From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Wed, 30 Aug 2017 08:25:59 +0000
Subject: Initial file dump from open source release

---
 arch/arm/mm/cache-v7.S | 448 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 448 insertions(+)
 create mode 100644 arch/arm/mm/cache-v7.S

(limited to 'arch/arm/mm/cache-v7.S')

diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
new file mode 100644
index 00000000..a84e0536
--- /dev/null
+++ b/arch/arm/mm/cache-v7.S
@@ -0,0 +1,448 @@
+/*
+ *  linux/arch/arm/mm/cache-v7.S
+ *
+ *  Copyright (C) 2001 Deep Blue Solutions Ltd.
+ *  Copyright (C) 2005 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  This is the "shell" of the ARMv7 processor support.
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+#include <asm/unwind.h>
+
+#include "proc-macros.S"
+
+/*
+ * The secondary kernel init calls v7_flush_dcache_all before it enables
+ * the L1; however, the L1 comes out of reset in an undefined state, so
+ * the clean + invalidate performed by v7_flush_dcache_all causes a bunch
+ * of cache lines with uninitialized data and uninitialized tags to get
+ * written out to memory, which does really unpleasant things to the main
+ * processor.  We fix this by performing an invalidate, rather than a
+ * clean + invalidate, before jumping into the kernel.
+ *
+ * This function is cloned from arch/arm/mach-tegra/headsmp.S, and needs
+ * to be called for both secondary cores startup and primary core resume
+ * procedures.
+ */
+ENTRY(v7_invalidate_l1)
+       mov     r0, #0
+       mcr     p15, 2, r0, c0, c0, 0
+       mrc     p15, 1, r0, c0, c0, 0
+
+       ldr     r1, =0x7fff
+       and     r2, r1, r0, lsr #13
+
+       ldr     r1, =0x3ff
+
+       and     r3, r1, r0, lsr #3      @ NumWays - 1
+       add     r2, r2, #1              @ NumSets
+
+       and     r0, r0, #0x7
+       add     r0, r0, #4      @ SetShift
+
+       clz     r1, r3          @ WayShift
+       add     r4, r3, #1      @ NumWays
+1:     sub     r2, r2, #1      @ NumSets--
+       mov     r3, r4          @ Temp = NumWays
+2:     subs    r3, r3, #1      @ Temp--
+       mov     r5, r3, lsl r1
+       mov     r6, r2, lsl r0
+       orr     r5, r5, r6      @ Reg = (Temp<<WayShift)|(NumSets<<SetShift)
+       mcr     p15, 0, r5, c7, c6, 2
+       bgt     2b
+       cmp     r2, #0
+       bgt     1b
+       dsb
+       isb
+       mov     pc, lr
+ENDPROC(v7_invalidate_l1)
+
+/*
+ *	v7_flush_icache_all()
+ *
+ *	Flush the whole I-cache.
+ *
+ *	Registers:
+ *	r0 - set to 0
+ */
+ENTRY(v7_flush_icache_all)
+	mov	r0, #0
+	ALT_SMP(mcr	p15, 0, r0, c7, c1, 0)		@ invalidate I-cache inner shareable
+	ALT_UP(mcr	p15, 0, r0, c7, c5, 0)		@ I+BTB cache invalidate
+	mov	pc, lr
+ENDPROC(v7_flush_icache_all)
+
+ /*
+ *     v7_flush_dcache_louis()
+ *
+ *     Flush the D-cache up to the Level of Unification Inner Shareable
+ *
+ *     Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
+ */
+
+ENTRY(v7_flush_dcache_louis)
+	dmb					@ ensure ordering with previous memory accesses
+	mrc	p15, 1, r0, c0, c0, 1		@ read clidr, r0 = clidr
+	ALT_SMP(ands	r3, r0, #(7 << 21))	@ extract LoUIS from clidr
+	ALT_UP(ands	r3, r0, #(7 << 27))	@ extract LoUU from clidr
+#ifdef CONFIG_ARM_ERRATA_643719
+	ALT_SMP(mrceq	p15, 0, r2, c0, c0, 0)	@ read main ID register
+	ALT_UP(moveq	pc, lr)			@ LoUU is zero, so nothing to do
+	ldreq	r1, =0x410fc090                 @ ID of ARM Cortex A9 r0p?
+	biceq	r2, r2, #0x0000000f             @ clear minor revision number
+	teqeq	r2, r1                          @ test for errata affected core and if so...
