From: Huacai Chen <chenhuacai@loongson.cn>
To: Arnd Bergmann <arnd@arndb.de>, Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
David Airlie <airlied@linux.ie>, Jonathan Corbet <corbet@lwn.net>,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, Xuefeng Li <lixuefeng@loongson.cn>,
Yanteng Si <siyanteng@loongson.cn>,
Huacai Chen <chenhuacai@gmail.com>, Guo Ren <guoren@kernel.org>,
Xuerui Wang <kernel@xen0n.name>,
Jiaxun Yang <jiaxun.yang@flygoat.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Huacai Chen <chenhuacai@loongson.cn>,
dri-devel@lists.freedesktop.org, WANG Xuerui <git@xen0n.name>
Subject: [PATCH V11 04/22] LoongArch: Add writecombine support for drm
Date: Wed, 18 May 2022 17:26:01 +0800 [thread overview]
Message-ID: <20220518092619.1269111-5-chenhuacai@loongson.cn> (raw)
In-Reply-To: <20220518092619.1269111-1-chenhuacai@loongson.cn>
LoongArch maintains cache coherency in hardware, but its WUC attribute
(Weak-ordered UnCached, which is similar to WC) is out of the scope of
cache coherency machanism. This means WUC can only used for write-only
memory regions.
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
drivers/gpu/drm/drm_vm.c | 2 +-
drivers/gpu/drm/ttm/ttm_module.c | 2 +-
include/drm/drm_cache.h | 8 ++++++++
3 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
index e957d4851dc0..f024dc93939e 100644
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -69,7 +69,7 @@ static pgprot_t drm_io_prot(struct drm_local_map *map,
pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
#if defined(__i386__) || defined(__x86_64__) || defined(__powerpc__) || \
- defined(__mips__)
+ defined(__mips__) || defined(__loongarch__)
if (map->type == _DRM_REGISTERS && !(map->flags & _DRM_WRITE_COMBINING))
tmp = pgprot_noncached(tmp);
else
diff --git a/drivers/gpu/drm/ttm/ttm_module.c b/drivers/gpu/drm/ttm/ttm_module.c
index a3ad7c9736ec..b3fffe7b5062 100644
--- a/drivers/gpu/drm/ttm/ttm_module.c
+++ b/drivers/gpu/drm/ttm/ttm_module.c
@@ -74,7 +74,7 @@ pgprot_t ttm_prot_from_caching(enum ttm_caching caching, pgprot_t tmp)
#endif /* CONFIG_UML */
#endif /* __i386__ || __x86_64__ */
#if defined(__ia64__) || defined(__arm__) || defined(__aarch64__) || \
- defined(__powerpc__) || defined(__mips__)
+ defined(__powerpc__) || defined(__mips__) || defined(__loongarch__)
if (caching == ttm_write_combined)
tmp = pgprot_writecombine(tmp);
else
diff --git a/include/drm/drm_cache.h b/include/drm/drm_cache.h
index 22deb216b59c..08e0e3ffad13 100644
--- a/include/drm/drm_cache.h
+++ b/include/drm/drm_cache.h
@@ -67,6 +67,14 @@ static inline bool drm_arch_can_wc_memory(void)
* optimization entirely for ARM and arm64.
*/
return false;
+#elif defined(CONFIG_LOONGARCH)
+ /*
+ * LoongArch maintains cache coherency in hardware, but its WUC attribute
+ * (Weak-ordered UnCached, which is similar to WC) is out of the scope of
+ * cache coherency machanism. This means WUC can only used for write-only
+ * memory regions.
