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6ae4b6e057
The DCache clean & ICache invalidation requirements for instructions
to be data coherence are discoverable through new fields in CTR_EL0.
The following two control bits DIC and IDC were defined for this
purpose. No need to perform point of unification cache maintenance
operations from software on systems where CPU caches are transparent.
This patch optimize the three functions __flush_cache_user_range(),
clean_dcache_area_pou() and invalidate_icache_range() if the hardware
reports CTR_EL0.IDC and/or CTR_EL0.IDC. Basically it skips the two
instructions 'DC CVAU' and 'IC IVAU', and the associated loop logic
in order to avoid the unnecessary overhead.
CTR_EL0.DIC: Instruction cache invalidation requirements for
instruction to data coherence. The meaning of this bit[29].
0: Instruction cache invalidation to the point of unification
is required for instruction to data coherence.
1: Instruction cache cleaning to the point of unification is
not required for instruction to data coherence.
CTR_EL0.IDC: Data cache clean requirements for instruction to data
coherence. The meaning of this bit[28].
0: Data cache clean to the point of unification is required for
instruction to data coherence, unless CLIDR_EL1.LoC == 0b000
or (CLIDR_EL1.LoUIS == 0b000 && CLIDR_EL1.LoUU == 0b000).
1: Data cache clean to the point of unification is not required
for instruction to data coherence.
Co-authored-by: Philip Elcan <pelcan@codeaurora.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
255 lines
5.8 KiB
ArmAsm
255 lines
5.8 KiB
ArmAsm
/*
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* Cache maintenance
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*
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* Copyright (C) 2001 Deep Blue Solutions Ltd.
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/errno.h>
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#include <linux/linkage.h>
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#include <linux/init.h>
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#include <asm/assembler.h>
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#include <asm/cpufeature.h>
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#include <asm/alternative.h>
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#include <asm/asm-uaccess.h>
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/*
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* flush_icache_range(start,end)
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*
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* Ensure that the I and D caches are coherent within specified region.
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* This is typically used when code has been written to a memory region,
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* and will be executed.
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*
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* - start - virtual start address of region
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* - end - virtual end address of region
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*/
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ENTRY(flush_icache_range)
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/* FALLTHROUGH */
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/*
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* __flush_cache_user_range(start,end)
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*
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* Ensure that the I and D caches are coherent within specified region.
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* This is typically used when code has been written to a memory region,
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* and will be executed.
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*
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* - start - virtual start address of region
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* - end - virtual end address of region
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*/
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ENTRY(__flush_cache_user_range)
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uaccess_ttbr0_enable x2, x3, x4
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alternative_if ARM64_HAS_CACHE_IDC
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dsb ishst
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b 7f
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alternative_else_nop_endif
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dcache_line_size x2, x3
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sub x3, x2, #1
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bic x4, x0, x3
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1:
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user_alt 9f, "dc cvau, x4", "dc civac, x4", ARM64_WORKAROUND_CLEAN_CACHE
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add x4, x4, x2
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cmp x4, x1
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b.lo 1b
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dsb ish
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7:
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alternative_if ARM64_HAS_CACHE_DIC
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isb
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b 8f
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alternative_else_nop_endif
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invalidate_icache_by_line x0, x1, x2, x3, 9f
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8: mov x0, #0
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1:
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uaccess_ttbr0_disable x1, x2
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ret
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9:
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mov x0, #-EFAULT
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b 1b
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ENDPROC(flush_icache_range)
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ENDPROC(__flush_cache_user_range)
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/*
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* invalidate_icache_range(start,end)
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*
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* Ensure that the I cache is invalid within specified region.
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*
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* - start - virtual start address of region
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* - end - virtual end address of region
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*/
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ENTRY(invalidate_icache_range)
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alternative_if ARM64_HAS_CACHE_DIC
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mov x0, xzr
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isb
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ret
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alternative_else_nop_endif
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uaccess_ttbr0_enable x2, x3, x4
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invalidate_icache_by_line x0, x1, x2, x3, 2f
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mov x0, xzr
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1:
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uaccess_ttbr0_disable x1, x2
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ret
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2:
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mov x0, #-EFAULT
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b 1b
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ENDPROC(invalidate_icache_range)
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/*
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* __flush_dcache_area(kaddr, size)
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*
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* Ensure that any D-cache lines for the interval [kaddr, kaddr+size)
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* are cleaned and invalidated to the PoC.
