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[ARM] 3814/1: move 80200 dma_inv_range() erratum check out of line
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On stepping A0/A1 of the 80200, invalidating D-cache by line doesn't
clear the dirty bits, which means that if we invalidate a dirty line,
the dirty data can still be written back to memory later on.

To work around this, dma_inv_range() on these two processors is
implemented as dma_flush_range() (i.e. do a clean D-cache line before
doing the invalidate D-cache line.)  For this, we currently have a
processor ID check in xscale_dma_inv_range(), but a better solution
is to add a separate cache_fns and proc_info for A0/A1 80200.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Lennert Buytenhek authored and Russell King committed Sep 25, 2006
1 parent 51635ad commit 197c944
Showing 1 changed file with 52 additions and 6 deletions.
58 changes: 52 additions & 6 deletions arch/arm/mm/proc-xscale.S
Original file line number Diff line number Diff line change
Expand Up @@ -311,12 +311,6 @@ ENTRY(xscale_flush_kern_dcache_page)
* - end - virtual end address
*/
ENTRY(xscale_dma_inv_range)
mrc p15, 0, r2, c0, c0, 0 @ read ID
eor r2, r2, #0x69000000
eor r2, r2, #0x00052000
bics r2, r2, #1
beq xscale_dma_flush_range

tst r0, #CACHELINESIZE - 1
bic r0, r0, #CACHELINESIZE - 1
mcrne p15, 0, r0, c7, c10, 1 @ clean D entry
Expand Down Expand Up @@ -375,6 +369,30 @@ ENTRY(xscale_cache_fns)
.long xscale_dma_clean_range
.long xscale_dma_flush_range

/*
* On stepping A0/A1 of the 80200, invalidating D-cache by line doesn't
* clear the dirty bits, which means that if we invalidate a dirty line,
* the dirty data can still be written back to external memory later on.
*
* The recommended workaround is to always do a clean D-cache line before
* doing an invalidate D-cache line, so on the affected processors,
* dma_inv_range() is implemented as dma_flush_range().
*
* See erratum #25 of "Intel 80200 Processor Specification Update",
* revision January 22, 2003, available at:
* http://www.intel.com/design/iio/specupdt/273415.htm
*/
ENTRY(xscale_80200_A0_A1_cache_fns)
.long xscale_flush_kern_cache_all
.long xscale_flush_user_cache_all
.long xscale_flush_user_cache_range
.long xscale_coherent_kern_range
.long xscale_coherent_user_range
.long xscale_flush_kern_dcache_page
.long xscale_dma_flush_range
.long xscale_dma_clean_range
.long xscale_dma_flush_range

ENTRY(cpu_xscale_dcache_clean_area)
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, #CACHELINESIZE
Expand Down Expand Up @@ -531,6 +549,11 @@ cpu_elf_name:
.asciz "v5"
.size cpu_elf_name, . - cpu_elf_name

.type cpu_80200_A0_A1_name, #object
cpu_80200_A0_A1_name:
.asciz "XScale-80200 A0/A1"
.size cpu_80200_A0_A1_name, . - cpu_80200_A0_A1_name

.type cpu_80200_name, #object
cpu_80200_name:
.asciz "XScale-80200"
Expand Down Expand Up @@ -595,6 +618,29 @@ cpu_pxa270_name:

.section ".proc.info.init", #alloc, #execinstr

.type __80200_A0_A1_proc_info,#object
__80200_A0_A1_proc_info:
.long 0x69052000
.long 0xfffffffe
.long PMD_TYPE_SECT | \
PMD_SECT_BUFFERABLE | \
PMD_SECT_CACHEABLE | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
.long PMD_TYPE_SECT | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
b __xscale_setup
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP
.long cpu_80200_name
.long xscale_processor_functions
.long v4wbi_tlb_fns
.long xscale_mc_user_fns
.long xscale_80200_A0_A1_cache_fns
.size __80200_A0_A1_proc_info, . - __80200_A0_A1_proc_info

.type __80200_proc_info,#object
__80200_proc_info:
.long 0x69052000
Expand Down

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