[PPC64] pgtable.h and other header cleanups
From: David Gibson
Date: Mon May 02 2005 - 19:30:06 EST
Andrew, please apply.
This patch started as simply removing a few never-used macros from
asm-ppc64/pgtable.h, then kind of grew. It now makes a bunch of
cleanups to the ppc64 low-level header files (with corresponding
changes to .c files where necessary) such as:
- Abolishing never-used macros
- Eliminating multiple #defines with the same purpose
- Removing pointless macros (cases where just expanding the
macro everywhere turns out clearer and more sensible)
- Removing some cases where macros which could be defined in
terms of each other weren't
- Moving imalloc() related definitions from pgtable.h to their
own header file (imalloc.h)
- Re-arranging headers to group things more logically
- Moving all VSID allocation related things to mmu.h, instead
of being split between mmu.h and mmu_context.h
- Removing some reserved space for flags from the PMD - we're
not using it.
Signed-off-by: David Gibson <dwg@xxxxxxxxxxx>
Index: working-2.6/include/asm-ppc64/pgtable.h
===================================================================
--- working-2.6.orig/include/asm-ppc64/pgtable.h 2005-05-02 16:21:09.000000000 +1000
+++ working-2.6/include/asm-ppc64/pgtable.h 2005-05-02 17:58:29.000000000 +1000
@@ -17,16 +17,6 @@
#include <asm-generic/pgtable-nopud.h>
-/* PMD_SHIFT determines what a second-level page table entry can map */
-#define PMD_SHIFT (PAGE_SHIFT + PAGE_SHIFT - 3)
-#define PMD_SIZE (1UL << PMD_SHIFT)
-#define PMD_MASK (~(PMD_SIZE-1))
-
-/* PGDIR_SHIFT determines what a third-level page table entry can map */
-#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT - 3) + (PAGE_SHIFT - 2))
-#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
-#define PGDIR_MASK (~(PGDIR_SIZE-1))
-
/*
* Entries per page directory level. The PTE level must use a 64b record
* for each page table entry. The PMD and PGD level use a 32b record for
@@ -40,40 +30,30 @@
#define PTRS_PER_PMD (1 << PMD_INDEX_SIZE)
#define PTRS_PER_PGD (1 << PGD_INDEX_SIZE)
-#define USER_PTRS_PER_PGD (1024)
-#define FIRST_USER_ADDRESS 0
+/* PMD_SHIFT determines what a second-level page table entry can map */
+#define PMD_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE)
+#define PMD_SIZE (1UL << PMD_SHIFT)
+#define PMD_MASK (~(PMD_SIZE-1))
-#define EADDR_SIZE (PTE_INDEX_SIZE + PMD_INDEX_SIZE + \
- PGD_INDEX_SIZE + PAGE_SHIFT)
+/* PGDIR_SHIFT determines what a third-level page table entry can map */
+#define PGDIR_SHIFT (PMD_SHIFT + PMD_INDEX_SIZE)
+#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
+#define PGDIR_MASK (~(PGDIR_SIZE-1))
+
+#define FIRST_USER_ADDRESS 0
/*
* Size of EA range mapped by our pagetables.
*/
-#define PGTABLE_EA_BITS 41
-#define PGTABLE_EA_MASK ((1UL<<PGTABLE_EA_BITS)-1)
+#define EADDR_SIZE (PTE_INDEX_SIZE + PMD_INDEX_SIZE + \
+ PGD_INDEX_SIZE + PAGE_SHIFT)
+#define EADDR_MASK ((1UL << EADDR_SIZE) - 1)
/*
* Define the address range of the vmalloc VM area.
*/
#define VMALLOC_START (0xD000000000000000ul)
-#define VMALLOC_END (VMALLOC_START + PGTABLE_EA_MASK)
-
-/*
- * Define the address range of the imalloc VM area.