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*
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* - kaddr - kernel address
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* - size - size in question
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*/
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ENTRY(__flush_dcache_area)
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dcache_by_line_op civac, sy, x0, x1, x2, x3
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ret
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ENDPIPROC(__flush_dcache_area)
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/*
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* __clean_dcache_area_pou(kaddr, size)
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*
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* Ensure that any D-cache lines for the interval [kaddr, kaddr+size)
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* are cleaned to the PoU.
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*
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* - kaddr - kernel address
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* - size - size in question
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*/
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ENTRY(__clean_dcache_area_pou)
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alternative_if ARM64_HAS_CACHE_IDC
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dsb ishst
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ret
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alternative_else_nop_endif
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dcache_by_line_op cvau, ish, x0, x1, x2, x3
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ret
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ENDPROC(__clean_dcache_area_pou)
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/*
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* __inval_dcache_area(kaddr, size)
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*
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* Ensure that any D-cache lines for the interval [kaddr, kaddr+size)
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* are invalidated. Any partial lines at the ends of the interval are
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* also cleaned to PoC to prevent data loss.
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*
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* - kaddr - kernel address
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* - size - size in question
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*/
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ENTRY(__inval_dcache_area)
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/* FALLTHROUGH */
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/*
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* __dma_inv_area(start, size)
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* - start - virtual start address of region
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* - size - size in question
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*/
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__dma_inv_area:
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add x1, x1, x0
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dcache_line_size x2, x3
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sub x3, x2, #1
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tst x1, x3 // end cache line aligned?
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bic x1, x1, x3
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b.eq 1f
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dc civac, x1 // clean & invalidate D / U line
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1: tst x0, x3 // start cache line aligned?
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bic x0, x0, x3
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b.eq 2f
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dc civac, x0 // clean & invalidate D / U line
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b 3f
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2: dc ivac, x0 // invalidate D / U line
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3: add x0, x0, x2
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cmp x0, x1
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b.lo 2b
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dsb sy
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ret
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ENDPIPROC(__inval_dcache_area)
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ENDPROC(__dma_inv_area)
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/*
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* __clean_dcache_area_poc(kaddr, size)
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*
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* Ensure that any D-cache lines for the interval [kaddr, kaddr+size)
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* are cleaned to the PoC.
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*
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* - kaddr - kernel address
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* - size - size in question
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*/
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ENTRY(__clean_dcache_area_poc)
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/* FALLTHROUGH */
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/*
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* __dma_clean_area(start, size)
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* - start - virtual start address of region
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* - size - size in question
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*/
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__dma_clean_area:
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dcache_by_line_op cvac, sy, x0, x1, x2, x3
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ret
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ENDPIPROC(__clean_dcache_area_poc)
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ENDPROC(__dma_clean_area)
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/*
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* __clean_dcache_area_pop(kaddr, size)
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*
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* Ensure that any D-cache lines for the interval [kaddr, kaddr+size)
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* are cleaned to the PoP.
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*
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* - kaddr - kernel address
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* - size - size in question
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*/
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ENTRY(__clean_dcache_area_pop)
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dcache_by_line_op cvap, sy, x0, x1, x2, x3
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ret
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ENDPIPROC(__clean_dcache_area_pop)
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/*
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* __dma_flush_area(start, size)
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*
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* clean & invalidate D / U line
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*
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* - start - virtual start address of region
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* - size - size in question
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*/
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ENTRY(__dma_flush_area)
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dcache_by_line_op civac, sy, x0, x1, x2, x3
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ret
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ENDPIPROC(__dma_flush_area)
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/*
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* __dma_map_area(start, size, dir)
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* - start - kernel virtual start address
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* - size - size of region
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* - dir - DMA direction
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*/
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ENTRY(__dma_map_area)
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cmp w2, #DMA_FROM_DEVICE
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b.eq __dma_inv_area
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b __dma_clean_area
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ENDPIPROC(__dma_map_area)
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/*
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* __dma_unmap_area(start, size, dir)
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* - start - kernel virtual start address
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* - size - size of region
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* - dir - DMA direction
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*/
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ENTRY(__dma_unmap_area)
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cmp w2, #DMA_TO_DEVICE
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b.ne __dma_inv_area
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ret
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ENDPIPROC(__dma_unmap_area)
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