6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ricardo Neri ricardo.neri-calderon@linux.intel.com
[ Upstream commit 97566d09fd02d2ab329774bb89a2cdf2267e86d9 ]
The kernel allocates a memory buffer and provides its location to the hardware, which uses it to update the HFI table. This allocation occurs during boot and remains constant throughout runtime.
When resuming from hibernation, the restore kernel allocates a second memory buffer and reprograms the HFI hardware with the new location as part of a normal boot. The location of the second memory buffer may differ from the one allocated by the image kernel.
When the restore kernel transfers control to the image kernel, its HFI buffer becomes invalid, potentially leading to memory corruption if the hardware writes to it (the hardware continues to use the buffer from the restore kernel).
It is also possible that the hardware "forgets" the address of the memory buffer when resuming from "deep" suspend. Memory corruption may also occur in such a scenario.
To prevent the described memory corruption, disable HFI when preparing to suspend or hibernate. Enable it when resuming.
Add syscore callbacks to handle the package of the boot CPU (packages of non-boot CPUs are handled via CPU offline). Syscore ops always run on the boot CPU. Additionally, HFI only needs to be disabled during "deep" suspend and hibernation. Syscore ops only run in these cases.
Cc: 6.1+ stable@vger.kernel.org # 6.1+ Signed-off-by: Ricardo Neri ricardo.neri-calderon@linux.intel.com [ rjw: Comment adjustment, subject and changelog edits ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/thermal/intel/intel_hfi.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/drivers/thermal/intel/intel_hfi.c b/drivers/thermal/intel/intel_hfi.c index bb25c75acd45..1c5a429b2e3e 100644 --- a/drivers/thermal/intel/intel_hfi.c +++ b/drivers/thermal/intel/intel_hfi.c @@ -35,7 +35,9 @@ #include <linux/processor.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/suspend.h> #include <linux/string.h> +#include <linux/syscore_ops.h> #include <linux/topology.h> #include <linux/workqueue.h>
@@ -568,6 +570,30 @@ static __init int hfi_parse_features(void) return 0; }
+static void hfi_do_enable(void) +{ + /* This code runs only on the boot CPU. */ + struct hfi_cpu_info *info = &per_cpu(hfi_cpu_info, 0); + struct hfi_instance *hfi_instance = info->hfi_instance; + + /* No locking needed. There is no concurrency with CPU online. */ + hfi_set_hw_table(hfi_instance); + hfi_enable(); +} + +static int hfi_do_disable(void) +{ + /* No locking needed. There is no concurrency with CPU offline. */ + hfi_disable(); + + return 0; +} + +static struct syscore_ops hfi_pm_ops = { + .resume = hfi_do_enable, + .suspend = hfi_do_disable, +}; + void __init intel_hfi_init(void) { struct hfi_instance *hfi_instance; @@ -599,6 +625,8 @@ void __init intel_hfi_init(void) if (!hfi_updates_wq) goto err_nomem;
+ register_syscore_ops(&hfi_pm_ops); + return;
err_nomem: