diff options
Diffstat (limited to 'bsp/meta-synopsys/recipes-kernel/linux/linux-arc/0006-devres-Really-align-data-field-to-unsigned-long-long.patch')
| -rw-r--r-- | bsp/meta-synopsys/recipes-kernel/linux/linux-arc/0006-devres-Really-align-data-field-to-unsigned-long-long.patch | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/bsp/meta-synopsys/recipes-kernel/linux/linux-arc/0006-devres-Really-align-data-field-to-unsigned-long-long.patch b/bsp/meta-synopsys/recipes-kernel/linux/linux-arc/0006-devres-Really-align-data-field-to-unsigned-long-long.patch new file mode 100644 index 00000000..349f729c --- /dev/null +++ b/bsp/meta-synopsys/recipes-kernel/linux/linux-arc/0006-devres-Really-align-data-field-to-unsigned-long-long.patch @@ -0,0 +1,42 @@ +From 0b124e661d4dbb1b04031cc37c0359f7344d1bfb Mon Sep 17 00:00:00 2001 +From: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> +Date: Wed, 10 Oct 2018 18:53:14 +0300 +Subject: [PATCH 6/7] devres: Really align data field to unsigned long long + +It looks like on most of architectures "data" member of devres struture +gets aligned to 8-byte "unsigned long long" boundary as one may expect: +if we don't explicitly pack a structure then natural alignment +(which matches each member data type) is used. + +But at least on 32-bit ARC architecture ABI requires "long long" types +to be aligned by normal 32-bit word. This makes "data" field aligned to +12 bytes. This is still OK as long as we use 32-bit data only. + +But once we want to use native atomic64_t type (i.e. when we use special +instructions LLOCKD/SCONDD for accessing 64-bit data) we easily hit +misaligned access exception. + +That's because even on CPUs capable of non-aligned data access LL/SC +instructions require strict alignment. + +Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> +--- + drivers/base/devres.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/drivers/base/devres.c b/drivers/base/devres.c +index f98a097e73f2..1a444f043c68 100644 +--- a/drivers/base/devres.c ++++ b/drivers/base/devres.c +@@ -25,7 +25,7 @@ struct devres_node { + struct devres { + struct devres_node node; + /* -- 3 pointers */ +- unsigned long long data[]; /* guarantee ull alignment */ ++ unsigned long long data[] __aligned(sizeof(unsigned long long)); /* guarantee ull alignment */ + }; + + struct devres_group { +-- +2.16.2 + |