+	orreqs	r3, #(1 << 21)			@   fix LoUIS value (and set flags state to 'ne')
+#endif
+	ALT_SMP(mov	r3, r3, lsr #20)	@ r3 = LoUIS * 2
+	ALT_UP(mov	r3, r3, lsr #26)	@ r3 = LoUU * 2
+	moveq	pc, lr				@ return if level == 0
+	mov	r10, #0				@ r10 (starting level) = 0
+	b	flush_levels			@ start flushing cache levels
+ENDPROC(v7_flush_dcache_louis)
+
+/*
+ *	v7_flush_dcache_all()
+ *
+ *	Flush the whole D-cache.
+ *
+ *	Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
+ *
+ *	- mm    - mm_struct describing address space
+ */
+ENTRY(v7_flush_dcache_all)
+	dmb					@ ensure ordering with previous memory accesses
+	mrc	p15, 1, r0, c0, c0, 1		@ read clidr
+	ands	r3, r0, #0x7000000		@ extract loc from clidr
+	mov	r3, r3, lsr #23			@ left align loc bit field
+	beq	finished			@ if loc is 0, then no need to clean
+	mov	r10, #0				@ start clean at cache level 0
+flush_levels:
+	add	r2, r10, r10, lsr #1		@ work out 3x current cache level
+	mov	r1, r0, lsr r2			@ extract cache type bits from clidr
+	and	r1, r1, #7			@ mask of the bits for current cache only
+	cmp	r1, #2				@ see what cache we have at this level
+	blt	skip				@ skip if no cache, or just i-cache
+#ifdef CONFIG_PREEMPT
+	save_and_disable_irqs_notrace r9	@ make cssr&csidr read atomic
+#endif
+	mcr	p15, 2, r10, c0, c0, 0		@ select current cache level in cssr
+	isb					@ isb to sych the new cssr&csidr
+	mrc	p15, 1, r1, c0, c0, 0		@ read the new csidr
+#ifdef CONFIG_PREEMPT
+	restore_irqs_notrace r9
+#endif
+	and	r2, r1, #7			@ extract the length of the cache lines
+	add	r2, r2, #4			@ add 4 (line length offset)
+	ldr	r4, =0x3ff
+	ands	r4, r4, r1, lsr #3		@ find maximum number on the way size
+	clz	r5, r4				@ find bit position of way size increment
+	ldr	r7, =0x7fff
+	ands	r7, r7, r1, lsr #13		@ extract max number of the index size
+loop1:
+	mov	r9, r7				@ create working copy of max index
+loop2:
+ ARM(	orr	r11, r10, r4, lsl r5	)	@ factor way and cache number into r11
+ THUMB(	lsl	r6, r4, r5		)
+ THUMB(	orr	r11, r10, r6		)	@ factor way and cache number into r11
+ ARM(	orr	r11, r11, r9, lsl r2	)	@ factor index number into r11
+ THUMB(	lsl	r6, r9, r2		)
+ THUMB(	orr	r11, r11, r6		)	@ factor index number into r11
+	mcr	p15, 0, r11, c7, c14, 2		@ clean & invalidate by set/way
+	subs	r9, r9, #1			@ decrement the index
+	bge	loop2
+	subs	r4, r4, #1			@ decrement the way
+	bge	loop1
+skip:
+	add	r10, r10, #2			@ increment cache number
+	cmp	r3, r10
+	bgt	flush_levels
+finished:
+	mov	r10, #0				@ swith back to cache level 0
+	mcr	p15, 2, r10, c0, c0, 0		@ select current cache level in cssr
+	dsb
+	isb
+	mov	pc, lr
+ENDPROC(v7_flush_dcache_all)
+
+/*
+ *	v7_flush_cache_all()
+ *
+ *	Flush the entire cache system.
+ *  The data cache flush is now achieved using atomic clean / invalidates
+ *  working outwards from L1 cache. This is done using Set/Way based cache
+ *  maintenance instructions.
+ *  The instruction cache can still be invalidated back to the point of
+ *  unification in a single instruction.
