iwlwifi: pcie: add firmware monitor capabilities

This allows to use the firmware monitor. This capability
uses a lot of contiguous memory (up to 64MB), so make its
usage module parameter dependent.

The driver will try to allocate as much contiguous memory
as possible downgrading its requirements until the
allocation succeeds.

Dump this data into the fw-error dump file when an error
happens.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/iwl-drv.c

@@ -1405,3 +1405,7 @@ module_param_named(power_level, iwlwifi_mod_params.power_level,
 		int, S_IRUGO);
 MODULE_PARM_DESC(power_level,
 		 "default power save level (range from 1 - 5, default: 1)");
+
+module_param_named(fw_monitor, iwlwifi_mod_params.fw_monitor, bool, S_IRUGO);
+MODULE_PARM_DESC(dbgm,
+		 "firmware monitor - to debug FW (default: false - needs lots of memory)");

drivers/net/wireless/iwlwifi/iwl-fw-error-dump.h

@@ -76,6 +76,7 @@
  *	&struct iwl_fw_error_dump_txcmd packets
  * @IWL_FW_ERROR_DUMP_DEV_FW_INFO:  struct %iwl_fw_error_dump_info
  *	info on the device / firmware.
+ * @IWL_FW_ERROR_DUMP_FW_MONITOR: firmware monitor
  */
 enum iwl_fw_error_dump_type {
 	IWL_FW_ERROR_DUMP_SRAM = 0,
@@ -83,6 +84,7 @@ enum iwl_fw_error_dump_type {
 	IWL_FW_ERROR_DUMP_RXF = 2,
 	IWL_FW_ERROR_DUMP_TXCMD = 3,
 	IWL_FW_ERROR_DUMP_DEV_FW_INFO = 4,
+	IWL_FW_ERROR_DUMP_FW_MONITOR = 5,
 
 	IWL_FW_ERROR_DUMP_MAX,
 };
@@ -144,6 +146,22 @@ struct iwl_fw_error_dump_info {
 	u8 bus_human_readable[8];
 } __packed;
 
+/**
+ * struct iwl_fw_error_fw_mon - FW monitor data
+ * @fw_mon_wr_ptr: the position of the write pointer in the cyclic buffer
+ * @fw_mon_base_ptr: base pointer of the data
+ * @fw_mon_cycle_cnt: number of wrap arounds
+ * @reserved: for future use
+ * @data: captured data
+ */
+struct iwl_fw_error_fw_mon {
+	__le32 fw_mon_wr_ptr;
+	__le32 fw_mon_base_ptr;
+	__le32 fw_mon_cycle_cnt;
+	__le32 reserved[3];
+	u8 data[];
+} __packed;
+
 /**
  * iwl_fw_error_next_data - advance fw error dump data pointer
  * @data: previous data block

drivers/net/wireless/iwlwifi/iwl-modparams.h

@@ -103,6 +103,7 @@ enum iwl_disable_11n {
  * @power_level: power level, default = 1
  * @debug_level: levels are IWL_DL_*
  * @ant_coupling: antenna coupling in dB, default = 0
+ * @fw_monitor: allow to use firmware monitor
  */
 struct iwl_mod_params {
 	int sw_crypto;
@@ -120,6 +121,7 @@ struct iwl_mod_params {
 	int ant_coupling;
 	char *nvm_file;
 	bool uapsd_disable;
+	bool fw_monitor;
 };
 
 #endif /* #__iwl_modparams_h__ */

drivers/net/wireless/iwlwifi/iwl-prph.h

@@ -359,4 +359,10 @@ enum secure_load_status_reg {
 #define RXF_LD_FENCE_OFFSET_ADDR	(0xa00c10)
 #define RXF_FIFO_RD_FENCE_ADDR		(0xa00c0c)
 
