)
#define __EMT_ENABLE __VPECONTROL_TE
static inline void __emt(unsigned int previous)
{
if ((previous & __EMT_ENABLE))
__asm__ __volatile__(
" .set mips32r2 \n"
" .word 0x41600be1 # emt \n"
" ehb \n"
" .set mips0 \n");
}
static inline void __ehb(void)
{
__asm__ __volatile__(
" .set mips32r2 \n"
" ehb \n" " .set mips0 \n");
}
/*
* Note that local_irq_save/restore affect TC-specific IXMT state,
* not Status.IE as in non-SMTC kernel.
*/
#define __BUILD_SET_C0(name) \
static inline unsigned int \
set_c0_##name(unsigned int set) \
{ \
unsigned int res; \
unsigned int new; \
unsigned int omt; \
unsigned long flags; \
\
local_irq_save(flags); \
omt = __dmt(); \
res = read_c0_##name(); \
new = res | set; \
write_c0_##name(new); \
__emt(omt); \
local_irq_restore(flags); \
\
return res; \
} \
\
static inline unsigned int \
clear_c0_##name(unsigned int clear) \
{ \
unsigned int res; \
unsigned int new; \
unsigned int omt; \
unsigned long flags; \
\
local_irq_save(flags); \
omt = __dmt(); \
res = read_c0_##name(); \
new = res & ~clear; \
write_c0_##name(new); \
__emt(omt); \
local_irq_restore(flags); \
\
return res; \
} \
\
static inline unsigned int \
change_c0_##name(unsigned int change, unsigned int newbits) \
{ \
unsigned int res; \
unsigned int new; \
unsigned int omt; \
unsigned long flags; \
\
local_irq_save(flags); \
\
omt = __dmt(); \
res = read_c0_##name(); \
new = res & ~change; \
new |= (newbits & change); \
write_c0_##name(new); \
__emt(omt); \
local_irq_restore(flags); \
\
return res; \
}
#endif
__BUILD_SET_C0(status)
__BUILD_SET_C0(cause)
__BUILD_SET_C0(config)