[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/arch/tile/mm/highmem.c b/src/kernel/linux/v4.14/arch/tile/mm/highmem.c
new file mode 100644
index 0000000..eca2855
--- /dev/null
+++ b/src/kernel/linux/v4.14/arch/tile/mm/highmem.c
@@ -0,0 +1,277 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <asm/homecache.h>
+
+#define kmap_get_pte(vaddr) \
+ pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
+ (vaddr)), (vaddr))
+
+
+void *kmap(struct page *page)
+{
+ void *kva;
+ unsigned long flags;
+ pte_t *ptep;
+
+ might_sleep();
+ if (!PageHighMem(page))
+ return page_address(page);
+ kva = kmap_high(page);
+
+ /*
+ * Rewrite the PTE under the lock. This ensures that the page
+ * is not currently migrating.
+ */
+ ptep = kmap_get_pte((unsigned long)kva);
+ flags = homecache_kpte_lock();
+ set_pte_at(&init_mm, kva, ptep, mk_pte(page, page_to_kpgprot(page)));
+ homecache_kpte_unlock(flags);
+
+ return kva;
+}
+EXPORT_SYMBOL(kmap);
+
+void kunmap(struct page *page)
+{
+ if (in_interrupt())
+ BUG();
+ if (!PageHighMem(page))
+ return;
+ kunmap_high(page);
+}
+EXPORT_SYMBOL(kunmap);
+
+/*
+ * Describe a single atomic mapping of a page on a given cpu at a
+ * given address, and allow it to be linked into a list.
+ */
+struct atomic_mapped_page {
+ struct list_head list;
+ struct page *page;
+ int cpu;
+ unsigned long va;
+};
+
+static spinlock_t amp_lock = __SPIN_LOCK_UNLOCKED(&_lock);
+static struct list_head amp_list = LIST_HEAD_INIT(amp_list);
+
+/*
+ * Combining this structure with a per-cpu declaration lets us give
+ * each cpu an atomic_mapped_page structure per type.
+ */
+struct kmap_amps {
+ struct atomic_mapped_page per_type[KM_TYPE_NR];
+};
+static DEFINE_PER_CPU(struct kmap_amps, amps);
+
+/*
+ * Add a page and va, on this cpu, to the list of kmap_atomic pages,
+ * and write the new pte to memory. Writing the new PTE under the
+ * lock guarantees that it is either on the list before migration starts
+ * (if we won the race), or set_pte() sets the migrating bit in the PTE
+ * (if we lost the race). And doing it under the lock guarantees
+ * that when kmap_atomic_fix_one_pte() comes along, it finds a valid
+ * PTE in memory, iff the mapping is still on the amp_list.
+ *
+ * Finally, doing it under the lock lets us safely examine the page
+ * to see if it is immutable or not, for the generic kmap_atomic() case.
+ * If we examine it earlier we are exposed to a race where it looks
+ * writable earlier, but becomes immutable before we write the PTE.
+ */
+static void kmap_atomic_register(struct page *page, int type,
+ unsigned long va, pte_t *ptep, pte_t pteval)
+{
+ unsigned long flags;
+ struct atomic_mapped_page *amp;
+
+ flags = homecache_kpte_lock();
+ spin_lock(&_lock);
+
+ /* With interrupts disabled, now fill in the per-cpu info. */
+ amp = this_cpu_ptr(&s.per_type[type]);
+ amp->page = page;
+ amp->cpu = smp_processor_id();
+ amp->va = va;
+
+ /* For generic kmap_atomic(), choose the PTE writability now. */
+ if (!pte_read(pteval))
+ pteval = mk_pte(page, page_to_kpgprot(page));
+
+ list_add(&->list, &_list);
+ set_pte(ptep, pteval);
+
+ spin_unlock(&_lock);
+ homecache_kpte_unlock(flags);
+}
+
+/*
+ * Remove a page and va, on this cpu, from the list of kmap_atomic pages.
+ * Linear-time search, but we count on the lists being short.
+ * We don't need to adjust the PTE under the lock (as opposed to the
+ * kmap_atomic_register() case), since we're just unconditionally
+ * zeroing the PTE after it's off the list.