+ */
+ return false;
#else
return true;
#endif
--
2.27.0
next prev parent reply other threads:[~2022-05-18 9:30 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-18 9:25 [PATCH V11 00/22] arch: Add basic LoongArch support Huacai Chen
2022-05-18 9:25 ` [PATCH V11 01/22] Documentation: LoongArch: Add basic documentations Huacai Chen
2022-05-18 15:34 ` WANG Xuerui
2022-05-18 9:25 ` [PATCH V11 02/22] Documentation/zh_CN: Add basic LoongArch documentations Huacai Chen
2022-05-18 15:32 ` WANG Xuerui
2022-05-20 7:37 ` Guo Ren
2022-05-20 7:43 ` WANG Xuerui
2022-05-18 9:26 ` [PATCH V11 03/22] LoongArch: Add ELF-related definitions Huacai Chen
2022-05-18 9:26 ` Huacai Chen [this message]
2022-05-18 9:26 ` [PATCH V11 05/22] LoongArch: Add build infrastructure Huacai Chen
2022-05-18 15:22 ` WANG Xuerui
2022-05-20 7:25 ` Guo Ren
2022-05-18 9:26 ` [PATCH V11 06/22] LoongArch: Add CPU definition headers Huacai Chen
2022-05-18 15:45 ` WANG Xuerui
2022-05-18 16:12 ` Huacai Chen
2022-05-18 9:26 ` [PATCH V11 07/22] LoongArch: Add atomic/locking headers Huacai Chen
2022-05-18 15:54 ` WANG Xuerui
2022-05-20 7:54 ` Guo Ren
2022-05-20 9:50 ` Huacai Chen
2022-05-20 18:14 ` Guo Ren
2022-05-21 1:55 ` Huacai Chen
2022-05-18 9:26 ` [PATCH V11 08/22] LoongArch: Add other common headers Huacai Chen
2022-05-18 16:04 ` WANG Xuerui
2022-05-18 9:26 ` [PATCH V11 09/22] LoongArch: Add boot and setup routines Huacai Chen
2022-05-18 15:17 ` WANG Xuerui
2022-05-18 16:08 ` Huacai Chen
2022-05-20 9:17 ` Ard Biesheuvel
2022-05-20 9:41 ` Javier Martinez Canillas
2022-05-20 14:09 ` Huacai Chen
2022-05-20 14:23 ` Javier Martinez Canillas
2022-05-20 15:19 ` Huacai Chen
2022-05-20 16:32 ` Javier Martinez Canillas
2022-05-21 1:40 ` Huacai Chen
2022-05-21 7:06 ` Javier Martinez Canillas
2022-05-21 7:37 ` Huacai Chen
2022-05-21 9:06 ` Javier Martinez Canillas
2022-05-21 9:13 ` Huacai Chen
2022-05-21 9:43 ` Javier Martinez Canillas
2022-05-20 15:53 ` Huacai Chen
2022-05-24 8:27 ` Xi Ruoyao
2022-05-24 10:59 ` Huacai Chen
2022-05-24 12:48 ` 李超
2022-05-18 9:26 ` [PATCH V11 10/22] LoongArch: Add exception/interrupt handling Huacai Chen
2022-05-18 9:26 ` [PATCH V11 11/22] LoongArch: Add process management Huacai Chen
2022-05-18 9:26 ` [PATCH V11 12/22] LoongArch: Add memory management Huacai Chen
2022-05-18 9:26 ` [PATCH V11 13/22] LoongArch: Add system call support Huacai Chen
2022-05-18 9:26 ` [PATCH V11 14/22] LoongArch: Add signal handling support Huacai Chen
2022-05-18 16:13 ` WANG Xuerui
2022-05-18 16:39 ` Eric W. Biederman
2022-05-18 16:54 ` Huacai Chen
2022-05-18 17:17 ` WANG Xuerui
2022-05-18 9:26 ` [PATCH V11 15/22] LoongArch: Add ELF and module support Huacai Chen
2022-05-18 9:26 ` [PATCH V11 16/22] LoongArch: Add misc common routines Huacai Chen
2022-05-18 9:57 ` [PATCH V11 17/22] LoongArch: Add some library functions Huacai Chen
2022-05-18 9:57 ` [PATCH V11 18/22] LoongArch: Add PCI controller support Huacai Chen
2022-05-18 9:57 ` [PATCH V11 19/22] LoongArch: Add VDSO and VSYSCALL support Huacai Chen
2022-05-18 9:57 ` [PATCH V11 20/22] LoongArch: Add multi-processor (SMP) support Huacai Chen
2022-05-18 9:57 ` [PATCH V11 21/22] LoongArch: Add Non-Uniform Memory Access (NUMA) support Huacai Chen
2022-05-18 9:57 ` [PATCH V11 22/22] LoongArch: Add Loongson-3 default config file Huacai Chen
2022-05-18 13:42 ` [PATCH V11 00/22] arch: Add basic LoongArch support Arnd Bergmann
2022-05-18 17:18 ` Huacai Chen
2022-05-18 22:36 ` Stephen Rothwell
2022-05-22 4:18 ` WANG Xuerui
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