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>

arch/tile/Kconfig

@@ -139,6 +139,31 @@ config NR_CPUS
 	  smaller kernel memory footprint results from using a smaller
 	  value on chips with fewer tiles.
 
+if TILEGX
+
+choice
+	prompt "Kernel page size"
+	default PAGE_SIZE_64KB
+	help
+	  This lets you select the page size of the kernel.  For best
+	  performance on memory-intensive applications, a page size of 64KB
+	  is recommended.  For workloads involving many small files, many
+	  connections, etc., it may be better to select 16KB, which uses
+	  memory more efficiently at some cost in TLB performance.
+
+	  Note that this option is TILE-Gx specific; currently
+	  TILEPro page size is set by rebuilding the hypervisor.
+
+config PAGE_SIZE_16KB
+	bool "16KB"
+
+config PAGE_SIZE_64KB
+	bool "64KB"
+
+endchoice
+
+endif
+
 source "kernel/time/Kconfig"
 
 source "kernel/Kconfig.hz"

arch/tile/include/asm/Kbuild

@@ -21,7 +21,6 @@ generic-y += ipcbuf.h
 generic-y += irq_regs.h
 generic-y += kdebug.h
 generic-y += local.h
-generic-y += module.h
 generic-y += msgbuf.h
 generic-y += mutex.h
 generic-y += param.h

arch/tile/include/asm/mmu.h

@@ -21,7 +21,7 @@ struct mm_context {
 	 * Written under the mmap_sem semaphore; read without the
 	 * semaphore but atomically, but it is conservatively set.
 	 */
-	unsigned int priority_cached;
+	unsigned long priority_cached;
 };
 
 typedef struct mm_context mm_context_t;

arch/tile/include/asm/mmu_context.h

@@ -30,11 +30,15 @@ init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 	return 0;
 }
 
-/* Note that arch/tile/kernel/head.S also calls hv_install_context() */
+/*
+ * Note that arch/tile/kernel/head_NN.S and arch/tile/mm/migrate_NN.S
+ * also call hv_install_context().
+ */
 static inline void __install_page_table(pgd_t *pgdir, int asid, pgprot_t prot)
 {
 	/* FIXME: DIRECTIO should not always be set. FIXME. */
-	int rc = hv_install_context(__pa(pgdir), prot, asid, HV_CTX_DIRECTIO);
+	int rc = hv_install_context(__pa(pgdir), prot, asid,
+				    HV_CTX_DIRECTIO | CTX_PAGE_FLAG);
 	if (rc < 0)
 		panic("hv_install_context failed: %d", rc);
 }

arch/tile/include/asm/module.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2011 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.
+ */
+
+#ifndef _ASM_TILE_MODULE_H
+#define _ASM_TILE_MODULE_H
+
+#include <arch/chip.h>
+
+#include <asm-generic/module.h>
+
+/* We can't use modules built with different page sizes. */
+#if defined(CONFIG_PAGE_SIZE_16KB)
+# define MODULE_PGSZ " 16KB"
+#elif defined(CONFIG_PAGE_SIZE_64KB)
+# define MODULE_PGSZ " 64KB"
+#else
+# define MODULE_PGSZ ""
+#endif
+
+/* We don't really support no-SMP so tag if someone tries. */
+#ifdef CONFIG_SMP
+#define MODULE_NOSMP ""
+#else
+#define MODULE_NOSMP " nosmp"
+#endif
+
+#define MODULE_ARCH_VERMAGIC CHIP_ARCH_NAME MODULE_PGSZ MODULE_NOSMP
+
+#endif /* _ASM_TILE_MODULE_H */

arch/tile/include/asm/page.h

@@ -20,8 +20,17 @@
 #include <arch/chip.h>
 
 /* PAGE_SHIFT and HPAGE_SHIFT determine the page sizes. */
-#define PAGE_SHIFT	HV_LOG2_PAGE_SIZE_SMALL
-#define HPAGE_SHIFT	HV_LOG2_PAGE_SIZE_LARGE
+#if defined(CONFIG_PAGE_SIZE_16KB)
+#define PAGE_SHIFT	14
+#define CTX_PAGE_FLAG	HV_CTX_PG_SM_16K
+#elif defined(CONFIG_PAGE_SIZE_64KB)
+#define PAGE_SHIFT	16
+#define CTX_PAGE_FLAG	HV_CTX_PG_SM_64K
+#else
+#define PAGE_SHIFT	HV_LOG2_DEFAULT_PAGE_SIZE_SMALL
+#define CTX_PAGE_FLAG	0
+#endif
+#define HPAGE_SHIFT	HV_LOG2_DEFAULT_PAGE_SIZE_LARGE
 
 #define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
 #define HPAGE_SIZE	(_AC(1, UL) << HPAGE_SHIFT)

arch/tile/include/asm/pgalloc.h

@@ -19,24 +19,24 @@
 #include <linux/mm.h>
 #include <linux/mmzone.h>
 #include <asm/fixmap.h>
+#include <asm/page.h>
 #include <hv/hypervisor.h>
 
 /* Bits for the size of the second-level page table. */
-#define L2_KERNEL_PGTABLE_SHIFT \
-  (HV_LOG2_PAGE_SIZE_LARGE - HV_LOG2_PAGE_SIZE_SMALL + HV_LOG2_PTE_SIZE)
+#define L2_KERNEL_PGTABLE_SHIFT _HV_LOG2_L2_SIZE(HPAGE_SHIFT, PAGE_SHIFT)
+
+/* How big is a kernel L2 page table? */
+#define L2_KERNEL_PGTABLE_SIZE (1UL << L2_KERNEL_PGTABLE_SHIFT)
 
 /* We currently allocate user L2 page tables by page (unlike kernel L2s). */
-#if L2_KERNEL_PGTABLE_SHIFT < HV_LOG2_PAGE_SIZE_SMALL
-#define L2_USER_PGTABLE_SHIFT HV_LOG2_PAGE_SIZE_SMALL
+#if L2_KERNEL_PGTABLE_SHIFT < PAGE_SHIFT
+#define L2_USER_PGTABLE_SHIFT PAGE_SHIFT
 #else
 #define L2_USER_PGTABLE_SHIFT L2_KERNEL_PGTABLE_SHIFT
 #endif
 
 /* How many pages do we need, as an "order", for a user L2 page table? */
-#define L2_USER_PGTABLE_ORDER (L2_USER_PGTABLE_SHIFT - HV_LOG2_PAGE_SIZE_SMALL)
-
-/* How big is a kernel L2 page table? */
-#define L2_KERNEL_PGTABLE_SIZE (1 << L2_KERNEL_PGTABLE_SHIFT)
+#define L2_USER_PGTABLE_ORDER (L2_USER_PGTABLE_SHIFT - PAGE_SHIFT)
 
 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 {
@@ -50,14 +50,14 @@ static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 static inline void pmd_populate_kernel(struct mm_struct *mm,
 				       pmd_t *pmd, pte_t *ptep)
 {
-	set_pmd(pmd, ptfn_pmd(__pa(ptep) >> HV_LOG2_PAGE_TABLE_ALIGN,
+	set_pmd(pmd, ptfn_pmd(HV_CPA_TO_PTFN(__pa(ptep)),
 			      __pgprot(_PAGE_PRESENT)));
 }
 
 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
 				pgtable_t page)
 {
-	set_pmd(pmd, ptfn_pmd(HV_PFN_TO_PTFN(page_to_pfn(page)),
+	set_pmd(pmd, ptfn_pmd(HV_CPA_TO_PTFN(PFN_PHYS(page_to_pfn(page))),
 			      __pgprot(_PAGE_PRESENT)));
 }
 
@@ -68,8 +68,20 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
 extern pgd_t *pgd_alloc(struct mm_struct *mm);
 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
 
-extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address);
-extern void pte_free(struct mm_struct *mm, struct page *pte);
+extern pgtable_t pgtable_alloc_one(struct mm_struct *mm, unsigned long address,
+				   int order);
+extern void pgtable_free(struct mm_struct *mm, struct page *pte, int order);
+
+static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
+				      unsigned long address)
+{
+	return pgtable_alloc_one(mm, address, L2_USER_PGTABLE_ORDER);
+}
+
+static inline void pte_free(struct mm_struct *mm, struct page *pte)
+{
+	pgtable_free(mm, pte, L2_USER_PGTABLE_ORDER);
+}
 
 #define pmd_pgtable(pmd) pmd_page(pmd)
 
@@ -85,8 +97,13 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 	pte_free(mm, virt_to_page(pte));
 }
 
-extern void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
-			   unsigned long address);
+extern void __pgtable_free_tlb(struct mmu_gather *tlb, struct page *pte,
+			       unsigned long address, int order);
+static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
+				  unsigned long address)
+{
+	__pgtable_free_tlb(tlb, pte, address, L2_USER_PGTABLE_ORDER);
+}
 
 #define check_pgt_cache()	do { } while (0)
 
@@ -104,19 +121,44 @@ void shatter_pmd(pmd_t *pmd);
 void shatter_huge_page(unsigned long addr);
 
 #ifdef __tilegx__
-/* We share a single page allocator for both L1 and L2 page tables. */
-#if HV_L1_SIZE != HV_L2_SIZE
-# error Rework assumption that L1 and L2 page tables are same size.
-#endif
-#define L1_USER_PGTABLE_ORDER L2_USER_PGTABLE_ORDER
+
 #define pud_populate(mm, pud, pmd) \
   pmd_populate_kernel((mm), (pmd_t *)(pud), (pte_t *)(pmd))
-#define pmd_alloc_one(mm, addr) \
-  ((pmd_t *)page_to_virt(pte_alloc_one((mm), (addr))))
-#define pmd_free(mm, pmdp) \
-  pte_free((mm), virt_to_page(pmdp))
-#define __pmd_free_tlb(tlb, pmdp, address) \
-  __pte_free_tlb((tlb), virt_to_page(pmdp), (address))
+
+/* Bits for the size of the L1 (intermediate) page table. */
+#define L1_KERNEL_PGTABLE_SHIFT _HV_LOG2_L1_SIZE(HPAGE_SHIFT)
+
+/* How big is a kernel L2 page table? */
+#define L1_KERNEL_PGTABLE_SIZE (1UL << L1_KERNEL_PGTABLE_SHIFT)
+
+/* We currently allocate L1 page tables by page. */
+#if L1_KERNEL_PGTABLE_SHIFT < PAGE_SHIFT
+#define L1_USER_PGTABLE_SHIFT PAGE_SHIFT
+#else
+#define L1_USER_PGTABLE_SHIFT L1_KERNEL_PGTABLE_SHIFT
 #endif
 
+/* How many pages do we need, as an "order", for an L1 page table? */
+#define L1_USER_PGTABLE_ORDER (L1_USER_PGTABLE_SHIFT - PAGE_SHIFT)
+
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+	struct page *p = pgtable_alloc_one(mm, address, L1_USER_PGTABLE_ORDER);
+	return (pmd_t *)page_to_virt(p);
+}
+
+static inline void pmd_free(struct mm_struct *mm, pmd_t *pmdp)
+{
+	pgtable_free(mm, virt_to_page(pmdp), L1_USER_PGTABLE_ORDER);
+}
+
+static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
+				  unsigned long address)
+{
+	__pgtable_free_tlb(tlb, virt_to_page(pmdp), address,
+			   L1_USER_PGTABLE_ORDER);
+}
+
+#endif /* __tilegx__ */
+
 #endif /* _ASM_TILE_PGALLOC_H */

arch/tile/include/asm/pgtable.h

@@ -27,8 +27,10 @@
 #include <linux/slab.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
+#include <linux/pfn.h>
 #include <asm/processor.h>
 #include <asm/fixmap.h>
+#include <asm/page.h>
 
 struct mm_struct;
 struct vm_area_struct;
@@ -162,7 +164,7 @@ extern void set_page_homes(void);
   (pgprot_t) { ((oldprot).val & ~_PAGE_ALL) | (newprot).val }
 
