--- /dev/null
+/*
+ * arch/ppc64/mm/slb_low.S
+ *
+ * Low-level SLB routines
+ *
+ * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
+ *
+ * Based on earlier C version:
+ * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
+ * Copyright (c) 2001 Dave Engebretsen
+ * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <asm/processor.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/cputable.h>
+
+/* void slb_allocate(unsigned long ea);
+ *
+ * Create an SLB entry for the given EA (user or kernel).
+ * r3 = faulting address, r13 = PACA
+ * r9, r10, r11 are clobbered by this function
+ * No other registers are examined or changed.
+ */
+_GLOBAL(slb_allocate)
+ /*
+ * First find a slot, round robin. Previously we tried to find
+ * a free slot first but that took too long. Unfortunately we
+ * dont have any LRU information to help us choose a slot.
+ */
+#ifdef CONFIG_PPC_ISERIES
+ /*
+ * On iSeries, the "bolted" stack segment can be cast out on
+ * shared processor switch so we need to check for a miss on
+ * it and restore it to the right slot.
+ */
+ ld r9,PACAKSAVE(r13)
+ clrrdi r9,r9,28
+ clrrdi r11,r3,28
+ li r10,SLB_NUM_BOLTED-1 /* Stack goes in last bolted slot */
+ cmpld r9,r11
+ beq 3f
+#endif /* CONFIG_PPC_ISERIES */
+
+ ld r10,PACASTABRR(r13)
+ addi r10,r10,1
+ /* use a cpu feature mask if we ever change our slb size */
+ cmpldi r10,SLB_NUM_ENTRIES
+
+ blt+ 4f
+ li r10,SLB_NUM_BOLTED
+
+4:
+ std r10,PACASTABRR(r13)
+3:
+ /* r3 = faulting address, r10 = entry */
+
+ srdi r9,r3,60 /* get region */
+ srdi r3,r3,28 /* get esid */
+ cmpldi cr7,r9,0xc /* cmp KERNELBASE for later use */
+
+ rldimi r10,r3,28,0 /* r10= ESID<<28 | entry */
+ oris r10,r10,SLB_ESID_V@h /* r10 |= SLB_ESID_V */
+
+ /* r3 = esid, r10 = esid_data, cr7 = <>KERNELBASE */
+
+ blt cr7,0f /* user or kernel? */
+
+ /* kernel address: proto-VSID = ESID */
+ /* WARNING - MAGIC: we don't use the VSID 0xfffffffff, but
+ * this code will generate the protoVSID 0xfffffffff for the
+ * top segment. That's ok, the scramble below will translate
+ * it to VSID 0, which is reserved as a bad VSID - one which
+ * will never have any pages in it. */
+ li r11,SLB_VSID_KERNEL
+BEGIN_FTR_SECTION
+ bne cr7,9f
+ li r11,(SLB_VSID_KERNEL|SLB_VSID_L)
+END_FTR_SECTION_IFSET(CPU_FTR_16M_PAGE)
+ b 9f
+
+0: /* user address: proto-VSID = context<<15 | ESID */
+ srdi. r9,r3,USER_ESID_BITS
+ bne- 8f /* invalid ea bits set */
+
+#ifdef CONFIG_HUGETLB_PAGE
+BEGIN_FTR_SECTION
+ lhz r9,PACAHIGHHTLBAREAS(r13)
+ srdi r11,r3,(HTLB_AREA_SHIFT-SID_SHIFT)
+ srd r9,r9,r11
+ lhz r11,PACALOWHTLBAREAS(r13)
+ srd r11,r11,r3
+ or r9,r9,r11
+END_FTR_SECTION_IFSET(CPU_FTR_16M_PAGE)
+#endif /* CONFIG_HUGETLB_PAGE */
+
+ li r11,SLB_VSID_USER
+
+#ifdef CONFIG_HUGETLB_PAGE
+BEGIN_FTR_SECTION
+ rldimi r11,r9,8,55 /* shift masked bit into SLB_VSID_L */
+END_FTR_SECTION_IFSET(CPU_FTR_16M_PAGE)
+#endif /* CONFIG_HUGETLB_PAGE */
+
+ ld r9,PACACONTEXTID(r13)
+ rldimi r3,r9,USER_ESID_BITS,0
+
+9: /* r3 = protovsid, r11 = flags, r10 = esid_data, cr7 = <>KERNELBASE */
+ ASM_VSID_SCRAMBLE(r3,r9)
+
+ rldimi r11,r3,SLB_VSID_SHIFT,16 /* combine VSID and flags */
+
+ /*
+ * No need for an isync before or after this slbmte. The exception
+ * we enter with and the rfid we exit with are context synchronizing.
+ */
+ slbmte r11,r10
+
+ bgelr cr7 /* we're done for kernel addresses */
+
+ /* Update the slb cache */
+ lhz r3,PACASLBCACHEPTR(r13) /* offset = paca->slb_cache_ptr */
+ cmpldi r3,SLB_CACHE_ENTRIES
+ bge 1f
+
+ /* still room in the slb cache */
+ sldi r11,r3,1 /* r11 = offset * sizeof(u16) */
+ rldicl r10,r10,36,28 /* get low 16 bits of the ESID */
+ add r11,r11,r13 /* r11 = (u16 *)paca + offset */
+ sth r10,PACASLBCACHE(r11) /* paca->slb_cache[offset] = esid */
+ addi r3,r3,1 /* offset++ */
+ b 2f
+1: /* offset >= SLB_CACHE_ENTRIES */
+ li r3,SLB_CACHE_ENTRIES+1
+2:
+ sth r3,PACASLBCACHEPTR(r13) /* paca->slb_cache_ptr = offset */
+ blr
+
+8: /* invalid EA */
+ li r3,0 /* BAD_VSID */
+ li r11,SLB_VSID_USER /* flags don't much matter */
+ b 9b
git.openpandora.org / pandora-kernel.git / blobdiff