ath11k: Add direct buffer ring support

Add direct buffer ring (dbring) with helper API, which is used by the
spectral scan. Initialise the direct buffer ring based on the dma ring
capability, which get announced in the wmi service ready extended event.
This ring is slightly changed from data path rings. Compare to data path
ring this ring shares the hp and tp address to firmware though WMI commands.
Also the replenish buffer size is derived from firmware announcement.
driver receive indication through WMI event
WMI_PDEV_DMA_RING_BUF_RELEASE_EVENTID.

Tested-on: IPQ8074 WLAN.HK.2.1.0.1-01228-QCAHKSWPL_SILICONZ-1

Signed-off-by: Karthikeyan Periyasamy <periyasa@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1591688014-26441-1-git-send-email-periyasa@codeaurora.org

drivers/net/wireless/ath/ath11k/Makefile

@@ -15,7 +15,8 @@ ath11k-y += core.o \
 	    dp_rx.o \
 	    debug.o \
 	    ce.o \
-	    peer.o
+	    peer.o \
+	    dbring.o
 
 ath11k-$(CONFIG_ATH11K_DEBUGFS) += debug_htt_stats.o debugfs_sta.o
 ath11k-$(CONFIG_NL80211_TESTMODE) += testmode.o

drivers/net/wireless/ath/ath11k/core.h

@@ -21,6 +21,7 @@
 #include "hal_rx.h"
 #include "reg.h"
 #include "thermal.h"
+#include "dbring.h"
 
 #define SM(_v, _f) (((_v) << _f##_LSB) & _f##_MASK)
 
@@ -673,6 +674,9 @@ struct ath11k_base {
 	/* Round robbin based TCL ring selector */
 	atomic_t tcl_ring_selector;
 
+	struct ath11k_dbring_cap *db_caps;
+	u32 num_db_cap;
+
 	/* must be last */
 	u8 drv_priv[0] __aligned(sizeof(void *));
 };

