dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

powerpc: Add relocation on exception vector handlers 

POWER8/v2.07 allows exceptions to be taken with the MMU still on.

A new set of exception vectors is added at 0xc000_0000_0000_4xxx.  When the HW
takes us here, MSR IR/DR will be set already and we no longer need a costly
RFID to turn the MMU back on again.

The original 0x0 based exception vectors remain for when the HW can't leave the
MMU on.  Examples of this are when we can't trust the current MMU mappings,
like when we are changing from guest to hypervisor (HV 0 -> 1) or when the MMU
was off already.  In these cases the HW will take us to the original 0x0 based
exception vectors with the MMU off as before.

This uses the new macros added previously too implement these new execption
vectors at 0xc000_0000_0000_4xxx.  We exit these exception vectors using
mflr/blr (rather than mtspr SSR0/RFID), since we don't need the costly MMU
switch anymore.

This moves the __end_interrupts marker down past these new 0x4000 vectors since
they will need to be copied down to 0x0 when the kernel is not at 0x0.

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 2012-11-02 17:21:43 +11:00 committed by Benjamin Herrenschmidt
parent 4700dfaf1e
commit c1fb6816fb
3 changed files with 177 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/powerpc/include/asm/exception-64s.h
View File

@ -115,6 +115,7 @@
mfspr r10,SPRN_CFAR; \
std r10,area+EX_CFAR(r13); \
END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 66); \
SAVE_LR(r10, area); \
mfcr r9; \
extra(vec); \
std r11,area+EX_R11(r13); \
@ -215,6 +216,7 @@ do_kvm_##n: \
sth r1,PACA_TRAP_SAVE(r13); \
std r3,area+EX_R3(r13); \
addi r3,r13,area; /* r3 -> where regs are saved*/ \
RESTORE_LR(r1, area); \
b bad_stack; \
3: std r9,_CCR(r1); /* save CR in stackframe */ \
std r11,_NIP(r1); /* save SRR0 in stackframe */ \
@ -240,8 +242,8 @@ do_kvm_##n: \
ld r10,area+EX_CFAR(r13); \
std r10,ORIG_GPR3(r1); \
END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 66); \
GET_LR(r9,area); /* Get LR, later save to stack */ \
ld r2,PACATOC(r13); /* get kernel TOC into r2 */ \
mflr r9; /* save LR in stackframe */ \
std r9,_LINK(r1); \
mfctr r10; /* save CTR in stackframe */ \
std r10,_CTR(r1); \

