[PATCH 09/10] platform/x86: ISST: Restore state on resume

From: Srinivas Pandruvada
Date: Wed Jun 26 2019 - 18:39:27 EST


Commands which causes PUNIT writes, store them and restore them on system
resume. The driver stores all such requests in a hash table and stores the
the latest mailbox request parameters. On resume these commands mail box
commands are executed again. There are only 5 such mail box commands which
will trigger such processing so a very low overhead in store and execute
on resume. Also there is no order requirement for mail box commands for
these write/set commands. There is one MSR request for changing turbo
ratio limits, this also stored and get restored on resume and cpu online.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
.../intel_speed_select_if/isst_if_common.c | 154 ++++++++++++++++++
.../intel_speed_select_if/isst_if_common.h | 3 +
.../intel_speed_select_if/isst_if_mbox_msr.c | 38 ++++-
.../intel_speed_select_if/isst_if_mbox_pci.c | 15 ++
.../x86/intel_speed_select_if/isst_if_mmio.c | 49 ++++++
5 files changed, 258 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_common.c b/drivers/platform/x86/intel_speed_select_if/isst_if_common.c
index de2fb5292f1c..68d75391db57 100644
--- a/drivers/platform/x86/intel_speed_select_if/isst_if_common.c
+++ b/drivers/platform/x86/intel_speed_select_if/isst_if_common.c
@@ -10,6 +10,7 @@
#include <linux/cpufeature.h>
#include <linux/cpuhotplug.h>
#include <linux/fs.h>
+#include <linux/hashtable.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/pci.h>
@@ -58,6 +59,151 @@ static const struct isst_cmd_set_req_type isst_cmd_set_reqs[] = {
{0x7F, 0x08, 0x00},
};