+/* FW monitor */
+#define MON_BUFF_BASE_ADDR		(0xa03c3c)
+#define MON_BUFF_END_ADDR		(0xa03c40)
+#define MON_BUFF_WRPTR			(0xa03c44)
+#define MON_BUFF_CYCLE_CNT		(0xa03c48)
+
 #endif				/* __iwl_prph_h__ */

drivers/net/wireless/iwlwifi/pcie/internal.h

@@ -260,6 +260,9 @@ iwl_pcie_get_scratchbuf_dma(struct iwl_txq *txq, int idx)
  * @wd_timeout: queue watchdog timeout (jiffies)
  * @reg_lock: protect hw register access
  * @cmd_in_flight: true when we have a host command in flight
+ * @fw_mon_phys: physical address of the buffer for the firmware monitor
+ * @fw_mon_page: points to the first page of the buffer for the firmware monitor
+ * @fw_mon_size: size of the buffer for the firmware monitor
  */
 struct iwl_trans_pcie {
 	struct iwl_rxq rxq;
@@ -312,6 +315,10 @@ struct iwl_trans_pcie {
 	/*protect hw register */
 	spinlock_t reg_lock;
 	bool cmd_in_flight;
+
+	dma_addr_t fw_mon_phys;
+	struct page *fw_mon_page;
+	u32 fw_mon_size;
 };
 
 #define IWL_TRANS_GET_PCIE_TRANS(_iwl_trans) \

drivers/net/wireless/iwlwifi/pcie/trans.c

@@ -76,6 +76,68 @@
 #include "iwl-fw-error-dump.h"
 #include "internal.h"
 
+static void iwl_pcie_free_fw_monitor(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+
+	if (!trans_pcie->fw_mon_page)
+		return;
+
+	dma_unmap_page(trans->dev, trans_pcie->fw_mon_phys,
+		       trans_pcie->fw_mon_size, DMA_FROM_DEVICE);
+	__free_pages(trans_pcie->fw_mon_page,
+		     get_order(trans_pcie->fw_mon_size));
+	trans_pcie->fw_mon_page = NULL;
+	trans_pcie->fw_mon_phys = 0;
+	trans_pcie->fw_mon_size = 0;
+}
+
+static void iwl_pcie_alloc_fw_monitor(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct page *page;
+	dma_addr_t phys;
+	u32 size;
+	u8 power;
+
+	if (trans_pcie->fw_mon_page) {
+		dma_sync_single_for_device(trans->dev, trans_pcie->fw_mon_phys,
+					   trans_pcie->fw_mon_size,
+					   DMA_FROM_DEVICE);
+		return;
+	}
+
+	phys = 0;
+	for (power = 26; power >= 11; power--) {
+		int order;
+
+		size = BIT(power);
+		order = get_order(size);
+		page = alloc_pages(__GFP_COMP | __GFP_NOWARN | __GFP_ZERO,
+				   order);
+		if (!page)
+			continue;
+
+		phys = dma_map_page(trans->dev, page, 0, PAGE_SIZE << order,
+				    DMA_FROM_DEVICE);
+		if (dma_mapping_error(trans->dev, phys)) {
+			__free_pages(page, order);
+			continue;
+		}
+		IWL_INFO(trans,
+			 "Allocated 0x%08x bytes (order %d) for firmware monitor.\n",
+			 size, order);
+		break;
+	}
+
+	if (!page)
+		return;
+
+	trans_pcie->fw_mon_page = page;
+	trans_pcie->fw_mon_phys = phys;
+	trans_pcie->fw_mon_size = size;
+}
+
 static u32 iwl_trans_pcie_read_shr(struct iwl_trans *trans, u32 reg)
 {
 	iwl_write32(trans, HEEP_CTRL_WRD_PCIEX_CTRL_REG,
@@ -675,6 +737,7 @@ static int iwl_pcie_load_cpu_sections(struct iwl_trans *trans,
 static int iwl_pcie_load_given_ucode(struct iwl_trans *trans,
 				const struct fw_img *image)
 {
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	int ret = 0;
 	int first_ucode_section;
 
@@ -733,6 +796,20 @@ static int iwl_pcie_load_given_ucode(struct iwl_trans *trans,
 			return ret;
 	}
 
