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-rw-r--r--arch/sparc64/kernel/head.S61
1 files changed, 26 insertions, 35 deletions
diff --git a/arch/sparc64/kernel/head.S b/arch/sparc64/kernel/head.S
index 4c942f7..b49dcd4 100644
--- a/arch/sparc64/kernel/head.S
+++ b/arch/sparc64/kernel/head.S
@@ -28,19 +28,14 @@
#include <asm/mmu.h>
/* This section from from _start to sparc64_boot_end should fit into
- * 0x0000.0000.0040.4000 to 0x0000.0000.0040.8000 and will be sharing space
- * with bootup_user_stack, which is from 0x0000.0000.0040.4000 to
- * 0x0000.0000.0040.6000 and empty_bad_page, which is from
- * 0x0000.0000.0040.6000 to 0x0000.0000.0040.8000.
+ * 0x0000000000404000 to 0x0000000000408000.
*/
-
.text
.globl start, _start, stext, _stext
_start:
start:
_stext:
stext:
-bootup_user_stack:
! 0x0000000000404000
b sparc64_boot
flushw /* Flush register file. */
@@ -392,31 +387,30 @@ tlb_fixup_done:
* former does use this code, the latter does not yet due
* to some complexities. That should be fixed up at some
* point.
+ *
+ * There used to be enormous complexity wrt. transferring
+ * over from the firwmare's trap table to the Linux kernel's.
+ * For example, there was a chicken & egg problem wrt. building
+ * the OBP page tables, yet needing to be on the Linux kernel
+ * trap table (to translate PAGE_OFFSET addresses) in order to
+ * do that.
+ *
+ * We now handle OBP tlb misses differently, via linear lookups
+ * into the prom_trans[] array. So that specific problem no
+ * longer exists. Yet, unfortunately there are still some issues
+ * preventing trampoline.S from using this code... ho hum.
*/
.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.
- */
+ /* Force interrupts to be disabled. */
rdpr %pstate, %o1
andn %o1, PSTATE_IE, %o1
wrpr %o1, 0x0, %pstate
wrpr %g0, 15, %pil
- /* Ok, now make the final valid firmware call to jump over
- * to the Linux trap table.
- */
+ /* Make the firmware call to jump over to the Linux trap table. */
call prom_set_trap_table
sethi %hi(sparc64_ttable_tl0), %o0
@@ -540,15 +534,21 @@ setup_tba: /* i0 = is_starfire */
ret
restore
+sparc64_boot_end:
+
+#include "systbls.S"
+#include "ktlb.S"
+#include "etrap.S"
+#include "rtrap.S"
+#include "winfixup.S"
+#include "entry.S"
/*
- * The following skips make sure the trap table in ttable.S is aligned
+ * The following skip makes sure the trap table in ttable.S is aligned
* on a 32K boundary as required by the v9 specs for TBA register.
*/
-sparc64_boot_end:
- .skip 0x2000 + _start - sparc64_boot_end
-bootup_user_stack_end:
- .skip 0x2000
+1:
+ .skip 0x4000 + _start - 1b
#ifdef CONFIG_SBUS
/* This is just a hack to fool make depend config.h discovering
@@ -560,15 +560,6 @@ bootup_user_stack_end:
! 0x0000000000408000
#include "ttable.S"
-#include "systbls.S"
-#include "ktlb.S"
-#include "etrap.S"
-#include "rtrap.S"
-#include "winfixup.S"
-#include "entry.S"
-
- /* This is just anal retentiveness on my part... */
- .align 16384
.data
.align 8