+ *
+ */
+ENTRY(v7_flush_kern_cache_all)
+ ARM(	stmfd	sp!, {r4-r5, r7, r9-r11, lr}	)
+ THUMB(	stmfd	sp!, {r4-r7, r9-r11, lr}	)
+	bl	v7_flush_dcache_all
+	mov	r0, #0
+	ALT_SMP(mcr	p15, 0, r0, c7, c1, 0)	@ invalidate I-cache inner shareable
+	ALT_UP(mcr	p15, 0, r0, c7, c5, 0)	@ I+BTB cache invalidate
+ ARM(	ldmfd	sp!, {r4-r5, r7, r9-r11, lr}	)
+ THUMB(	ldmfd	sp!, {r4-r7, r9-r11, lr}	)
+	mov	pc, lr
+ENDPROC(v7_flush_kern_cache_all)
+
+ /*
+ *     v7_flush_kern_cache_louis(void)
+ *
+ *     Flush the data cache up to Level of Unification Inner Shareable.
+ *     Invalidate the I-cache to the point of unification.
+ */
+ENTRY(v7_flush_kern_cache_louis)
+ ARM(	stmfd	sp!, {r4-r5, r7, r9-r11, lr}	)
+ THUMB(	stmfd	sp!, {r4-r7, r9-r11, lr}	)
+	bl	v7_flush_dcache_louis
+	mov	r0, #0
+	ALT_SMP(mcr	p15, 0, r0, c7, c1, 0)	@ invalidate I-cache inner shareable
+	ALT_UP(mcr	p15, 0, r0, c7, c5, 0)	@ I+BTB cache invalidate
+ ARM(	ldmfd	sp!, {r4-r5, r7, r9-r11, lr}	)
+ THUMB(	ldmfd	sp!, {r4-r7, r9-r11, lr}	)
+	mov	pc, lr
+ENDPROC(v7_flush_kern_cache_louis)
+
+/*
+ *	v7_flush_cache_all()
+ *
+ *	Flush all TLB entries in a particular address space
+ *
+ *	- mm    - mm_struct describing address space
+ */
+ENTRY(v7_flush_user_cache_all)
+	/*FALLTHROUGH*/
+
+/*
+ *	v7_flush_cache_range(start, end, flags)
+ *
+ *	Flush a range of TLB entries in the specified address space.
+ *
+ *	- start - start address (may not be aligned)
+ *	- end   - end address (exclusive, may not be aligned)
+ *	- flags	- vm_area_struct flags describing address space
+ *
+ *	It is assumed that:
+ *	- we have a VIPT cache.
+ */
+ENTRY(v7_flush_user_cache_range)
+	mov	pc, lr
+ENDPROC(v7_flush_user_cache_all)
+ENDPROC(v7_flush_user_cache_range)
+
+/*
+ *	v7_coherent_kern_range(start,end)
+ *
+ *	Ensure that the I and D caches are coherent within specified
+ *	region.  This is typically used when code has been written to
+ *	a memory region, and will be executed.
+ *
+ *	- start   - virtual start address of region
+ *	- end     - virtual end address of region
+ *
+ *	It is assumed that:
+ *	- the Icache does not read data from the write buffer
+ */
+ENTRY(v7_coherent_kern_range)
+	/* FALLTHROUGH */
+
+/*
+ *	v7_coherent_user_range(start,end)
+ *
+ *	Ensure that the I and D caches are coherent within specified
+ *	region.  This is typically used when code has been written to
+ *	a memory region, and will be executed.
+ *
+ *	- start   - virtual start address of region
+ *	- end     - virtual end address of region
+ *
+ *	It is assumed that:
+ *	- the Icache does not read data from the write buffer
+ */
+ENTRY(v7_coherent_user_range)
+ UNWIND(.fnstart		)
+	dcache_line_size r2, r3
+	sub	r3, r2, #1
+	bic	r12, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+	ALT_SMP(W(dsb))
+	ALT_UP(W(nop))
+#endif
+1:
+ USER(	mcr	p15, 0, r12, c7, c11, 1	)	@ clean D line to the point of unification
+	add	r12, r12, r2
+	cmp	r12, r1
+	blo	1b
+	dsb
+	icache_line_size r2, r3
+	sub	r3, r2, #1
+	bic	r12, r0, r3
+2:
+ USER(	mcr	p15, 0, r12, c7, c5, 1	)	@ invalidate I line
+	add	r12, r12, r2
+	cmp	r12, r1
+	blo	2b
+	mov	r0, #0
+	ALT_SMP(mcr	p15, 0, r0, c7, c1, 6)	@ invalidate BTB Inner Shareable
+	ALT_UP(mcr	p15, 0, r0, c7, c5, 6)	@ invalidate BTB
+	dsb
+	isb
+	mov	pc, lr
+
+/*
+ * Fault handling for the cache operation above. If the virtual address in r0
+ * isn't mapped, fail with -EFAULT.