- * (used for ioremap)
- */
-#define IMALLOC_START (ioremap_bot)
-#define IMALLOC_VMADDR(x) ((unsigned long)(x))
-#define PHBS_IO_BASE (0xE000000000000000ul) /* Reserve 2 gigs for PHBs */
-#define IMALLOC_BASE (0xE000000080000000ul)
-#define IMALLOC_END (IMALLOC_BASE + PGTABLE_EA_MASK)
-
-/*
- * Define the user address range
- */
-#define USER_START (0UL)
-#define USER_END (USER_START + PGTABLE_EA_MASK)
-
+#define VMALLOC_END (VMALLOC_START + EADDR_MASK)
/*
* Bits in a linux-style PTE. These match the bits in the
@@ -168,10 +148,6 @@
/* shift to put page number into pte */
#define PTE_SHIFT (17)
-/* We allow 2^41 bytes of real memory, so we need 29 bits in the PMD
- * to give the PTE page number. The bottom two bits are for flags. */
-#define PMD_TO_PTEPAGE_SHIFT (2)
-
#ifdef CONFIG_HUGETLB_PAGE
#ifndef __ASSEMBLY__
@@ -220,13 +196,12 @@
#define pte_page(x) pfn_to_page(pte_pfn(x))
#define pmd_set(pmdp, ptep) \
- (pmd_val(*(pmdp)) = (__ba_to_bpn(ptep) << PMD_TO_PTEPAGE_SHIFT))
+ (pmd_val(*(pmdp)) = __ba_to_bpn(ptep))
#define pmd_none(pmd) (!pmd_val(pmd))
#define pmd_bad(pmd) (pmd_val(pmd) == 0)
#define pmd_present(pmd) (pmd_val(pmd) != 0)
#define pmd_clear(pmdp) (pmd_val(*(pmdp)) = 0)
-#define pmd_page_kernel(pmd) \
- (__bpn_to_ba(pmd_val(pmd) >> PMD_TO_PTEPAGE_SHIFT))
+#define pmd_page_kernel(pmd) (__bpn_to_ba(pmd_val(pmd)))
#define pmd_page(pmd) virt_to_page(pmd_page_kernel(pmd))
#define pud_set(pudp, pmdp) (pud_val(*(pudp)) = (__ba_to_bpn(pmdp)))
@@ -266,8 +241,6 @@
/* to find an entry in the ioremap page-table-directory */
#define pgd_offset_i(address) (ioremap_pgd + pgd_index(address))
-#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
-
/*
* The following only work if pte_present() is true.
* Undefined behaviour if not..
@@ -487,18 +460,13 @@
extern unsigned long ioremap_bot, ioremap_base;
-#define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT)
-#define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS)
-
-#define pte_ERROR(e) \
- printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
#define pmd_ERROR(e) \
printk("%s:%d: bad pmd %08x.\n", __FILE__, __LINE__, pmd_val(e))
#define pgd_ERROR(e) \
printk("%s:%d: bad pgd %08x.\n", __FILE__, __LINE__, pgd_val(e))
-extern pgd_t swapper_pg_dir[1024];
-extern pgd_t ioremap_dir[1024];
+extern pgd_t swapper_pg_dir[];
+extern pgd_t ioremap_dir[];
extern void paging_init(void);
@@ -540,43 +508,11 @@
*/
#define kern_addr_valid(addr) (1)
-#define io_remap_page_range(vma, vaddr, paddr, size, prot) \
- remap_pfn_range(vma, vaddr, (paddr) >> PAGE_SHIFT, size, prot)
-
#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \
remap_pfn_range(vma, vaddr, pfn, size, prot)
-#define MK_IOSPACE_PFN(space, pfn) (pfn)
-#define GET_IOSPACE(pfn) 0
-#define GET_PFN(pfn) (pfn)
-
void pgtable_cache_init(void);
-extern void hpte_init_native(void);
-extern void hpte_init_lpar(void);
-extern void hpte_init_iSeries(void);
-
-/* imalloc region types */
-#define IM_REGION_UNUSED 0x1
-#define IM_REGION_SUBSET 0x2
-#define IM_REGION_EXISTS 0x4
-#define IM_REGION_OVERLAP 0x8
-#define IM_REGION_SUPERSET 0x10
-
-extern struct vm_struct * im_get_free_area(unsigned long size);
-extern struct vm_struct * im_get_area(unsigned long v_addr, unsigned long size,
- int region_type);
-unsigned long im_free(void *addr);
-
-extern long pSeries_lpar_hpte_insert(unsigned long hpte_group,
- unsigned long va, unsigned long prpn,
- int secondary, unsigned long hpteflags,
- int bolted, int large);
-
-extern long native_hpte_insert(unsigned long hpte_group, unsigned long va,
- unsigned long prpn, int secondary,
- unsigned long hpteflags, int bolted, int large);
-
/*
* find_linux_pte returns the address of a linux pte for a given
* effective address and directory. If not found, it returns zero.
