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Commit 208984f3 authored by Rohit Vaswani's avatar Rohit Vaswani Committed by Gerrit - the friendly Code Review server
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Revert "arm64: kill flush_cache_all()" 



This reverts the upstream commit <68234df4>
("arm64: kill flush_cache_all()"). This is required internally
for certain use-cases like flushing cache before reboot to
ensure all the data is available in the ramdump.

Change-Id: I6dfd240603c05053b7d341faa613dd4866bb7f62
Signed-off-by: default avatarRohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: default avatarVenkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>
parent fe53b823

arch/arm64/include/asm/cacheflush.h

+5 −0
Original line number Diff line number Diff line
@@ -40,6 +40,10 @@ 
 *	the implementation assumes non-aliasing VIPT D-cache and (aliasing)

 *	VIPT I-cache.

 *

 *	flush_cache_all()

 *

 *		Unconditionally clean and invalidate the entire cache.

 *

 *	flush_cache_mm(mm)

 *

 *		Clean and invalidate all user space cache entries
@@ -71,6 +75,7 @@ 
 *		- kaddr  - page address

 *		- size   - region size

 */

extern void flush_cache_all(void);

extern void flush_icache_range(unsigned long start, unsigned long end);

extern int  invalidate_icache_range(unsigned long start, unsigned long end);

extern void __flush_dcache_area(void *addr, size_t len);

arch/arm64/include/asm/proc-fns.h

+4 −0
Original line number Diff line number Diff line
@@ -28,8 +28,12 @@ 
struct mm_struct;

struct cpu_suspend_ctx;



extern void cpu_cache_off(void);

extern void cpu_do_idle(void);

extern void cpu_do_switch_mm(unsigned long pgd_phys, struct mm_struct *mm);

extern void cpu_reset(unsigned long addr) __attribute__((noreturn));

void cpu_soft_restart(phys_addr_t cpu_reset,

		unsigned long addr) __attribute__((noreturn));

extern void cpu_do_suspend(struct cpu_suspend_ctx *ptr);

extern u64 cpu_do_resume(phys_addr_t ptr, u64 idmap_ttbr);

arch/arm64/mm/cache.S

+73 −0
Original line number Diff line number Diff line
@@ -25,6 +25,79 @@ 
#include <asm/alternative.h>

#include <asm/asm-uaccess.h>



/*

 *	__flush_dcache_all()

 *

 *	Flush the whole D-cache.

 *

 *	Corrupted registers: x0-x7, x9-x11

 */

__flush_dcache_all:

	dmb	sy				// ensure ordering with previous memory accesses

	mrs	x0, clidr_el1			// read clidr

	and	x3, x0, #0x7000000		// extract loc from clidr

	lsr	x3, x3, #23			// left align loc bit field

	cbz	x3, finished			// if loc is 0, then no need to clean

	mov	x10, #0				// start clean at cache level 0

loop1:

	add	x2, x10, x10, lsr #1		// work out 3x current cache level

	lsr	x1, x0, x2			// extract cache type bits from clidr

	and	x1, x1, #7			// mask of the bits for current cache only

	cmp	x1, #2				// see what cache we have at this level

	b.lt	skip				// skip if no cache, or just i-cache

	save_and_disable_irqs x9		// make CSSELR and CCSIDR access atomic

	msr	csselr_el1, x10			// select current cache level in csselr

	isb					// isb to sych the new cssr&csidr

	mrs	x1, ccsidr_el1			// read the new ccsidr

	restore_irqs x9

	and	x2, x1, #7			// extract the length of the cache lines

	add	x2, x2, #4			// add 4 (line length offset)

	mov	x4, #0x3ff

	and	x4, x4, x1, lsr #3		// find maximum number on the way size

	clz	w5, w4				// find bit position of way size increment

	mov	x7, #0x7fff

	and	x7, x7, x1, lsr #13		// extract max number of the index size

loop2:

	mov	x9, x4				// create working copy of max way size

loop3:

	lsl	x6, x9, x5

	orr	x11, x10, x6			// factor way and cache number into x11

	lsl	x6, x7, x2

	orr	x11, x11, x6			// factor index number into x11

	dc	cisw, x11			// clean & invalidate by set/way

	subs	x9, x9, #1			// decrement the way

	b.ge	loop3

	subs	x7, x7, #1			// decrement the index

	b.ge	loop2

skip:

	add	x10, x10, #2			// increment cache number

	cmp	x3, x10

	b.gt	loop1

finished:

	mov	x10, #0				// swith back to cache level 0

	msr	csselr_el1, x10			// select current cache level in csselr

	dsb	sy

	isb

	ret

ENDPROC(__flush_dcache_all)



/*

 *	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(flush_cache_all)

	mov	x12, lr

	bl	__flush_dcache_all

	mov	x0, #0

	ic	ialluis				// I+BTB cache invalidate

	ret	x12

ENDPROC(flush_cache_all)



/*

 *	flush_icache_range(start,end)

 *

arch/arm64/mm/flush.c

+1 −0
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ EXPORT_SYMBOL(flush_dcache_page); 
/*

 * Additional functions defined in assembly.

 */

EXPORT_SYMBOL(flush_cache_all);

EXPORT_SYMBOL(flush_icache_range);



#ifdef CONFIG_ARCH_HAS_PMEM_API

arch/arm64/mm/proc.S

+46 −0
Original line number Diff line number Diff line
@@ -49,6 +49,52 @@ 


#define MAIR(attr, mt)	((attr) << ((mt) * 8))



/*

 *	cpu_cache_off()

 *

 *	Turn the CPU D-cache off.

 */

ENTRY(cpu_cache_off)

	mrs	x0, sctlr_el1

	bic	x0, x0, #1 << 2			// clear SCTLR.C

	msr	sctlr_el1, x0

	isb

	ret

ENDPROC(cpu_cache_off)



/*

 *	cpu_reset(loc)

 *

 *	Perform a soft reset of the system.  Put the CPU into the same state

 *	as it would be if it had been reset, and branch to what would be the

 *	reset vector. It must be executed with the flat identity mapping.

 *

 *	- loc   - location to jump to for soft reset

 */

	.align	5

ENTRY(cpu_reset)

	mrs	x1, sctlr_el1

	bic	x1, x1, #1

	msr	sctlr_el1, x1			// disable the MMU

	isb

	ret	x0

ENDPROC(cpu_reset)



ENTRY(cpu_soft_restart)

	/* Save address of cpu_reset() and reset address */

	mov	x19, x0

	mov	x20, x1



	/* Turn D-cache off */

	bl	cpu_cache_off



	/* Push out all dirty data, and ensure cache is empty */

	bl	flush_cache_all



	mov	x0, x20

	ret	x19

ENDPROC(cpu_soft_restart)



/*

 *	cpu_do_idle()

 *