+++ /dev/null
-/* arch/sparc64/mm/tsb.c
- *
- * Copyright (C) 2006, 2008 David S. Miller <davem@davemloft.net>
- */
-
-#include <linux/kernel.h>
-#include <linux/preempt.h>
-#include <asm/system.h>
-#include <asm/page.h>
-#include <asm/tlbflush.h>
-#include <asm/tlb.h>
-#include <asm/mmu_context.h>
-#include <asm/pgtable.h>
-#include <asm/tsb.h>
-#include <asm/oplib.h>
-
-extern struct tsb swapper_tsb[KERNEL_TSB_NENTRIES];
-
-static inline unsigned long tsb_hash(unsigned long vaddr, unsigned long hash_shift, unsigned long nentries)
-{
- vaddr >>= hash_shift;
- return vaddr & (nentries - 1);
-}
-
-static inline int tag_compare(unsigned long tag, unsigned long vaddr)
-{
- return (tag == (vaddr >> 22));
-}
-
-/* TSB flushes need only occur on the processor initiating the address
- * space modification, not on each cpu the address space has run on.
- * Only the TLB flush needs that treatment.
- */
-
-void flush_tsb_kernel_range(unsigned long start, unsigned long end)
-{
- unsigned long v;
-
- for (v = start; v < end; v += PAGE_SIZE) {
- unsigned long hash = tsb_hash(v, PAGE_SHIFT,
- KERNEL_TSB_NENTRIES);
- struct tsb *ent = &swapper_tsb[hash];
-
- if (tag_compare(ent->tag, v))
- ent->tag = (1UL << TSB_TAG_INVALID_BIT);
- }
-}
-
-static void __flush_tsb_one(struct mmu_gather *mp, unsigned long hash_shift, unsigned long tsb, unsigned long nentries)
-{
- unsigned long i;
-
- for (i = 0; i < mp->tlb_nr; i++) {
- unsigned long v = mp->vaddrs[i];
- unsigned long tag, ent, hash;
-
- v &= ~0x1UL;
-
- hash = tsb_hash(v, hash_shift, nentries);
- ent = tsb + (hash * sizeof(struct tsb));
- tag = (v >> 22UL);
-
- tsb_flush(ent, tag);
- }
-}
-
-void flush_tsb_user(struct mmu_gather *mp)
-{
- struct mm_struct *mm = mp->mm;
- unsigned long nentries, base, flags;
-
- spin_lock_irqsave(&mm->context.lock, flags);
-
- base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
- nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
- if (tlb_type == cheetah_plus || tlb_type == hypervisor)
- base = __pa(base);
- __flush_tsb_one(mp, PAGE_SHIFT, base, nentries);
-
-#ifdef CONFIG_HUGETLB_PAGE
- if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
- base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
- nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
- if (tlb_type == cheetah_plus || tlb_type == hypervisor)
- base = __pa(base);
- __flush_tsb_one(mp, HPAGE_SHIFT, base, nentries);
- }
-#endif
- spin_unlock_irqrestore(&mm->context.lock, flags);
-}
-
-#if defined(CONFIG_SPARC64_PAGE_SIZE_8KB)
-#define HV_PGSZ_IDX_BASE HV_PGSZ_IDX_8K
-#define HV_PGSZ_MASK_BASE HV_PGSZ_MASK_8K
-#elif defined(CONFIG_SPARC64_PAGE_SIZE_64KB)
-#define HV_PGSZ_IDX_BASE HV_PGSZ_IDX_64K
-#define HV_PGSZ_MASK_BASE HV_PGSZ_MASK_64K
-#else
-#error Broken base page size setting...
-#endif
-
-#ifdef CONFIG_HUGETLB_PAGE
-#if defined(CONFIG_HUGETLB_PAGE_SIZE_64K)
-#define HV_PGSZ_IDX_HUGE HV_PGSZ_IDX_64K
-#define HV_PGSZ_MASK_HUGE HV_PGSZ_MASK_64K
-#elif defined(CONFIG_HUGETLB_PAGE_SIZE_512K)
-#define HV_PGSZ_IDX_HUGE HV_PGSZ_IDX_512K
-#define HV_PGSZ_MASK_HUGE HV_PGSZ_MASK_512K
-#elif defined(CONFIG_HUGETLB_PAGE_SIZE_4MB)
-#define HV_PGSZ_IDX_HUGE HV_PGSZ_IDX_4MB
-#define HV_PGSZ_MASK_HUGE HV_PGSZ_MASK_4MB
-#else
-#error Broken huge page size setting...
