ath10k: fix module load regression with iram-recovery feature

Commit 9af7c32c ("ath10k: add target IRAM recovery feature support")
introduced a new firmware feature flag ATH10K_FW_FEATURE_IRAM_RECOVERY. But
this caused ath10k_pci module load to fail if ATH10K_FW_CRASH_DUMP_RAM_DATA bit
was not enabled in the ath10k coredump_mask module parameter:

[ 2209.328190] ath10k_pci 0000:02:00.0: qca9984/qca9994 hw1.0 target 0x01000000 chip_id 0x00000000 sub 168c:cafe
[ 2209.434414] ath10k_pci 0000:02:00.0: kconfig debug 1 debugfs 1 tracing 1 dfs 1 testmode 1
[ 2209.547191] ath10k_pci 0000:02:00.0: firmware ver 10.4-3.9.0.2-00099 api 5 features no-p2p,mfp,peer-flow-ctrl,btcoex-param,allows-mesh-bcast,no-ps,peer-fixed-rate,iram-recovery crc32 cbade90a
[ 2210.896485] ath10k_pci 0000:02:00.0: board_file api 1 bmi_id 0:1 crc32 a040efc2
[ 2213.603339] ath10k_pci 0000:02:00.0: failed to copy target iram contents: -12
[ 2213.839027] ath10k_pci 0000:02:00.0: could not init core (-12)
[ 2213.933910] ath10k_pci 0000:02:00.0: could not probe fw (-12)

And by default coredump_mask does not have ATH10K_FW_CRASH_DUMP_RAM_DATA
enabled so anyone using a firmware with iram-recovery feature would fail. To my
knowledge only QCA9984 firmwares starting from release 10.4-3.9.0.2-00099
enabled the feature.

The reason for regression was that ath10k_core_copy_target_iram() used
ath10k_coredump_get_mem_layout() to get the memory layout, but when
ATH10K_FW_CRASH_DUMP_RAM_DATA was disabled it would get just NULL and bail out
with an error.

While looking at all this I noticed another bug: if CONFIG_DEV_COREDUMP is
disabled but the firmware has iram-recovery enabled the module load fails with
similar error messages. I fixed that by returning 0 from
ath10k_core_copy_target_iram() when _ath10k_coredump_get_mem_layout() returns
NULL.

Tested-on: QCA9984 hw2.0 PCI 10.4-3.9.0.2-00139

Fixes: 9af7c32c ("ath10k: add target IRAM recovery feature support")
Signed-off-by: Abinaya Kalaiselvan <akalaise@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211020075054.23061-1-kvalo@codeaurora.org

drivers/net/wireless/ath/ath10k/core.c

@@ -2690,9 +2690,16 @@ static int ath10k_core_copy_target_iram(struct ath10k *ar)
 	int i, ret;
 	u32 len, remaining_len;
 
-	hw_mem = ath10k_coredump_get_mem_layout(ar);
+	/* copy target iram feature must work also when
+	 * ATH10K_FW_CRASH_DUMP_RAM_DATA is disabled, so
+	 * _ath10k_coredump_get_mem_layout() to accomplist that
+	 */
+	hw_mem = _ath10k_coredump_get_mem_layout(ar);
 	if (!hw_mem)
-		return -ENOMEM;
+		/* if CONFIG_DEV_COREDUMP is disabled we get NULL, then
+		 * just silently disable the feature by doing nothing
+		 */
+		return 0;
 
 	for (i = 0; i < hw_mem->region_table.size; i++) {
 		tmp = &hw_mem->region_table.regions[i];

drivers/net/wireless/ath/ath10k/coredump.c

@@ -1447,11 +1447,17 @@ static u32 ath10k_coredump_get_ramdump_size(struct ath10k *ar)
 
 const struct ath10k_hw_mem_layout *ath10k_coredump_get_mem_layout(struct ath10k *ar)
 {
-	int i;
-
 	if (!test_bit(ATH10K_FW_CRASH_DUMP_RAM_DATA, &ath10k_coredump_mask))
 		return NULL;
 
+	return _ath10k_coredump_get_mem_layout(ar);
+}
+EXPORT_SYMBOL(ath10k_coredump_get_mem_layout);
+
+const struct ath10k_hw_mem_layout *_ath10k_coredump_get_mem_layout(struct ath10k *ar)
+{
+	int i;
+
 	if (WARN_ON(ar->target_version == 0))
 		return NULL;
 
@@ -1464,7 +1470,6 @@ const struct ath10k_hw_mem_layout *ath10k_coredump_get_mem_layout(struct ath10k
 
 	return NULL;
 }
-EXPORT_SYMBOL(ath10k_coredump_get_mem_layout);
 
 struct ath10k_fw_crash_data *ath10k_coredump_new(struct ath10k *ar)
 {

drivers/net/wireless/ath/ath10k/coredump.h

@@ -176,6 +176,7 @@ int ath10k_coredump_register(struct ath10k *ar);
 void ath10k_coredump_unregister(struct ath10k *ar);
 void ath10k_coredump_destroy(struct ath10k *ar);
 
+const struct ath10k_hw_mem_layout *_ath10k_coredump_get_mem_layout(struct ath10k *ar);
 const struct ath10k_hw_mem_layout *ath10k_coredump_get_mem_layout(struct ath10k *ar);
 
 #else /* CONFIG_DEV_COREDUMP */
@@ -214,6 +215,12 @@ ath10k_coredump_get_mem_layout(struct ath10k *ar)
 	return NULL;
 }
 
+static inline const struct ath10k_hw_mem_layout *
+_ath10k_coredump_get_mem_layout(struct ath10k *ar)
+{
+	return NULL;
+}
+
 #endif /* CONFIG_DEV_COREDUMP */
 
 #endif /* _COREDUMP_H_ */