Index: working-2.6/include/asm-ppc64/page.h
===================================================================
--- working-2.6.orig/include/asm-ppc64/page.h 2005-05-02 16:21:09.000000000 +1000
+++ working-2.6/include/asm-ppc64/page.h 2005-05-02 16:21:43.000000000 +1000
@@ -23,7 +23,6 @@
#define PAGE_SHIFT 12
#define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
-#define PAGE_OFFSET_MASK (PAGE_SIZE-1)
#define SID_SHIFT 28
#define SID_MASK 0xfffffffffUL
@@ -85,9 +84,6 @@
/* align addr on a size boundary - adjust address up if needed */
#define _ALIGN(addr,size) _ALIGN_UP(addr,size)
-/* to align the pointer to the (next) double word boundary */
-#define DOUBLEWORD_ALIGN(addr) _ALIGN(addr,sizeof(unsigned long))
-
/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr) _ALIGN(addr, PAGE_SIZE)
@@ -100,7 +96,6 @@
#define REGION_SIZE 4UL
#define REGION_SHIFT 60UL
#define REGION_MASK (((1UL<<REGION_SIZE)-1UL)<<REGION_SHIFT)
-#define REGION_STRIDE (1UL << REGION_SHIFT)
static __inline__ void clear_page(void *addr)
{
@@ -209,13 +204,13 @@
#define VMALLOCBASE ASM_CONST(0xD000000000000000)
#define IOREGIONBASE ASM_CONST(0xE000000000000000)
-#define IO_REGION_ID (IOREGIONBASE>>REGION_SHIFT)
-#define VMALLOC_REGION_ID (VMALLOCBASE>>REGION_SHIFT)
-#define KERNEL_REGION_ID (KERNELBASE>>REGION_SHIFT)
+#define IO_REGION_ID (IOREGIONBASE >> REGION_SHIFT)
+#define VMALLOC_REGION_ID (VMALLOCBASE >> REGION_SHIFT)
+#define KERNEL_REGION_ID (KERNELBASE >> REGION_SHIFT)
#define USER_REGION_ID (0UL)
-#define REGION_ID(X) (((unsigned long)(X))>>REGION_SHIFT)
+#define REGION_ID(ea) (((unsigned long)(ea)) >> REGION_SHIFT)
-#define __bpn_to_ba(x) ((((unsigned long)(x))<<PAGE_SHIFT) + KERNELBASE)
+#define __bpn_to_ba(x) ((((unsigned long)(x)) << PAGE_SHIFT) + KERNELBASE)
#define __ba_to_bpn(x) ((((unsigned long)(x)) & ~REGION_MASK) >> PAGE_SHIFT)
#define __va(x) ((void *)((unsigned long)(x) + KERNELBASE))
Index: working-2.6/arch/ppc64/mm/imalloc.c
===================================================================
--- working-2.6.orig/arch/ppc64/mm/imalloc.c 2005-04-26 15:37:55.000000000 +1000
+++ working-2.6/arch/ppc64/mm/imalloc.c 2005-05-02 16:59:40.000000000 +1000
@@ -14,6 +14,7 @@
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/semaphore.h>
+#include <asm/imalloc.h>
static DECLARE_MUTEX(imlist_sem);
struct vm_struct * imlist = NULL;
@@ -23,11 +24,11 @@
unsigned long addr;
struct vm_struct **p, *tmp;
- addr = IMALLOC_START;
+ addr = ioremap_bot;
for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
if (size + addr < (unsigned long) tmp->addr)
break;
- if ((unsigned long)tmp->addr >= IMALLOC_START)
+ if ((unsigned long)tmp->addr >= ioremap_bot)
addr = tmp->size + (unsigned long) tmp->addr;
if (addr > IMALLOC_END-size)
return 1;
Index: working-2.6/arch/ppc64/mm/hash_utils.c
===================================================================
--- working-2.6.orig/arch/ppc64/mm/hash_utils.c 2005-04-26 15:37:55.000000000 +1000
