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-rw-r--r--arch/sparc/include/asm/atomic_64.h4
-rw-r--r--arch/sparc/include/asm/backoff.h69
-rw-r--r--arch/sparc/include/asm/compat.h5
-rw-r--r--arch/sparc/include/asm/processor_64.h17
-rw-r--r--arch/sparc/include/asm/prom.h8
-rw-r--r--arch/sparc/include/asm/thread_info_64.h5
-rw-r--r--arch/sparc/include/asm/ttable.h24
7 files changed, 110 insertions, 22 deletions
diff --git a/arch/sparc/include/asm/atomic_64.h b/arch/sparc/include/asm/atomic_64.h
index ce35a1cf1a20..be56a244c9cf 100644
--- a/arch/sparc/include/asm/atomic_64.h
+++ b/arch/sparc/include/asm/atomic_64.h
@@ -1,7 +1,7 @@
/* atomic.h: Thankfully the V9 is at least reasonable for this
* stuff.
*
- * Copyright (C) 1996, 1997, 2000 David S. Miller (davem@redhat.com)
+ * Copyright (C) 1996, 1997, 2000, 2012 David S. Miller (davem@redhat.com)
*/
#ifndef __ARCH_SPARC64_ATOMIC__
@@ -106,6 +106,8 @@ static inline long atomic64_add_unless(atomic64_t *v, long a, long u)
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+extern long atomic64_dec_if_positive(atomic64_t *v);
+
/* Atomic operations are already serializing */
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec() barrier()
diff --git a/arch/sparc/include/asm/backoff.h b/arch/sparc/include/asm/backoff.h
index db3af0d30fb1..4e02086b839c 100644
--- a/arch/sparc/include/asm/backoff.h
+++ b/arch/sparc/include/asm/backoff.h
@@ -1,6 +1,46 @@
#ifndef _SPARC64_BACKOFF_H
#define _SPARC64_BACKOFF_H
+/* The macros in this file implement an exponential backoff facility
+ * for atomic operations.
+ *
+ * When multiple threads compete on an atomic operation, it is
+ * possible for one thread to be continually denied a successful
+ * completion of the compare-and-swap instruction. Heavily
+ * threaded cpu implementations like Niagara can compound this
+ * problem even further.
+ *
+ * When an atomic operation fails and needs to be retried, we spin a
+ * certain number of times. At each subsequent failure of the same
+ * operation we double the spin count, realizing an exponential
+ * backoff.
+ *
+ * When we spin, we try to use an operation that will cause the
+ * current cpu strand to block, and therefore make the core fully
+ * available to any other other runnable strands. There are two
+ * options, based upon cpu capabilities.
+ *
+ * On all cpus prior to SPARC-T4 we do three dummy reads of the
+ * condition code register. Each read blocks the strand for something
+ * between 40 and 50 cpu cycles.
+ *
+ * For SPARC-T4 and later we have a special "pause" instruction
+ * available. This is implemented using writes to register %asr27.
+ * The cpu will block the number of cycles written into the register,
+ * unless a disrupting trap happens first. SPARC-T4 specifically
+ * implements pause with a granularity of 8 cycles. Each strand has
+ * an internal pause counter which decrements every 8 cycles. So the
+ * chip shifts the %asr27 value down by 3 bits, and writes the result
+ * into the pause counter. If a value smaller than 8 is written, the
+ * chip blocks for 1 cycle.
+ *
+ * To achieve the same amount of backoff as the three %ccr reads give
+ * on earlier chips, we shift the backoff value up by 7 bits. (Three
+ * %ccr reads block for about 128 cycles, 1 << 7 == 128) We write the
+ * whole amount we want to block into the pause register, rather than
+ * loop writing 128 each time.
