[PATCH v2 04/15] arm_mpam: propagate MSC read errors for mpam_msc_read_mbwu_l()
From: Andre Przywara <andre.przywara@arm.com>
Date: 2026-07-02 16:23:07
Also in:
linux-acpi, lkml
Subsystem:
mpam driver, the rest · Maintainers:
James Morse, Ben Horgan, Linus Torvalds
Allow the mpam_msc_read_mbwu_l() function to return an error, and propagate read errors from the lower level up. Signed-off-by: Andre Przywara <andre.przywara@arm.com> --- drivers/resctrl/mpam_devices.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 011d1e3544d7..1d06902fb970 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c@@ -1106,6 +1106,7 @@ static bool mpam_ris_has_mbwu_long_counter(struct mpam_msc_ris *ris) static u64 mpam_msc_read_mbwu_l(struct mpam_msc *msc) { + int ret; int retry = 3; u32 mbwu_l_low; u32 mbwu_l_high1, mbwu_l_high2;
@@ -1115,11 +1116,17 @@ static u64 mpam_msc_read_mbwu_l(struct mpam_msc *msc) WARN_ON_ONCE((MSMON_MBWU_L + sizeof(u64)) > msc->mapped_hwpage_sz); WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility)); - __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); + ret = __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); + if (ret) + return MSMON___L_NRDY; + do { mbwu_l_high1 = mbwu_l_high2; - __mpam_read_reg(msc, MSMON_MBWU_L, &mbwu_l_low); - __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); + ret = __mpam_read_reg(msc, MSMON_MBWU_L, &mbwu_l_low); + if (!ret) + ret = __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); + if (ret) + return MSMON___L_NRDY; retry--; } while (mbwu_l_high1 != mbwu_l_high2 && retry > 0);
--
2.43.0