+++ working-2.6/arch/ppc64/mm/hash_utils.c 2005-05-02 16:56:17.000000000 +1000
@@ -298,24 +298,23 @@
int local = 0;
cpumask_t tmp;
+ if ((ea & ~REGION_MASK) > EADDR_MASK)
+ return 1;
+
switch (REGION_ID(ea)) {
case USER_REGION_ID:
user_region = 1;
mm = current->mm;
- if ((ea > USER_END) || (! mm))
+ if (! mm)
return 1;
vsid = get_vsid(mm->context.id, ea);
break;
case IO_REGION_ID:
- if (ea > IMALLOC_END)
- return 1;
mm = &ioremap_mm;
vsid = get_kernel_vsid(ea);
break;
case VMALLOC_REGION_ID:
- if (ea > VMALLOC_END)
- return 1;
mm = &init_mm;
vsid = get_kernel_vsid(ea);
break;
@@ -362,7 +361,7 @@
unsigned long vsid, vpn, va, hash, secondary, slot;
unsigned long huge = pte_huge(pte);
- if ((ea >= USER_START) && (ea <= USER_END))
+ if (ea < KERNELBASE)
vsid = get_vsid(context, ea);
else
vsid = get_kernel_vsid(ea);
Index: working-2.6/arch/ppc64/mm/hash_native.c
===================================================================
--- working-2.6.orig/arch/ppc64/mm/hash_native.c 2005-04-26 15:37:55.000000000 +1000
+++ working-2.6/arch/ppc64/mm/hash_native.c 2005-05-02 16:51:44.000000000 +1000
@@ -320,8 +320,7 @@
j = 0;
for (i = 0; i < number; i++) {
- if ((batch->addr[i] >= USER_START) &&
- (batch->addr[i] <= USER_END))
+ if (batch->addr[i] < KERNELBASE)
vsid = get_vsid(context, batch->addr[i]);
else
vsid = get_kernel_vsid(batch->addr[i]);
Index: working-2.6/arch/ppc64/mm/init.c
===================================================================
--- working-2.6.orig/arch/ppc64/mm/init.c 2005-05-02 08:57:20.000000000 +1000
+++ working-2.6/arch/ppc64/mm/init.c 2005-05-02 16:38:18.000000000 +1000
@@ -64,6 +64,7 @@
#include <asm/iommu.h>
#include <asm/abs_addr.h>
#include <asm/vdso.h>
+#include <asm/imalloc.h>
int mem_init_done;
unsigned long ioremap_bot = IMALLOC_BASE;
Index: working-2.6/include/asm-ppc64/mmu.h
===================================================================
--- working-2.6.orig/include/asm-ppc64/mmu.h 2005-04-26 15:38:02.000000000 +1000
+++ working-2.6/include/asm-ppc64/mmu.h 2005-05-02 17:45:59.000000000 +1000
@@ -15,19 +15,10 @@
#include <linux/config.h>
#include <asm/page.h>
-#include <linux/stringify.h>
-#ifndef __ASSEMBLY__
-
-/* Time to allow for more things here */
-typedef unsigned long mm_context_id_t;
-typedef struct {
- mm_context_id_t id;
-#ifdef CONFIG_HUGETLB_PAGE
- pgd_t *huge_pgdir;
- u16 htlb_segs; /* bitmask */
-#endif
-} mm_context_t;
+/*
+ * Segment table
+ */
#define STE_ESID_V 0x80
#define STE_ESID_KS 0x20
@@ -36,15 +27,48 @@
#define STE_VSID_SHIFT 12
-struct stab_entry {
- unsigned long esid_data;
- unsigned long vsid_data;
-};
+/* Location of cpu0's segment table */
+#define STAB0_PAGE 0x9
+#define STAB0_PHYS_ADDR (STAB0_PAGE<<PAGE_SHIFT)
+#define STAB0_VIRT_ADDR (KERNELBASE+STAB0_PHYS_ADDR)
+
+/*
+ * SLB
+ */
-/* Hardware Page Table Entry */
+#define SLB_NUM_BOLTED 3
+#define SLB_CACHE_ENTRIES 8
+
+/* Bits in the SLB ESID word */
+#define SLB_ESID_V ASM_CONST(0x0000000008000000) /* valid */
+
+/* Bits in the SLB VSID word */
