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linux/arch/microblaze/kernel/misc.S

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microblaze_mmu_v2: TLB low level code Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-05-26 16:30:10 +02:00
/*
* Miscellaneous low-level MMU functions.
*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008-2009 PetaLogix
* Copyright (C) 2007 Xilinx, Inc. All rights reserved.
*
* Derived from arch/ppc/kernel/misc.S
*
* 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 for more details.
*/
#include <linux/linkage.h>
#include <linux/sys.h>
#include <asm/unistd.h>
#include <linux/errno.h>
#include <asm/mmu.h>
#include <asm/page.h>
.text
/*
* Flush MMU TLB
*
* We avoid flushing the pinned 0, 1 and possibly 2 entries.
*/
.globl _tlbia;
microblaze: Add .type and .size to ASM functions Cachegrind analysis need this fix to be able to log asm functions. Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-03-23 08:09:32 +01:00
.type _tlbia, @function
microblaze_mmu_v2: TLB low level code Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-05-26 16:30:10 +02:00
.align 4;
_tlbia:
microblaze: Handle TLB skip size dynamically This patch fix the problem with rootfs on JFFS2 with early printk console turned on. The origin version used TLB63 for temporary early printk mapping. The code expect that kernel is not able to use all 64 TLB entries till early printk console is remapped by ioremap. After that temporary mapping on TLB63 is silently lost. This expectation give the opportunity to have early console pretty early. Microblaze systems with JFFS2 rootfs with early printk console turned on used more than 64 TLB entries before kernel can remap early console. Based on that kernel does access to bad area because early printk mapping is rewritten. This patch introduces tlb_skip variable which dynamically stores number of skipped TLB entries from the TLB0. skip_tlb=2 means that TLB0 and TLB1 should be skipped. MICROBLAZE_TLB_SKIP defines how many TLB is skipped at the kernel start. They can be used for user purpose. TLB 63 is used for temporary LMB mapping (MICROBLAZE_LMB_TLB_ID). Also clean TLBLO when kernel starts. For specific kernel sizes kernel can use just one TLB. Detect this case and use the second TLB for general purpose. Change _tlbia function to flush TLB entries from tlb_skip to TLB_SIZE. Export tlb_skip size through debugfs. Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-02-08 16:41:38 +01:00
lwi r12, r0, tlb_skip;
microblaze_mmu_v2: TLB low level code Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-05-26 16:30:10 +02:00
/* isync */
_tlbia_1:
mts rtlbx, r12
nop
mts rtlbhi, r0 /* flush: ensure V is clear */
nop
microblaze: Handle TLB skip size dynamically This patch fix the problem with rootfs on JFFS2 with early printk console turned on. The origin version used TLB63 for temporary early printk mapping. The code expect that kernel is not able to use all 64 TLB entries till early printk console is remapped by ioremap. After that temporary mapping on TLB63 is silently lost. This expectation give the opportunity to have early console pretty early. Microblaze systems with JFFS2 rootfs with early printk console turned on used more than 64 TLB entries before kernel can remap early console. Based on that kernel does access to bad area because early printk mapping is rewritten. This patch introduces tlb_skip variable which dynamically stores number of skipped TLB entries from the TLB0. skip_tlb=2 means that TLB0 and TLB1 should be skipped. MICROBLAZE_TLB_SKIP defines how many TLB is skipped at the kernel start. They can be used for user purpose. TLB 63 is used for temporary LMB mapping (MICROBLAZE_LMB_TLB_ID). Also clean TLBLO when kernel starts. For specific kernel sizes kernel can use just one TLB. Detect this case and use the second TLB for general purpose. Change _tlbia function to flush TLB entries from tlb_skip to TLB_SIZE. Export tlb_skip size through debugfs. Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-02-08 16:41:38 +01:00
rsubi r11, r12, MICROBLAZE_TLB_SIZE - 1
microblaze_mmu_v2: TLB low level code Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-05-26 16:30:10 +02:00
bneid r11, _tlbia_1 /* loop for all entries */
microblaze: Handle TLB skip size dynamically This patch fix the problem with rootfs on JFFS2 with early printk console turned on. The origin version used TLB63 for temporary early printk mapping. The code expect that kernel is not able to use all 64 TLB entries till early printk console is remapped by ioremap. After that temporary mapping on TLB63 is silently lost. This expectation give the opportunity to have early console pretty early. Microblaze systems with JFFS2 rootfs with early printk console turned on used more than 64 TLB entries before kernel can remap early console. Based on that kernel does access to bad area because early printk mapping is rewritten. This patch introduces tlb_skip variable which dynamically stores number of skipped TLB entries from the TLB0. skip_tlb=2 means that TLB0 and TLB1 should be skipped. MICROBLAZE_TLB_SKIP defines how many TLB is skipped at the kernel start. They can be used for user purpose. TLB 63 is used for temporary LMB mapping (MICROBLAZE_LMB_TLB_ID). Also clean TLBLO when kernel starts. For specific kernel sizes kernel can use just one TLB. Detect this case and use the second TLB for general purpose. Change _tlbia function to flush TLB entries from tlb_skip to TLB_SIZE. Export tlb_skip size through debugfs. Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-02-08 16:41:38 +01:00
addik r12, r12, 1
microblaze: Add sync to tlb operations Do the real sync by using mbar instruction. Signed-off-by: Stefan Asserhall <stefan.asserhall@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2020-02-04 17:55:28 +01:00
mbar 1 /* sync */
microblaze_mmu_v2: TLB low level code Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-05-26 16:30:10 +02:00
rtsd r15, 8
nop
microblaze: Add .type and .size to ASM functions Cachegrind analysis need this fix to be able to log asm functions. Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-03-23 08:09:32 +01:00
.size _tlbia, . - _tlbia
microblaze_mmu_v2: TLB low level code Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-05-26 16:30:10 +02:00
/*
* Flush MMU TLB for a particular address (in r5)
*/
.globl _tlbie;
microblaze: Add .type and .size to ASM functions Cachegrind analysis need this fix to be able to log asm functions. Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-03-23 08:09:32 +01:00
.type _tlbie, @function
microblaze_mmu_v2: TLB low level code Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-05-26 16:30:10 +02:00
.align 4;
_tlbie:
mts rtlbsx, r5 /* look up the address in TLB */
nop
mfs r12, rtlbx /* Retrieve index */
nop
blti r12, _tlbie_1 /* Check if found */
mts rtlbhi, r0 /* flush: ensure V is clear */
nop
microblaze: Add sync to tlb operations Do the real sync by using mbar instruction. Signed-off-by: Stefan Asserhall <stefan.asserhall@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2020-02-04 17:55:28 +01:00
mbar 1 /* sync */
microblaze_mmu_v2: TLB low level code Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-05-26 16:30:10 +02:00
_tlbie_1:
rtsd r15, 8
nop
microblaze: Add .type and .size to ASM functions Cachegrind analysis need this fix to be able to log asm functions. Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-03-23 08:09:32 +01:00
.size _tlbie, . - _tlbie
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