+ */
+static void kmap_atomic_unregister(struct page *page, unsigned long va)
+{
+ unsigned long flags;
+ struct atomic_mapped_page *amp;
+ int cpu = smp_processor_id();
+ spin_lock_irqsave(&_lock, flags);
+ list_for_each_entry(amp, &_list, list) {
+ if (amp->page == page && amp->cpu == cpu && amp->va == va)
+ break;
+ }
+ BUG_ON(&->list == &_list);
+ list_del(&->list);
+ spin_unlock_irqrestore(&_lock, flags);
+}
+
+/* Helper routine for kmap_atomic_fix_kpte(), below. */
+static void kmap_atomic_fix_one_kpte(struct atomic_mapped_page *amp,
+ int finished)
+{
+ pte_t *ptep = kmap_get_pte(amp->va);
+ if (!finished) {
+ set_pte(ptep, pte_mkmigrate(*ptep));
+ flush_remote(0, 0, NULL, amp->va, PAGE_SIZE, PAGE_SIZE,
+ cpumask_of(amp->cpu), NULL, 0);
+ } else {
+ /*
+ * Rewrite a default kernel PTE for this page.
+ * We rely on the fact that set_pte() writes the
+ * present+migrating bits last.
+ */
+ pte_t pte = mk_pte(amp->page, page_to_kpgprot(amp->page));
+ set_pte(ptep, pte);
+ }
+}
+
+/*
+ * This routine is a helper function for homecache_fix_kpte(); see
+ * its comments for more information on the "finished" argument here.
+ *
+ * Note that we hold the lock while doing the remote flushes, which
+ * will stall any unrelated cpus trying to do kmap_atomic operations.
+ * We could just update the PTEs under the lock, and save away copies
+ * of the structs (or just the va+cpu), then flush them after we
+ * release the lock, but it seems easier just to do it all under the lock.
+ */
+void kmap_atomic_fix_kpte(struct page *page, int finished)
+{
+ struct atomic_mapped_page *amp;
+ unsigned long flags;
+ spin_lock_irqsave(&_lock, flags);
+ list_for_each_entry(amp, &_list, list) {
+ if (amp->page == page)
+ kmap_atomic_fix_one_kpte(amp, finished);
+ }
+ spin_unlock_irqrestore(&_lock, flags);
+}
+
+/*
+ * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap
+ * because the kmap code must perform a global TLB invalidation when
+ * the kmap pool wraps.
+ *
+ * Note that they may be slower than on x86 (etc.) because unlike on
+ * those platforms, we do have to take a global lock to map and unmap
+ * pages on Tile (see above).
+ *
+ * When holding an atomic kmap is is not legal to sleep, so atomic
+ * kmaps are appropriate for short, tight code paths only.
+ */
+void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ unsigned long vaddr;
+ int idx, type;
+ pte_t *pte;
+
+ preempt_disable();
+ pagefault_disable();
+
+ /* Avoid icache flushes by disallowing atomic executable mappings. */
+ BUG_ON(pte_exec(prot));
+
+ if (!PageHighMem(page))
+ return page_address(page);
+
+ type = kmap_atomic_idx_push();
+ idx = type + KM_TYPE_NR*smp_processor_id();
+ vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+ pte = kmap_get_pte(vaddr);
+ BUG_ON(!pte_none(*pte));
+
+ /* Register that this page is mapped atomically on this cpu. */
+ kmap_atomic_register(page, type, vaddr, pte, mk_pte(page, prot));
+
+ return (void *)vaddr;
+}
+EXPORT_SYMBOL(kmap_atomic_prot);
+
+void *kmap_atomic(struct page *page)
+{
+ /* PAGE_NONE is a magic value that tells us to check immutability. */
+ return kmap_atomic_prot(page, PAGE_NONE);
+}
+EXPORT_SYMBOL(kmap_atomic);
+
+void __kunmap_atomic(void *kvaddr)
+{
+ unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
+
+ if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
+ vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
+ pte_t *pte = kmap_get_pte(vaddr);
+ pte_t pteval = *pte;
+ int idx, type;
+
+ type = kmap_atomic_idx();
+ idx = type + KM_TYPE_NR*smp_processor_id();
+
+ /*
+ * Force other mappings to Oops if they try to access this pte
+ * without first remapping it. Keeping stale mappings around
+ * is a bad idea.
+ */
+ BUG_ON(!pte_present(pteval) && !pte_migrating(pteval));
+ kmap_atomic_unregister(pte_page(pteval), vaddr);
+ kpte_clear_flush(pte, vaddr);
+ kmap_atomic_idx_pop();
+ } else {
+ /* Must be a lowmem page */
+ BUG_ON(vaddr < PAGE_OFFSET);
+ BUG_ON(vaddr >= (unsigned long)high_memory);
+ }
+
+ pagefault_enable();
+ preempt_enable();
+}
+EXPORT_SYMBOL(__kunmap_atomic);
+
+/*
+ * This API is supposed to allow us to map memory without a "struct page".
+ * Currently we don't support this, though this may change in the future.
+ */
+void *kmap_atomic_pfn(unsigned long pfn)
+{
+ return kmap_atomic(pfn_to_page(pfn));
+}
+void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
+{
+ return kmap_atomic_prot(pfn_to_page(pfn), prot);
+}