+struct isst_cmd {
+ struct hlist_node hnode;
+ u64 data;
+ u32 cmd;
+ int cpu;
+ int mbox_cmd_type;
+ u32 param;
+};
+
+static DECLARE_HASHTABLE(isst_hash, 8);
+static DEFINE_MUTEX(isst_hash_lock);
+
+static int isst_store_new_cmd(int cmd, u32 cpu, int mbox_cmd_type, u32 param,
+ u32 data)
+{
+ struct isst_cmd *sst_cmd;
+
+ sst_cmd = kmalloc(sizeof(*sst_cmd), GFP_KERNEL);
+ if (!sst_cmd)
+ return -ENOMEM;
+
+ sst_cmd->cpu = cpu;
+ sst_cmd->cmd = cmd;
+ sst_cmd->mbox_cmd_type = mbox_cmd_type;
+ sst_cmd->param = param;
+ sst_cmd->data = data;
+
+ hash_add(isst_hash, &sst_cmd->hnode, sst_cmd->cmd);
+
+ return 0;
+}
+
+static void isst_delete_hash(void)
+{
+ struct isst_cmd *sst_cmd;
+ struct hlist_node *tmp;
+ int i;
+
+ hash_for_each_safe(isst_hash, i, tmp, sst_cmd, hnode) {
+ hash_del(&sst_cmd->hnode);
+ kfree(sst_cmd);
+ }
+}
+
+/**
+ * isst_store_cmd() - Store command to a hash table
+ * @cmd: Mailbox command.
+ * @sub_cmd: Mailbox sub-command or MSR id.
+ * @mbox_cmd_type: Mailbox or MSR command.
+ * @param: Mailbox parameter.
+ * @data: Mailbox request data or MSR data.
+ *
+ * Stores the command to a hash table if there is no such command already
+ * stored. If already stored update the latest parameter and data for the
+ * command.
+ *
+ * Return: Return result of store to hash table, 0 for success, others for
+ * failure.
+ */
+int isst_store_cmd(int cmd, int sub_cmd, u32 cpu, int mbox_cmd_type,
+ u32 param, u64 data)
+{
+ struct isst_cmd *sst_cmd;
+ int full_cmd, ret;
+
+ full_cmd = (cmd & GENMASK_ULL(15, 0)) << 16;
+ full_cmd |= (sub_cmd & GENMASK_ULL(15, 0));
+ mutex_lock(&isst_hash_lock);
+ hash_for_each_possible(isst_hash, sst_cmd, hnode, full_cmd) {
+ if (sst_cmd->cmd == full_cmd && sst_cmd->cpu == cpu &&
+ sst_cmd->mbox_cmd_type == mbox_cmd_type) {
+ sst_cmd->param = param;
+ sst_cmd->data = data;
+ mutex_unlock(&isst_hash_lock);
+ return 0;
+ }
+ }
+
+ ret = isst_store_new_cmd(full_cmd, cpu, mbox_cmd_type, param, data);
+ mutex_unlock(&isst_hash_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(isst_store_cmd);
+
+static void isst_mbox_resume_command(struct isst_if_cmd_cb *cb,
+ struct isst_cmd *sst_cmd)
+{
+ struct isst_if_mbox_cmd mbox_cmd;
+ int wr_only;
+
+ mbox_cmd.command = (sst_cmd->cmd & GENMASK_ULL(31, 16)) >> 16;
+ mbox_cmd.sub_command = sst_cmd->cmd & GENMASK_ULL(15, 0);
+ mbox_cmd.parameter = sst_cmd->param;
+ mbox_cmd.req_data = sst_cmd->data;
+ mbox_cmd.logical_cpu = sst_cmd->cpu;
+ (cb->cmd_callback)((u8 *)&mbox_cmd, &wr_only, 1);
+}
+
+/**
+ * isst_resume_common() - Process Resume request
+ *
+ * On resume replay all mailbox commands and MSRs.
+ *
+ * Return: None.
+ */
+void isst_resume_common(void)
+{
+ struct isst_cmd *sst_cmd;
+ int i;
+
+ hash_for_each(isst_hash, i, sst_cmd, hnode) {
+ struct isst_if_cmd_cb *cb;
+
+ if (sst_cmd->mbox_cmd_type) {
+ cb = &punit_callbacks[ISST_IF_DEV_MBOX];
+ if (cb->registered)
+ isst_mbox_resume_command(cb, sst_cmd);
+ } else {
+ wrmsrl_safe_on_cpu(sst_cmd->cpu, sst_cmd->cmd,
+ sst_cmd->data);
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(isst_resume_common);
+
+static void isst_restore_msr_local(int cpu)
+{
+ struct isst_cmd *sst_cmd;
+ int i;
+
+ mutex_lock(&isst_hash_lock);
+ for (i = 0; i < ARRAY_SIZE(punit_msr_white_list); ++i) {
+ if (!punit_msr_white_list[i])
+ break;
+
+ hash_for_each_possible(isst_hash, sst_cmd, hnode,
+ punit_msr_white_list[i]) {
+ if (!sst_cmd->mbox_cmd_type && sst_cmd->cpu == cpu)
+ wrmsrl_safe(sst_cmd->cmd, sst_cmd->data);
+ }
+ }
+ mutex_unlock(&isst_hash_lock);
+}
+
/**
* isst_if_mbox_cmd_invalid() - Check invalid mailbox commands
* @cmd: Pointer to the command structure to verify.
@@ -185,6 +331,8 @@ static int isst_if_cpu_online(unsigned int cpu)
}
isst_cpu_info[cpu].punit_cpu_id = data;

+ isst_restore_msr_local(cpu);
+
return 0;
}

@@ -267,6 +415,10 @@ static long isst_if_msr_cmd_req(u8 *cmd_ptr, int *write_only, int resume)
msr_cmd->msr,
msr_cmd->data);
*write_only = 1;
+ if (!ret && !resume)
+ ret = isst_store_cmd(0, msr_cmd->msr,
+ msr_cmd->logical_cpu,
+ 0, 0, msr_cmd->data);
} else {
u64 data;

