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* [PATCH 0/20] powerpc: base 64-bit Book3E processor support (v2)
@ 2009-07-24  9:15 Benjamin Herrenschmidt
  2009-07-24  9:15 ` [PATCH 1/20] powerpc/mm: Fix misplaced #endif in pgtable-ppc64-64k.h Benjamin Herrenschmidt
                   ` (19 more replies)
  0 siblings, 20 replies; 31+ messages in thread
From: Benjamin Herrenschmidt @ 2009-07-24  9:15 UTC (permalink / raw)
  To: linuxppc-dev

Here is a series of patches that implement some basic support
for 64-bit Book3E processors that comply to architecture 2.06.

There is no specific processor announced yet. The patches make
some shortcut which means they currently rely on an implementation
that supports MMU v2 with support for the "HES" feature (HW entry
select) and with support for the "TLB reservation" feature. They
also assume a single unified TLB array. I shouldn't be very hard
to implement support for other variants of the architecture on
top of this though.

The current set of patch has no proper support yet for hugetlb,
nor for "special" interrupt levels (debug, critical and machine
check). Some minimal support for debug/critical levels is provided
specifically for the "Debug" interrupt (single step etc...) only
when it occurs from within user space code. 

The intend is to merge these in 2.6.32. They rely on pretty much
all the other patches I've been posting lately including the
generic changes to add the virtual address argument to pte_free_tlb.

v2. Various fixes, some addressing comments recieved and a whole
bunch fixing other issues including breakage of existing platforms

^ permalink raw reply	[flat|nested] 31+ messages in thread
* [PATCH 3/20] powerpc/mm: Add HW threads support to no_hash TLB management
@ 2009-07-23  5:59 Benjamin Herrenschmidt
  0 siblings, 0 replies; 31+ messages in thread
From: Benjamin Herrenschmidt @ 2009-07-23  5:59 UTC (permalink / raw)
  To: linuxppc-dev

The current "no hash" MMU context management code is written with
the assumption that one CPU == one TLB. This is not the case on
implementations that support HW multithreading, where several
linux CPUs can share the same TLB.

This adds some basic support for this to our context management
and our TLB flushing code.

It also cleans up the optional debugging output a bit

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

 arch/powerpc/include/asm/cputhreads.h |   16 +++++
 arch/powerpc/mm/mmu_context_nohash.c  |   93 ++++++++++++++++++++++------------
 arch/powerpc/mm/tlb_nohash.c          |   10 ++-
 3 files changed, 86 insertions(+), 33 deletions(-)

--- linux-work.orig/arch/powerpc/mm/mmu_context_nohash.c	2009-07-21 12:43:27.000000000 +1000
+++ linux-work/arch/powerpc/mm/mmu_context_nohash.c	2009-07-21 12:56:16.000000000 +1000
@@ -25,10 +25,20 @@
  *     also clear mm->cpu_vm_mask bits when processes are migrated
  */
 
-#undef DEBUG
-#define DEBUG_STEAL_ONLY
-#undef DEBUG_MAP_CONSISTENCY
-/*#define DEBUG_CLAMP_LAST_CONTEXT   15 */
+#define DEBUG_MAP_CONSISTENCY
+#define DEBUG_CLAMP_LAST_CONTEXT   31
+//#define DEBUG_HARDER
+
+/* We don't use DEBUG because it tends to be compiled in always nowadays
+ * and this would generate way too much output
+ */
+#ifdef DEBUG_HARDER
+#define pr_hard(args...)	printk(KERN_DEBUG args)
+#define pr_hardcont(args...)	printk(KERN_CONT args)
+#else
+#define pr_hard(args...)	do { } while(0)
+#define pr_hardcont(args...)	do { } while(0)
+#endif
 
 #include <linux/kernel.h>
 #include <linux/mm.h>
@@ -71,7 +81,7 @@ static DEFINE_SPINLOCK(context_lock);
 static unsigned int steal_context_smp(unsigned int id)
 {
 	struct mm_struct *mm;
-	unsigned int cpu, max;
+	unsigned int cpu, max, i;
 
 	max = last_context - first_context;
 