drivers/net/wireless/ath/ath11k/dbring.c

@@ -0,0 +1,353 @@
+// SPDX-License-Identifier: BSD-3-Clause-Clear
+/*
+ * Copyright (c) 2019-2020 The Linux Foundation. All rights reserved.
+ */
+
+#include "core.h"
+#include "debug.h"
+
+static int ath11k_dbring_bufs_replenish(struct ath11k *ar,
+					struct ath11k_dbring *ring,
+					struct ath11k_dbring_element *buff,
+					gfp_t gfp)
+{
+	struct ath11k_base *ab = ar->ab;
+	struct hal_srng *srng;
+	dma_addr_t paddr;
+	void *ptr_aligned, *ptr_unaligned, *desc;
+	int ret;
+	int buf_id;
+	u32 cookie;
+
+	srng = &ab->hal.srng_list[ring->refill_srng.ring_id];
+
+	lockdep_assert_held(&srng->lock);
+
+	ath11k_hal_srng_access_begin(ab, srng);
+
+	ptr_unaligned = buff->payload;
+	ptr_aligned = PTR_ALIGN(ptr_unaligned, ring->buf_align);
+	paddr = dma_map_single(ab->dev, ptr_aligned, ring->buf_sz,
+			       DMA_FROM_DEVICE);
+
+	ret = dma_mapping_error(ab->dev, paddr);
+	if (ret)
+		goto err;
+
+	spin_lock_bh(&ring->idr_lock);
+	buf_id = idr_alloc(&ring->bufs_idr, buff, 0, ring->bufs_max, gfp);
+	spin_unlock_bh(&ring->idr_lock);
+	if (buf_id < 0) {
+		ret = -ENOBUFS;
+		goto err_dma_unmap;
+	}
+
+	desc = ath11k_hal_srng_src_get_next_entry(ab, srng);
+	if (!desc) {
+		ret = -ENOENT;
+		goto err_idr_remove;
+	}
+
+	buff->paddr = paddr;
+
+	cookie = FIELD_PREP(DP_RXDMA_BUF_COOKIE_PDEV_ID, ar->pdev_idx) |
+		 FIELD_PREP(DP_RXDMA_BUF_COOKIE_BUF_ID, buf_id);
+
+	ath11k_hal_rx_buf_addr_info_set(desc, paddr, cookie, 0);
+
+	ath11k_hal_srng_access_end(ab, srng);
+
+	return 0;
+
+err_idr_remove:
+	spin_lock_bh(&ring->idr_lock);
+	idr_remove(&ring->bufs_idr, buf_id);
+	spin_unlock_bh(&ring->idr_lock);
+err_dma_unmap:
+	dma_unmap_single(ab->dev, paddr, ring->buf_sz,
+			 DMA_FROM_DEVICE);
+err:
+	ath11k_hal_srng_access_end(ab, srng);
+	return ret;
+}
+
+static int ath11k_dbring_fill_bufs(struct ath11k *ar,
+				   struct ath11k_dbring *ring,
+				   gfp_t gfp)
+{
+	struct ath11k_dbring_element *buff;
+	struct hal_srng *srng;
+	int num_remain, req_entries, num_free;
+	u32 align;
+	int size, ret;
+
+	srng = &ar->ab->hal.srng_list[ring->refill_srng.ring_id];
+
+	spin_lock_bh(&srng->lock);
+
+	num_free = ath11k_hal_srng_src_num_free(ar->ab, srng, true);
+	req_entries = min(num_free, ring->bufs_max);
+	num_remain = req_entries;
+	align = ring->buf_align;
+	size = sizeof(*buff) + ring->buf_sz + align - 1;
+
+	while (num_remain > 0) {
+		buff = kzalloc(size, gfp);
+		if (!buff)
+			break;
+
+		ret = ath11k_dbring_bufs_replenish(ar, ring, buff, gfp);
+		if (ret) {
+			ath11k_warn(ar->ab, "failed to replenish db ring num_remain %d req_ent %d\n",
+				    num_remain, req_entries);
+			kfree(buff);
+			break;
+		}
+		num_remain--;
+	}
+
+	spin_unlock_bh(&srng->lock);
+
+	return num_remain;
+}
+
+int ath11k_dbring_wmi_cfg_setup(struct ath11k *ar,
+				struct ath11k_dbring *ring,
+				enum wmi_direct_buffer_module id)
+{
+	struct ath11k_wmi_pdev_dma_ring_cfg_req_cmd param = {0};
+	int ret;
+
+	if (id >= WMI_DIRECT_BUF_MAX)
+		return -EINVAL;
+
+	param.pdev_id		= DP_SW2HW_MACID(ring->pdev_id);
+	param.module_id		= id;
+	param.base_paddr_lo	= lower_32_bits(ring->refill_srng.paddr);
+	param.base_paddr_hi	= upper_32_bits(ring->refill_srng.paddr);
+	param.head_idx_paddr_lo	= lower_32_bits(ring->hp_addr);
+	param.head_idx_paddr_hi = upper_32_bits(ring->hp_addr);
+	param.tail_idx_paddr_lo = lower_32_bits(ring->tp_addr);
+	param.tail_idx_paddr_hi = upper_32_bits(ring->tp_addr);
+	param.num_elems		= ring->bufs_max;
+	param.buf_size		= ring->buf_sz;
+	param.num_resp_per_event = ring->num_resp_per_event;
+	param.event_timeout_ms	= ring->event_timeout_ms;
+
+	ret = ath11k_wmi_pdev_dma_ring_cfg(ar, &param);
+	if (ret) {
+		ath11k_warn(ar->ab, "failed to setup db ring cfg\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+int ath11k_dbring_set_cfg(struct ath11k *ar, struct ath11k_dbring *ring,
+			  u32 num_resp_per_event, u32 event_timeout_ms,
+			  int (*handler)(struct ath11k *,
+					 struct ath11k_dbring_data *))
+{
+	if (WARN_ON(!ring))
+		return -EINVAL;
+
+	ring->num_resp_per_event = num_resp_per_event;
+	ring->event_timeout_ms = event_timeout_ms;
+	ring->handler = handler;
+
+	return 0;
+}
+
+int ath11k_dbring_buf_setup(struct ath11k *ar,
+			    struct ath11k_dbring *ring,
+			    struct ath11k_dbring_cap *db_cap)
+{
+	struct ath11k_base *ab = ar->ab;
+	struct hal_srng *srng;
+	int ret;
+
+	srng = &ab->hal.srng_list[ring->refill_srng.ring_id];
+	ring->bufs_max = ring->refill_srng.size /