+	/* supported for 7000 only for the moment */
+	if (iwlwifi_mod_params.fw_monitor &&
+	    trans->cfg->device_family == IWL_DEVICE_FAMILY_7000) {
+		iwl_pcie_alloc_fw_monitor(trans);
+
+		if (trans_pcie->fw_mon_size) {
+			iwl_write_prph(trans, MON_BUFF_BASE_ADDR,
+				       trans_pcie->fw_mon_phys >> 4);
+			iwl_write_prph(trans, MON_BUFF_END_ADDR,
+				       (trans_pcie->fw_mon_phys +
+					trans_pcie->fw_mon_size) >> 4);
+		}
+	}
+
 	/* release CPU reset */
 	if (trans->cfg->device_family == IWL_DEVICE_FAMILY_8000)
 		iwl_write_prph(trans, RELEASE_CPU_RESET, RELEASE_CPU_RESET_BIT);
@@ -1126,6 +1203,8 @@ void iwl_trans_pcie_free(struct iwl_trans *trans)
 	if (trans_pcie->napi.poll)
 		netif_napi_del(&trans_pcie->napi);
 
+	iwl_pcie_free_fw_monitor(trans);
+
 	kfree(trans);
 }
 
@@ -1698,10 +1777,15 @@ static u32 iwl_trans_pcie_dump_data(struct iwl_trans *trans,
 	u32 len;
 	int i, ptr;
 
+	len = sizeof(*data) +
+		cmdq->q.n_window * (sizeof(*txcmd) + TFD_MAX_PAYLOAD_SIZE);
+
+	if (trans_pcie->fw_mon_page)
+		len += sizeof(*data) + sizeof(struct iwl_fw_error_fw_mon) +
+			trans_pcie->fw_mon_size;
+
 	if (!buf)
-		return sizeof(*data) +
-		       cmdq->q.n_window * (sizeof(*txcmd) +
-					   TFD_MAX_PAYLOAD_SIZE);
+		return len;
 
 	len = 0;
 	data = buf;
@@ -1729,7 +1813,40 @@ static u32 iwl_trans_pcie_dump_data(struct iwl_trans *trans,
 	spin_unlock_bh(&cmdq->lock);
 
 	data->len = cpu_to_le32(len);
-	return sizeof(*data) + len;
+	len += sizeof(*data);
+
+	if (trans_pcie->fw_mon_page) {
+		struct iwl_fw_error_fw_mon *fw_mon_data;
+
+		data = iwl_fw_error_next_data(data);
+		data->type = cpu_to_le32(IWL_FW_ERROR_DUMP_FW_MONITOR);
+		data->len = cpu_to_le32(trans_pcie->fw_mon_size +
+					sizeof(*fw_mon_data));
+		fw_mon_data = (void *)data->data;
+		fw_mon_data->fw_mon_wr_ptr =
+			cpu_to_le32(iwl_read_prph(trans, MON_BUFF_WRPTR));
+		fw_mon_data->fw_mon_cycle_cnt =
+			cpu_to_le32(iwl_read_prph(trans, MON_BUFF_CYCLE_CNT));
+		fw_mon_data->fw_mon_base_ptr =
+			cpu_to_le32(iwl_read_prph(trans, MON_BUFF_BASE_ADDR));
+
+		/*
+		 * The firmware is now asserted, it won't write anything to
+		 * the buffer. CPU can take ownership to fetch the data.
+		 * The buffer will be handed back to the device before the
+		 * firmware will be restarted.
+		 */
+		dma_sync_single_for_cpu(trans->dev, trans_pcie->fw_mon_phys,
+					trans_pcie->fw_mon_size,
+					DMA_FROM_DEVICE);
+		memcpy(fw_mon_data->data, page_address(trans_pcie->fw_mon_page),
+		       trans_pcie->fw_mon_size);
+
+		len += sizeof(*data) + sizeof(*fw_mon_data) +
+			trans_pcie->fw_mon_size;
+	}
+
+	return len;
 }
 #else
 static int iwl_trans_pcie_dbgfs_register(struct iwl_trans *trans,