@@ -89,15 +99,22 @@ static unsigned int steal_context_smp(un
 				id = first_context;
 			continue;
 		}
-		pr_devel("[%d] steal context %d from mm @%p\n",
-			 smp_processor_id(), id, mm);
+		pr_hardcont(" | steal %d from 0x%p", id, mm);
 
 		/* Mark this mm has having no context anymore */
 		mm->context.id = MMU_NO_CONTEXT;
 
-		/* Mark it stale on all CPUs that used this mm */
-		for_each_cpu(cpu, mm_cpumask(mm))
-			__set_bit(id, stale_map[cpu]);
+		/* Mark it stale on all CPUs that used this mm. For threaded
+		 * implementations, we set it on all threads on each core
+		 * represented in the mask. A future implementation will use
+		 * a core map instead but this will do for now.
+		 */
+		for_each_cpu(cpu, mm_cpumask(mm)) {
+			for (i = cpu_first_thread_in_core(cpu);
+			     i <= cpu_last_thread_in_core(cpu); i++)
+				__set_bit(id, stale_map[i]);
+			cpu = i - 1;
+		}
 		return id;
 	}
 
@@ -126,7 +143,7 @@ static unsigned int steal_context_up(uns
 	/* Pick up the victim mm */
 	mm = context_mm[id];
 
-	pr_devel("[%d] steal context %d from mm @%p\n", cpu, id, mm);
+	pr_hardcont(" | steal %d from 0x%p", id, mm);
 
 	/* Flush the TLB for that context */
 	local_flush_tlb_mm(mm);
@@ -179,19 +196,14 @@ void switch_mmu_context(struct mm_struct
 	/* No lockless fast path .. yet */
 	spin_lock(&context_lock);
 
-#ifndef DEBUG_STEAL_ONLY
-	pr_devel("[%d] activating context for mm @%p, active=%d, id=%d\n",
-		 cpu, next, next->context.active, next->context.id);
-#endif
+	pr_hard("[%d] activating context for mm @%p, active=%d, id=%d",
+		cpu, next, next->context.active, next->context.id);
 
 #ifdef CONFIG_SMP
 	/* Mark us active and the previous one not anymore */
 	next->context.active++;
 	if (prev) {
-#ifndef DEBUG_STEAL_ONLY
-		pr_devel(" old context %p active was: %d\n",
-			 prev, prev->context.active);
-#endif
+		pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active);
 		WARN_ON(prev->context.active < 1);
 		prev->context.active--;
 	}
@@ -201,8 +213,14 @@ void switch_mmu_context(struct mm_struct
 
 	/* If we already have a valid assigned context, skip all that */
 	id = next->context.id;
-	if (likely(id != MMU_NO_CONTEXT))
+	if (likely(id != MMU_NO_CONTEXT)) {
+#ifdef DEBUG_MAP_CONSISTENCY
+		if (context_mm[id] != next)
+			pr_err("MMU: mm 0x%p has id %d but context_mm[%d] says 0x%p\n",
+			       next, id, id, context_mm[id]);
+#endif
 		goto ctxt_ok;
+	}
 
 	/* We really don't have a context, let's try to acquire one */
 	id = next_context;
@@ -234,11 +252,7 @@ void switch_mmu_context(struct mm_struct
 	next_context = id + 1;
 	context_mm[id] = next;
 	next->context.id = id;
-
-#ifndef DEBUG_STEAL_ONLY
-	pr_devel("[%d] picked up new id %d, nrf is now %d\n",
-		 cpu, id, nr_free_contexts);
-#endif
+	pr_hardcont(" | new id=%d,nrf=%d", id, nr_free_contexts);
 
 	context_check_map();
  ctxt_ok:
@@ -247,15 +261,20 @@ void switch_mmu_context(struct mm_struct
 	 * local TLB for it and unmark it before we use it
 	 */
 	if (test_bit(id, stale_map[cpu])) {
-		pr_devel("[%d] flushing stale context %d for mm @%p !\n",
-			 cpu, id, next);
+		pr_hardcont(" | stale flush %d [%d..%d]",
+			    id, cpu_first_thread_in_core(cpu),
+			    cpu_last_thread_in_core(cpu));
+
 		local_flush_tlb_mm(next);
 