 /* Just setting the PFN to zero suffices. */
-#define pte_pgprot(x) hv_pte_set_pfn((x), 0)
+#define pte_pgprot(x) hv_pte_set_pa((x), 0)
 
 /*
  * For PTEs and PDEs, we must clear the Present bit first when
@@ -262,7 +264,7 @@ static inline int pte_none(pte_t pte)
 
 static inline unsigned long pte_pfn(pte_t pte)
 {
-	return hv_pte_get_pfn(pte);
+	return PFN_DOWN(hv_pte_get_pa(pte));
 }
 
 /* Set or get the remote cache cpu in a pgprot with remote caching. */
@@ -271,7 +273,7 @@ extern int get_remote_cache_cpu(pgprot_t prot);
 
 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
 {
-	return hv_pte_set_pfn(prot, pfn);
+	return hv_pte_set_pa(prot, PFN_PHYS(pfn));
 }
 
 /* Support for priority mappings. */
@@ -471,7 +473,7 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
  * OK for pte_lockptr(), since we just end up with potentially one
  * lock being used for several pte_t arrays.
  */
-#define pmd_page(pmd) pfn_to_page(HV_PTFN_TO_PFN(pmd_ptfn(pmd)))
+#define pmd_page(pmd) pfn_to_page(PFN_DOWN(HV_PTFN_TO_CPA(pmd_ptfn(pmd))))
 
 static inline void pmd_clear(pmd_t *pmdp)
 {

arch/tile/include/asm/pgtable_32.h

@@ -20,11 +20,12 @@
  * The level-1 index is defined by the huge page size.  A PGD is composed
  * of PTRS_PER_PGD pgd_t's and is the top level of the page table.
  */
-#define PGDIR_SHIFT	HV_LOG2_PAGE_SIZE_LARGE
-#define PGDIR_SIZE	HV_PAGE_SIZE_LARGE
+#define PGDIR_SHIFT	HPAGE_SHIFT
+#define PGDIR_SIZE	HPAGE_SIZE
 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
-#define PTRS_PER_PGD	(1 << (32 - PGDIR_SHIFT))
-#define SIZEOF_PGD	(PTRS_PER_PGD * sizeof(pgd_t))
+#define PTRS_PER_PGD	_HV_L1_ENTRIES(HPAGE_SHIFT)
+#define PGD_INDEX(va)	_HV_L1_INDEX(va, HPAGE_SHIFT)
+#define SIZEOF_PGD	_HV_L1_SIZE(HPAGE_SHIFT)
 
 /*
  * The level-2 index is defined by the difference between the huge
@@ -33,8 +34,9 @@
  * Note that the hypervisor docs use PTE for what we call pte_t, so
  * this nomenclature is somewhat confusing.
  */
-#define PTRS_PER_PTE (1 << (HV_LOG2_PAGE_SIZE_LARGE - HV_LOG2_PAGE_SIZE_SMALL))
-#define SIZEOF_PTE	(PTRS_PER_PTE * sizeof(pte_t))
+#define PTRS_PER_PTE	_HV_L2_ENTRIES(HPAGE_SHIFT, PAGE_SHIFT)
+#define PTE_INDEX(va)	_HV_L2_INDEX(va, HPAGE_SHIFT, PAGE_SHIFT)
+#define SIZEOF_PTE	_HV_L2_SIZE(HPAGE_SHIFT, PAGE_SHIFT)
 
 #ifndef __ASSEMBLY__