+ */
+9001:
+#ifdef CONFIG_ARM_ERRATA_775420
+	dsb
+#endif
+	mov	r0, #-EFAULT
+	mov	pc, lr
+ UNWIND(.fnend		)
+ENDPROC(v7_coherent_kern_range)
+ENDPROC(v7_coherent_user_range)
+
+/*
+ *	v7_flush_kern_dcache_area(void *addr, size_t size)
+ *
+ *	Ensure that the data held in the page kaddr is written back
+ *	to the page in question.
+ *
+ *	- addr	- kernel address
+ *	- size	- region size
+ */
+ENTRY(v7_flush_kern_dcache_area)
+	dcache_line_size r2, r3
+	add	r1, r0, r1
+	sub	r3, r2, #1
+	bic	r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+	ALT_SMP(W(dsb))
+	ALT_UP(W(nop))
+#endif
+1:
+	mcr	p15, 0, r0, c7, c14, 1		@ clean & invalidate D line / unified line
+	add	r0, r0, r2
+	cmp	r0, r1
+	blo	1b
+	dsb
+	mov	pc, lr
+ENDPROC(v7_flush_kern_dcache_area)
+
+/*
+ *	v7_dma_inv_range(start,end)
+ *
+ *	Invalidate the data cache within the specified region; we will
+ *	be performing a DMA operation in this region and we want to
+ *	purge old data in the cache.
+ *
+ *	- start   - virtual start address of region
+ *	- end     - virtual end address of region
+ */
+v7_dma_inv_range:
+	dcache_line_size r2, r3
+	sub	r3, r2, #1
+	tst	r0, r3
+	bic	r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+	ALT_SMP(W(dsb))
+	ALT_UP(W(nop))
+#endif
+	mcrne	p15, 0, r0, c7, c14, 1		@ clean & invalidate D / U line
+
+	tst	r1, r3
+	bic	r1, r1, r3
+	mcrne	p15, 0, r1, c7, c14, 1		@ clean & invalidate D / U line
+1:
+	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D / U line
+	add	r0, r0, r2
+	cmp	r0, r1
+	blo	1b
+	dsb
+	mov	pc, lr
+ENDPROC(v7_dma_inv_range)
+
+/*
+ *	v7_dma_clean_range(start,end)
+ *	- start   - virtual start address of region
+ *	- end     - virtual end address of region
+ */
+v7_dma_clean_range:
+	dcache_line_size r2, r3
+	sub	r3, r2, #1
+	bic	r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+	ALT_SMP(W(dsb))
+	ALT_UP(W(nop))
+#endif
+1:
+	mcr	p15, 0, r0, c7, c10, 1		@ clean D / U line
+	add	r0, r0, r2
+	cmp	r0, r1
+	blo	1b
+	dsb
+	mov	pc, lr
+ENDPROC(v7_dma_clean_range)
+
+/*
+ *	v7_dma_flush_range(start,end)
+ *	- start   - virtual start address of region
+ *	- end     - virtual end address of region
+ */
+ENTRY(v7_dma_flush_range)
+	dcache_line_size r2, r3
+	sub	r3, r2, #1
+	bic	r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+	ALT_SMP(W(dsb))
+	ALT_UP(W(nop))
+#endif
+1:
+	mcr	p15, 0, r0, c7, c14, 1		@ clean & invalidate D / U line
+	add	r0, r0, r2
+	cmp	r0, r1
+	blo	1b
+	dsb
+	mov	pc, lr
+ENDPROC(v7_dma_flush_range)
+
+/*
+ *	dma_map_area(start, size, dir)
+ *	- start	- kernel virtual start address
+ *	- size	- size of region
+ *	- dir	- DMA direction
+ */
+ENTRY(v7_dma_map_area)
+	add	r1, r1, r0
+	teq	r2, #DMA_FROM_DEVICE
+	beq	v7_dma_inv_range
+	b	v7_dma_clean_range
+ENDPROC(v7_dma_map_area)
+
+/*
+ *	dma_unmap_area(start, size, dir)
+ *	- start	- kernel virtual start address
+ *	- size	- size of region
+ *	- dir	- DMA direction
+ */
+ENTRY(v7_dma_unmap_area)
+	add	r1, r1, r0
+	teq	r2, #DMA_TO_DEVICE
+	bne	v7_dma_inv_range
+	mov	pc, lr
+ENDPROC(v7_dma_unmap_area)
+
+	__INITDATA
+
+	@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
+	define_cache_functions v7
-- 
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