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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * offload engine driver for the Marvell XOR engine4 * Copyright (C) 2007, 2008, Marvell International Ltd.5 */6 7#include <linux/init.h>8#include <linux/slab.h>9#include <linux/delay.h>10#include <linux/dma-mapping.h>11#include <linux/spinlock.h>12#include <linux/interrupt.h>13#include <linux/platform_device.h>14#include <linux/property.h>15#include <linux/memory.h>16#include <linux/clk.h>17#include <linux/of.h>18#include <linux/of_irq.h>19#include <linux/irqdomain.h>20#include <linux/cpumask.h>21#include <linux/platform_data/dma-mv_xor.h>22 23#include "dmaengine.h"24#include "mv_xor.h"25 26enum mv_xor_type {27	XOR_ORION,28	XOR_ARMADA_38X,29	XOR_ARMADA_37XX,30};31 32enum mv_xor_mode {33	XOR_MODE_IN_REG,34	XOR_MODE_IN_DESC,35};36 37static void mv_xor_issue_pending(struct dma_chan *chan);38 39#define to_mv_xor_chan(chan)		\40	container_of(chan, struct mv_xor_chan, dmachan)41 42#define to_mv_xor_slot(tx)		\43	container_of(tx, struct mv_xor_desc_slot, async_tx)44 45#define mv_chan_to_devp(chan)           \46	((chan)->dmadev.dev)47 48static void mv_desc_init(struct mv_xor_desc_slot *desc,49			 dma_addr_t addr, u32 byte_count,50			 enum dma_ctrl_flags flags)51{52	struct mv_xor_desc *hw_desc = desc->hw_desc;53 54	hw_desc->status = XOR_DESC_DMA_OWNED;55	hw_desc->phy_next_desc = 0;56	/* Enable end-of-descriptor interrupts only for DMA_PREP_INTERRUPT */57	hw_desc->desc_command = (flags & DMA_PREP_INTERRUPT) ?58				XOR_DESC_EOD_INT_EN : 0;59	hw_desc->phy_dest_addr = addr;60	hw_desc->byte_count = byte_count;61}62 63static void mv_desc_set_mode(struct mv_xor_desc_slot *desc)64{65	struct mv_xor_desc *hw_desc = desc->hw_desc;66 67	switch (desc->type) {68	case DMA_XOR:69	case DMA_INTERRUPT:70		hw_desc->desc_command |= XOR_DESC_OPERATION_XOR;71		break;72	case DMA_MEMCPY:73		hw_desc->desc_command |= XOR_DESC_OPERATION_MEMCPY;74		break;75	default:76		BUG();77		return;78	}79}80 81static void mv_desc_set_next_desc(struct mv_xor_desc_slot *desc,82				  u32 next_desc_addr)83{84	struct mv_xor_desc *hw_desc = desc->hw_desc;85	BUG_ON(hw_desc->phy_next_desc);86	hw_desc->phy_next_desc = next_desc_addr;87}88 89static void mv_desc_set_src_addr(struct mv_xor_desc_slot *desc,90				 int index, dma_addr_t addr)91{92	struct mv_xor_desc *hw_desc = desc->hw_desc;93	hw_desc->phy_src_addr[mv_phy_src_idx(index)] = addr;94	if (desc->type == DMA_XOR)95		hw_desc->desc_command |= (1 << index);96}97 98static u32 mv_chan_get_current_desc(struct mv_xor_chan *chan)99{100	return readl_relaxed(XOR_CURR_DESC(chan));101}102 103static void mv_chan_set_next_descriptor(struct mv_xor_chan *chan,104					u32 next_desc_addr)105{106	writel_relaxed(next_desc_addr, XOR_NEXT_DESC(chan));107}108 109static void mv_chan_unmask_interrupts(struct mv_xor_chan *chan)110{111	u32 val = readl_relaxed(XOR_INTR_MASK(chan));112	val |= XOR_INTR_MASK_VALUE << (chan->idx * 16);113	writel_relaxed(val, XOR_INTR_MASK(chan));114}115 116static u32 mv_chan_get_intr_cause(struct mv_xor_chan *chan)117{118	u32 intr_cause = readl_relaxed(XOR_INTR_CAUSE(chan));119	intr_cause = (intr_cause >> (chan->idx * 16)) & 0xFFFF;120	return intr_cause;121}122 123static void mv_chan_clear_eoc_cause(struct mv_xor_chan *chan)124{125	u32 val;126 127	val = XOR_INT_END_OF_DESC | XOR_INT_END_OF_CHAIN | XOR_INT_STOPPED;128	val = ~(val << (chan->idx * 16));129	dev_dbg(mv_chan_to_devp(chan), "%s, val 0x%08x\n", __func__, val);130	writel_relaxed(val, XOR_INTR_CAUSE(chan));131}132 133static void mv_chan_clear_err_status(struct mv_xor_chan *chan)134{135	