+#define SLB_VSID_SHIFT 12
+#define SLB_VSID_KS ASM_CONST(0x0000000000000800)
+#define SLB_VSID_KP ASM_CONST(0x0000000000000400)
+#define SLB_VSID_N ASM_CONST(0x0000000000000200) /* no-execute */
+#define SLB_VSID_L ASM_CONST(0x0000000000000100) /* largepage 16M */
+#define SLB_VSID_C ASM_CONST(0x0000000000000080) /* class */
+
+#define SLB_VSID_KERNEL (SLB_VSID_KP|SLB_VSID_C)
+#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS)
+
+/*
+ * Hash table
+ */
#define HPTES_PER_GROUP 8
+/* Values for PP (assumes Ks=0, Kp=1) */
+/* pp0 will always be 0 for linux */
+#define PP_RWXX 0 /* Supervisor read/write, User none */
+#define PP_RWRX 1 /* Supervisor read/write, User read */
+#define PP_RWRW 2 /* Supervisor read/write, User read/write */
+#define PP_RXRX 3 /* Supervisor read, User read */
+
+#ifndef __ASSEMBLY__
+
+/* Hardware Page Table Entry */
typedef struct {
unsigned long avpn:57; /* vsid | api == avpn */
unsigned long : 2; /* Software use */
@@ -90,14 +114,6 @@
} dw1;
} HPTE;
-/* Values for PP (assumes Ks=0, Kp=1) */
-/* pp0 will always be 0 for linux */
-#define PP_RWXX 0 /* Supervisor read/write, User none */
-#define PP_RWRX 1 /* Supervisor read/write, User read */
-#define PP_RWRW 2 /* Supervisor read/write, User read/write */
-#define PP_RXRX 3 /* Supervisor read, User read */
-
-
extern HPTE * htab_address;
extern unsigned long htab_hash_mask;
@@ -174,31 +190,70 @@
extern void htab_finish_init(void);
+extern void hpte_init_native(void);
+extern void hpte_init_lpar(void);
+extern void hpte_init_iSeries(void);
+
+extern long pSeries_lpar_hpte_insert(unsigned long hpte_group,
+ unsigned long va, unsigned long prpn,
+ int secondary, unsigned long hpteflags,
+ int bolted, int large);
+extern long native_hpte_insert(unsigned long hpte_group, unsigned long va,
+ unsigned long prpn, int secondary,
+ unsigned long hpteflags, int bolted, int large);
+
#endif /* __ASSEMBLY__ */
/*
- * Location of cpu0's segment table
+ * VSID allocation
+ *
+ * We first generate a 36-bit "proto-VSID". For kernel addresses this
+ * is equal to the ESID, for user addresses it is:
+ * (context << 15) | (esid & 0x7fff)
+ *
+ * The two forms are distinguishable because the top bit is 0 for user
+ * addresses, whereas the top two bits are 1 for kernel addresses.
+ * Proto-VSIDs with the top two bits equal to 0b10 are reserved for
+ * now.
+ *
+ * The proto-VSIDs are then scrambled into real VSIDs with the
+ * multiplicative hash:
+ *
+ * VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
+ * where VSID_MULTIPLIER = 268435399 = 0xFFFFFC7
+ * VSID_MODULUS = 2^36-1 = 0xFFFFFFFFF
+ *
+ * This scramble is only well defined for proto-VSIDs below
+ * 0xFFFFFFFFF, so both proto-VSID and actual VSID 0xFFFFFFFFF are
+ * reserved. VSID_MULTIPLIER is prime, so in particular it is
+ * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
+ * Because the modulus is 2^n-1 we can compute it efficiently without
+ * a divide or extra multiply (see below).