 		/* XXX This clear should ultimately be part of local_flush_tlb_mm */
-		__clear_bit(id, stale_map[cpu]);
+		for (cpu = cpu_first_thread_in_core(cpu);
+		     cpu <= cpu_last_thread_in_core(cpu); cpu++)
+			__clear_bit(id, stale_map[cpu]);
 	}
 
 	/* Flick the MMU and release lock */
+	pr_hardcont(" -> %d\n", id);
 	set_context(id, next->pgd);
 	spin_unlock(&context_lock);
 }
@@ -265,6 +284,8 @@ void switch_mmu_context(struct mm_struct
  */
 int init_new_context(struct task_struct *t, struct mm_struct *mm)
 {
+	pr_hard("initing context for mm @%p\n", mm);
+
 	mm->context.id = MMU_NO_CONTEXT;
 	mm->context.active = 0;
 
@@ -304,7 +325,9 @@ static int __cpuinit mmu_context_cpu_not
 					    unsigned long action, void *hcpu)
 {
 	unsigned int cpu = (unsigned int)(long)hcpu;
-
+#ifdef CONFIG_HOTPLUG_CPU
+	struct task_struct *p;
+#endif
 	/* We don't touch CPU 0 map, it's allocated at aboot and kept
 	 * around forever
 	 */
@@ -323,8 +346,16 @@ static int __cpuinit mmu_context_cpu_not
 		pr_devel("MMU: Freeing stale context map for CPU %d\n", cpu);
 		kfree(stale_map[cpu]);
 		stale_map[cpu] = NULL;
-		break;
-#endif
+
+		/* We also clear the cpu_vm_mask bits of CPUs going away */
+		read_lock(&tasklist_lock);
+		for_each_process(p) {
+			if (p->mm)
+				cpu_mask_clear_cpu(cpu, mm_cpumask(p->mm));
+		}
+		read_unlock(&tasklist_lock);
+	break;
+#endif /* CONFIG_HOTPLUG_CPU */
 	}
 	return NOTIFY_OK;
 }
Index: linux-work/arch/powerpc/include/asm/cputhreads.h
===================================================================
--- linux-work.orig/arch/powerpc/include/asm/cputhreads.h	2009-07-21 12:43:27.000000000 +1000
+++ linux-work/arch/powerpc/include/asm/cputhreads.h	2009-07-21 12:56:16.000000000 +1000
@@ -5,6 +5,15 @@
 
 /*
  * Mapping of threads to cores
+ *
+ * Note: This implementation is limited to a power of 2 number of
+ * threads per core and the same number for each core in the system
+ * (though it would work if some processors had less threads as long
+ * as the CPU numbers are still allocated, just not brought offline).
+ *
+ * However, the API allows for a different implementation in the future
+ * if needed, as long as you only use the functions and not the variables
+ * directly.
  */
 
 #ifdef CONFIG_SMP
@@ -67,5 +76,12 @@ static inline int cpu_first_thread_in_co
 	return cpu & ~(threads_per_core - 1);
 }
 
+static inline int cpu_last_thread_in_core(int cpu)
+{
+	return cpu | (threads_per_core - 1);
+}
+
+
+
 #endif /* _ASM_POWERPC_CPUTHREADS_H */
 
Index: linux-work/arch/powerpc/mm/tlb_nohash.c
===================================================================
--- linux-work.orig/arch/powerpc/mm/tlb_nohash.c	2009-07-21 12:43:31.000000000 +1000
+++ linux-work/arch/powerpc/mm/tlb_nohash.c	2009-07-21 12:57:21.000000000 +1000
@@ -87,6 +87,12 @@ EXPORT_SYMBOL(local_flush_tlb_page);
 
 static DEFINE_SPINLOCK(tlbivax_lock);
 
