arch/tile: Allow tilegx to build with either 16K or 64K page size

This change introduces new flags for the hv_install_context()
API that passes a page table pointer to the hypervisor.  Clients
can explicitly request 4K, 16K, or 64K small pages when they
install a new context.  In practice, the page size is fixed at
kernel compile time and the same size is always requested every
time a new page table is installed.

The <hv/hypervisor.h> header changes so that it provides more abstract
macros for managing "page" things like PFNs and page tables.  For
example there is now a HV_DEFAULT_PAGE_SIZE_SMALL instead of the old
HV_PAGE_SIZE_SMALL.  The various PFN routines have been eliminated and
only PA- or PTFN-based ones remain (since PTFNs are always expressed
in fixed 2KB "page" size).  The page-table management macros are
renamed with a leading underscore and take page-size arguments with
the presumption that clients will use those macros in some single
place to provide the "real" macros they will use themselves.

I happened to notice the old hv_set_caching() API was totally broken
(it assumed 4KB pages) so I changed it so it would nominally work
correctly with other page sizes.

Tag modules with the page size so you can't load a module built with
a conflicting page size.  (And add a test for SMP while we're at it.)

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

2 files changed, 15 insertions, 23 deletions

diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c
index 1e4633520b3..c04fbfd93fc 100644
--- a/arch/tile/mm/init.c
+++ b/arch/tile/mm/init.c
@@ -82,7 +82,7 @@ static int num_l2_ptes[MAX_NUMNODES];
 
 static void init_prealloc_ptes(int node, int pages)
 {
-	BUG_ON(pages & (HV_L2_ENTRIES-1));
+	BUG_ON(pages & (PTRS_PER_PTE - 1));
 	if (pages) {
 		num_l2_ptes[node] = pages;
 		l2_ptes[node] = __alloc_bootmem(pages * sizeof(pte_t),
@@ -131,14 +131,9 @@ static void __init assign_pte(pmd_t *pmd, pte_t *page_table)
 
 #ifdef __tilegx__
 
-#if HV_L1_SIZE != HV_L2_SIZE
-# error Rework assumption that L1 and L2 page tables are same size.
-#endif
-
-/* Since pmd_t arrays and pte_t arrays are the same size, just use casts. */
 static inline pmd_t *alloc_pmd(void)
 {
-	return (pmd_t *)alloc_pte();
+	return __alloc_bootmem(L1_KERNEL_PGTABLE_SIZE, HV_PAGE_TABLE_ALIGN, 0);
 }
 
 static inline void assign_pmd(pud_t *pud, pmd_t *pmd)
@@ -811,7 +806,7 @@ void __init paging_init(void)
 	 * changing init_mm once we get up and running, and there's no
 	 * need for e.g. vmalloc_sync_all().
 	 */
-	BUILD_BUG_ON(pgd_index(VMALLOC_START) != pgd_index(VMALLOC_END));
+	BUILD_BUG_ON(pgd_index(VMALLOC_START) != pgd_index(VMALLOC_END - 1));
 	pud = pud_offset(pgd_base + pgd_index(VMALLOC_START), VMALLOC_START);
 	assign_pmd(pud, alloc_pmd());
 #endif
diff --git a/arch/tile/mm/pgtable.c b/arch/tile/mm/pgtable.c
index 2410aa899b3..3d7074347e6 100644
--- a/arch/tile/mm/pgtable.c
+++ b/arch/tile/mm/pgtable.c
@@ -289,13 +289,12 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 
 #define L2_USER_PGTABLE_PAGES (1 << L2_USER_PGTABLE_ORDER)
 
-struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
+struct page *pgtable_alloc_one(struct mm_struct *mm, unsigned long address,
+			       int order)
 {
 	gfp_t flags = GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO;
 	struct page *p;
-#if L2_USER_PGTABLE_ORDER > 0
 	int i;
-#endif
 
 #ifdef CONFIG_HIGHPTE
 	flags |= __GFP_HIGHMEM;
@@ -305,17 +304,15 @@ struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 	if (p == NULL)
 		return NULL;
 
-#if L2_USER_PGTABLE_ORDER > 0
 	/*
 	 * Make every page have a page_count() of one, not just the first.
 	 * We don't use __GFP_COMP since it doesn't look like it works
 	 * correctly with tlb_remove_page().
 	 */
-	for (i = 1; i < L2_USER_PGTABLE_PAGES; ++i) {
+	for (i = 1; i < order; ++i) {
 		init_page_count(p+i);
 		inc_zone_page_state(p+i, NR_PAGETABLE);
 	}
-#endif
 
 	pgtable_page_ctor(p);
 	return p;
@@ -326,28 +323,28 @@ struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
  * process).  We have to correct whatever pte_alloc_one() did before
  * returning the pages to the allocator.
  */
-void pte_free(struct mm_struct *mm, struct page *p)
+void pgtable_free(struct mm_struct *mm, struct page *p, int order)
 {
 	int i;
 
 	pgtable_page_dtor(p);
 	__free_page(p);
 
-	for (i = 1; i < L2_USER_PGTABLE_PAGES; ++i) {
+	for (i = 1; i < order; ++i) {
 		__free_page(p+i);
 		dec_zone_page_state(p+i, NR_PAGETABLE);
 	}
 }
 
-void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
-		    unsigned long address)
+void __pgtable_free_tlb(struct mmu_gather *tlb, struct page *pte,
+			unsigned long address, int order)
 {
 	int i;
 
 	pgtable_page_dtor(pte);
 	tlb_remove_page(tlb, pte);
 
-	for (i = 1; i < L2_USER_PGTABLE_PAGES; ++i) {
+	for (i = 1; i < order; ++i) {
 		tlb_remove_page(tlb, pte + i);
 		dec_zone_page_state(pte + i, NR_PAGETABLE);
 	}
@@ -490,7 +487,7 @@ void set_pte(pte_t *ptep, pte_t pte)
 /* Can this mm load a PTE with cached_priority set? */
 static inline int mm_is_priority_cached(struct mm_struct *mm)
 {
-	return mm->context.priority_cached;
+	return mm->context.priority_cached != 0;
 }
 
 /*
@@ -500,8 +497,8 @@ static inline int mm_is_priority_cached(struct mm_struct *mm)
 void start_mm_caching(struct mm_struct *mm)
 {
 	if (!mm_is_priority_cached(mm)) {
-		mm->context.priority_cached = -1U;
-		hv_set_caching(-1U);
+		mm->context.priority_cached = -1UL;
+		hv_set_caching(-1UL);
 	}
 }
 
@@ -516,7 +513,7 @@ void start_mm_caching(struct mm_struct *mm)
  * Presumably we'll come back later and have more luck and clear
  * the value then; for now we'll just keep the cache marked for priority.
  */
-static unsigned int update_priority_cached(struct mm_struct *mm)
+static unsigned long update_priority_cached(struct mm_struct *mm)
 {
 	if (mm->context.priority_cached && down_write_trylock(&mm->mmap_sem)) {
 		struct vm_area_struct *vm;