u32 val = 0xFFFF0000 >> (chan->idx * 16);136	writel_relaxed(val, XOR_INTR_CAUSE(chan));137}138 139static void mv_chan_set_mode(struct mv_xor_chan *chan,140			     u32 op_mode)141{142	u32 config = readl_relaxed(XOR_CONFIG(chan));143 144	config &= ~0x7;145	config |= op_mode;146 147#if defined(__BIG_ENDIAN)148	config |= XOR_DESCRIPTOR_SWAP;149#else150	config &= ~XOR_DESCRIPTOR_SWAP;151#endif152 153	writel_relaxed(config, XOR_CONFIG(chan));154}155 156static void mv_chan_activate(struct mv_xor_chan *chan)157{158	dev_dbg(mv_chan_to_devp(chan), " activate chan.\n");159 160	/* writel ensures all descriptors are flushed before activation */161	writel(BIT(0), XOR_ACTIVATION(chan));162}163 164static char mv_chan_is_busy(struct mv_xor_chan *chan)165{166	u32 state = readl_relaxed(XOR_ACTIVATION(chan));167 168	state = (state >> 4) & 0x3;169 170	return (state == 1) ? 1 : 0;171}172 173/*174 * mv_chan_start_new_chain - program the engine to operate on new175 * chain headed by sw_desc176 * Caller must hold &mv_chan->lock while calling this function177 */178static void mv_chan_start_new_chain(struct mv_xor_chan *mv_chan,179				    struct mv_xor_desc_slot *sw_desc)180{181	dev_dbg(mv_chan_to_devp(mv_chan), "%s %d: sw_desc %p\n",182		__func__, __LINE__, sw_desc);183 184	/* set the hardware chain */185	mv_chan_set_next_descriptor(mv_chan, sw_desc->async_tx.phys);186 187	mv_chan->pending++;188	mv_xor_issue_pending(&mv_chan->dmachan);189}190 191static dma_cookie_t192mv_desc_run_tx_complete_actions(struct mv_xor_desc_slot *desc,193				struct mv_xor_chan *mv_chan,194				dma_cookie_t cookie)195{196	BUG_ON(desc->async_tx.cookie < 0);197 198	if (desc->async_tx.cookie > 0) {199		cookie = desc->async_tx.cookie;200 201		dma_descriptor_unmap(&desc->async_tx);202		/* call the callback (must not sleep or submit new203		 * operations to this channel)204		 */205		dmaengine_desc_get_callback_invoke(&desc->async_tx, NULL);206	}207 208	/* run dependent operations */209	dma_run_dependencies(&desc->async_tx);210 211	return cookie;212}213 214static int215mv_chan_clean_completed_slots(struct mv_xor_chan *mv_chan)216{217	struct mv_xor_desc_slot *iter, *_iter;218 219	dev_dbg(mv_chan_to_devp(mv_chan), "%s %d\n", __func__, __LINE__);220	list_for_each_entry_safe(iter, _iter, &mv_chan->completed_slots,221				 node) {222 223		if (async_tx_test_ack(&iter->async_tx)) {224			list_move_tail(&iter->node, &mv_chan->free_slots);225			if (!list_empty(&iter->sg_tx_list)) {226				list_splice_tail_init(&iter->sg_tx_list,227							&mv_chan->free_slots);228			}229		}230	}231	return 0;232}233 234static int235mv_desc_clean_slot(struct mv_xor_desc_slot *desc,236		   struct mv_xor_chan *mv_chan)237{238	dev_dbg(mv_chan_to_devp(mv_chan), "%s %d: desc %p flags %d\n",239		__func__, __LINE__, desc, desc->async_tx.flags);240 241	/* the client is allowed to attach dependent operations242	 * until 'ack' is set243	 */244	if (!async_tx_test_ack(&desc->async_tx)) {245		/* move this slot to the completed_slots */246		list_move_tail(&desc->node, &mv_chan->completed_slots);247		if (!list_empty(&desc->sg_tx_list)) {248			list_splice_tail_init(&desc->sg_tx_list,249					      &mv_chan->completed_slots);250		}251	} else {252		list_move_tail(&desc->node, &mv_chan->free_slots);253		if (!list_empty(&desc->sg_tx_list)) {254			list_splice_tail_init(&desc->sg_tx_list,255					      &mv_chan->free_slots);256		}257	}258 259	return 0;260}261 262/* This function must be called with the mv_xor_chan spinlock held */263static void mv_chan_slot_cleanup(struct mv_xor_chan *mv_chan)264{265	struct mv_xor_desc_slot *iter, *_iter;266	