@@ -507,6 +659,8 @@ void isst_if_cdev_unregister(int device_type)
mutex_lock(&punit_misc_dev_lock);
misc_usage_count--;
punit_callbacks[device_type].registered = 0;
+ if (device_type == ISST_IF_DEV_MBOX)
+ isst_delete_hash();
if (!misc_usage_count && !misc_device_ret) {
misc_deregister(&isst_if_char_driver);
isst_if_cpu_info_exit();
diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_common.h b/drivers/platform/x86/intel_speed_select_if/isst_if_common.h
index 7c0f71221da7..1409a5bb5582 100644
--- a/drivers/platform/x86/intel_speed_select_if/isst_if_common.h
+++ b/drivers/platform/x86/intel_speed_select_if/isst_if_common.h
@@ -63,4 +63,7 @@ void isst_if_cdev_unregister(int type);
struct pci_dev *isst_if_get_pci_dev(int cpu, int bus, int dev, int fn);
bool isst_if_mbox_cmd_set_req(struct isst_if_mbox_cmd *mbox_cmd);
bool isst_if_mbox_cmd_invalid(struct isst_if_mbox_cmd *cmd);
+int isst_store_cmd(int cmd, int sub_command, u32 cpu, int mbox_cmd,
+ u32 param, u64 data);
+void isst_resume_common(void);
#endif
diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_msr.c b/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_msr.c
index a949ec436c73..afd0b23be5ba 100644
--- a/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_msr.c
+++ b/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_msr.c
@@ -12,6 +12,7 @@
#include <linux/pci.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
+#include <linux/suspend.h>
#include <linux/topology.h>
#include <linux/uaccess.h>
#include <uapi/linux/isst_if.h>
@@ -128,11 +129,37 @@ static long isst_if_mbox_proc_cmd(u8 *cmd_ptr, int *write_only, int resume)
if (ret)
return ret;

+ if (!action.err && !resume && isst_if_mbox_cmd_set_req(action.mbox_cmd))
+ action.err = isst_store_cmd(action.mbox_cmd->command,
+ action.mbox_cmd->sub_command,
+ action.mbox_cmd->logical_cpu, 1,
+ action.mbox_cmd->parameter,
+ action.mbox_cmd->req_data);
*write_only = 0;

return action.err;
}

+
+static int isst_pm_notify(struct notifier_block *nb,
+ unsigned long mode, void *_unused)
+{
+ switch (mode) {
+ case PM_POST_HIBERNATION:
+ case PM_POST_RESTORE:
+ case PM_POST_SUSPEND:
+ isst_resume_common();
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+static struct notifier_block isst_pm_nb = {
+ .notifier_call = isst_pm_notify,
+};
+
#define ICPU(model) { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }

static const struct x86_cpu_id isst_if_cpu_ids[] = {
@@ -166,12 +193,21 @@ static int __init isst_if_mbox_init(void)
cb.offset = offsetof(struct isst_if_mbox_cmds, mbox_cmd);
cb.cmd_callback = isst_if_mbox_proc_cmd;
cb.owner = THIS_MODULE;
- return isst_if_cdev_register(ISST_IF_DEV_MBOX, &cb);
+ ret = isst_if_cdev_register(ISST_IF_DEV_MBOX, &cb);
+ if (ret)
+ return ret;
+
+ ret = register_pm_notifier(&isst_pm_nb);
+ if (ret)
+ isst_if_cdev_unregister(ISST_IF_DEV_MBOX);
+
+ return ret;
}
module_init(isst_if_mbox_init)

