linux-kernel - [PATCH 1/4] thermal: intel: hfi: Refactor enabling code into helper functions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20231227062940.10780-2-ricardo.neri-calderon@linux.intel.com>
Date: Tue, 26 Dec 2023 22:29:37 -0800
From: Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
To: "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>
Cc: Chen Yu <yu.c.chen@...el.com>,
	Len Brown <len.brown@...el.com>,
	Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
	Stanislaw Gruszka <stanislaw.gruszka@...ux.intel.com>,
	Zhang Rui <rui.zhang@...el.com>,
	Zhao Liu <zhao1.liu@...el.com>,
	stable@...r.kernel.org,
	linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>,
	Zhao Liu <zhao1.liu@...ux.intel.com>
Subject: [PATCH 1/4] thermal: intel: hfi: Refactor enabling code into helper functions

In preparation to add a suspend notifier, wrap the logic to enable HFI and
program its memory buffer into helper functions. Both the CPU hotplug
callback and the suspend notifier will use it.

Cc: Chen Yu <yu.c.chen@...el.com>
Cc: Len Brown <len.brown@...el.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Cc: Stanislaw Gruszka <stanislaw.gruszka@...ux.intel.com>
Cc: Zhang Rui <rui.zhang@...el.com>
Cc: Zhao Liu <zhao1.liu@...ux.intel.com>
Cc: linux-pm@...r.kernel.org
Cc: stable@...r.kernel.org
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
---
 drivers/thermal/intel/intel_hfi.c | 46 +++++++++++++++++--------------
 1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/drivers/thermal/intel/intel_hfi.c b/drivers/thermal/intel/intel_hfi.c
index c69db6c90869..87ac7b196981 100644
--- a/drivers/thermal/intel/intel_hfi.c
+++ b/drivers/thermal/intel/intel_hfi.c
@@ -347,6 +347,25 @@ static void init_hfi_instance(struct hfi_instance *hfi_instance)
 	hfi_instance->data = hfi_instance->hdr + hfi_features.hdr_size;
 }
 
+static void hfi_enable(void)
+{
+	u64 msr_val;
+
+	rdmsrl(MSR_IA32_HW_FEEDBACK_CONFIG, msr_val);
+	msr_val |= HW_FEEDBACK_CONFIG_HFI_ENABLE_BIT;
+	wrmsrl(MSR_IA32_HW_FEEDBACK_CONFIG, msr_val);
+}
+
+static void hfi_set_hw_table(struct hfi_instance *hfi_instance)
+{
+	phys_addr_t hw_table_pa;
+	u64 msr_val;
+
+	hw_table_pa = virt_to_phys(hfi_instance->hw_table);
+	msr_val = hw_table_pa | HW_FEEDBACK_PTR_VALID_BIT;
+	wrmsrl(MSR_IA32_HW_FEEDBACK_PTR, msr_val);
+}
+
 /**
  * intel_hfi_online() - Enable HFI on @cpu
  * @cpu:	CPU in which the HFI will be enabled
@@ -364,8 +383,6 @@ void intel_hfi_online(unsigned int cpu)
 {
 	struct hfi_instance *hfi_instance;
 	struct hfi_cpu_info *info;
-	phys_addr_t hw_table_pa;
-	u64 msr_val;
 	u16 die_id;
 
 	/* Nothing to do if hfi_instances are missing. */
@@ -403,14 +420,16 @@ void intel_hfi_online(unsigned int cpu)
 	/*
 	 * Hardware is programmed with the physical address of the first page
 	 * frame of the table. Hence, the allocated memory must be page-aligned.
+	 *
+	 * Some processors do not forget the initial address of the HFI table
+	 * even after having been reprogrammed. Keep using the same pages. Do
+	 * not free them.
 	 */
 	hfi_instance->hw_table = alloc_pages_exact(hfi_features.nr_table_pages,
 						   GFP_KERNEL | __GFP_ZERO);
 	if (!hfi_instance->hw_table)
 		goto unlock;
 
-	hw_table_pa = virt_to_phys(hfi_instance->hw_table);
-
 	/*
 	 * Allocate memory to keep a local copy of the table that
 	 * hardware generates.
@@ -420,16 +439,6 @@ void intel_hfi_online(unsigned int cpu)
 	if (!hfi_instance->local_table)
 		goto free_hw_table;
 
-	/*
-	 * Program the address of the feedback table of this die/package. On
-	 * some processors, hardware remembers the old address of the HFI table
-	 * even after having been reprogrammed and re-enabled. Thus, do not free
-	 * the pages allocated for the table or reprogram the hardware with a
-	 * new base address. Namely, program the hardware only once.
-	 */
-	msr_val = hw_table_pa | HW_FEEDBACK_PTR_VALID_BIT;
-	wrmsrl(MSR_IA32_HW_FEEDBACK_PTR, msr_val);
-
 	init_hfi_instance(hfi_instance);
 
 	INIT_DELAYED_WORK(&hfi_instance->update_work, hfi_update_work_fn);
@@ -438,13 +447,8 @@ void intel_hfi_online(unsigned int cpu)
 
 	cpumask_set_cpu(cpu, hfi_instance->cpus);
 
-	/*
-	 * Enable the hardware feedback interface and never disable it. See
-	 * comment on programming the address of the table.
-	 */
-	rdmsrl(MSR_IA32_HW_FEEDBACK_CONFIG, msr_val);
-	msr_val |= HW_FEEDBACK_CONFIG_HFI_ENABLE_BIT;
-	wrmsrl(MSR_IA32_HW_FEEDBACK_CONFIG, msr_val);
+	hfi_set_hw_table(hfi_instance);
+	hfi_enable();
 
 unlock:
 	mutex_unlock(&hfi_instance_lock);
-- 
2.25.1