-#endif
-#endif
-
-static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_idx, unsigned long tsb_bytes)
-{
- unsigned long tsb_reg, base, tsb_paddr;
- unsigned long page_sz, tte;
-
- mm->context.tsb_block[tsb_idx].tsb_nentries =
- tsb_bytes / sizeof(struct tsb);
-
- base = TSBMAP_BASE;
- tte = pgprot_val(PAGE_KERNEL_LOCKED);
- tsb_paddr = __pa(mm->context.tsb_block[tsb_idx].tsb);
- BUG_ON(tsb_paddr & (tsb_bytes - 1UL));
-
- /* Use the smallest page size that can map the whole TSB
- * in one TLB entry.
- */
- switch (tsb_bytes) {
- case 8192 << 0:
- tsb_reg = 0x0UL;
-#ifdef DCACHE_ALIASING_POSSIBLE
- base += (tsb_paddr & 8192);
-#endif
- page_sz = 8192;
- break;
-
- case 8192 << 1:
- tsb_reg = 0x1UL;
- page_sz = 64 * 1024;
- break;
-
- case 8192 << 2:
- tsb_reg = 0x2UL;
- page_sz = 64 * 1024;
- break;
-
- case 8192 << 3:
- tsb_reg = 0x3UL;
- page_sz = 64 * 1024;
- break;
-
- case 8192 << 4:
- tsb_reg = 0x4UL;
- page_sz = 512 * 1024;
- break;
-
- case 8192 << 5:
- tsb_reg = 0x5UL;
- page_sz = 512 * 1024;
- break;
-
- case 8192 << 6:
- tsb_reg = 0x6UL;
- page_sz = 512 * 1024;
- break;
-
- case 8192 << 7:
- tsb_reg = 0x7UL;
- page_sz = 4 * 1024 * 1024;
- break;
-
- default:
- printk(KERN_ERR "TSB[%s:%d]: Impossible TSB size %lu, killing process.\n",
- current->comm, current->pid, tsb_bytes);
- do_exit(SIGSEGV);
- };
- tte |= pte_sz_bits(page_sz);
-
- if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
- /* Physical mapping, no locked TLB entry for TSB. */
- tsb_reg |= tsb_paddr;
-
- mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
- mm->context.tsb_block[tsb_idx].tsb_map_vaddr = 0;
- mm->context.tsb_block[tsb_idx].tsb_map_pte = 0;
- } else {
- tsb_reg |= base;
- tsb_reg |= (tsb_paddr & (page_sz - 1UL));
- tte |= (tsb_paddr & ~(page_sz - 1UL));
-
- mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
- mm->context.tsb_block[tsb_idx].tsb_map_vaddr = base;
- mm->context.tsb_block[tsb_idx].tsb_map_pte = tte;
- }
-
- /* Setup the Hypervisor TSB descriptor. */
- if (tlb_type == hypervisor) {
- struct hv_tsb_descr *hp = &mm->context.tsb_descr[tsb_idx];
-
- switch (tsb_idx) {
- case MM_TSB_BASE:
- hp->pgsz_idx = HV_PGSZ_IDX_BASE;
- break;
-#ifdef CONFIG_HUGETLB_PAGE
- case MM_TSB_HUGE:
- hp->pgsz_idx = HV_PGSZ_IDX_HUGE;
- break;
-#endif
- default:
- BUG();
- };
- hp->assoc = 1;
- hp->num_ttes = tsb_bytes / 16;
- hp->ctx_idx = 0;
- switch (tsb_idx) {
- case MM_TSB_BASE:
- hp->pgsz_mask = HV_PGSZ_MASK_BASE;
- break;
-#ifdef CONFIG_HUGETLB_PAGE
- case MM_TSB_HUGE:
- hp->pgsz_mask = HV_PGSZ_MASK_HUGE;
- break;
-#endif
- default:
- BUG();
- };
- hp->tsb_base = tsb_paddr;
- hp->resv = 0;
- }
-}
-
-static struct kmem_cache *tsb_caches[8] __read_mostly;
-
-static const char *tsb_cache_names[8] = {
- "tsb_8KB",
- "tsb_16KB",
- "tsb_32KB",
- "tsb_64KB",
- "tsb_128KB",
- "tsb_256KB",
- "tsb_512KB",
- "tsb_1MB",
-};
-
-void __init pgtable_cache_init(void)
-{
- unsigned long i;
-
- for (i = 0; i < 8; i++) {
- unsigned long size = 8192 << i;
- const char *name = tsb_cache_names[i];
-
- tsb_caches[i] = kmem_cache_create(name,
- size, size,
- 0, NULL);
- if (!tsb_caches[i]) {
- prom_printf("Could not create %s cache\n", name);
- prom_halt();
- }
- }
-}
-
-/* When the RSS of an address space exceeds tsb_rss_limit for a TSB,
- * do_sparc64_fault() invokes this routine to try and grow it.