static void __exit isst_if_mbox_exit(void)
{
+ unregister_pm_notifier(&isst_pm_nb);
isst_if_cdev_unregister(ISST_IF_DEV_MBOX);
}
module_exit(isst_if_mbox_exit)
diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c b/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c
index f03e79afd3f1..100a76cc27a5 100644
--- a/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c
+++ b/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c
@@ -131,6 +131,12 @@ static long isst_if_mbox_proc_cmd(u8 *cmd_ptr, int *write_only, int resume)
*/
mutex_lock(&punit_dev->mutex);
ret = isst_if_mbox_cmd(pdev, mbox_cmd);
+ if (!ret && !resume && isst_if_mbox_cmd_set_req(mbox_cmd))
+ ret = isst_store_cmd(mbox_cmd->command,
+ mbox_cmd->sub_command,
+ mbox_cmd->logical_cpu, 1,
+ mbox_cmd->parameter,
+ mbox_cmd->req_data);
mutex_unlock(&punit_dev->mutex);
if (ret)
return ret;
@@ -186,11 +192,20 @@ static void isst_if_mbox_remove(struct pci_dev *pdev)
mutex_destroy(&punit_dev->mutex);
}

+static int __maybe_unused isst_if_resume(struct device *device)
+{
+ isst_resume_common();
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(isst_if_pm_ops, NULL, isst_if_resume);
+
static struct pci_driver isst_if_pci_driver = {
.name = "isst_if_mbox_pci",
.id_table = isst_if_mbox_ids,
.probe = isst_if_mbox_probe,
.remove = isst_if_mbox_remove,
+ .driver.pm = &isst_if_pm_ops,
};

module_pci_driver(isst_if_pci_driver);
diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_mmio.c b/drivers/platform/x86/intel_speed_select_if/isst_if_mmio.c
index 1c25a1235b9e..f7266a115a08 100644
--- a/drivers/platform/x86/intel_speed_select_if/isst_if_mmio.c
+++ b/drivers/platform/x86/intel_speed_select_if/isst_if_mmio.c
@@ -15,8 +15,20 @@

#include "isst_if_common.h"

+struct isst_mmio_range {
+ int beg;
+ int end;
+};
+
+struct isst_mmio_range mmio_range[] = {
+ {0x04, 0x14},
+ {0x20, 0xD0},
+};
+
struct isst_if_device {
void __iomem *punit_mmio;
+ u32 range_0[5];
+ u32 range_1[45];
struct mutex mutex;
};

@@ -118,11 +130,48 @@ static void isst_if_remove(struct pci_dev *pdev)
mutex_destroy(&punit_dev->mutex);
}

+static int __maybe_unused isst_if_suspend(struct device *device)
+{
+ struct pci_dev *pdev = to_pci_dev(device);
+ struct isst_if_device *punit_dev;
+ int i;
+
+ punit_dev = pci_get_drvdata(pdev);
+ for (i = 0; i < ARRAY_SIZE(punit_dev->range_0); ++i)
+ punit_dev->range_0[i] = readl(punit_dev->punit_mmio +
+ mmio_range[0].beg + 4 * i);
+ for (i = 0; i < ARRAY_SIZE(punit_dev->range_1); ++i)
+ punit_dev->range_1[i] = readl(punit_dev->punit_mmio +
+ mmio_range[1].beg + 4 * i);
+
+ return 0;
+}
+
+static int __maybe_unused isst_if_resume(struct device *device)
+{
+ struct pci_dev *pdev = to_pci_dev(device);
+ struct isst_if_device *punit_dev;
+ int i;
+
+ punit_dev = pci_get_drvdata(pdev);
+ for (i = 0; i < ARRAY_SIZE(punit_dev->range_0); ++i)
+ writel(punit_dev->range_0[i], punit_dev->punit_mmio +
+ mmio_range[0].beg + 4 * i);
+ for (i = 0; i < ARRAY_SIZE(punit_dev->range_1); ++i)
+ writel(punit_dev->range_1[i], punit_dev->punit_mmio +
+ mmio_range[1].beg + 4 * i);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(isst_if_pm_ops, isst_if_suspend, isst_if_resume);
+
static struct pci_driver isst_if_pci_driver = {
.name = "isst_if_pci",
.id_table = isst_if_ids,
.probe = isst_if_probe,
.remove = isst_if_remove,
+ .driver.pm = &isst_if_pm_ops,
};

module_pci_driver(isst_if_pci_driver);
--
2.17.2