+			 ath11k_hal_srng_get_entrysize(HAL_RXDMA_DIR_BUF);
+
+	ring->buf_sz = db_cap->min_buf_sz;
+	ring->buf_align = db_cap->min_buf_align;
+	ring->pdev_id = db_cap->pdev_id;
+	ring->hp_addr = ath11k_hal_srng_get_hp_addr(ar->ab, srng);
+	ring->tp_addr = ath11k_hal_srng_get_tp_addr(ar->ab, srng);
+
+	ret = ath11k_dbring_fill_bufs(ar, ring, GFP_KERNEL);
+
+	return ret;
+}
+
+int ath11k_dbring_srng_setup(struct ath11k *ar, struct ath11k_dbring *ring,
+			     int ring_num, int num_entries)
+{
+	int ret;
+
+	ret = ath11k_dp_srng_setup(ar->ab, &ring->refill_srng, HAL_RXDMA_DIR_BUF,
+				   ring_num, ar->pdev_idx, num_entries);
+	if (ret < 0) {
+		ath11k_warn(ar->ab, "failed to setup srng: %d ring_id %d\n",
+			    ret, ring_num);
+		goto err;
+	}
+
+	return 0;
+err:
+	ath11k_dp_srng_cleanup(ar->ab, &ring->refill_srng);
+	return ret;
+}
+
+int ath11k_dbring_get_cap(struct ath11k_base *ab,
+			  u8 pdev_idx,
+			  enum wmi_direct_buffer_module id,
+			  struct ath11k_dbring_cap *db_cap)
+{
+	int i;
+
+	if (!ab->num_db_cap || !ab->db_caps)
+		return -ENOENT;
+
+	if (id >= WMI_DIRECT_BUF_MAX)
+		return -EINVAL;
+
+	for (i = 0; i < ab->num_db_cap; i++) {
+		if (pdev_idx == ab->db_caps[i].pdev_id &&
+		    id == ab->db_caps[i].id) {
+			*db_cap = ab->db_caps[i];
+
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+int ath11k_dbring_buffer_release_event(struct ath11k_base *ab,
+				       struct ath11k_dbring_buf_release_event *ev)
+{
+	struct ath11k_dbring *ring;
+	struct hal_srng *srng;
+	struct ath11k *ar;
+	struct ath11k_dbring_element *buff;
+	struct ath11k_dbring_data handler_data;
+	struct ath11k_buffer_addr desc;
+	u8 *vaddr_unalign;
+	u32 num_entry, num_buff_reaped;
+	u8 pdev_idx, rbm;
+	u32 cookie;
+	int buf_id;
+	int size;
+	dma_addr_t paddr;
+	int ret = 0;
+
+	pdev_idx = ev->fixed.pdev_id;
+
+	if (pdev_idx >= ab->num_radios) {
+		ath11k_warn(ab, "Invalid pdev id %d\n", pdev_idx);
+		return -EINVAL;
+	}
+
+	if (ev->fixed.num_buf_release_entry !=
+	    ev->fixed.num_meta_data_entry) {
+		ath11k_warn(ab, "Buffer entry %d mismatch meta entry %d\n",
+			    ev->fixed.num_buf_release_entry,
+			    ev->fixed.num_meta_data_entry);
+		return -EINVAL;
+	}
+
+	ar = ab->pdevs[pdev_idx].ar;
+
+	rcu_read_lock();
+	if (!rcu_dereference(ab->pdevs_active[pdev_idx])) {
+		ret = -EINVAL;
+		goto rcu_unlock;
+	}
+
+	switch (ev->fixed.module_id) {
+	default:
+		ring = NULL;
+		ath11k_warn(ab, "Recv dma buffer release ev on unsupp module %d\n",
+			    ev->fixed.module_id);
+		break;
+	}
+
+	if (!ring) {
+		ret = -EINVAL;
+		goto rcu_unlock;
+	}
+
+	srng = &ab->hal.srng_list[ring->refill_srng.ring_id];
+	num_entry = ev->fixed.num_buf_release_entry;
+	size = sizeof(*buff) + ring->buf_sz + ring->buf_align - 1;
+	num_buff_reaped = 0;
+
+	spin_lock_bh(&srng->lock);
+
+	while (num_buff_reaped < num_entry) {
+		desc.info0 = ev->buf_entry[num_buff_reaped].paddr_lo;
+		desc.info1 = ev->buf_entry[num_buff_reaped].paddr_hi;
+		handler_data.meta = ev->meta_data[num_buff_reaped];
+
+		num_buff_reaped++;
+
+		ath11k_hal_rx_buf_addr_info_get(&desc, &paddr, &cookie, &rbm);
+
+		buf_id = FIELD_GET(DP_RXDMA_BUF_COOKIE_BUF_ID, cookie);
+
+		spin_lock_bh(&ring->idr_lock);
+		buff = idr_find(&ring->bufs_idr, buf_id);
+		if (!buff) {
+			spin_unlock_bh(&ring->idr_lock);
+			continue;
+		}
+		idr_remove(&ring->bufs_idr, buf_id);
+		spin_unlock_bh(&ring->idr_lock);
+
+		dma_unmap_single(ab->dev, buff->paddr, ring->buf_sz,
+				 DMA_FROM_DEVICE);
+
+		if (ring->handler) {
+			vaddr_unalign = buff->payload;
+			handler_data.data = PTR_ALIGN(vaddr_unalign,
+						      ring->buf_align);
+			handler_data.data_sz = ring->buf_sz;
+
+			ring->handler(ar, &handler_data);
+		}
+
+		memset(buff, 0, size);
+		ath11k_dbring_bufs_replenish(ar, ring, buff, GFP_ATOMIC);
+	}
+
+	spin_unlock_bh(&srng->lock);
+
+rcu_unlock:
+	rcu_read_unlock();
+
+	return ret;
+}
+
+void ath11k_dbring_srng_cleanup(struct ath11k *ar, struct ath11k_dbring *ring)
+{
+	ath11k_dp_srng_cleanup(ar->ab, &ring->refill_srng);
+}
+
+void ath11k_dbring_buf_cleanup(struct ath11k *ar, struct ath11k_dbring *ring)
+{
+	struct ath11k_dbring_element *buff;
+	int buf_id;
+
+	spin_lock_bh(&ring->idr_lock);
+	idr_for_each_entry(&ring->bufs_idr, buff, buf_id) {
+		idr_remove(&ring->bufs_idr, buf_id);
+		dma_unmap_single(ar->ab->dev, buff->paddr,
+				 ring->buf_sz, DMA_FROM_DEVICE);
+		kfree(buff);
+	}
+
+	idr_destroy(&ring->bufs_idr);
+	spin_unlock_bh(&ring->idr_lock);
+}