- *
- * When we reach the maximum TSB size supported, we stick ~0UL into
- * tsb_rss_limit for that TSB so the grow checks in do_sparc64_fault()
- * will not trigger any longer.
- *
- * The TSB can be anywhere from 8K to 1MB in size, in increasing powers
- * of two. The TSB must be aligned to it's size, so f.e. a 512K TSB
- * must be 512K aligned. It also must be physically contiguous, so we
- * cannot use vmalloc().
- *
- * The idea here is to grow the TSB when the RSS of the process approaches
- * the number of entries that the current TSB can hold at once. Currently,
- * we trigger when the RSS hits 3/4 of the TSB capacity.
- */
-void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long rss)
-{
- unsigned long max_tsb_size = 1 * 1024 * 1024;
- unsigned long new_size, old_size, flags;
- struct tsb *old_tsb, *new_tsb;
- unsigned long new_cache_index, old_cache_index;
- unsigned long new_rss_limit;
- gfp_t gfp_flags;
-
- if (max_tsb_size > (PAGE_SIZE << MAX_ORDER))
- max_tsb_size = (PAGE_SIZE << MAX_ORDER);
-
- new_cache_index = 0;
- for (new_size = 8192; new_size < max_tsb_size; new_size <<= 1UL) {
- unsigned long n_entries = new_size / sizeof(struct tsb);
-
- n_entries = (n_entries * 3) / 4;
- if (n_entries > rss)
- break;
-
- new_cache_index++;
- }
-
- if (new_size == max_tsb_size)
- new_rss_limit = ~0UL;
- else
- new_rss_limit = ((new_size / sizeof(struct tsb)) * 3) / 4;
-
-retry_tsb_alloc:
- gfp_flags = GFP_KERNEL;
- if (new_size > (PAGE_SIZE * 2))
- gfp_flags = __GFP_NOWARN | __GFP_NORETRY;
-
- new_tsb = kmem_cache_alloc_node(tsb_caches[new_cache_index],
- gfp_flags, numa_node_id());
- if (unlikely(!new_tsb)) {
- /* Not being able to fork due to a high-order TSB
- * allocation failure is very bad behavior. Just back
- * down to a 0-order allocation and force no TSB
- * growing for this address space.
- */
- if (mm->context.tsb_block[tsb_index].tsb == NULL &&
- new_cache_index > 0) {
- new_cache_index = 0;
- new_size = 8192;
- new_rss_limit = ~0UL;
- goto retry_tsb_alloc;
- }
-
- /* If we failed on a TSB grow, we are under serious
- * memory pressure so don't try to grow any more.
- */
- if (mm->context.tsb_block[tsb_index].tsb != NULL)
- mm->context.tsb_block[tsb_index].tsb_rss_limit = ~0UL;
- return;
- }
-
- /* Mark all tags as invalid. */
- tsb_init(new_tsb, new_size);
-
- /* Ok, we are about to commit the changes. If we are
- * growing an existing TSB the locking is very tricky,
- * so WATCH OUT!
- *
- * We have to hold mm->context.lock while committing to the
- * new TSB, this synchronizes us with processors in
- * flush_tsb_user() and switch_mm() for this address space.
- *
- * But even with that lock held, processors run asynchronously
- * accessing the old TSB via TLB miss handling. This is OK
- * because those actions are just propagating state from the
- * Linux page tables into the TSB, page table mappings are not
- * being changed. If a real fault occurs, the processor will
- * synchronize with us when it hits flush_tsb_user(), this is
- * also true for the case where vmscan is modifying the page
- * tables. The only thing we need to be careful with is to
- * skip any locked TSB entries during copy_tsb().
- *
- * When we finish committing to the new TSB, we have to drop
- * the lock and ask all other cpus running this address space
- * to run tsb_context_switch() to see the new TSB table.
- */
- spin_lock_irqsave(&mm->context.lock, flags);
-
- old_tsb = mm->context.tsb_block[tsb_index].tsb;
- old_cache_index =
- (mm->context.tsb_block[tsb_index].tsb_reg_val & 0x7UL);
- old_size = (mm->context.tsb_block[tsb_index].tsb_nentries *
- sizeof(struct tsb));
-
-
- /* Handle multiple threads trying to grow the TSB at the same time.
