msm: ipa: Reduce stack memory used in ipa_init_drop_stats

Reduce stack memory in ipa_init_drop_stats to avoid stack
overflow.

Change-Id: I38d7284430f24e726aaf0b8e8b6c41d960eb89cd

drivers/platform/msm/ipa/ipa_v3/ipa_hw_stats.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2017-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
  */
 
 #include <linux/debugfs.h>
@@ -1897,7 +1898,7 @@ int ipa_init_drop_stats(u32 *pipe_bitmask)
 	struct ipahal_imm_cmd_pyld *drop_mask_pyld[IPAHAL_IPA5_PIPE_REG_NUM] =
 		{0};
 	struct ipahal_imm_cmd_pyld *coal_cmd_pyld = NULL;
-	struct ipa3_desc desc[IPA_INIT_DROP_STATS_MAX_CMD_NUM] = { {0} };
+	struct ipa3_desc *desc = NULL;
 	struct ipa_hw_stats_drop tmp_drop;
 	dma_addr_t dma_address;
 	int ret, i;
@@ -1909,6 +1910,12 @@ int ipa_init_drop_stats(u32 *pipe_bitmask)
 	if (!pipe_bitmask)
 		return -EPERM;
 
+	desc = kzalloc(sizeof(*desc) * IPA_INIT_DROP_STATS_MAX_CMD_NUM, GFP_KERNEL);
+	if (!desc) {
+		IPAERR("failed to allocate memory\n");
+		return -ENOMEM;
+	}
+
 	/* check if IPA has enough space for # of pipes drop stats enabled*/
 	memset(&tmp_drop, 0, sizeof(tmp_drop));
 	for (i = 0; i < IPA5_PIPE_REG_NUM; i++) {
@@ -1920,7 +1927,8 @@ int ipa_init_drop_stats(u32 *pipe_bitmask)
 		&tmp_drop.init, false);
 	if (!pyld) {
 		IPAERR("failed to generate pyld\n");
-		return -EPERM;
+		ret = -EPERM;
+		goto fail_free_desc;
 	}
 
 	if (pyld->len > IPA_MEM_PART(stats_drop_size)) {
@@ -2074,6 +2082,8 @@ unmap:
 	dma_unmap_single(ipa3_ctx->pdev, dma_address, pyld->len, DMA_TO_DEVICE);
 destroy_init_pyld:
 	ipahal_destroy_stats_init_pyld(pyld);
+fail_free_desc:
+		kfree(desc);
 	return ret;
 }