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-rw-r--r--arch/powerpc/kernel/misc_32.S171
1 files changed, 171 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 998a100..f7d760a 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -8,6 +8,8 @@
* kexec bits:
* Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com>
* GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
+ * PPC44x port. Copyright (C) 2011, IBM Corporation
+ * Author: Suzuki Poulose <suzuki@in.ibm.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -736,6 +738,175 @@ relocate_new_kernel:
mr r5, r31
li r0, 0
+#elif defined(CONFIG_44x) && !defined(CONFIG_47x)
+
+/*
+ * Code for setting up 1:1 mapping for PPC440x for KEXEC
+ *
+ * We cannot switch off the MMU on PPC44x.
+ * So we:
+ * 1) Invalidate all the mappings except the one we are running from.
+ * 2) Create a tmp mapping for our code in the other address space(TS) and
+ * jump to it. Invalidate the entry we started in.
+ * 3) Create a 1:1 mapping for 0-2GiB in chunks of 256M in original TS.
+ * 4) Jump to the 1:1 mapping in original TS.
+ * 5) Invalidate the tmp mapping.
+ *
+ * - Based on the kexec support code for FSL BookE
+ * - Doesn't support 47x yet.
+ *
+ */
+ /* Save our parameters */
+ mr r29, r3
+ mr r30, r4
+ mr r31, r5
+
+ /* Load our MSR_IS and TID to MMUCR for TLB search */
+ mfspr r3,SPRN_PID
+ mfmsr r4
+ andi. r4,r4,MSR_IS@l
+ beq wmmucr
+ oris r3,r3,PPC44x_MMUCR_STS@h
+wmmucr:
+ mtspr SPRN_MMUCR,r3
+ sync
+
+ /*
+ * Invalidate all the TLB entries except the current entry
+ * where we are running from
+ */
+ bl 0f /* Find our address */
+0: mflr r5 /* Make it accessible */
+ tlbsx r23,0,r5 /* Find entry we are in */
+ li r4,0 /* Start at TLB entry 0 */
+ li r3,0 /* Set PAGEID inval value */
+1: cmpw r23,r4 /* Is this our entry? */
+ beq skip /* If so, skip the inval */
+ tlbwe r3,r4,PPC44x_TLB_PAGEID /* If not, inval the entry */
+skip:
+ addi r4,r4,1 /* Increment */
+ cmpwi r4,64 /* Are we done? */
+ bne 1b /* If not, repeat */
+ isync
+
+ /* Create a temp mapping and jump to it */
+ andi. r6, r23, 1 /* Find the index to use */
+ addi r24, r6, 1 /* r24 will contain 1 or 2 */
+
+ mfmsr r9 /* get the MSR */
+ rlwinm r5, r9, 27, 31, 31 /* Extract the MSR[IS] */
+ xori r7, r5, 1 /* Use the other address space */
+
+ /* Read the current mapping entries */
+ tlbre r3, r23, PPC44x_TLB_PAGEID
+ tlbre r4, r23, PPC44x_TLB_XLAT
+ tlbre r5, r23, PPC44x_TLB_ATTRIB
+
+ /* Save our current XLAT entry */
+ mr r25, r4
+
+ /* Extract the TLB PageSize */
+ li r10, 1 /* r10 will hold PageSize */
+ rlwinm r11, r3, 0, 24, 27 /* bits 24-27 */
+
+ /* XXX: As of now we use 256M, 4K pages */
+ cmpwi r11, PPC44x_TLB_256M
+ bne tlb_4k
+ rotlwi r10, r10, 28 /* r10 = 256M */
+ b write_out
+tlb_4k:
+ cmpwi r11, PPC44x_TLB_4K
+ bne default
+ rotlwi r10, r10, 12 /* r10 = 4K */
+ b write_out
+default:
+ rotlwi r10, r10, 10 /* r10 = 1K */
+
+write_out:
+ /*
+ * Write out the tmp 1:1 mapping for this code in other address space
+ * Fixup EPN = RPN , TS=other address space
+ */
+ insrwi r3, r7, 1, 23 /* Bit 23 is TS for PAGEID field */
+
+ /* Write out the tmp mapping entries */
+ tlbwe r3, r24, PPC44x_TLB_PAGEID
+ tlbwe r4, r24, PPC44x_TLB_XLAT
+ tlbwe r5, r24, PPC44x_TLB_ATTRIB
+
+ subi r11, r10, 1 /* PageOffset Mask = PageSize - 1 */
+ not r10, r11 /* Mask for PageNum */
+
+ /* Switch to other address space in MSR */
+ insrwi r9, r7, 1, 26 /* Set MSR[IS] = r7 */
+
+ bl 1f
+1: mflr r8
+ addi r8, r8, (2f-1b) /* Find the target offset */
+
+ /* Jump to the tmp mapping */
+ mtspr SPRN_SRR0, r8
+ mtspr SPRN_SRR1, r9
+ rfi
+
+2:
+ /* Invalidate the entry we were executing from */
+ li r3, 0
+ tlbwe r3, r23, PPC44x_TLB_PAGEID
+
+ /* attribute fields. rwx for SUPERVISOR mode */
+ li r5, 0
+ ori r5, r5, (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G)
+
+ /* Create 1:1 mapping in 256M pages */
+ xori r7, r7, 1 /* Revert back to Original TS */
+
+ li r8, 0 /* PageNumber */
+ li r6, 3 /* TLB Index, start at 3 */
+
+next_tlb:
+ rotlwi r3, r8, 28 /* Create EPN (bits 0-3) */
+ mr r4, r3 /* RPN = EPN */
+ ori r3, r3, (PPC44x_TLB_VALID | PPC44x_TLB_256M) /* SIZE = 256M, Valid */
+ insrwi r3, r7, 1, 23 /* Set TS from r7 */
+
+ tlbwe r3, r6, PPC44x_TLB_PAGEID /* PageID field : EPN, V, SIZE */
+ tlbwe r4, r6, PPC44x_TLB_XLAT /* Address translation : RPN */
+ tlbwe r5, r6, PPC44x_TLB_ATTRIB /* Attributes */
+
+ addi r8, r8, 1 /* Increment PN */
+ addi r6, r6, 1 /* Increment TLB Index */
+ cmpwi r8, 8 /* Are we done ? */
+ bne next_tlb
+ isync
+
+ /* Jump to the new mapping 1:1 */
+ li r9,0
+ insrwi r9, r7, 1, 26 /* Set MSR[IS] = r7 */
+
+ bl 1f
+1: mflr r8
+ and r8, r8, r11 /* Get our offset within page */
+ addi r8, r8, (2f-1b)
+
+ and r5, r25, r10 /* Get our target PageNum */
+ or r8, r8, r5 /* Target jump address */
+
+ mtspr SPRN_SRR0, r8
+ mtspr SPRN_SRR1, r9
+ rfi
+2:
+ /* Invalidate the tmp entry we used */
+ li r3, 0
+ tlbwe r3, r24, PPC44x_TLB_PAGEID
+ sync
+
+ /* Restore the parameters */
+ mr r3, r29
+ mr r4, r30
+ mr r5, r31
+
+ li r0, 0
#else
li r0, 0
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