[PATCH 5.5 254/399] vme: bridges: reduce stack usage

Greg Kroah-Hartman
2020-02-21T07:54:35Z

From: Arnd Bergmann <arnd@arndb.de>

[ Upstream commit 7483e7a939c074d887450ef1c4d9ccc5909405f8 ]

With CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3, the stack usage in vme_fake
grows above the warning limit:

drivers/vme/bridges/vme_fake.c: In function 'fake_master_read':
drivers/vme/bridges/vme_fake.c:610:1: error: the frame size of 1160 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
drivers/vme/bridges/vme_fake.c: In function 'fake_master_write':
drivers/vme/bridges/vme_fake.c:797:1: error: the frame size of 1160 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

The problem is that in some configurations, each call to
fake_vmereadX() puts another variable on the stack.

Reduce the amount of inlining to get back to the previous state,
with no function using more than 200 bytes each.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200107200610.3482901-1-arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/vme/bridges/vme_fake.c | 30 ++++++++++++++++++------------
1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/drivers/vme/bridges/vme_fake.c b/drivers/vme/bridges/vme_fake.c
index 3208a4409e44e..6a1bc284f297c 100644
--- a/drivers/vme/bridges/vme_fake.c
+++ b/drivers/vme/bridges/vme_fake.c
@@ -414,8 +414,9 @@ static void fake_lm_check(struct fake_driver *bridge, unsigned long long addr,
}
}

-static u8 fake_vmeread8(struct fake_driver *bridge, unsigned long long addr,
- u32 aspace, u32 cycle)
+static noinline_for_stack u8 fake_vmeread8(struct fake_driver *bridge,
+ unsigned long long addr,
+ u32 aspace, u32 cycle)
{
u8 retval = 0xff;
int i;
@@ -446,8 +447,9 @@ static u8 fake_vmeread8(struct fake_driver *bridge, unsigned long long addr,
return retval;
}

-static u16 fake_vmeread16(struct fake_driver *bridge, unsigned long long addr,
- u32 aspace, u32 cycle)
+static noinline_for_stack u16 fake_vmeread16(struct fake_driver *bridge,
+ unsigned long long addr,
+ u32 aspace, u32 cycle)
{
u16 retval = 0xffff;
int i;
@@ -478,8 +480,9 @@ static u16 fake_vmeread16(struct fake_driver *bridge, unsigned long long addr,
return retval;
}

-static u32 fake_vmeread32(struct fake_driver *bridge, unsigned long long addr,
- u32 aspace, u32 cycle)
+static noinline_for_stack u32 fake_vmeread32(struct fake_driver *bridge,
+ unsigned long long addr,
+ u32 aspace, u32 cycle)
{
u32 retval = 0xffffffff;
int i;
@@ -609,8 +612,9 @@ out:
return retval;
}

-static void fake_vmewrite8(struct fake_driver *bridge, u8 *buf,
- unsigned long long addr, u32 aspace, u32 cycle)
+static noinline_for_stack void fake_vmewrite8(struct fake_driver *bridge,
+ u8 *buf, unsigned long long addr,
+ u32 aspace, u32 cycle)
{
int i;
unsigned long long start, end, offset;
@@ -639,8 +643,9 @@ static void fake_vmewrite8(struct fake_driver *bridge, u8 *buf,

}

-static void fake_vmewrite16(struct fake_driver *bridge, u16 *buf,
- unsigned long long addr, u32 aspace, u32 cycle)
+static noinline_for_stack void fake_vmewrite16(struct fake_driver *bridge,
+ u16 *buf, unsigned long long addr,
+ u32 aspace, u32 cycle)
{
int i;
unsigned long long start, end, offset;
@@ -669,8 +674,9 @@ static void fake_vmewrite16(struct fake_driver *bridge, u16 *buf,

}

-static void fake_vmewrite32(struct fake_driver *bridge, u32 *buf,
- unsigned long long addr, u32 aspace, u32 cycle)
+static noinline_for_stack void fake_vmewrite32(struct fake_driver *bridge,
+ u32 *buf, unsigned long long addr,
+ u32 aspace, u32 cycle)
{
int i;
unsigned long long start, end, offset;
--
2.20.1