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authorDavid S. Miller <davem@sunset.davemloft.net>2007-09-16 11:51:15 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-09-16 11:51:15 -0700
commit301feb652441a7168b59256fc44918075dcab0d5 (patch)
tree68721bebf1375659be165c4810bb439785d6e96f
parent58ea1aa07e3cb4674ab0261b45aa1ba68282a79d (diff)
downloadlinux-linaro-301feb652441a7168b59256fc44918075dcab0d5.tar.gz
[SPARC64]: Fix lockdep, particularly on SMP.
As noted by Al Viro, when we try to call prom_set_trap_table() in the SMP trampoline code we try to take the PROM call spinlock which doesn't work because the current thread pointer isn't valid yet and lockdep depends upon that being correct. Furthermore, we cannot set the current thread pointer register because it can't be properly dereferenced until we return from prom_set_trap_table(). Kernel TLB misses only work after that call. So do the PROM call to set the trap table directly instead of going through the OBP library C code, and thus avoid the lock altogether. These calls are guarenteed to be serialized fully. Since there are now no calls to the prom_set_trap_table{_sun4v}() library functions, they can be deleted. Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--arch/sparc64/kernel/head.S35
-rw-r--r--arch/sparc64/kernel/trampoline.S33
-rw-r--r--arch/sparc64/prom/misc.c16
-rw-r--r--include/asm-sparc64/oplib.h4
4 files changed, 58 insertions, 30 deletions
diff --git a/arch/sparc64/kernel/head.S b/arch/sparc64/kernel/head.S
index 63144ad476f..c4147ad8677 100644
--- a/arch/sparc64/kernel/head.S
+++ b/arch/sparc64/kernel/head.S
@@ -98,7 +98,7 @@ sparc64_boot:
.globl prom_boot_mapped_pc, prom_boot_mapping_mode
.globl prom_boot_mapping_phys_high, prom_boot_mapping_phys_low
.globl prom_compatible_name, prom_cpu_path, prom_cpu_compatible
- .globl is_sun4v, sun4v_chip_type
+ .globl is_sun4v, sun4v_chip_type, prom_set_trap_table_name
prom_peer_name:
.asciz "peer"
prom_compatible_name:
@@ -121,6 +121,8 @@ prom_map_name:
.asciz "map"
prom_unmap_name:
.asciz "unmap"
+prom_set_trap_table_name:
+ .asciz "SUNW,set-trap-table"
prom_sun4v_name:
.asciz "sun4v"
prom_niagara_prefix:
@@ -691,15 +693,38 @@ setup_trap_table:
sethi %hi(kern_base), %g3
ldx [%g3 + %lo(kern_base)], %g3
add %g2, %g3, %o1
+ sethi %hi(sparc64_ttable_tl0), %o0
- call prom_set_trap_table_sun4v
- sethi %hi(sparc64_ttable_tl0), %o0
+ set prom_set_trap_table_name, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x00]
+ mov 2, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x08]
+ mov 0, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x10]
+ stx %o0, [%sp + 2047 + 128 + 0x18]
+ stx %o1, [%sp + 2047 + 128 + 0x20]
+ sethi %hi(p1275buf), %g2
+ or %g2, %lo(p1275buf), %g2
+ ldx [%g2 + 0x08], %o1
+ call %o1
+ add %sp, (2047 + 128), %o0
ba,pt %xcc, 2f
nop
-1: call prom_set_trap_table
- sethi %hi(sparc64_ttable_tl0), %o0
+1: sethi %hi(sparc64_ttable_tl0), %o0
+ set prom_set_trap_table_name, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x00]
+ mov 1, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x08]
+ mov 0, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x10]
+ stx %o0, [%sp + 2047 + 128 + 0x18]
+ sethi %hi(p1275buf), %g2