- * One will get in here first, and bump the size and the RSS limit.
- * The others will get in here next and hit this check.
- */
- if (unlikely(old_tsb &&
- (rss < mm->context.tsb_block[tsb_index].tsb_rss_limit))) {
- spin_unlock_irqrestore(&mm->context.lock, flags);
-
- kmem_cache_free(tsb_caches[new_cache_index], new_tsb);
- return;
- }
-
- mm->context.tsb_block[tsb_index].tsb_rss_limit = new_rss_limit;
-
- if (old_tsb) {
- extern void copy_tsb(unsigned long old_tsb_base,
- unsigned long old_tsb_size,
- unsigned long new_tsb_base,
- unsigned long new_tsb_size);
- unsigned long old_tsb_base = (unsigned long) old_tsb;
- unsigned long new_tsb_base = (unsigned long) new_tsb;
-
- if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
- old_tsb_base = __pa(old_tsb_base);
- new_tsb_base = __pa(new_tsb_base);
- }
- copy_tsb(old_tsb_base, old_size, new_tsb_base, new_size);
- }
-
- mm->context.tsb_block[tsb_index].tsb = new_tsb;
- setup_tsb_params(mm, tsb_index, new_size);
-
- spin_unlock_irqrestore(&mm->context.lock, flags);
-
- /* If old_tsb is NULL, we're being invoked for the first time
- * from init_new_context().
- */
- if (old_tsb) {
- /* Reload it on the local cpu. */
- tsb_context_switch(mm);
-
- /* Now force other processors to do the same. */
- preempt_disable();
- smp_tsb_sync(mm);
- preempt_enable();
-
- /* Now it is safe to free the old tsb. */
- kmem_cache_free(tsb_caches[old_cache_index], old_tsb);
- }
-}
-
-int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
-{
-#ifdef CONFIG_HUGETLB_PAGE
- unsigned long huge_pte_count;
-#endif
- unsigned int i;
-
- spin_lock_init(&mm->context.lock);
-
- mm->context.sparc64_ctx_val = 0UL;
-
-#ifdef CONFIG_HUGETLB_PAGE
- /* We reset it to zero because the fork() page copying
- * will re-increment the counters as the parent PTEs are
- * copied into the child address space.
- */
- huge_pte_count = mm->context.huge_pte_count;
- mm->context.huge_pte_count = 0;
-#endif
-
- /* copy_mm() copies over the parent's mm_struct before calling
- * us, so we need to zero out the TSB pointer or else tsb_grow()
- * will be confused and think there is an older TSB to free up.
- */
- for (i = 0; i < MM_NUM_TSBS; i++)
- mm->context.tsb_block[i].tsb = NULL;
-
- /* If this is fork, inherit the parent's TSB size. We would
- * grow it to that size on the first page fault anyways.
- */
- tsb_grow(mm, MM_TSB_BASE, get_mm_rss(mm));
-
-#ifdef CONFIG_HUGETLB_PAGE
- if (unlikely(huge_pte_count))
- tsb_grow(mm, MM_TSB_HUGE, huge_pte_count);
-#endif
-
- if (unlikely(!mm->context.tsb_block[MM_TSB_BASE].tsb))
- return -ENOMEM;
-
- return 0;
-}
-
-static void tsb_destroy_one(struct tsb_config *tp)
-{
- unsigned long cache_index;
-
- if (!tp->tsb)
- return;
- cache_index = tp->tsb_reg_val & 0x7UL;
- kmem_cache_free(tsb_caches[cache_index], tp->tsb);
- tp->tsb = NULL;
- tp->tsb_reg_val = 0UL;
-}
-
-void destroy_context(struct mm_struct *mm)
-{
- unsigned long flags, i;
-
- for (i = 0; i < MM_NUM_TSBS; i++)
- tsb_destroy_one(&mm->context.tsb_block[i]);
-
- spin_lock_irqsave(&ctx_alloc_lock, flags);
-
- if (CTX_VALID(mm->context)) {
- unsigned long nr = CTX_NRBITS(mm->context);
- mmu_context_bmap[nr>>6] &= ~(1UL << (nr & 63));
- }
-
- spin_unlock_irqrestore(&ctx_alloc_lock, flags);
-}
git.openpandora.org / pandora-kernel.git / blobdiff