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authorLennert Buytenhek <buytenh@wantstofly.org>2008-06-22 22:45:04 +0200
committerLennert Buytenhek <buytenh@marvell.com>2008-06-22 22:45:04 +0200
commit99c6dc117d27d6259214812bd0b113aaf467f600 (patch)
tree0baadd0827fc39f9d2b052305f9447e4b50c5162 /arch/arm/mm/proc-feroceon.S
parent836a8051d54525e0782f156dcfa3c13d30f22840 (diff)
[ARM] Feroceon: L2 cache support
This patch adds support for the unified Feroceon L2 cache controller as found in e.g. the Marvell Kirkwood and Marvell Discovery Duo families of ARM SoCs. Note that: - Page table walks are outer uncacheable on Kirkwood and Discovery Duo, since the ARMv5 spec provides no way to indicate outer cacheability of page table walks (specifying it in TTBR[4:3] is an ARMv6+ feature). This requires adding L2 cache clean instructions to proc-feroceon.S (dcache_clean_area(), set_pte()) as well as to tlbflush.h ({flush,clean}_pmd_entry()). The latter case is handled by defining a new TLB type (TLB_FEROCEON) which is almost identical to the v4wbi one but provides a TLB_L2CLEAN_FR flag. - The Feroceon L2 cache controller supports L2 range (i.e. 'clean L2 range by MVA' and 'invalidate L2 range by MVA') operations, and this patch uses those range operations for all Linux outer cache operations, as they are faster than the regular per-line operations. L2 range operations are not interruptible on this hardware, which avoids potential livelock issues, but can be bad for interrupt latency, so there is a compile-time tunable (MAX_RANGE_SIZE) which allows you to select the maximum range size to operate on at once. (Valid range is between one cache line and one 4KiB page, and must be a multiple of the line size.) Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Diffstat (limited to 'arch/arm/mm/proc-feroceon.S')
-rw-r--r--arch/arm/mm/proc-feroceon.S20
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm/mm/proc-feroceon.S b/arch/arm/mm/proc-feroceon.S
index c279652a98f..cecf96ee07d 100644
--- a/arch/arm/mm/proc-feroceon.S
+++ b/arch/arm/mm/proc-feroceon.S
@@ -79,6 +79,13 @@ ENTRY(cpu_feroceon_proc_fin)
mov ip, #PSR_F_BIT | PSR_I_BIT | SVC_MODE
msr cpsr_c, ip
bl feroceon_flush_kern_cache_all
+
+#if defined(CONFIG_CACHE_FEROCEON_L2) && !defined(CONFIG_L2_CACHE_WRITETHROUGH)
+ mov r0, #0
+ mcr p15, 1, r0, c15, c9, 0 @ clean L2
+ mcr p15, 0, r0, c7, c10, 4 @ drain WB
+#endif
+
mrc p15, 0, r0, c1, c0, 0 @ ctrl register
bic r0, r0, #0x1000 @ ...i............
bic r0, r0, #0x000e @ ............wca.
@@ -382,10 +389,20 @@ ENTRY(feroceon_range_cache_fns)
.align 5
ENTRY(cpu_feroceon_dcache_clean_area)
+#if defined(CONFIG_CACHE_FEROCEON_L2) && !defined(CONFIG_L2_CACHE_WRITETHROUGH)
+ mov r2, r0
+ mov r3, r1
+#endif
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, #CACHE_DLINESIZE
subs r1, r1, #CACHE_DLINESIZE
bhi 1b
+#if defined(CONFIG_CACHE_FEROCEON_L2) && !defined(CONFIG_L2_CACHE_WRITETHROUGH)
+1: mcr p15, 1, r2, c15, c9, 1 @ clean L2 entry
+ add r2, r2, #CACHE_DLINESIZE
+ subs r3, r3, #CACHE_DLINESIZE
+ bhi 1b
+#endif
mcr p15, 0, r0, c7, c10, 4 @ drain WB
mov pc, lr
@@ -449,6 +466,9 @@ ENTRY(cpu_feroceon_set_pte_ext)
str r2, [r0] @ hardware version
mov r0, r0
mcr p15, 0, r0, c7, c10, 1 @ clean D entry
+#if defined(CONFIG_CACHE_FEROCEON_L2) && !defined(CONFIG_L2_CACHE_WRITETHROUGH)
+ mcr p15, 1, r0, c15, c9, 1 @ clean L2 entry
+#endif
mcr p15, 0, r0, c7, c10, 4 @ drain WB
#endif
mov pc, lr