dma_cookie_t cookie = 0;267	int busy = mv_chan_is_busy(mv_chan);268	u32 current_desc = mv_chan_get_current_desc(mv_chan);269	int current_cleaned = 0;270	struct mv_xor_desc *hw_desc;271 272	dev_dbg(mv_chan_to_devp(mv_chan), "%s %d\n", __func__, __LINE__);273	dev_dbg(mv_chan_to_devp(mv_chan), "current_desc %x\n", current_desc);274	mv_chan_clean_completed_slots(mv_chan);275 276	/* free completed slots from the chain starting with277	 * the oldest descriptor278	 */279 280	list_for_each_entry_safe(iter, _iter, &mv_chan->chain,281				 node) {282 283		/* clean finished descriptors */284		hw_desc = iter->hw_desc;285		if (hw_desc->status & XOR_DESC_SUCCESS) {286			cookie = mv_desc_run_tx_complete_actions(iter, mv_chan,287								 cookie);288 289			/* done processing desc, clean slot */290			mv_desc_clean_slot(iter, mv_chan);291 292			/* break if we did cleaned the current */293			if (iter->async_tx.phys == current_desc) {294				current_cleaned = 1;295				break;296			}297		} else {298			if (iter->async_tx.phys == current_desc) {299				current_cleaned = 0;300				break;301			}302		}303	}304 305	if ((busy == 0) && !list_empty(&mv_chan->chain)) {306		if (current_cleaned) {307			/*308			 * current descriptor cleaned and removed, run309			 * from list head310			 */311			iter = list_entry(mv_chan->chain.next,312					  struct mv_xor_desc_slot,313					  node);314			mv_chan_start_new_chain(mv_chan, iter);315		} else {316			if (!list_is_last(&iter->node, &mv_chan->chain)) {317				/*318				 * descriptors are still waiting after319				 * current, trigger them320				 */321				iter = list_entry(iter->node.next,322						  struct mv_xor_desc_slot,323						  node);324				mv_chan_start_new_chain(mv_chan, iter);325			} else {326				/*327				 * some descriptors are still waiting328				 * to be cleaned329				 */330				tasklet_schedule(&mv_chan->irq_tasklet);331			}332		}333	}334 335	if (cookie > 0)336		mv_chan->dmachan.completed_cookie = cookie;337}338 339static void mv_xor_tasklet(struct tasklet_struct *t)340{341	struct mv_xor_chan *chan = from_tasklet(chan, t, irq_tasklet);342 343	spin_lock(&chan->lock);344	mv_chan_slot_cleanup(chan);345	spin_unlock(&chan->lock);346}347 348static struct mv_xor_desc_slot *349mv_chan_alloc_slot(struct mv_xor_chan *mv_chan)350{351	struct mv_xor_desc_slot *iter;352 353	spin_lock_bh(&mv_chan->lock);354 355	if (!list_empty(&mv_chan->free_slots)) {356		iter = list_first_entry(&mv_chan->free_slots,357					struct mv_xor_desc_slot,358					node);359 360		list_move_tail(&iter->node, &mv_chan->allocated_slots);361 362		spin_unlock_bh(&mv_chan->lock);363 364		/* pre-ack descriptor */365		async_tx_ack(&iter->async_tx);366		iter->async_tx.cookie = -EBUSY;367 368		return iter;369 370	}371 372	spin_unlock_bh(&mv_chan->lock);373 374	/* try to free some slots if the allocation fails */375	tasklet_schedule(&mv_chan->irq_tasklet);376 377	return NULL;378}379 380/************************ DMA engine API functions ****************************/381static dma_cookie_t382mv_xor_tx_submit(struct dma_async_tx_descriptor *tx)383{384	struct mv_xor_desc_slot *sw_desc = to_mv_xor_slot(tx);385	struct mv_xor_chan *mv_chan = to_mv_xor_chan(tx->chan);386	struct mv_xor_desc_slot *old_chain_tail;387	dma_cookie_t cookie;388	int new_hw_chain = 1;389 390	dev_dbg(mv_chan_to_devp(mv_chan),391		"%s sw_desc %p: async_tx %p\n",392		__func__, sw_desc, &sw_desc->async_tx);393 394	spin_lock_bh(&mv_chan->lock);395	cookie = dma_cookie_assign(tx);396 397	if (list_empty(&mv_chan->chain))398		list_move_tail(&sw_desc->node, &mv_chan->chain);399	else {400		new_hw_chain = 0;401 402		old_chain_tail = list_entry(mv_chan->chain.prev,403					    struct mv_xor_desc_slot,404					    node);405		list_move_tail(&sw_desc->node, &mv_chan->chain);406 407		dev_dbg(mv_chan_to_devp(mv_chan), "Append to last desc %pa\n",408			&old_chain_tail->async_tx.phys);409 410		/* fix up the hardware chain */411		mv_desc_set_next_desc(old_chain_tail, sw_desc->async_tx.phys);412 413		/* if the channel is not busy */414		if (!mv_chan_is_busy(mv_chan)) {415			u32 current_desc = mv_chan_get_current_desc(mv_chan);416			/*417			 * and the current desc is the end of the chain before418			 * the append, then we need to start the channel419			 */420			if (current_desc == old_chain_tail->async_tx.phys)421				new_hw_chain = 1;422		}423	}424 425	if (new_hw_chain)426		mv_chan_start_new_chain(mv_chan, sw_desc);427 428	spin_unlock_bh(&mv_chan->lock);429 430	return cookie;431}432 433/* returns the number of allocated descriptors */434static int mv_xor_alloc_chan_resources(struct dma_chan *chan)435{436	void *virt_desc;437	dma_addr_t dma_desc;438	int idx;439	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);440	struct mv_xor_desc_slot *slot = NULL;441	int num_descs_in_pool = MV_XOR_POOL_SIZE/MV_XOR_SLOT_SIZE;442 443	/* Allocate descriptor slots */444	idx = mv_chan->slots_allocated;445	while (idx < num_descs_in_pool) {446		slot = kzalloc(sizeof(*slot), GFP_KERNEL);447		if (!slot) {448			dev_info(mv_chan_to_devp(mv_chan),449				 "channel only initialized %d descriptor slots",450				 idx);451			break;452		}453		virt_desc = mv_chan->dma_desc_pool_virt;454		slot->hw_desc = virt_desc + idx * MV_XOR_SLOT_SIZE;455 456		dma_async_tx_descriptor_init(&slot->async_tx, chan);457		slot->async_tx.tx_submit = mv_xor_tx_submit;458		INIT_LIST_HEAD(&slot->node);459		INIT_LIST_HEAD(&slot->sg_tx_list);460		dma_desc = mv_chan->dma_desc_pool;461		slot->async_tx.phys = dma_desc + idx * MV_XOR_SLOT_SIZE;462		slot->idx = idx++;463 464		spin_lock_bh(&mv_chan->lock);465		mv_chan->slots_allocated = idx;466		list_add_tail(&slot->node, &mv_chan->free_slots);467		spin_unlock_bh(&mv_chan->lock);468	}469 470	dev_dbg(mv_chan_to_devp(mv_chan),471		"allocated %d descriptor slots\n",472		mv_chan->slots_allocated);473 474	return mv_chan->slots_allocated ? : -ENOMEM;475}476 477/*478 * Check if source or destination is an PCIe/IO address (non-SDRAM) and add479 * a new MBus window if necessary. Use a cache for these check so that480 * the MMIO mapped registers don't have to be accessed for this check481 * to speed up this process.482 */483static int mv_xor_add_io_win(struct mv_xor_chan *mv_chan, u32 addr)484{485	struct mv_xor_device *xordev = mv_chan->xordev;486	void __iomem *base = mv_chan->mmr_high_base;487	u32 win_enable;488	u32 size;489	u8 target, attr;490	int ret;491	int i;492 493	/* Nothing needs to get done for the Armada 3700 */494	if (xordev->xor_type == XOR_ARMADA_37XX)495		return 0;496 497	/*498	 * Loop over the cached windows to check, if the requested area499	 * is already mapped. If this the case, nothing needs to be done500	 * and we can return.501	 */502	for (i = 0; i < WINDOW_COUNT; i++) {503		if (addr >= xordev->win_start[i] &&504		    addr <= xordev->win_end[i]) {505			/* Window is already mapped */506			return 0;507		}508	}509 510	/*511	 * The window is not mapped, so we need to create the new mapping512	 */513 514	/* If no IO window is found that addr has to be located in SDRAM */515	ret = mvebu_mbus_get_io_win_info(addr, &size, &target, &attr);516	if (ret < 0)517		return 0;518 519	/*520	 * Mask the base addr 'addr' according to 'size' read back from the521	 * MBus window. Otherwise we might