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Diffstat (limited to 'arch/powerpc/mm/nohash/mmu_context.c')
-rw-r--r--arch/powerpc/mm/nohash/mmu_context.c173
1 files changed, 55 insertions, 118 deletions
diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c
index aac81c9f84a5..44b2b5e7cabe 100644
--- a/arch/powerpc/mm/nohash/mmu_context.c
+++ b/arch/powerpc/mm/nohash/mmu_context.c
@@ -21,21 +21,6 @@
* also clear mm->cpu_vm_mask bits when processes are migrated
*/
-//#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>
#include <linux/init.h>
@@ -47,10 +32,17 @@
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
+#include <asm/smp.h>
#include <mm/mmu_decl.h>
/*
+ * Room for two PTE table pointers, usually the kernel and current user
+ * pointer to their respective root page table (pgdir).
+ */
+void *abatron_pteptrs[2];
+
+/*
* The MPC8xx has only 16 contexts. We rotate through them on each task switch.
* A better way would be to keep track of tasks that own contexts, and implement
* an LRU usage. That way very active tasks don't always have to pay the TLB
@@ -68,9 +60,7 @@
* -- BenH
*/
#define FIRST_CONTEXT 1
-#ifdef DEBUG_CLAMP_LAST_CONTEXT
-#define LAST_CONTEXT DEBUG_CLAMP_LAST_CONTEXT
-#elif defined(CONFIG_PPC_8xx)
+#if defined(CONFIG_PPC_8xx)
#define LAST_CONTEXT 16
#elif defined(CONFIG_PPC_47x)
#define LAST_CONTEXT 65535
@@ -80,9 +70,7 @@
static unsigned int next_context, nr_free_contexts;
static unsigned long *context_map;
-#ifdef CONFIG_SMP
static unsigned long *stale_map[NR_CPUS];
-#endif
static struct mm_struct **context_mm;
static DEFINE_RAW_SPINLOCK(context_lock);
@@ -105,7 +93,6 @@ static DEFINE_RAW_SPINLOCK(context_lock);
* the stale map as we can just flush the local CPU
* -- benh
*/
-#ifdef CONFIG_SMP
static unsigned int steal_context_smp(unsigned int id)
{
struct mm_struct *mm;
@@ -127,7 +114,6 @@ static unsigned int steal_context_smp(unsigned int id)
id = FIRST_CONTEXT;
continue;
}
- pr_hardcont(" | steal %d from 0x%p", id, mm);
/* Mark this mm has having no context anymore */
mm->context.id = MMU_NO_CONTEXT;
@@ -158,34 +144,25 @@ static unsigned int steal_context_smp(unsigned int id)
/* This will cause the caller to try again */
return MMU_NO_CONTEXT;
}
-#endif /* CONFIG_SMP */
static unsigned int steal_all_contexts(void)
{
struct mm_struct *mm;
-#ifdef CONFIG_SMP
int cpu = smp_processor_id();
-#endif
unsigned int id;
for (id = FIRST_CONTEXT; id <= LAST_CONTEXT; id++) {
/* Pick up the victim mm */
mm = context_mm[id];
- pr_hardcont(" | steal %d from 0x%p", id, mm);
-
/* Mark this mm as having no context anymore */
mm->context.id = MMU_NO_CONTEXT;
if (id != FIRST_CONTEXT) {
context_mm[id] = NULL;
__clear_bit(id, context_map);
-#ifdef DEBUG_MAP_CONSISTENCY
- mm->context.active = 0;
-#endif
}
-#ifdef CONFIG_SMP
- __clear_bit(id, stale_map[cpu]);
-#endif
+ if (IS_ENABLED(CONFIG_SMP))
+ __clear_bit(id, stale_map[cpu]);
}
/* Flush the TLB for all contexts (not to be used on SMP) */
@@ -204,15 +181,11 @@ static unsigned int steal_all_contexts(void)
static unsigned int steal_context_up(unsigned int id)
{
struct mm_struct *mm;
-#ifdef CONFIG_SMP
int cpu = smp_processor_id();
-#endif
/* Pick up the victim mm */
mm = context_mm[id];
- pr_hardcont(" | steal %d from 0x%p", id, mm);
-
/* Flush the TLB for that context */
local_flush_tlb_mm(mm);
@@ -220,81 +193,64 @@ static unsigned int steal_context_up(unsigned int id)
mm->context.id = MMU_NO_CONTEXT;
/* XXX This clear should ultimately be part of local_flush_tlb_mm */
-#ifdef CONFIG_SMP
- __clear_bit(id, stale_map[cpu]);
-#endif
+ if (IS_ENABLED(CONFIG_SMP))
+ __clear_bit(id, stale_map[cpu]);
return id;
}
-#ifdef DEBUG_MAP_CONSISTENCY
-static void context_check_map(void)
+static void set_context(unsigned long id, pgd_t *pgd)
{
- unsigned int id, nrf, nact;
+ if (IS_ENABLED(CONFIG_PPC_8xx)) {
+ s16 offset = (s16)(__pa(swapper_pg_dir));
+
+ /*
+ * Register M_TWB will contain base address of level 1 table minus the
+ * lower part of the kernel PGDIR base address, so that all accesses to
+ * level 1 table are done relative to lower part of kernel PGDIR base
+ * address.
