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authorDavid S. Miller <davem@davemloft.net>2005-10-12 12:22:46 -0700
committerDavid S. Miller <davem@davemloft.net>2005-10-12 12:22:46 -0700
commitc9c10830740df1b5e7848d6fbb68c93a73e8f7cd (patch)
treeb614058c3291ebccb996b27cee9b709956df7791 /arch/sparc64/kernel
parentd8e998c58a870770905495a1d45ebf7285b5b1c5 (diff)
[SPARC64]: Fix boot failures on SunBlade-150
The sequence to move over to the Linux trap tables from the firmware ones needs to be more air tight. It turns out that to be %100 safe we do need to be able to translate OBP mappings in our TLB miss handlers early. In order not to eat up a lot of kernel image memory with static page tables, just use the translations array in the OBP TLB miss handlers. That solves the bulk of the problem. Furthermore, to make sure the OBP TLB miss path will work even before the fixed MMU globals are loaded, explicitly load %g1 to TLB_SFSR at the beginning of the i-TLB and d-TLB miss handlers. To ease the OBP TLB miss walking of the prom_trans[] array, we sort it then delete all of the non-OBP entries in there (for example, there are entries for the kernel image itself which we're not interested in at all). We also save about 32K of kernel image size with this change. Not a bad side effect :-) There are still some reasons why trampoline.S can't use the setup_trap_table() yet. The most noteworthy are: 1) OBP boots secondary processors with non-bias'd stack for some reason. This is easily fixed by using a small bootup stack in the kernel image explicitly for this purpose. 2) Doing a firmware call via the normal C call prom_set_trap_table() goes through the whole OBP enter/exit sequence that saves and restores OBP and Linux kernel state in the MMUs. This path unfortunately does a "flush %g6" while loading up the OBP locked TLB entries for the firmware call. If we setup the %g6 in the trampoline.S code properly, that is in the PAGE_OFFSET linear mapping, but we're not on the kernel trap table yet so those addresses won't translate properly. One idea is to do a by-hand firmware call like we do in the early bootup code and elsewhere here in trampoline.S But this fails as well, as aparently the secondary processors are not booted with OBP's special locked TLB entries loaded. These are necessary for the firwmare to processes TLB misses correctly up until the point where we take over the trap table. This does need to be resolved at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc64/kernel')
-rw-r--r--arch/sparc64/kernel/dtlb_base.S14
-rw-r--r--arch/sparc64/kernel/dtlb_prot.S12
-rw-r--r--arch/sparc64/kernel/head.S61
-rw-r--r--arch/sparc64/kernel/itlb_base.S26
-rw-r--r--arch/sparc64/kernel/ktlb.S92
5 files changed, 92 insertions, 113 deletions
diff --git a/arch/sparc64/kernel/dtlb_base.S b/arch/sparc64/kernel/dtlb_base.S
index 702d349c1e8..6528786840c 100644
--- a/arch/sparc64/kernel/dtlb_base.S
+++ b/arch/sparc64/kernel/dtlb_base.S
@@ -53,19 +53,18 @@
* be guaranteed to be 0 ... mmu_context.h does guarantee this
* by only using 10 bits in the hwcontext value.
*/
-#define CREATE_VPTE_OFFSET1(r1, r2)
+#define CREATE_VPTE_OFFSET1(r1, r2) nop
#define CREATE_VPTE_OFFSET2(r1, r2) \
srax r1, 10, r2
-#define CREATE_VPTE_NOP nop
#else
#define CREATE_VPTE_OFFSET1(r1, r2) \
srax r1, PAGE_SHIFT, r2
#define CREATE_VPTE_OFFSET2(r1, r2) \
sllx r2, 3, r2
-#define CREATE_VPTE_NOP
#endif
/* DTLB ** ICACHE line 1: Quick user TLB misses */
+ mov TLB_SFSR, %g1
ldxa [%g1 + %g1] ASI_DMMU, %g4 ! Get TAG_ACCESS
andcc %g4, TAG_CONTEXT_BITS, %g0 ! From Nucleus?
from_tl1_trap:
@@ -74,18 +73,16 @@ from_tl1_trap:
be,pn %xcc, kvmap ! Yep, special processing
CREATE_VPTE_OFFSET2(%g4, %g6) ! Create VPTE offset
cmp %g5, 4 ! Last trap level?
