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powerpc: Hook in new transactional memory code

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This hooks the new transactional memory code into context switching, FP/VMX/VMX
unavailable and exception return.

Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Michael Neuling 2013-02-13 16:21:40 +00:00 committed by Benjamin Herrenschmidt
parent f54db641b9
commit bc2a9408fa
4 changed files with 115 additions and 4 deletions
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56
arch/powerpc/kernel/exceptions-64s.S
View File

@ -1176,9 +1176,26 @@ fp_unavailable_common:
addi r3,r1,STACK_FRAME_OVERHEAD
bl .kernel_fp_unavailable_exception
BUG_OPCODE
1: bl .load_up_fpu
1:
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
BEGIN_FTR_SECTION
/* Test if 2 TM state bits are zero. If non-zero (ie. userspace was in
* transaction), go do TM stuff
*/
rldicl. r0, r12, (64-MSR_TS_LG), (64-2)
bne- 2f
END_FTR_SECTION_IFSET(CPU_FTR_TM)
#endif
bl .load_up_fpu
b fast_exception_return
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2: /* User process was in a transaction */
bl .save_nvgprs
DISABLE_INTS
addi r3,r1,STACK_FRAME_OVERHEAD
bl .fp_unavailable_tm
b .ret_from_except
#endif
.align 7
.globl altivec_unavailable_common
altivec_unavailable_common:
@ -1186,8 +1203,25 @@ altivec_unavailable_common:
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
beq 1f
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
BEGIN_FTR_SECTION_NESTED(69)
/* Test if 2 TM state bits are zero. If non-zero (ie. userspace was in
* transaction), go do TM stuff
*/
rldicl. r0, r12, (64-MSR_TS_LG), (64-2)
bne- 2f
END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
#endif
bl .load_up_altivec
b fast_exception_return
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2: /* User process was in a transaction */
bl .save_nvgprs
DISABLE_INTS
addi r3,r1,STACK_FRAME_OVERHEAD
bl .altivec_unavailable_tm
b .ret_from_except
#endif
1:
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
@ -1204,7 +1238,24 @@ vsx_unavailable_common:
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
beq 1f
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
BEGIN_FTR_SECTION_NESTED(69)
/* Test if 2 TM state bits are zero. If non-zero (ie. userspace was in
* transaction), go do TM stuff
*/
rldicl. r0, r12, (64-MSR_TS_LG), (64-2)
bne- 2f
END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
#endif
b .load_up_vsx
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2: /* User process was in a transaction */
bl .save_nvgprs
DISABLE_INTS
addi r3,r1,STACK_FRAME_OVERHEAD
bl .vsx_unavailable_tm
b .ret_from_except
#endif
1:
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
@ -1219,6 +1270,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
tm_unavailable_common:
EXCEPTION_PROLOG_COMMON(0xf60, PACA_EXGEN)
bl .save_nvgprs
DISABLE_INTS
addi r3,r1,STACK_FRAME_OVERHEAD
bl .tm_unavailable_exception
b .ret_from_except

15
arch/powerpc/kernel/process.c
View File

@ -515,7 +515,7 @@ out_and_saveregs:
tm_save_sprs(thr);
}
static inline void __maybe_unused tm_recheckpoint_new_task(struct task_struct *new)
static inline void tm_recheckpoint_new_task(struct task_struct *new)
{
unsigned long msr;
@ -590,6 +590,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
struct ppc64_tlb_batch *batch;
#endif
__switch_to_tm(prev);
#ifdef CONFIG_SMP
/* avoid complexity of lazy save/restore of fpu
* by just saving it every time we switch out if
@ -705,6 +707,9 @@ struct task_struct *__switch_to(struct task_struct *prev,
* of sync. Hard disable here.
*/
hard_irq_disable();
tm_recheckpoint_new_task(new);
last = _switch(old_thread, new_thread);
#ifdef CONFIG_PPC_BOOK3S_64
@ -1080,7 +1085,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
regs->msr = MSR_USER32;
}
#endif
discard_lazy_cpu_state();
#ifdef CONFIG_VSX
current->thread.used_vsr = 0;
@ -1100,6 +1104,13 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
current->thread.spefscr = 0;
current->thread.used_spe = 0;
#endif /* CONFIG_SPE */
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
if (cpu_has_feature(CPU_FTR_TM))
regs->msr |= MSR_TM;
current->thread.tm_tfhar = 0;
current->thread.tm_texasr = 0;
current->thread.tm_tfiar = 0;
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
}
#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \

32
arch/powerpc/kernel/traps.c
View File

@ -1029,6 +1029,38 @@ void __kprobes program_check_exception(struct pt_regs *regs)
_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
return;
}
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
if (reason & REASON_TM) {
/* This is a TM "Bad Thing Exception" program check.
* This occurs when:
* - An rfid/hrfid/mtmsrd attempts to cause an illegal
* transition in TM states.
* - A trechkpt is attempted when transactional.
* - A treclaim is attempted when non transactional.
* - A tend is illegally attempted.
* - writing a TM SPR when transactional.
*/
if (!user_mode(regs) &&
report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
regs->nip += 4;
return;
}
/* If usermode caused this, it's done something illegal and
* gets a SIGILL slap on the wrist. We call it an illegal
* operand to distinguish from the instruction just being bad
* (e.g. executing a 'tend' on a CPU without TM!); it's an
* illegal /placement/ of a valid instruction.
*/
if (user_mode(regs)) {
_exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
return;
} else {
printk(KERN_EMERG "Unexpected TM Bad Thing exception "
"at %lx (msr 0x%x)\n", regs->nip, reason);
die("Unrecoverable exception", regs, SIGABRT);
}
}
#endif
/* We restore the interrupt state now */
if (!arch_irq_disabled_regs(regs))

16
arch/powerpc/mm/hash_utils_64.c
View File

@ -55,6 +55,7 @@
#include <asm/code-patching.h>
#include <asm/fadump.h>
#include <asm/firmware.h>
#include <asm/tm.h>
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
@ -1171,6 +1172,21 @@ void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx);
ppc_md.hpte_invalidate(slot, vpn, psize, ssize, local);
} pte_iterate_hashed_end();
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/* Transactions are not aborted by tlbiel, only tlbie.
* Without, syncing a page back to a block device w/ PIO could pick up
* transactional data (bad!) so we force an abort here. Before the
* sync the page will be made read-only, which will flush_hash_page.
* BIG ISSUE here: if the kernel uses a page from userspace without
* unmapping it first, it may see the speculated version.
*/
if (local && cpu_has_feature(CPU_FTR_TM) &&
MSR_TM_ACTIVE(current->thread.regs->msr)) {
tm_enable();
tm_abort(TM_CAUSE_TLBI);
}
#endif
}
void flush_hash_range(unsigned long number, int local)