+ */
+
#define BACKOFF_LIMIT (4 * 1024)
#ifdef CONFIG_SMP
@@ -11,16 +51,25 @@
#define BACKOFF_LABEL(spin_label, continue_label) \
spin_label
-#define BACKOFF_SPIN(reg, tmp, label) \
- mov reg, tmp; \
-88: brnz,pt tmp, 88b; \
- sub tmp, 1, tmp; \
- set BACKOFF_LIMIT, tmp; \
- cmp reg, tmp; \
- bg,pn %xcc, label; \
- nop; \
- ba,pt %xcc, label; \
- sllx reg, 1, reg;
+#define BACKOFF_SPIN(reg, tmp, label) \
+ mov reg, tmp; \
+88: rd %ccr, %g0; \
+ rd %ccr, %g0; \
+ rd %ccr, %g0; \
+ .section .pause_3insn_patch,"ax";\
+ .word 88b; \
+ sllx tmp, 7, tmp; \
+ wr tmp, 0, %asr27; \
+ clr tmp; \
+ .previous; \
+ brnz,pt tmp, 88b; \
+ sub tmp, 1, tmp; \
+ set BACKOFF_LIMIT, tmp; \
+ cmp reg, tmp; \
+ bg,pn %xcc, label; \
+ nop; \
+ ba,pt %xcc, label; \
+ sllx reg, 1, reg;
#else
diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
index cef99fbc0a21..830502fe62b4 100644
--- a/arch/sparc/include/asm/compat.h
+++ b/arch/sparc/include/asm/compat.h
@@ -232,9 +232,10 @@ static inline void __user *arch_compat_alloc_user_space(long len)
struct pt_regs *regs = current_thread_info()->kregs;
unsigned long usp = regs->u_regs[UREG_I6];
- if (!(test_thread_flag(TIF_32BIT)))
+ if (test_thread_64bit_stack(usp))
usp += STACK_BIAS;
- else
+
+ if (test_thread_flag(TIF_32BIT))
usp &= 0xffffffffUL;
usp -= len;
diff --git a/arch/sparc/include/asm/processor_64.h b/arch/sparc/include/asm/processor_64.h
index 4e5a483122a0..721e25f0e2ea 100644
--- a/arch/sparc/include/asm/processor_64.h
+++ b/arch/sparc/include/asm/processor_64.h
@@ -196,7 +196,22 @@ extern unsigned long get_wchan(struct task_struct *task);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->tpc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->u_regs[UREG_FP])
-#define cpu_relax() barrier()
+/* Please see the commentary in asm/backoff.h for a description of
+ * what these instructions are doing and how they have been choosen.
+ * To make a long story short, we are trying to yield the current cpu
+ * strand during busy loops.
+ */
+#define cpu_relax() asm volatile("\n99:\n\t" \
+ "rd %%ccr, %%g0\n\t" \
+ "rd %%ccr, %%g0\n\t" \
+ "rd %%ccr, %%g0\n\t" \
+ ".section .pause_3insn_patch,\"ax\"\n\t"\
+ ".word 99b\n\t" \
+ "wr %%g0, 128, %%asr27\n\t" \
+ "nop\n\t" \
+ "nop\n\t" \
+ ".previous" \
+ ::: "memory")
/* Prefetch support. This is tuned for UltraSPARC-III and later.