- be,pn %xcc, longpath ! Yep, cannot risk VPTE miss
- nop ! delay slot
/* DTLB ** ICACHE line 2: User finish + quick kernel TLB misses */
+ be,pn %xcc, longpath ! Yep, cannot risk VPTE miss
+ nop ! delay slot
ldxa [%g3 + %g6] ASI_S, %g5 ! Load VPTE
1: brgez,pn %g5, longpath ! Invalid, branch out
nop ! Delay-slot
9: stxa %g5, [%g0] ASI_DTLB_DATA_IN ! Reload TLB
retry ! Trap return
nop
- nop
- nop
/* DTLB ** ICACHE line 3: winfixups+real_faults */
longpath:
@@ -106,8 +103,7 @@ longpath:
nop
nop
nop
- CREATE_VPTE_NOP
+ nop
#undef CREATE_VPTE_OFFSET1
#undef CREATE_VPTE_OFFSET2
-#undef CREATE_VPTE_NOP
diff --git a/arch/sparc64/kernel/dtlb_prot.S b/arch/sparc64/kernel/dtlb_prot.S
index d848bb7374b..e0a92016260 100644
--- a/arch/sparc64/kernel/dtlb_prot.S
+++ b/arch/sparc64/kernel/dtlb_prot.S
@@ -14,14 +14,14 @@
*/
/* PROT ** ICACHE line 1: User DTLB protection trap */
- stxa %g0, [%g1] ASI_DMMU ! Clear SFSR FaultValid bit
- membar #Sync ! Synchronize ASI stores
- rdpr %pstate, %g5 ! Move into alternate globals
+ mov TLB_SFSR, %g1
+ stxa %g0, [%g1] ASI_DMMU ! Clear FaultValid bit
+ membar #Sync ! Synchronize stores
+ rdpr %pstate, %g5 ! Move into alt-globals
wrpr %g5, PSTATE_AG|PSTATE_MG, %pstate
- rdpr %tl, %g1 ! Need to do a winfixup?
+ rdpr %tl, %g1 ! Need a winfixup?
cmp %g1, 1 ! Trap level >1?
- mov TLB_TAG_ACCESS, %g4 ! Prepare reload of vaddr
- nop
+ mov TLB_TAG_ACCESS, %g4 ! For reload of vaddr
/* PROT ** ICACHE line 2: More real fault processing */
bgu,pn %xcc, winfix_trampoline ! Yes, perform winfixup
diff --git a/arch/sparc64/kernel/head.S b/arch/sparc64/kernel/head.S
index 4c942f71184..b49dcd4504b 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
diff --git a/arch/sparc64/kernel/itlb_base.S b/arch/sparc64/kernel/itlb_base.S
index b5e32dfa4fb..4951ff8f687 100644
--- a/arch/sparc64/kernel/itlb_base.S
+++ b/arch/sparc64/kernel/itlb_base.S
@@ -15,14 +15,12 @@
*/
#define CREATE_VPTE_OFFSET1(r1, r2) \
srax r1, 10, r2
-#define CREATE_VPTE_OFFSET2(r1, r2)
-#define CREATE_VPTE_NOP nop
+#define CREATE_VPTE_OFFSET2(r1, r2) nop
#else /* PAGE_SHIFT */
#define CREATE_VPTE_OFFSET1(r1, r2) \
srax r1, PAGE_SHIFT, r2
#define CREATE_VPTE_OFFSET2(r1, r2) \
sllx r2, 3, r2
-#define CREATE_VPTE_NOP
#endif /* PAGE_SHIFT */
@@ -36,6 +34,7 @@
*/
/* ITLB ** ICACHE line 1: Quick user TLB misses */
+ mov TLB_SFSR, %g1
ldxa [%g1 + %g1] ASI_IMMU, %g4 ! Get TAG_ACCESS
CREATE_VPTE_OFFSET1(%g4, %g6) ! Create VPTE offset
CREATE_VPTE_OFFSET2(%g4, %g6) ! Create VPTE offset
@@ -43,41 +42,38 @@
1: brgez,pn %g5, 3f ! Not valid, branch out
sethi %hi(_PAGE_EXEC), %g4 ! Delay-slot
andcc %g5, %g4, %g0 ! Executable?
+
+/* ITLB ** ICACHE line 2: Real faults */
be,pn %xcc, 3f ! Nope, branch.
nop ! Delay-slot
2: stxa %g5, [%g0] ASI_ITLB_DATA_IN ! Load PTE into TLB
retry ! Trap return
-3: rdpr %pstate, %g4 ! Move into alternate globals
-
-/* ITLB ** ICACHE line 2: Real faults */
+3: rdpr %pstate, %g4 ! Move into alt-globals
wrpr %g4, PSTATE_AG|PSTATE_MG, %pstate
rdpr %tpc, %g5 ! And load faulting VA
mov FAULT_CODE_ITLB, %g4 ! It was read from ITLB
-sparc64_realfault_common: ! Called by TL0 dtlb_miss too
+
+/* ITLB ** ICACHE line 3: Finish faults */
+sparc64_realfault_common: ! Called by dtlb_miss
stb %g4, [%g6 + TI_FAULT_CODE]
stx %g5, [%g6 + TI_FAULT_ADDR]
ba,pt %xcc, etrap ! Save state
1: rd %pc, %g7 ! ...
