ath10k: add memory dump support for QCA6174/QCA9377

Add memory dump to the firmware crash data file which is provided to user space
via devcoredump interface. This makes it easier for firmware engineers to debug
firmware crashes.

Due to increased memory consumption the memory dump is disabled by default. To
enable it make sure that bit 3 is set in coredump_mask module parameter:

modprobe ath10k_core coredump_mask=0xffffffff

When RAMDUMP is enabled a buffer for the dump is allocated with vmalloc during
device probe. The actual memory layout is different in hardware versions and
the layouts are defined in coredump.c. The memory is split to regions and, to
get even finegrained control of what to copy, the region can split to smaller
sections as not all registers are readable (which could cause the whole system
to stall).

Signed-off-by: Alan Liu <alanliu@qca.qualcomm.com>
[kvalo@qca.qualcomm.com: refactoring and cleanup]
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 218 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c
index 61406bba2b5e..962310023126 100644
--- a/drivers/net/wireless/ath/ath10k/pci.c
+++ b/drivers/net/wireless/ath/ath10k/pci.c
@@ -52,6 +52,11 @@ MODULE_PARM_DESC(reset_mode, "0: auto, 1: warm only (default: 0)");
 #define ATH10K_PCI_TARGET_WAIT 3000
 #define ATH10K_PCI_NUM_WARM_RESET_ATTEMPTS 3
 
+/* Maximum number of bytes that can be handled atomically by
+ * diag read and write.
+ */
+#define ATH10K_DIAG_TRANSFER_LIMIT	0x5000
+
 static const struct pci_device_id ath10k_pci_id_table[] = {
 	{ PCI_VDEVICE(ATHEROS, QCA988X_2_0_DEVICE_ID) }, /* PCI-E QCA988X V2 */
 	{ PCI_VDEVICE(ATHEROS, QCA6164_2_1_DEVICE_ID) }, /* PCI-E QCA6164 V2.1 */
@@ -1462,6 +1467,218 @@ static void ath10k_pci_dump_registers(struct ath10k *ar,
 		crash_data->registers[i] = reg_dump_values[i];
 }
 