180
arch/powerpc/kernel/exceptions-64s.S
View File

@ -19,11 +19,13 @@
/*
* We layout physical memory as follows:
* 0x0000 - 0x00ff : Secondary processor spin code
* 0x0100 - 0x2fff : pSeries Interrupt prologs
* 0x3000 - 0x5fff : interrupt support common interrupt prologs
* 0x6000 - 0x6fff : Initial (CPU0) segment table
* 0x0100 - 0x17ff : pSeries Interrupt prologs
* 0x1800 - 0x4000 : interrupt support common interrupt prologs
* 0x4000 - 0x5fff : pSeries interrupts with IR=1,DR=1
* 0x6000 - 0x6fff : more interrupt support including for IR=1,DR=1
* 0x7000 - 0x7fff : FWNMI data area
* 0x8000 - : Early init and support code
* 0x8000 - 0x8fff : Initial (CPU0) segment table
* 0x9000 - : Early init and support code
*/
/* Syscall routine is used twice, in reloc-off and reloc-on paths */
#define SYSCALL_PSERIES_1 \
@ -619,10 +621,6 @@ slb_miss_user_pseries:
b . /* prevent spec. execution */
#endif /* __DISABLED__ */
.align 7
.globl __end_interrupts
__end_interrupts:
/*
* Code from here down to __end_handlers is invoked from the
* exception prologs above. Because the prologs assemble the
@ -673,7 +671,158 @@ machine_check_common:
STD_EXCEPTION_COMMON(0x1800, cbe_thermal, .cbe_thermal_exception)
#endif /* CONFIG_CBE_RAS */
/*
* Relocation-on interrupts: A subset of the interrupts can be delivered
* with IR=1/DR=1, if AIL==2 and MSR.HV won't be changed by delivering
* it. Addresses are the same as the original interrupt addresses, but
* offset by 0xc000000000004000.
* It's impossible to receive interrupts below 0x300 via this mechanism.
* KVM: None of these traps are from the guest ; anything that escalated
* to HV=1 from HV=0 is delivered via real mode handlers.
*/
/*
* This uses the standard macro, since the original 0x300 vector
* only has extra guff for STAB-based processors -- which never
* come here.
*/
STD_RELON_EXCEPTION_PSERIES(0x4300, 0x300, data_access)
. = 0x4380
.globl data_access_slb_relon_pSeries
data_access_slb_relon_pSeries:
HMT_MEDIUM
SET_SCRATCH0(r13)
EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x380)
std r3,PACA_EXSLB+EX_R3(r13)
mfspr r3,SPRN_DAR
mfspr r12,SPRN_SRR1
#ifndef CONFIG_RELOCATABLE
b .slb_miss_realmode
#else
/*
* We can't just use a direct branch to .slb_miss_realmode
* because the distance from here to there depends on where
* the kernel ends up being put.
*/
mfctr r11
ld r10,PACAKBASE(r13)
LOAD_HANDLER(r10, .slb_miss_realmode)
mtctr r10
bctr
#endif
STD_RELON_EXCEPTION_PSERIES(0x4400, 0x400, instruction_access)
. = 0x4480
.globl instruction_access_slb_relon_pSeries
instruction_access_slb_relon_pSeries:
HMT_MEDIUM
SET_SCRATCH0(r13)
EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x480)
std r3,PACA_EXSLB+EX_R3(r13)
mfspr r3,SPRN_SRR0 /* SRR0 is faulting address */
mfspr r12,SPRN_SRR1
#ifndef CONFIG_RELOCATABLE
b .slb_miss_realmode
#else
mfctr r11
ld r10,PACAKBASE(r13)
LOAD_HANDLER(r10, .slb_miss_realmode)
mtctr r10
bctr
#endif
. = 0x4500
.globl hardware_interrupt_relon_pSeries;
.globl hardware_interrupt_relon_hv;
hardware_interrupt_relon_pSeries:
hardware_interrupt_relon_hv:
BEGIN_FTR_SECTION
_MASKABLE_RELON_EXCEPTION_PSERIES(0x502, hardware_interrupt, EXC_HV, SOFTEN_TEST_HV)
FTR_SECTION_ELSE
_MASKABLE_RELON_EXCEPTION_PSERIES(0x500, hardware_interrupt, EXC_STD, SOFTEN_TEST_PR)
ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_206)
STD_RELON_EXCEPTION_PSERIES(0x4600, 0x600, alignment)
STD_RELON_EXCEPTION_PSERIES(0x4700, 0x700, program_check)
STD_RELON_EXCEPTION_PSERIES(0x4800, 0x800, fp_unavailable)
MASKABLE_RELON_EXCEPTION_PSERIES(0x4900, 0x900, decrementer)
STD_RELON_EXCEPTION_HV(0x4980, 0x982, hdecrementer)
STD_RELON_EXCEPTION_PSERIES(0x4b00, 0xb00, trap_0b)
. = 0x4c00
.globl system_call_relon_pSeries
system_call_relon_pSeries:
HMT_MEDIUM
SYSCALL_PSERIES_1
SYSCALL_PSERIES_2_DIRECT
SYSCALL_PSERIES_3
STD_RELON_EXCEPTION_PSERIES(0x4d00, 0xd00, single_step)
. = 0x4e00
b h_data_storage_relon_hv
. = 0x4e20
b h_instr_storage_relon_hv
. = 0x4e40
b emulation_assist_relon_hv
. = 0x4e50
b hmi_exception_relon_hv
. = 0x4e60
b hmi_exception_relon_hv
/* For when we support the doorbell interrupt:
STD_RELON_EXCEPTION_HYPERVISOR(0x4e80, 0xe80, doorbell_hyper)
*/
performance_monitor_relon_pSeries_1:
. = 0x4f00
b performance_monitor_relon_pSeries
altivec_unavailable_relon_pSeries_1:
. = 0x4f20
b altivec_unavailable_relon_pSeries
vsx_unavailable_relon_pSeries_1:
. = 0x4f40
b vsx_unavailable_relon_pSeries
#ifdef CONFIG_CBE_RAS
STD_RELON_EXCEPTION_HV(0x5200, 0x1202, cbe_system_error)
#endif /* CONFIG_CBE_RAS */
STD_RELON_EXCEPTION_PSERIES(0x5300, 0x1300, instruction_breakpoint)
#ifdef CONFIG_PPC_DENORMALISATION
. = 0x5500
b denorm_exception_hv
#endif
#ifdef CONFIG_CBE_RAS
STD_RELON_EXCEPTION_HV(0x5600, 0x1602, cbe_maintenance)
#else
#ifdef CONFIG_HVC_SCOM
STD_RELON_EXCEPTION_HV(0x5600, 0x1600, maintence_interrupt)
KVM_HANDLER_SKIP(PACA_EXGEN, EXC_HV, 0x1600)
#endif /* CONFIG_HVC_SCOM */
#endif /* CONFIG_CBE_RAS */
STD_RELON_EXCEPTION_PSERIES(0x5700, 0x1700, altivec_assist)
#ifdef CONFIG_CBE_RAS
STD_RELON_EXCEPTION_HV(0x5800, 0x1802, cbe_thermal)
#endif /* CONFIG_CBE_RAS */
/* Other future vectors */
.align 7
.globl __end_interrupts
__end_interrupts:
.align 7
system_call_entry_direct:
#if defined(CONFIG_RELOCATABLE)
/* The first level prologue may have used LR to get here, saving
* orig in r10. To save hacking/ifdeffing common code, restore here.
*/
mtlr r10
#endif
system_call_entry:
b system_call_common
@ -1196,6 +1345,21 @@ _GLOBAL(do_stab_bolted)
rfid
b . /* prevent speculative execution */
/* Equivalents to the above handlers for relocation-on interrupt vectors */
STD_RELON_EXCEPTION_HV(., 0xe00, h_data_storage)
KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe00)
STD_RELON_EXCEPTION_HV(., 0xe20, h_instr_storage)
KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe20)
STD_RELON_EXCEPTION_HV(., 0xe40, emulation_assist)
KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe40)
STD_RELON_EXCEPTION_HV(., 0xe60, hmi_exception)
KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe60)
STD_RELON_EXCEPTION_PSERIES(., 0xf00, performance_monitor)
STD_RELON_EXCEPTION_PSERIES(., 0xf20, altivec_unavailable)
STD_RELON_EXCEPTION_PSERIES(., 0xf40, vsx_unavailable)
#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
/*
* Data area reserved for FWNMI option.

3
arch/powerpc/kernel/head_64.S
View File

@ -432,7 +432,8 @@ _STATIC(__after_prom_start)
cmplwi cr0,r7,1
bne 3f
li r5,__end_interrupts - _stext /* just copy interrupts */
/* just copy interrupts */
LOAD_REG_IMMEDIATE(r5, __end_interrupts - _stext)
b 5f
3:
#endif