- nop
-
-/* ITLB ** ICACHE line 3: Finish faults + window fixups */
call do_sparc64_fault ! Call fault handler
add %sp, PTREGS_OFF, %o0! Compute pt_regs arg
ba,pt %xcc, rtrap_clr_l6 ! Restore cpu state
nop
+
+/* ITLB ** ICACHE line 4: Window fixups */
winfix_trampoline:
rdpr %tpc, %g3 ! Prepare winfixup TNPC
- or %g3, 0x7c, %g3 ! Compute offset to branch
+ or %g3, 0x7c, %g3 ! Compute branch offset
wrpr %g3, %tnpc ! Write it into TNPC
done ! Do it to it
-
-/* ITLB ** ICACHE line 4: Unused... */
nop
nop
nop
nop
- CREATE_VPTE_NOP
#undef CREATE_VPTE_OFFSET1
#undef CREATE_VPTE_OFFSET2
-#undef CREATE_VPTE_NOP
diff --git a/arch/sparc64/kernel/ktlb.S b/arch/sparc64/kernel/ktlb.S
index 7796b37f478..d9244d3c9f7 100644
--- a/arch/sparc64/kernel/ktlb.S
+++ b/arch/sparc64/kernel/ktlb.S
@@ -58,9 +58,6 @@ vpte_noent:
done
vpte_insn_obp:
- sethi %hi(prom_pmd_phys), %g5
- ldx [%g5 + %lo(prom_pmd_phys)], %g5
-
/* Behave as if we are at TL0. */
wrpr %g0, 1, %tl
rdpr %tpc, %g4 /* Find original faulting iaddr */
@@ -71,58 +68,57 @@ vpte_insn_obp:
mov TLB_SFSR, %g1
stxa %g4, [%g1 + %g1] ASI_IMMU
- /* Get PMD offset. */
- srlx %g4, 23, %g6
- and %g6, 0x7ff, %g6
- sllx %g6, 2, %g6
-
- /* Load PMD, is it valid? */
- lduwa [%g5 + %g6] ASI_PHYS_USE_EC, %g5
- brz,pn %g5, longpath
- sllx %g5, 11, %g5
-
- /* Get PTE offset. */
- srlx %g4, 13, %g6
- and %g6, 0x3ff, %g6
- sllx %g6, 3, %g6
-
- /* Load PTE. */
- ldxa [%g5 + %g6] ASI_PHYS_USE_EC, %g5
- brgez,pn %g5, longpath
- nop
-
- /* TLB load and return from trap. */
+ sethi %hi(prom_trans), %g5
+ or %g5, %lo(prom_trans), %g5
+
+1: ldx [%g5 + 0x00], %g6 ! base
+ brz,a,pn %g6, longpath ! no more entries, fail
+ mov TLB_SFSR, %g1 ! and restore %g1
+ ldx [%g5 + 0x08], %g1 ! len
+ add %g6, %g1, %g1 ! end
+ cmp %g6, %g4
+ bgu,pt %xcc, 2f
+ cmp %g4, %g1
+ bgeu,pt %xcc, 2f
+ ldx [%g5 + 0x10], %g1 ! PTE
+
+ /* TLB load, restore %g1, and return from trap. */
+ sub %g4, %g6, %g6
+ add %g1, %g6, %g5
+ mov TLB_SFSR, %g1
stxa %g5, [%g0] ASI_ITLB_DATA_IN
retry
-kvmap_do_obp:
- sethi %hi(prom_pmd_phys), %g5
- ldx [%g5 + %lo(prom_pmd_phys)], %g5
-
- /* Get PMD offset. */
- srlx %g4, 23, %g6
- and %g6, 0x7ff, %g6
- sllx %g6, 2, %g6
-
- /* Load PMD, is it valid? */
- lduwa [%g5 + %g6] ASI_PHYS_USE_EC, %g5
- brz,pn %g5, longpath
- sllx %g5, 11, %g5
-
- /* Get PTE offset. */
- srlx %g4, 13, %g6
- and %g6, 0x3ff, %g6
- sllx %g6, 3, %g6
-
- /* Load PTE. */
- ldxa [%g5 + %g6] ASI_PHYS_USE_EC, %g5
- brgez,pn %g5, longpath
- nop
+2: ba,pt %xcc, 1b
+ add %g5, (3 * 8), %g5 ! next entry
- /* TLB load and return from trap. */
+kvmap_do_obp:
+ sethi %hi(prom_trans), %g5
+ or %g5, %lo(prom_trans), %g5
+ srlx %g4, 13, %g4
+ sllx %g4, 13, %g4
+
+1: ldx [%g5 + 0x00], %g6 ! base
+ brz,a,pn %g6, longpath ! no more entries, fail
+ mov TLB_SFSR, %g1 ! and restore %g1
+ ldx [%g5 + 0x08], %g1 ! len
+ add %g6, %g1, %g1 ! end
+ cmp %g6, %g4
+ bgu,pt %xcc, 2f
+ cmp %g4, %g1
+ bgeu,pt %xcc, 2f
+ ldx [%g5 + 0x10], %g1 ! PTE
+
+ /* TLB load, restore %g1, and return from trap. */
+ sub %g4, %g6, %g6
+ add %g1, %g6, %g5
+ mov TLB_SFSR, %g1
stxa %g5, [%g0] ASI_DTLB_DATA_IN
retry
+2: ba,pt %xcc, 1b
+ add %g5, (3 * 8), %g5 ! next entry
+
/*
* On a first level data miss, check whether this is to the OBP range (note
* that such accesses can be made by prom, as well as by kernel using