+ */
+ mtspr(SPRN_M_TWB, __pa(pgd) - offset);
- nrf = nact = 0;
- for (id = FIRST_CONTEXT; id <= LAST_CONTEXT; id++) {
- int used = test_bit(id, context_map);
- if (!used)
- nrf++;
- if (used != (context_mm[id] != NULL))
- pr_err("MMU: Context %d is %s and MM is %p !\n",
- id, used ? "used" : "free", context_mm[id]);
- if (context_mm[id] != NULL)
- nact += context_mm[id]->context.active;
- }
- if (nrf != nr_free_contexts) {
- pr_err("MMU: Free context count out of sync ! (%d vs %d)\n",
- nr_free_contexts, nrf);
- nr_free_contexts = nrf;
+ /* Update context */
+ mtspr(SPRN_M_CASID, id - 1);
+
+ /* sync */
+ mb();
+ } else {
+ if (IS_ENABLED(CONFIG_40x))
+ mb(); /* sync */
+
+ mtspr(SPRN_PID, id);
+ isync();
}
- if (nact > num_online_cpus())
- pr_err("MMU: More active contexts than CPUs ! (%d vs %d)\n",
- nact, num_online_cpus());
- if (FIRST_CONTEXT > 0 && !test_bit(0, context_map))
- pr_err("MMU: Context 0 has been freed !!!\n");
}
-#else
-static void context_check_map(void) { }
-#endif
void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
unsigned int id;
-#ifdef CONFIG_SMP
unsigned int i, cpu = smp_processor_id();
-#endif
unsigned long *map;
/* No lockless fast path .. yet */
raw_spin_lock(&context_lock);
- 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) {
- pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active);
- WARN_ON(prev->context.active < 1);
- prev->context.active--;
+ if (IS_ENABLED(CONFIG_SMP)) {
+ /* Mark us active and the previous one not anymore */
+ next->context.active++;
+ if (prev) {
+ WARN_ON(prev->context.active < 1);
+ prev->context.active--;
+ }
}
again:
-#endif /* CONFIG_SMP */
/* If we already have a valid assigned context, skip all that */
id = next->context.id;
- 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
+ if (likely(id != MMU_NO_CONTEXT))
goto ctxt_ok;
- }
/* We really don't have a context, let's try to acquire one */
id = next_context;
@@ -304,14 +260,12 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
/* No more free contexts, let's try to steal one */
if (nr_free_contexts == 0) {
-#ifdef CONFIG_SMP
if (num_online_cpus() > 1) {
id = steal_context_smp(id);
if (id == MMU_NO_CONTEXT)
goto again;
goto stolen;
}
-#endif /* CONFIG_SMP */
if (IS_ENABLED(CONFIG_PPC_8xx))
id = steal_all_contexts();
else
@@ -330,20 +284,13 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
next_context = id + 1;
context_mm[id] = next;
next->context.id = id;
- pr_hardcont(" | new id=%d,nrf=%d", id, nr_free_contexts);
- context_check_map();
ctxt_ok:
/* If that context got marked stale on this CPU, then flush the
* local TLB for it and unmark it before we use it
*/
-#ifdef CONFIG_SMP
- if (test_bit(id, stale_map[cpu])) {
- pr_hardcont(" | stale flush %d [%d..%d]",
- id, cpu_first_thread_sibling(cpu),
- cpu_last_thread_sibling(cpu));
-