+ or %g2, %lo(p1275buf), %g2
+ ldx [%g2 + 0x08], %o1
+ call %o1
+ add %sp, (2047 + 128), %o0
/* Start using proper page size encodings in ctx register. */
2: sethi %hi(sparc64_kern_pri_context), %g3
diff --git a/arch/sparc64/kernel/trampoline.S b/arch/sparc64/kernel/trampoline.S
index 9533a25ce5d..04e81dda13d 100644
--- a/arch/sparc64/kernel/trampoline.S
+++ b/arch/sparc64/kernel/trampoline.S
@@ -345,7 +345,7 @@ after_lock_tlb:
sethi %hi(tramp_stack), %g1
or %g1, %lo(tramp_stack), %g1
add %g1, TRAMP_STACK_SIZE, %g1
- sub %g1, STACKFRAME_SZ + STACK_BIAS, %sp
+ sub %g1, STACKFRAME_SZ + STACK_BIAS + 256, %sp
mov 0, %fp
/* Put garbage in these registers to trap any access to them. */
@@ -411,15 +411,38 @@ after_lock_tlb:
sethi %hi(kern_base), %g3
ldx [%g3 + %lo(kern_base)], %g3
add %g2, %g3, %o1
+ sethi %hi(sparc64_ttable_tl0), %o0
- call prom_set_trap_table_sun4v
- sethi %hi(sparc64_ttable_tl0), %o0
+ set prom_set_trap_table_name, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x00]
+ mov 2, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x08]
+ mov 0, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x10]
+ stx %o0, [%sp + 2047 + 128 + 0x18]
+ stx %o1, [%sp + 2047 + 128 + 0x20]
+ sethi %hi(p1275buf), %g2
+ or %g2, %lo(p1275buf), %g2
+ ldx [%g2 + 0x08], %o1
+ call %o1
+ add %sp, (2047 + 128), %o0
ba,pt %xcc, 2f
nop
-1: call prom_set_trap_table
- sethi %hi(sparc64_ttable_tl0), %o0
+1: sethi %hi(sparc64_ttable_tl0), %o0
+ set prom_set_trap_table_name, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x00]
+ mov 1, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x08]
+ mov 0, %g2
+ stx %g2, [%sp + 2047 + 128 + 0x10]
+ stx %o0, [%sp + 2047 + 128 + 0x18]
+ sethi %hi(p1275buf), %g2
+ or %g2, %lo(p1275buf), %g2
+ ldx [%g2 + 0x08], %o1
+ call %o1
+ add %sp, (2047 + 128), %o0
2: ldx [%l0], %g6
ldx [%g6 + TI_TASK], %g4
diff --git a/arch/sparc64/prom/misc.c b/arch/sparc64/prom/misc.c
index 68c83ad04ad..bbec7522826 100644
--- a/arch/sparc64/prom/misc.c
+++ b/arch/sparc64/prom/misc.c
@@ -143,22 +143,6 @@ unsigned char prom_get_idprom(char *idbuf, int num_bytes)
return 0xff;
}
-/* Install Linux trap table so PROM uses that instead of its own. */
-void prom_set_trap_table(unsigned long tba)
-{
- p1275_cmd("SUNW,set-trap-table",
- (P1275_ARG(0, P1275_ARG_IN_64B) |
- P1275_INOUT(1, 0)), tba);
-}
-
-void prom_set_trap_table_sun4v(unsigned long tba, unsigned long mmfsa)
-{
- p1275_cmd("SUNW,set-trap-table",
- (P1275_ARG(0, P1275_ARG_IN_64B) |
- P1275_ARG(1, P1275_ARG_IN_64B) |
- P1275_INOUT(2, 0)), tba, mmfsa);
-}
-
int prom_get_mmu_ihandle(void)
{
int node, ret;
diff --git a/include/asm-sparc64/oplib.h b/include/asm-sparc64/oplib.h
index 86dc5c018a1..55c5bb27e4d 100644
--- a/include/asm-sparc64/oplib.h
+++ b/include/asm-sparc64/oplib.h
@@ -297,11 +297,7 @@ extern void prom_sun4v_guest_soft_state(void);
extern int prom_ihandle2path(int handle, char *buffer, int bufsize);
/* Client interface level routines. */
-extern void prom_set_trap_table(unsigned long tba);
-extern void prom_set_trap_table_sun4v(unsigned long tba, unsigned long mmfsa);
-
extern long p1275_cmd(const char *, long, ...);
-
#if 0
#define P1275_SIZE(x) ((((long)((x) / 32)) << 32) | (x))