* UltraSPARC-I will treat these as nops, and UltraSPARC-II has
diff --git a/arch/sparc/include/asm/prom.h b/arch/sparc/include/asm/prom.h
index c28765110706..67c62578d170 100644
--- a/arch/sparc/include/asm/prom.h
+++ b/arch/sparc/include/asm/prom.h
@@ -63,5 +63,13 @@ extern char *of_console_options;
extern void irq_trans_init(struct device_node *dp);
extern char *build_path_component(struct device_node *dp);
+/* SPARC has local implementations */
+extern int of_address_to_resource(struct device_node *dev, int index,
+ struct resource *r);
+#define of_address_to_resource of_address_to_resource
+
+void __iomem *of_iomap(struct device_node *node, int index);
+#define of_iomap of_iomap
+
#endif /* __KERNEL__ */
#endif /* _SPARC_PROM_H */
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index 4e2276631081..a3fe4dcc0aa6 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -259,6 +259,11 @@ static inline bool test_and_clear_restore_sigmask(void)
#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+#define thread32_stack_is_64bit(__SP) (((__SP) & 0x1) != 0)
+#define test_thread_64bit_stack(__SP) \
+ ((test_thread_flag(TIF_32BIT) && !thread32_stack_is_64bit(__SP)) ? \
+ false : true)
+
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */
diff --git a/arch/sparc/include/asm/ttable.h b/arch/sparc/include/asm/ttable.h
index 48f2807d3265..71b5a67522ab 100644
--- a/arch/sparc/include/asm/ttable.h
+++ b/arch/sparc/include/asm/ttable.h
@@ -372,7 +372,9 @@ etrap_spill_fixup_64bit: \
/* Normal 32bit spill */
#define SPILL_2_GENERIC(ASI) \
- srl %sp, 0, %sp; \
+ and %sp, 1, %g3; \
+ brnz,pn %g3, (. - (128 + 4)); \
+ srl %sp, 0, %sp; \
stwa %l0, [%sp + %g0] ASI; \
mov 0x04, %g3; \
stwa %l1, [%sp + %g3] ASI; \
@@ -398,14 +400,16 @@ etrap_spill_fixup_64bit: \
stwa %i6, [%g1 + %g0] ASI; \
stwa %i7, [%g1 + %g3] ASI; \
saved; \
- retry; nop; nop; \
+ retry; \
b,a,pt %xcc, spill_fixup_dax; \
b,a,pt %xcc, spill_fixup_mna; \
b,a,pt %xcc, spill_fixup;
#define SPILL_2_GENERIC_ETRAP \
etrap_user_spill_32bit: \
- srl %sp, 0, %sp; \
+ and %sp, 1, %g3; \
+ brnz,pn %g3, etrap_user_spill_64bit; \
+ srl %sp, 0, %sp; \
stwa %l0, [%sp + 0x00] %asi; \
stwa %l1, [%sp + 0x04] %asi; \
stwa %l2, [%sp + 0x08] %asi; \
@@ -427,7 +431,7 @@ etrap_user_spill_32bit: \
ba,pt %xcc, etrap_save; \
wrpr %g1, %cwp; \
nop; nop; nop; nop; \
- nop; nop; nop; nop; \
+ nop; nop; \
ba,a,pt %xcc, etrap_spill_fixup_32bit; \
ba,a,pt %xcc, etrap_spill_fixup_32bit; \
ba,a,pt %xcc, etrap_spill_fixup_32bit;
@@ -592,7 +596,9 @@ user_rtt_fill_64bit: \
/* Normal 32bit fill */
#define FILL_2_GENERIC(ASI) \
- srl %sp, 0, %sp; \
+ and %sp, 1, %g3; \
+ brnz,pn %g3, (. - (128 + 4)); \
+ srl %sp, 0, %sp; \
lduwa [%sp + %g0] ASI, %l0; \
mov 0x04, %g2; \
mov 0x08, %g3; \
@@ -616,14 +622,16 @@ user_rtt_fill_64bit: \
lduwa [%g1 + %g3] ASI, %i6; \
lduwa [%g1 + %g5] ASI, %i7; \
restored; \
- retry; nop; nop; nop; nop; \
+ retry; nop; nop; \
b,a,pt %xcc, fill_fixup_dax; \
b,a,pt %xcc, fill_fixup_mna; \
b,a,pt %xcc, fill_fixup;
#define FILL_2_GENERIC_RTRAP \
user_rtt_fill_32bit: \
- srl %sp, 0, %sp; \
+ and %sp, 1, %g3; \
+ brnz,pn %g3, user_rtt_fill_64bit; \
+ srl %sp, 0, %sp; \
lduwa [%sp + 0x00] %asi, %l0; \
lduwa [%sp + 0x04] %asi, %l1; \
lduwa [%sp + 0x08] %asi, %l2; \
@@ -643,7 +651,7 @@ user_rtt_fill_32bit: \
ba,pt %xcc, user_rtt_pre_restore; \
restored; \
nop; nop; nop; nop; nop; \
- nop; nop; nop; nop; nop; \
+ nop; nop; nop; \
ba,a,pt %xcc, user_rtt_fill_fixup; \
ba,a,pt %xcc, user_rtt_fill_fixup; \
ba,a,pt %xcc, user_rtt_fill_fixup;
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-27 23:06:16 +0000