+static int ath10k_pci_dump_memory_section(struct ath10k *ar,
+					  const struct ath10k_mem_region *mem_region,
+					  u8 *buf, size_t buf_len)
+{
+	const struct ath10k_mem_section *cur_section, *next_section;
+	unsigned int count, section_size, skip_size;
+	int ret, i, j;
+
+	if (!mem_region || !buf)
+		return 0;
+
+	if (mem_region->section_table.size < 0)
+		return 0;
+
+	cur_section = &mem_region->section_table.sections[0];
+
+	if (mem_region->start > cur_section->start) {
+		ath10k_warn(ar, "incorrect memdump region 0x%x with section start addrress 0x%x.\n",
+			    mem_region->start, cur_section->start);
+		return 0;
+	}
+
+	skip_size = cur_section->start - mem_region->start;
+
+	/* fill the gap between the first register section and register
+	 * start address
+	 */
+	for (i = 0; i < skip_size; i++) {
+		*buf = ATH10K_MAGIC_NOT_COPIED;
+		buf++;
+	}
+
+	count = 0;
+
+	for (i = 0; cur_section != NULL; i++) {
+		section_size = cur_section->end - cur_section->start;
+
+		if (section_size <= 0) {
+			ath10k_warn(ar, "incorrect ramdump format with start address 0x%x and stop address 0x%x\n",
+				    cur_section->start,
+				    cur_section->end);
+			break;
+		}
+
+		if ((i + 1) == mem_region->section_table.size) {
+			/* last section */
+			next_section = NULL;
+			skip_size = 0;
+		} else {
+			next_section = cur_section + 1;
+
+			if (cur_section->end > next_section->start) {
+				ath10k_warn(ar, "next ramdump section 0x%x is smaller than current end address 0x%x\n",
+					    next_section->start,
+					    cur_section->end);
+				break;
+			}
+
+			skip_size = next_section->start - cur_section->end;
+		}
+
+		if (buf_len < (skip_size + section_size)) {
+			ath10k_warn(ar, "ramdump buffer is too small: %zu\n", buf_len);
+			break;
+		}
+
+		buf_len -= skip_size + section_size;
+
+		/* read section to dest memory */
+		ret = ath10k_pci_diag_read_mem(ar, cur_section->start,
+					       buf, section_size);
+		if (ret) {
+			ath10k_warn(ar, "failed to read ramdump from section 0x%x: %d\n",
+				    cur_section->start, ret);
+			break;
+		}
+
+		buf += section_size;
+		count += section_size;
+
+		/* fill in the gap between this section and the next */
+		for (j = 0; j < skip_size; j++) {
+			*buf = ATH10K_MAGIC_NOT_COPIED;
+			buf++;
+		}
+
+		count += skip_size;
+
+		if (!next_section)
+			/* this was the last section */
+			break;
+
+		cur_section = next_section;
+	}
+
+	return count;
+}
+
+static int ath10k_pci_set_ram_config(struct ath10k *ar, u32 config)
+{
+	u32 val;
+
+	ath10k_pci_write32(ar, SOC_CORE_BASE_ADDRESS +
+			   FW_RAM_CONFIG_ADDRESS, config);
+
+	val = ath10k_pci_read32(ar, SOC_CORE_BASE_ADDRESS +
+				FW_RAM_CONFIG_ADDRESS);
+	if (val != config) {
+		ath10k_warn(ar, "failed to set RAM config from 0x%x to 0x%x\n",
+			    val, config);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void ath10k_pci_dump_memory(struct ath10k *ar,
+				   struct ath10k_fw_crash_data *crash_data)
+{
+	const struct ath10k_hw_mem_layout *mem_layout;
+	const struct ath10k_mem_region *current_region;
+	struct ath10k_dump_ram_data_hdr *hdr;
+	u32 count, shift;
+	size_t buf_len;
+	int ret, i;
+	u8 *buf;
+
+	lockdep_assert_held(&ar->data_lock);
+
+	if (!crash_data)
+		return;
+
+	mem_layout = ath10k_coredump_get_mem_layout(ar);
+	if (!mem_layout)
+		return;
+
+	current_region = &mem_layout->region_table.regions[0];
+
+	buf = crash_data->ramdump_buf;
+	buf_len = crash_data->ramdump_buf_len;
+
+	memset(buf, 0, buf_len);
+
+	for (i = 0; i < mem_layout->region_table.size; i++) {
+		count = 0;
+
+		if (current_region->len > buf_len) {
+			ath10k_warn(ar, "memory region %s size %d is larger that remaining ramdump buffer size %zu\n",
+				    current_region->name,
+				    current_region->len,
+				    buf_len);
+			break;
+		}
+
+		/* To get IRAM dump, the host driver needs to switch target
+		 * ram config from DRAM to IRAM.
+		 */
+		if (current_region->type == ATH10K_MEM_REGION_TYPE_IRAM1 ||
+		    current_region->type == ATH10K_MEM_REGION_TYPE_IRAM2) {
+			shift = current_region->start >> 20;
+
+			ret = ath10k_pci_set_ram_config(ar, shift);
+			if (ret) {
+				ath10k_warn(ar, "failed to switch ram config to IRAM for section %s: %d\n",
+					    current_region->name, ret);
+				break;
+			}
+		}
+
+		/* Reserve space for the header. */
+		hdr = (void *)buf;
+		buf += sizeof(*hdr);
+		buf_len -= sizeof(*hdr);
+
+		if (current_region->section_table.size > 0) {
+			/* Copy each section individually. */
+			count = ath10k_pci_dump_memory_section(ar,
+							       current_region,
+							       buf,
+							       current_region->len);
+		} else {
+			/* No individiual memory sections defined so we can
+			 * copy the entire memory region.
+			 */
+			ret = ath10k_pci_diag_read_mem(ar,
+						       current_region->start,
+						       buf,
+						       current_region->len);
+			if (ret) {
+				ath10k_warn(ar, "failed to copy ramdump region %s: %d\n",
+					    current_region->name, ret);
+				break;
+			}
+
+			count = current_region->len;
+		}
+
+		hdr->region_type = cpu_to_le32(current_region->type);
+		hdr->start = cpu_to_le32(current_region->start);
+		hdr->length = cpu_to_le32(count);
+
+		if (count == 0)
+			/* Note: the header remains, just with zero length. */
+			break;
+
+		buf += count;
+		buf_len -= count;
+
+		current_region++;
+	}
+}
+
 static void ath10k_pci_fw_crashed_dump(struct ath10k *ar)
 {
 	struct ath10k_fw_crash_data *crash_data;
@@ -1482,6 +1699,7 @@ static void ath10k_pci_fw_crashed_dump(struct ath10k *ar)
 	ath10k_print_driver_info(ar);
 	ath10k_pci_dump_registers(ar, crash_data);
 	ath10k_ce_dump_registers(ar, crash_data);
+	ath10k_pci_dump_memory(ar, crash_data);
 
 	spin_unlock_bh(&ar->data_lock);