From 72d92cedc30af23d855fec53b04d9266d88c6671 Mon Sep 17 00:00:00 2001
From: Kanoj Sarcar <kanoj@engr.sgi.com>
Date: Fri, 30 Jun 2000 00:48:29 +0000
Subject: Implement a functional vmalloc(). THe vmalloc range address
 translations are stashed in an array of page tables, starting from kptbl[].
 The fast tlbmiss handler quickly checks to see if the faulting address is in
 the vmalloc range, and if so, it uses the translations in the kptbl to update
 the tlbs. Still to do: tlb invalid faults in the vmalloc range needs to be
 handled properly.

---
 arch/mips64/kernel/r4k_tlb.S | 59 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 54 insertions(+), 5 deletions(-)

(limited to 'arch/mips64/kernel/r4k_tlb.S')

diff --git a/arch/mips64/kernel/r4k_tlb.S b/arch/mips64/kernel/r4k_tlb.S
index 2baa35ca1..54c4b934b 100644
--- a/arch/mips64/kernel/r4k_tlb.S
+++ b/arch/mips64/kernel/r4k_tlb.S
@@ -1,4 +1,4 @@
-/* $Id: r4k_tlb.S,v 1.1 2000/05/25 19:33:16 ulfc Exp $
+/* $Id: r4k_tlb.S,v 1.2 2000/06/13 23:48:20 kanoj Exp $
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
@@ -33,13 +33,14 @@
 #endif
 	dmfc0	\tmp, CP0_BADVADDR
 	ld	\ptr, (\ptr)
-	dsrl	\tmp, 28			# get pgd offset
-	andi	\tmp, 0x1ff8
+	bltz	\tmp, kaddr
+	 dsrl	\tmp, (PGDIR_SHIFT-3)		# get pgd offset in bytes
+	andi	\tmp, ((PTRS_PER_PGD - 1)<<3)
 	daddu	\ptr, \tmp			# add in pgd offset
 	dmfc0	\tmp, CP0_BADVADDR
 	ld	\ptr, (\ptr)			# get pmd pointer
-	dsrl	\tmp, 18			# get pmd offset
-	andi	\tmp, 0x1ff8
+	dsrl	\tmp, (PMD_SHIFT-3)		# get pmd offset in bytes
+	andi	\tmp, ((PTRS_PER_PMD - 1)<<3)
 	daddu	\ptr, \tmp			# add in pmd offset
 	dmfc0	\tmp, CP0_XCONTEXT
 	ld	\ptr, (\ptr)			# get pte pointer
@@ -82,3 +83,51 @@ FEXPORT(except_vec1_r10k)
 	nop
 	tlbwr
 	eret
+kaddr:
+	dla	k0, handle_vmalloc_address	# MAPPED kernel needs this
+	jr	k0
+	 nop
+
+	.align	5
+FEXPORT(handle_vmalloc_address)
+	.set	noat
+	/*
+	 * First, determine that the address is in/above vmalloc range.
+	 */
+	dmfc0	k0, CP0_BADVADDR
+	dli	k1, VMALLOC_START
+	sltu	k1, k0, k1
+	bne	k1, zero, not_vmalloc
+	 dli	k1, VMALLOC_START
+
+	/*
+	 * Now find offset into kptbl.
+	 */
+	dsubu	k0, k0, k1
+	dla	k1, kptbl
+	dsrl	k0, (PAGE_SHIFT+1)		# get vpn2
+	dsll	k0, 4				# byte offset of pte
+	daddu	k1, k1, k0
+
+	/*
+	 * Determine that fault address is within vmalloc range.
+	 */
+	dla	k0, ekptbl
+	sltu	k0, k1, k0
+	beq	k0, zero, not_vmalloc
+
+	/*
+	 * Load cp0 registers.
+	 */
+	ld	k0, 0(k1)			# get even pte
+	ld	k1, 8(k1)			# get odd pte
+1:
+	PTE_RELOAD k0 k1
+	nop
+	tlbwr
+	eret
+not_vmalloc:
+	daddu	k0, zero, zero
+	daddu	k1, zero, zero
+	j	1b
+	nop
-- 
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