+ if (IS_ENABLED(CONFIG_SMP) && test_bit(id, stale_map[cpu])) {
local_flush_tlb_mm(next);
/* XXX This clear should ultimately be part of local_flush_tlb_mm */
@@ -353,10 +300,10 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
__clear_bit(id, stale_map[i]);
}
}
-#endif
/* Flick the MMU and release lock */
- pr_hardcont(" -> %d\n", id);
+ if (IS_ENABLED(CONFIG_BDI_SWITCH))
+ abatron_pteptrs[1] = next->pgd;
set_context(id, next->pgd);
raw_spin_unlock(&context_lock);
}
@@ -366,8 +313,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
*/
int init_new_context(struct task_struct *t, struct mm_struct *mm)
{
- pr_hard("initing context for mm @%p\n", mm);
-
/*
* We have MMU_NO_CONTEXT set to be ~0. Hence check
* explicitly against context.id == 0. This ensures that we properly
@@ -401,16 +346,12 @@ void destroy_context(struct mm_struct *mm)
if (id != MMU_NO_CONTEXT) {
__clear_bit(id, context_map);
mm->context.id = MMU_NO_CONTEXT;
-#ifdef DEBUG_MAP_CONSISTENCY
- mm->context.active = 0;
-#endif
context_mm[id] = NULL;
nr_free_contexts++;
}
raw_spin_unlock_irqrestore(&context_lock, flags);
}
-#ifdef CONFIG_SMP
static int mmu_ctx_cpu_prepare(unsigned int cpu)
{
/* We don't touch CPU 0 map, it's allocated at aboot and kept
@@ -419,7 +360,6 @@ static int mmu_ctx_cpu_prepare(unsigned int cpu)
if (cpu == boot_cpuid)
return 0;
- pr_devel("MMU: Allocating stale context map for CPU %d\n", cpu);
stale_map[cpu] = kzalloc(CTX_MAP_SIZE, GFP_KERNEL);
return 0;
}
@@ -430,7 +370,6 @@ static int mmu_ctx_cpu_dead(unsigned int cpu)
if (cpu == boot_cpuid)
return 0;
- pr_devel("MMU: Freeing stale context map for CPU %d\n", cpu);
kfree(stale_map[cpu]);
stale_map[cpu] = NULL;
@@ -440,8 +379,6 @@ static int mmu_ctx_cpu_dead(unsigned int cpu)
return 0;
}
-#endif /* CONFIG_SMP */
-
/*
* Initialize the context management stuff.
*/
@@ -465,16 +402,16 @@ void __init mmu_context_init(void)
if (!context_mm)
panic("%s: Failed to allocate %zu bytes\n", __func__,
sizeof(void *) * (LAST_CONTEXT + 1));
-#ifdef CONFIG_SMP
- stale_map[boot_cpuid] = memblock_alloc(CTX_MAP_SIZE, SMP_CACHE_BYTES);
- if (!stale_map[boot_cpuid])
- panic("%s: Failed to allocate %zu bytes\n", __func__,
- CTX_MAP_SIZE);
-
- cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE,
- "powerpc/mmu/ctx:prepare",
- mmu_ctx_cpu_prepare, mmu_ctx_cpu_dead);
-#endif
+ if (IS_ENABLED(CONFIG_SMP)) {
+ stale_map[boot_cpuid] = memblock_alloc(CTX_MAP_SIZE, SMP_CACHE_BYTES);
+ if (!stale_map[boot_cpuid])
+ panic("%s: Failed to allocate %zu bytes\n", __func__,
+ CTX_MAP_SIZE);
+
+ cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE,
+ "powerpc/mmu/ctx:prepare",
+ mmu_ctx_cpu_prepare, mmu_ctx_cpu_dead);
+ }
printk(KERN_INFO
"MMU: Allocated %zu bytes of context maps for %d contexts\n",
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-08 18:33:26 +0300