+ *
+ * This scheme has several advantages over older methods:
+ *
+ * - We have VSIDs allocated for every kernel address
+ * (i.e. everything above 0xC000000000000000), except the very top
+ * segment, which simplifies several things.
+ *
+ * - We allow for 15 significant bits of ESID and 20 bits of
+ * context for user addresses. i.e. 8T (43 bits) of address space for
+ * up to 1M contexts (although the page table structure and context
+ * allocation will need changes to take advantage of this).
+ *
+ * - The scramble function gives robust scattering in the hash
+ * table (at least based on some initial results). The previous
+ * method was more susceptible to pathological cases giving excessive
+ * hash collisions.
+ */
+/*
+ * WARNING - If you change these you must make sure the asm
+ * implementations in slb_allocate (slb_low.S), do_stab_bolted
+ * (head.S) and ASM_VSID_SCRAMBLE (below) are changed accordingly.
+ *
+ * You'll also need to change the precomputed VSID values in head.S
+ * which are used by the iSeries firmware.
*/
-#define STAB0_PAGE 0x9
-#define STAB0_PHYS_ADDR (STAB0_PAGE<<PAGE_SHIFT)
-#define STAB0_VIRT_ADDR (KERNELBASE+STAB0_PHYS_ADDR)
-
-#define SLB_NUM_BOLTED 3
-#define SLB_CACHE_ENTRIES 8
-
-/* Bits in the SLB ESID word */
-#define SLB_ESID_V 0x0000000008000000 /* entry is valid */
-
-/* Bits in the SLB VSID word */
-#define SLB_VSID_SHIFT 12
-#define SLB_VSID_KS 0x0000000000000800
-#define SLB_VSID_KP 0x0000000000000400
-#define SLB_VSID_N 0x0000000000000200 /* no-execute */
-#define SLB_VSID_L 0x0000000000000100 /* largepage (4M) */
-#define SLB_VSID_C 0x0000000000000080 /* class */
-
-#define SLB_VSID_KERNEL (SLB_VSID_KP|SLB_VSID_C)
-#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS)
#define VSID_MULTIPLIER ASM_CONST(200730139) /* 28-bit prime */
#define VSID_BITS 36
@@ -239,4 +294,50 @@
srdi rx,rx,VSID_BITS; /* extract 2^36 bit */ \
add rt,rt,rx
+
+#ifndef __ASSEMBLY__
+
+typedef unsigned long mm_context_id_t;
+
+typedef struct {
+ mm_context_id_t id;
+#ifdef CONFIG_HUGETLB_PAGE
+ pgd_t *huge_pgdir;
+ u16 htlb_segs; /* bitmask */
+#endif
+} mm_context_t;
+
+
+static inline unsigned long vsid_scramble(unsigned long protovsid)
+{
+#if 0
+ /* The code below is equivalent to this function for arguments
+ * < 2^VSID_BITS, which is all this should ever be called
+ * with. However gcc is not clever enough to compute the
+ * modulus (2^n-1) without a second multiply. */
+ return ((protovsid * VSID_MULTIPLIER) % VSID_MODULUS);
+#else /* 1 */
+ unsigned long x;
+
+ x = protovsid * VSID_MULTIPLIER;
+ x = (x >> VSID_BITS) + (x & VSID_MODULUS);
+ return (x + ((x+1) >> VSID_BITS)) & VSID_MODULUS;
+#endif /* 1 */
+}
+
+/* This is only valid for addresses >= KERNELBASE */
+static inline unsigned long get_kernel_vsid(unsigned long ea)
+{
+ return vsid_scramble(ea >> SID_SHIFT);
+}
+
+/* This is only valid for user addresses (which are below 2^41) */
+static inline unsigned long get_vsid(unsigned long context, unsigned long ea)
+{
+ return vsid_scramble((context << USER_ESID_BITS)
+ | (ea >> SID_SHIFT));
+}
+
+#endif /* __ASSEMBLY */
+
#endif /* _PPC64_MMU_H_ */
Index: working-2.6/arch/ppc64/mm/stab.c
===================================================================
--- working-2.6.orig/arch/ppc64/mm/stab.c 2005-04-26 15:37:55.000000000 +1000
+++ working-2.6/arch/ppc64/mm/stab.c 2005-05-02 17:29:03.000000000 +1000
@@ -19,6 +19,11 @@
#include <asm/paca.h>
#include <asm/cputable.h>
+struct stab_entry {
+ unsigned long esid_data;
+ unsigned long vsid_data;
+};
+
/* Both the segment table and SLB code uses the following cache */
#define NR_STAB_CACHE_ENTRIES 8
DEFINE_PER_CPU(long, stab_cache_ptr);
Index: working-2.6/include/asm-ppc64/mmu_context.h
===================================================================
--- working-2.6.orig/include/asm-ppc64/mmu_context.h 2005-04-26 15:38:02.000000000 +1000
+++ working-2.6/include/asm-ppc64/mmu_context.h 2005-05-02 17:41:49.000000000 +1000
@@ -84,86 +84,4 @@
local_irq_restore(flags);
}
-/* VSID allocation
- * ===============
- *
- * We first generate a 36-bit "proto-VSID". For kernel addresses this
- * is equal to the ESID, for user addresses it is:
- * (context << 15) | (esid & 0x7fff)
- *
- * The two forms are distinguishable because the top bit is 0 for user
- * addresses, whereas the top two bits are 1 for kernel addresses.