+static int mm_is_core_local(struct mm_struct *mm)
+{
+	return cpumask_subset(mm_cpumask(mm),
+			      topology_thread_cpumask(smp_processor_id()));
+}
+
 struct tlb_flush_param {
 	unsigned long addr;
 	unsigned int pid;
@@ -131,7 +137,7 @@ void flush_tlb_mm(struct mm_struct *mm)
 	pid = mm->context.id;
 	if (unlikely(pid == MMU_NO_CONTEXT))
 		goto no_context;
-	if (!cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) {
+	if (!mm_is_core_local(mm)) {
 		struct tlb_flush_param p = { .pid = pid };
 		/* Ignores smp_processor_id() even if set. */
 		smp_call_function_many(mm_cpumask(mm),
@@ -153,7 +159,7 @@ void flush_tlb_page(struct vm_area_struc
 	if (unlikely(pid == MMU_NO_CONTEXT))
 		goto bail;
 	cpu_mask = mm_cpumask(vma->vm_mm);
-	if (!cpumask_equal(cpu_mask, cpumask_of(smp_processor_id()))) {
+	if (!mm_is_core_local(mm)) {
 		/* If broadcast tlbivax is supported, use it */
 		if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
 			int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);

^ permalink raw reply	[flat|nested] 31+ messages in thread

end of thread, other threads:[~2009-08-04  7:22 UTC | newest]

Thread overview: 31+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-07-24  9:15 [PATCH 0/20] powerpc: base 64-bit Book3E processor support (v2) Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 1/20] powerpc/mm: Fix misplaced #endif in pgtable-ppc64-64k.h Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 2/20] powerpc/of: Remove useless register save/restore when calling OF back Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 3/20] powerpc/mm: Add HW threads support to no_hash TLB management Benjamin Herrenschmidt
2009-07-31  3:12   ` Kumar Gala
2009-07-31  3:35     ` Kumar Gala
2009-07-31 22:29       ` Benjamin Herrenschmidt
2009-08-03  2:03         ` Michael Ellerman
2009-08-03 16:21           ` Kumar Gala
2009-08-03 17:06             ` Dave Kleikamp
2009-08-03 17:57               ` Dave Kleikamp
2009-08-04  7:22                 ` Benjamin Herrenschmidt
2009-08-03 21:03           ` Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 4/20] powerpc/mm: Add opcode definitions for tlbivax and tlbsrx Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 5/20] powerpc/mm: Add more bit definitions for Book3E MMU registers Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 6/20] powerpc/mm: Add support for early ioremap on non-hash 64-bit processors Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 7/20] powerpc: Modify some ppc_asm.h macros to accomodate 64-bits Book3E Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 8/20] powerpc/mm: Make low level TLB flush ops on BookE take additional args (v2) Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 9/20] powerpc/mm: Call mmu_context_init() from ppc64 (v2) Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 10/20] powerpc: Clean ifdef usage in copy_thread() Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 11/20] powerpc: Move definitions of secondary CPU spinloop to header file (v2) Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 12/20] powerpc/mm: Rework & cleanup page table freeing code path Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 13/20] powerpc: Add SPR definitions for new 64-bit BookE (v2) Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 14/20] powerpc: Add memory management headers " Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 15/20] powerpc: Add definitions used by exception handling on 64-bit Book3E (v2) Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 16/20] powerpc: Add PACA fields specific to 64-bit Book3E processors Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 17/20] powerpc/mm: Move around mmu_gathers definition on 64-bit (v2) Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 18/20] powerpc: Add TLB management code for 64-bit Book3E (v2) Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 19/20] powerpc/mm: Add support for SPARSEMEM_VMEMMAP on 64-bit Book3E Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 20/20] powerpc: Remaining 64-bit Book3E support (v2) Benjamin Herrenschmidt
  -- strict thread matches above, loose matches on Subject: below --
2009-07-23  5:59 [PATCH 3/20] powerpc/mm: Add HW threads support to no_hash TLB management Benjamin Herrenschmidt

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