Hi Shaokun,
On 9/5/19 10:37 AM, Shaokun Zhang wrote:
Hi Kyrill,
On 2019/9/3 19:13, Kyrill Tkachov wrote:
Hi Shaokun,
On 9/3/19 9:35 AM, Shaokun Zhang wrote:
The DCache clean & ICache invalidation requirements for instructions
to be data coherence are discoverable through new fields in CTR_EL0.
Let's support the two bits if they are enabled, the CPU core will
not execute the unnecessary DCache clean or Icache Invalidation
instructions.
2019-09-03 Shaokun Zhang <zhangshao...@hisilicon.com>
* config/aarch64/sync-cache.c: Support CTR_EL0.IDC and CTR_EL0.DIC in
__aarch64_sync_cache_range function.
This version looks ok to me. I've checked the assembly generated for
sync-cache.c and it looks as expected.
Can you please confirm that you've bootstrapped and tested this patch on an
aarch64 system?
Sorry to reply later.
I have bootstrapped and also check the
prev-aarch64-unknown-linux-gnu/libgcc/sync-cache.o file.
It has been compiled the patch.
About the test, I run the self-modify testcase which calls __clear_cache
directly,
and use the new GCC to compile it, it works ok on both Huawei Kunpeng 920
server whose cpu
is HiSilicon tsv110 core and HiSilicon D05 server board which uses A72 core.
Thanks, that looks good to me now.
Kyrill
Thanks,
Shaokun
Thanks,
Kyrill
---
libgcc/config/aarch64/sync-cache.c | 57 ++++++++++++++++++++++++--------------
1 file changed, 36 insertions(+), 21 deletions(-)
diff --git a/libgcc/config/aarch64/sync-cache.c
b/libgcc/config/aarch64/sync-cache.c
index 791f5e42ff44..ea3da4be02b3 100644
--- a/libgcc/config/aarch64/sync-cache.c
+++ b/libgcc/config/aarch64/sync-cache.c
@@ -23,6 +23,9 @@ a copy of the GCC Runtime Library Exception along with this
program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
+#define CTR_IDC_SHIFT 28
+#define CTR_DIC_SHIFT 29
+
void __aarch64_sync_cache_range (const void *, const void *);
void
@@ -41,32 +44,44 @@ __aarch64_sync_cache_range (const void *base, const void
*end)
icache_lsize = 4 << (cache_info & 0xF);
dcache_lsize = 4 << ((cache_info >> 16) & 0xF);
- /* Loop over the address range, clearing one cache line at once.
- Data cache must be flushed to unification first to make sure the
- instruction cache fetches the updated data. 'end' is exclusive,
- as per the GNU definition of __clear_cache. */
+ /* If CTR_EL0.IDC is enabled, Data cache clean to the Point of Unification is
+ not required for instruction to data coherence. */
+
+ if (((cache_info >> CTR_IDC_SHIFT) & 0x1) == 0x0) {
+ /* Loop over the address range, clearing one cache line at once.
+ Data cache must be flushed to unification first to make sure the
+ instruction cache fetches the updated data. 'end' is exclusive,
+ as per the GNU definition of __clear_cache. */
- /* Make the start address of the loop cache aligned. */
- address = (const char*) ((__UINTPTR_TYPE__) base
- & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
+ /* Make the start address of the loop cache aligned. */
+ address = (const char*) ((__UINTPTR_TYPE__) base
+ & ~ (__UINTPTR_TYPE__) (dcache_lsize - 1));
- for (; address < (const char *) end; address += dcache_lsize)
- asm volatile ("dc\tcvau, %0"
- :
- : "r" (address)
- : "memory");
+ for (; address < (const char *) end; address += dcache_lsize)
+ asm volatile ("dc\tcvau, %0"
+ :
+ : "r" (address)
+ : "memory");
+ }
asm volatile ("dsb\tish" : : : "memory");
- /* Make the start address of the loop cache aligned. */
- address = (const char*) ((__UINTPTR_TYPE__) base
- & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
+ /* If CTR_EL0.DIC is enabled, Instruction cache cleaning to the Point of
+ Unification is not required for instruction to data coherence. */
+
+ if (((cache_info >> CTR_DIC_SHIFT) & 0x1) == 0x0) {
+ /* Make the start address of the loop cache aligned. */
+ address = (const char*) ((__UINTPTR_TYPE__) base
+ & ~ (__UINTPTR_TYPE__) (icache_lsize - 1));
+
+ for (; address < (const char *) end; address += icache_lsize)
+ asm volatile ("ic\tivau, %0"
+ :
+ : "r" (address)
+ : "memory");
- for (; address < (const char *) end; address += icache_lsize)
- asm volatile ("ic\tivau, %0"
- :
- : "r" (address)
- : "memory");
+ asm volatile ("dsb\tish" : : : "memory");
+ }
- asm volatile ("dsb\tish; isb" : : : "memory");
+ asm volatile("isb" : : : "memory");
}
--
2.7.4
.
