scsi: hisi_sas: Alloc debugfs snapshot buffer memory for all registers

This patch allocates snapshot memory for global reg, port regs, CQ, DQ,
IOST, ITCT.

When we fail to allocate memory for some registers, we free the memory
and set hisi_sas_debugfs_enable as 0 to stop loading debugfs from running.
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hisi_sas/hisi_sas.h

@@ -221,6 +221,10 @@ struct hisi_sas_slot {
 	u16	idx;
 };
 
+struct hisi_sas_debugfs_reg {
+	int count;
+};
+
 struct hisi_sas_hw {
 	int (*hw_init)(struct hisi_hba *hisi_hba);
 	void (*setup_itct)(struct hisi_hba *hisi_hba,
@@ -265,6 +269,9 @@ struct hisi_sas_hw {
 	int max_command_entries;
 	int complete_hdr_size;
 	struct scsi_host_template *sht;
+
+	const struct hisi_sas_debugfs_reg *debugfs_reg_global;
+	const struct hisi_sas_debugfs_reg *debugfs_reg_port;
 };
 
 struct hisi_hba {
@@ -334,6 +341,14 @@ struct hisi_hba {
 	u32 intr_coal_ticks;	/* Time of interrupt coalesce in us */
 	u32 intr_coal_count;	/* Interrupt count to coalesce */
 
+	/* debugfs memories */
+	void *debugfs_global_reg;
+	void *debugfs_port_reg[HISI_SAS_MAX_PHYS];
+	void *debugfs_complete_hdr[HISI_SAS_MAX_QUEUES];
+	struct hisi_sas_cmd_hdr	*debugfs_cmd_hdr[HISI_SAS_MAX_QUEUES];
+	struct hisi_sas_iost *debugfs_iost;
+	struct hisi_sas_itct *debugfs_itct;
+
 	struct dentry *debugfs_dir;
 };
 

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -2461,10 +2461,86 @@ struct dentry *hisi_sas_debugfs_dir;
 
 void hisi_sas_debugfs_init(struct hisi_hba *hisi_hba)
 {
+	int max_command_entries = hisi_hba->hw->max_command_entries;
 	struct device *dev = hisi_hba->dev;
+	int p, i, c, d;
+	size_t sz;
 
 	hisi_hba->debugfs_dir = debugfs_create_dir(dev_name(dev),
 						   hisi_sas_debugfs_dir);
+
+	if (!hisi_hba->debugfs_dir)
+		return;
+
+	/* Alloc buffer for global */
+	sz = hisi_hba->hw->debugfs_reg_global->count * 4;
+	hisi_hba->debugfs_global_reg =
+		devm_kmalloc(dev, sz, GFP_KERNEL);
+
+	if (!hisi_hba->debugfs_global_reg)
+		goto fail_global;
+
+	/* Alloc buffer for port */
+	sz = hisi_hba->hw->debugfs_reg_port->count * 4;
+	for (p = 0; p < hisi_hba->n_phy; p++) {
+		hisi_hba->debugfs_port_reg[p] =
+			devm_kmalloc(dev, sz, GFP_KERNEL);
+
+		if (!hisi_hba->debugfs_port_reg[p])
+			goto fail_port;
+	}
+
+	/* Alloc buffer for cq */
+	sz = hisi_hba->hw->complete_hdr_size * HISI_SAS_QUEUE_SLOTS;
+	for (c = 0; c < hisi_hba->queue_count; c++) {
+		hisi_hba->debugfs_complete_hdr[c] =
+			devm_kmalloc(dev, sz, GFP_KERNEL);
+
+		if (!hisi_hba->debugfs_complete_hdr[c])
+			goto fail_cq;
+	}
+
+	/* Alloc buffer for dq */
+	sz = hisi_hba->hw->complete_hdr_size * HISI_SAS_QUEUE_SLOTS;
+	for (d = 0; d < hisi_hba->queue_count; d++) {
+		hisi_hba->debugfs_cmd_hdr[d] =
+			devm_kmalloc(dev, sz, GFP_KERNEL);
+
+		if (!hisi_hba->debugfs_cmd_hdr[d])
+			goto fail_iost_dq;
+	}
+
+	/* Alloc buffer for iost */
+	sz = max_command_entries * sizeof(struct hisi_sas_iost);
+
+	hisi_hba->debugfs_iost = devm_kmalloc(dev, sz, GFP_KERNEL);
+	if (!hisi_hba->debugfs_iost)
+		goto fail_iost_dq;
+
+	/* Alloc buffer for itct */
+	/* New memory allocation must be locate before itct */
+	sz = HISI_SAS_MAX_ITCT_ENTRIES * sizeof(struct hisi_sas_itct);
+
+	hisi_hba->debugfs_itct = devm_kmalloc(dev, sz, GFP_KERNEL);
+	if (!hisi_hba->debugfs_itct)
+		goto fail_itct;
+
+	return;
+fail_itct:
+	devm_kfree(dev, hisi_hba->debugfs_iost);
+fail_iost_dq:
+	for (i = 0; i < d; i++)
+		devm_kfree(dev, hisi_hba->debugfs_cmd_hdr[i]);
+fail_cq:
+	for (i = 0; i < c; i++)
+		devm_kfree(dev, hisi_hba->debugfs_complete_hdr[i]);
+fail_port:
+	for (i = 0; i < p; i++)
+		devm_kfree(dev, hisi_hba->debugfs_port_reg[i]);
+	devm_kfree(dev, hisi_hba->debugfs_global_reg);
+fail_global:
+	debugfs_remove_recursive(hisi_hba->debugfs_dir);
+	dev_dbg(dev, "failed to init debugfs!\n");
 }
 EXPORT_SYMBOL_GPL(hisi_sas_debugfs_init);
 

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

@@ -2332,6 +2332,12 @@ static struct device_attribute *host_attrs_v3_hw[] = {
 	NULL
 };
 
+static const struct hisi_sas_debugfs_reg debugfs_port_reg = {
+};
+
+static const struct hisi_sas_debugfs_reg debugfs_global_reg = {
+};
+
 static struct scsi_host_template sht_v3_hw = {
 	.name			= DRV_NAME,
 	.module			= THIS_MODULE,
@@ -2380,6 +2386,8 @@ static const struct hisi_sas_hw hisi_sas_v3_hw = {
 	.get_events = phy_get_events_v3_hw,
 	.write_gpio = write_gpio_v3_hw,
 	.wait_cmds_complete_timeout = wait_cmds_complete_timeout_v3_hw,
+	.debugfs_reg_global = &debugfs_global_reg,
+	.debugfs_reg_port = &debugfs_port_reg,
 };
 
 static struct Scsi_Host *