- * Proto-VSIDs with the top two bits equal to 0b10 are reserved for
- * now.
- *
- * The proto-VSIDs are then scrambled into real VSIDs with the
- * multiplicative hash:
- *
- * VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
- * where VSID_MULTIPLIER = 268435399 = 0xFFFFFC7
- * VSID_MODULUS = 2^36-1 = 0xFFFFFFFFF
- *
- * This scramble is only well defined for proto-VSIDs below
- * 0xFFFFFFFFF, so both proto-VSID and actual VSID 0xFFFFFFFFF are
- * reserved. VSID_MULTIPLIER is prime, so in particular it is
- * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
- * Because the modulus is 2^n-1 we can compute it efficiently without
- * a divide or extra multiply (see below).
- *
- * This scheme has several advantages over older methods:
- *
- * - We have VSIDs allocated for every kernel address
- * (i.e. everything above 0xC000000000000000), except the very top
- * segment, which simplifies several things.
- *
- * - We allow for 15 significant bits of ESID and 20 bits of
- * context for user addresses. i.e. 8T (43 bits) of address space for
- * up to 1M contexts (although the page table structure and context
- * allocation will need changes to take advantage of this).
- *
- * - The scramble function gives robust scattering in the hash
- * table (at least based on some initial results). The previous
- * method was more susceptible to pathological cases giving excessive
- * hash collisions.
- */
-
-/*
- * WARNING - If you change these you must make sure the asm
- * implementations in slb_allocate(), do_stab_bolted and mmu.h
- * (ASM_VSID_SCRAMBLE macro) are changed accordingly.
- *
- * You'll also need to change the precomputed VSID values in head.S
- * which are used by the iSeries firmware.
- */
-
-static inline unsigned long vsid_scramble(unsigned long protovsid)
-{
-#if 0
- /* The code below is equivalent to this function for arguments
- * < 2^VSID_BITS, which is all this should ever be called
- * with. However gcc is not clever enough to compute the
- * modulus (2^n-1) without a second multiply. */
- return ((protovsid * VSID_MULTIPLIER) % VSID_MODULUS);
-#else /* 1 */
- unsigned long x;
-
- x = protovsid * VSID_MULTIPLIER;
- x = (x >> VSID_BITS) + (x & VSID_MODULUS);
- return (x + ((x+1) >> VSID_BITS)) & VSID_MODULUS;
-#endif /* 1 */
-}
-
-/* This is only valid for addresses >= KERNELBASE */
-static inline unsigned long get_kernel_vsid(unsigned long ea)
-{
- return vsid_scramble(ea >> SID_SHIFT);
-}
-
-/* This is only valid for user addresses (which are below 2^41) */
-static inline unsigned long get_vsid(unsigned long context, unsigned long ea)
-{
- return vsid_scramble((context << USER_ESID_BITS)
- | (ea >> SID_SHIFT));
-}
-
#endif /* __PPC64_MMU_CONTEXT_H */
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/people/dgibson
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