1 files changed, 500 insertions, 0 deletions

diff --git a/arch/sparc64/mm/tsb.c b/arch/sparc64/mm/tsb.c
new file mode 100644
index 000000000000..beaa02810f0e
--- /dev/null
+++ b/arch/sparc64/mm/tsb.c
@@ -0,0 +1,500 @@
+/* arch/sparc64/mm/tsb.c
+ *
+ * Copyright (C) 2006 David S. Miller <davem@davemloft.net>
+ */
+
+#include <linux/kernel.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);
+                        membar_storeload_storestore();
+                }
+        }
+}
+
+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
+#elif defined(CONFIG_SPARC64_PAGE_SIZE_512KB)
+#define HV_PGSZ_IDX_BASE        HV_PGSZ_IDX_512K
+#define HV_PGSZ_MASK_BASE       HV_PGSZ_MASK_512K
+#elif defined(CONFIG_SPARC64_PAGE_SIZE_4MB)
+#define HV_PGSZ_IDX_BASE        HV_PGSZ_IDX_4MB
+#define HV_PGSZ_MASK_BASE       HV_PGSZ_MASK_4MB
+#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:
+                BUG();
+        };
+        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 kmem_cache_t *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 tsb_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,
+                                                  SLAB_HWCACHE_ALIGN |
+                                                  SLAB_MUST_HWCACHE_ALIGN,
+                                                  NULL, 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(tsb_caches[new_cache_index], gfp_flags);
+        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.  */
+                smp_tsb_sync(mm);
+
+                /* 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);
+}