end up with an address located522	 * somewhere in the middle of this area here.523	 */524	size -= 1;525	addr &= ~size;526 527	/*528	 * Reading one of both enabled register is enough, as they are always529	 * programmed to the identical values530	 */531	win_enable = readl(base + WINDOW_BAR_ENABLE(0));532 533	/* Set 'i' to the first free window to write the new values to */534	i = ffs(~win_enable) - 1;535	if (i >= WINDOW_COUNT)536		return -ENOMEM;537 538	writel((addr & 0xffff0000) | (attr << 8) | target,539	       base + WINDOW_BASE(i));540	writel(size & 0xffff0000, base + WINDOW_SIZE(i));541 542	/* Fill the caching variables for later use */543	xordev->win_start[i] = addr;544	xordev->win_end[i] = addr + size;545 546	win_enable |= (1 << i);547	win_enable |= 3 << (16 + (2 * i));548	writel(win_enable, base + WINDOW_BAR_ENABLE(0));549	writel(win_enable, base + WINDOW_BAR_ENABLE(1));550 551	return 0;552}553 554static struct dma_async_tx_descriptor *555mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,556		    unsigned int src_cnt, size_t len, unsigned long flags)557{558	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);559	struct mv_xor_desc_slot *sw_desc;560	int ret;561 562	if (unlikely(len < MV_XOR_MIN_BYTE_COUNT))563		return NULL;564 565	BUG_ON(len > MV_XOR_MAX_BYTE_COUNT);566 567	dev_dbg(mv_chan_to_devp(mv_chan),568		"%s src_cnt: %d len: %zu dest %pad flags: %ld\n",569		__func__, src_cnt, len, &dest, flags);570 571	/* Check if a new window needs to get added for 'dest' */572	ret = mv_xor_add_io_win(mv_chan, dest);573	if (ret)574		return NULL;575 576	sw_desc = mv_chan_alloc_slot(mv_chan);577	if (sw_desc) {578		sw_desc->type = DMA_XOR;579		sw_desc->async_tx.flags = flags;580		mv_desc_init(sw_desc, dest, len, flags);581		if (mv_chan->op_in_desc == XOR_MODE_IN_DESC)582			mv_desc_set_mode(sw_desc);583		while (src_cnt--) {584			/* Check if a new window needs to get added for 'src' */585			ret = mv_xor_add_io_win(mv_chan, src[src_cnt]);586			if (ret)587				return NULL;588			mv_desc_set_src_addr(sw_desc, src_cnt, src[src_cnt]);589		}590	}591 592	dev_dbg(mv_chan_to_devp(mv_chan),593		"%s sw_desc %p async_tx %p \n",594		__func__, sw_desc, &sw_desc->async_tx);595	return sw_desc ? &sw_desc->async_tx : NULL;596}597 598static struct dma_async_tx_descriptor *599mv_xor_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,600		size_t len, unsigned long flags)601{602	/*603	 * A MEMCPY operation is identical to an XOR operation with only604	 * a single source address.605	 */606	return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags);607}608 609static struct dma_async_tx_descriptor *610mv_xor_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)611{612	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);613	dma_addr_t src, dest;614	size_t len;615 616	src = mv_chan->dummy_src_addr;617	dest = mv_chan->dummy_dst_addr;618	len = MV_XOR_MIN_BYTE_COUNT;619 620	/*621	 * We implement the DMA_INTERRUPT operation as a minimum sized622	 * XOR operation with a single dummy source address.623	 */624	return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags);625}626 627static void mv_xor_free_chan_resources(struct dma_chan *chan)628{629	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);630	struct mv_xor_desc_slot *iter, *_iter;631	int in_use_descs = 0;632 633	spin_lock_bh(&mv_chan->lock);634 635	mv_chan_slot_cleanup(mv_chan);636 637	list_for_each_entry_safe(iter, _iter, &mv_chan->chain,638					node) {639		in_use_descs++;640		list_move_tail(&iter->node, &mv_chan->free_slots);641	}642	list_for_each_entry_safe(iter, _iter, &mv_chan->completed_slots,643				 