[PATCH 1/2] arm_mpam: Force __iomem casts
From: Krzysztof Kozlowski <hidden>
Date: 2026-02-16 11:02:49
Also in:
lkml
Subsystem:
mpam driver, the rest · Maintainers:
James Morse, Ben Horgan, Linus Torvalds
Code allocates standard kernel memory to pass to the MPAM, which expects __iomem. The code is safe, because __iomem accessors should work fine on kernel mapped memory, however leads to sparse warnings: test_mpam_devices.c:327:42: warning: incorrect type in initializer (different address spaces) test_mpam_devices.c:327:42: expected char [noderef] __iomem *buf test_mpam_devices.c:327:42: got void * test_mpam_devices.c:342:24: warning: cast removes address space '__iomem' of expression Cast the pointer to memory via __force to silence them. Signed-off-by: Krzysztof Kozlowski <redacted> --- drivers/resctrl/test_mpam_devices.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/resctrl/test_mpam_devices.c b/drivers/resctrl/test_mpam_devices.c
index 3e8d564a0c64..2de41b47c138 100644
--- a/drivers/resctrl/test_mpam_devices.c
+++ b/drivers/resctrl/test_mpam_devices.c@@ -324,7 +324,7 @@ static void test_mpam_enable_merge_features(struct kunit *test) static void test_mpam_reset_msc_bitmap(struct kunit *test) { - char __iomem *buf = kunit_kzalloc(test, SZ_16K, GFP_KERNEL); + char __iomem *buf = (__force char __iomem *)kunit_kzalloc(test, SZ_16K, GFP_KERNEL); struct mpam_msc fake_msc = {}; u32 *test_result;
@@ -339,7 +339,7 @@ static void test_mpam_reset_msc_bitmap(struct kunit *test) mutex_init(&fake_msc.part_sel_lock); mutex_lock(&fake_msc.part_sel_lock); - test_result = (u32 *)(buf + MPAMCFG_CPBM); + test_result = (__force u32 *)(buf + MPAMCFG_CPBM); mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 0); KUNIT_EXPECT_EQ(test, test_result[0], 0);
--
2.51.0