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authorLinus Torvalds <torvalds@g5.osdl.org>2005-10-10 16:32:32 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-10-10 16:32:32 -0700
commitaf74c3a61d24ab42c04052ddd2343de972a1cc07 (patch)
tree03d6ff52a9302b9c155a01dd4df0e916693639dc
parentd7dd8a72ab8d305fbe1c4bb571e0633eba3a8d23 (diff)
parent5d8e1b181c4ad63e6ca90d51287b31afd400d2eb (diff)
downloadlinux-linaro-af74c3a61d24ab42c04052ddd2343de972a1cc07.tar.gz
Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6
-rw-r--r--arch/sparc64/kernel/head.S127
1 files changed, 91 insertions, 36 deletions
diff --git a/arch/sparc64/kernel/head.S b/arch/sparc64/kernel/head.S
index 24340496cdd..f1dcdf8f743 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