diff options
Diffstat (limited to 'arch/sparc64/kernel')
| -rw-r--r-- | arch/sparc64/kernel/head.S | 127 |
1 files changed, 91 insertions, 36 deletions
diff --git a/arch/sparc64/kernel/head.S b/arch/sparc64/kernel/head.S index 24340496cdd3..f1dcdf8f7433 100644 --- a/arch/sparc64/kernel/head.S +++ b/arch/sparc64/kernel/head.S @@ -382,32 +382,79 @@ tlb_fixup_done: nop /* Not reached... */ -/* IMPORTANT NOTE: Whenever making changes here, check - * trampoline.S as well. -jj */ - .globl setup_tba -setup_tba: /* i0 = is_starfire */ - save %sp, -160, %sp + /* This is meant to allow the sharing of this code between + * boot processor invocation (via setup_tba() below) and + * secondary processor startup (via trampoline.S). The + * former does use this code, the latter does not yet due + * to some complexities. That should be fixed up at some + * point. + */ + .globl setup_trap_table +setup_trap_table: + save %sp, -192, %sp + + /* Force interrupts to be disabled. Transferring over to + * the Linux trap table is a very delicate operation. + * Until we are actually on the Linux trap table, we cannot + * get the PAGE_OFFSET linear mappings translated. We need + * that mapping to be setup in order to initialize the firmware + * page tables. + * + * So there is this window of time, from the return from + * prom_set_trap_table() until inherit_prom_mappings_post() + * (in arch/sparc64/mm/init.c) completes, during which no + * firmware address space accesses can be made. + */ + rdpr %pstate, %o1 + andn %o1, PSTATE_IE, %o1 + wrpr %o1, 0x0, %pstate + wrpr %g0, 15, %pil - rdpr %tba, %g7 - sethi %hi(prom_tba), %o1 - or %o1, %lo(prom_tba), %o1 - stx %g7, [%o1] + /* Ok, now make the final valid firmware call to jump over + * to the Linux trap table. + */ + call prom_set_trap_table + sethi %hi(sparc64_ttable_tl0), %o0 + + /* Start using proper page size encodings in ctx register. */ + sethi %hi(sparc64_kern_pri_context), %g3 + ldx [%g3 + %lo(sparc64_kern_pri_context)], %g2 + mov PRIMARY_CONTEXT, %g1 + stxa %g2, [%g1] ASI_DMMU + membar #Sync + + /* The Linux trap handlers expect various trap global registers + * to be setup with some fixed values. So here we set these + * up very carefully. These globals are: + * + * Alternate Globals (PSTATE_AG): + * + * %g6 --> current_thread_info() + * + * MMU Globals (PSTATE_MG): + * + * %g1 --> TLB_SFSR + * %g2 --> ((_PAGE_VALID | _PAGE_SZ4MB | + * _PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W) + * ^ 0xfffff80000000000) + * (this %g2 value is used for computing the PAGE_OFFSET kernel + * TLB entries quickly, the virtual address of the fault XOR'd + * with this %g2 value is the PTE to load into the TLB) + * %g3 --> VPTE_BASE_CHEETAH or VPTE_BASE_SPITFIRE + * + * Interrupt Globals (PSTATE_IG, setup by init_irqwork_curcpu()): + * + * %g6 --> __irq_work[smp_processor_id()] + */ - /* Setup "Linux" globals 8-) */ rdpr %pstate, %o1 mov %g6, %o2 - wrpr %o1, (PSTATE_AG|PSTATE_IE), %pstate - sethi %hi(sparc64_ttable_tl0), %g1 - wrpr %g1, %tba + wrpr %o1, PSTATE_AG, %pstate mov %o2, %g6 - /* Set up MMU globals */ - wrpr %o1, (PSTATE_MG|PSTATE_IE), %pstate - - /* Set fixed globals used by dTLB miss handler. */ #define KERN_HIGHBITS ((_PAGE_VALID|_PAGE_SZ4MB)^0xfffff80000000000) #define KERN_LOWBITS (_PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W) - + wrpr %o1, PSTATE_MG, %pstate mov TSB_REG, %g1 stxa %g0, [%g1] ASI_DMMU membar #Sync @@ -419,17 +466,17 @@ setup_tba: /* i0 = is_starfire */ sllx %g2, 32, %g2 or %g2, KERN_LOWBITS, %g2 - BRANCH_IF_ANY_CHEETAH(g3,g7,cheetah_vpte_base) - ba,pt %xcc, spitfire_vpte_base + BRANCH_IF_ANY_CHEETAH(g3,g7,8f) + ba,pt %xcc, 9f nop -cheetah_vpte_base: +8: sethi %uhi(VPTE_BASE_CHEETAH), %g3 or %g3, %ulo(VPTE_BASE_CHEETAH), %g3 ba,pt %xcc, 2f sllx %g3, 32, %g3 -spitfire_vpte_base: +9: sethi %uhi(VPTE_BASE_SPITFIRE), %g3 or %g3, %ulo(VPTE_BASE_SPITFIRE), %g3 sllx %g3, 32, %g3 @@ -455,29 +502,37 @@ spitfire_vpte_base: sllx %o2, 32, %o2 wr %o2, %asr25 - /* Ok, we're done setting up all the state our trap mechanims needs, - * now get back into normal globals and let the PROM know what is up. - */ 2: wrpr %g0, %g0, %wstate - wrpr %o1, PSTATE_IE, %pstate + wrpr %o1, 0x0, %pstate call init_irqwork_curcpu nop - call prom_set_trap_table - sethi %hi(sparc64_ttable_tl0), %o0 - - /* Start using proper page size encodings in ctx register. */ - sethi %hi(sparc64_kern_pri_context), %g3 - ldx [%g3 + %lo(sparc64_kern_pri_context)], %g2 - mov PRIMARY_CONTEXT, %g1 - stxa %g2, [%g1] ASI_DMMU - membar #Sync - + /* Now we can turn interrupts back on. */ rdpr %pstate, %o1 or %o1, PSTATE_IE, %o1 wrpr %o1, 0, %pstate + wrpr %g0, 0x0, %pil + + ret + restore + + .globl setup_tba +setup_tba: /* i0 = is_starfire */ + save %sp, -192, %sp + + /* The boot processor is the only cpu which invokes this + * routine, the other cpus set things up via trampoline.S. + * So save the OBP trap table address here. + */ + rdpr %tba, %g7 + sethi %hi(prom_tba), %o1 + or %o1, %lo(prom_tba), %o1 + stx %g7, [%o1] + + call setup_trap_table + nop ret restore |