node) {644		in_use_descs++;645		list_move_tail(&iter->node, &mv_chan->free_slots);646	}647	list_for_each_entry_safe(iter, _iter, &mv_chan->allocated_slots,648				 node) {649		in_use_descs++;650		list_move_tail(&iter->node, &mv_chan->free_slots);651	}652	list_for_each_entry_safe_reverse(653		iter, _iter, &mv_chan->free_slots, node) {654		list_del(&iter->node);655		kfree(iter);656		mv_chan->slots_allocated--;657	}658 659	dev_dbg(mv_chan_to_devp(mv_chan), "%s slots_allocated %d\n",660		__func__, mv_chan->slots_allocated);661	spin_unlock_bh(&mv_chan->lock);662 663	if (in_use_descs)664		dev_err(mv_chan_to_devp(mv_chan),665			"freeing %d in use descriptors!\n", in_use_descs);666}667 668/**669 * mv_xor_status - poll the status of an XOR transaction670 * @chan: XOR channel handle671 * @cookie: XOR transaction identifier672 * @txstate: XOR transactions state holder (or NULL)673 */674static enum dma_status mv_xor_status(struct dma_chan *chan,675					  dma_cookie_t cookie,676					  struct dma_tx_state *txstate)677{678	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);679	enum dma_status ret;680 681	ret = dma_cookie_status(chan, cookie, txstate);682	if (ret == DMA_COMPLETE)683		return ret;684 685	spin_lock_bh(&mv_chan->lock);686	mv_chan_slot_cleanup(mv_chan);687	spin_unlock_bh(&mv_chan->lock);688 689	return dma_cookie_status(chan, cookie, txstate);690}691 692static void mv_chan_dump_regs(struct mv_xor_chan *chan)693{694	u32 val;695 696	val = readl_relaxed(XOR_CONFIG(chan));697	dev_err(mv_chan_to_devp(chan), "config       0x%08x\n", val);698 699	val = readl_relaxed(XOR_ACTIVATION(chan));700	dev_err(mv_chan_to_devp(chan), "activation   0x%08x\n", val);701 702	val = readl_relaxed(XOR_INTR_CAUSE(chan));703	dev_err(mv_chan_to_devp(chan), "intr cause   0x%08x\n", val);704 705	val = readl_relaxed(XOR_INTR_MASK(chan));706	dev_err(mv_chan_to_devp(chan), "intr mask    0x%08x\n", val);707 708	val = readl_relaxed(XOR_ERROR_CAUSE(chan));709	dev_err(mv_chan_to_devp(chan), "error cause  0x%08x\n", val);710 711	val = readl_relaxed(XOR_ERROR_ADDR(chan));712	dev_err(mv_chan_to_devp(chan), "error addr   0x%08x\n", val);713}714 715static void mv_chan_err_interrupt_handler(struct mv_xor_chan *chan,716					  u32 intr_cause)717{718	if (intr_cause & XOR_INT_ERR_DECODE) {719		dev_dbg(mv_chan_to_devp(chan), "ignoring address decode error\n");720		return;721	}722 723	dev_err(mv_chan_to_devp(chan), "error on chan %d. intr cause 0x%08x\n",724		chan->idx, intr_cause);725 726	mv_chan_dump_regs(chan);727	WARN_ON(1);728}729 730static irqreturn_t mv_xor_interrupt_handler(int irq, void *data)731{732	struct mv_xor_chan *chan = data;733	u32 intr_cause = mv_chan_get_intr_cause(chan);734 735	dev_dbg(mv_chan_to_devp(chan), "intr cause %x\n", intr_cause);736 737	if (intr_cause & XOR_INTR_ERRORS)738		mv_chan_err_interrupt_handler(chan, intr_cause);739 740	tasklet_schedule(&chan->irq_tasklet);741 742	mv_chan_clear_eoc_cause(chan);743 744	return IRQ_HANDLED;745}746 747static void mv_xor_issue_pending(struct dma_chan *chan)748{749	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);750 751	if (mv_chan->pending >= MV_XOR_THRESHOLD) {752		mv_chan->pending = 0;753		mv_chan_activate(mv_chan);754	}755}756 757/*758 * Perform a transaction to verify the HW works.759 */760 761static int mv_chan_memcpy_self_test(struct mv_xor_chan *mv_chan)762{763	int i, ret;764	void *src, *dest;765	dma_addr_t src_dma, dest_dma;766	struct dma_chan *dma_chan;767	dma_cookie_t cookie;768	struct dma_async_tx_descriptor *tx;769	struct dmaengine_unmap_data *unmap;770	int err = 0;771 772	src = kmalloc(PAGE_SIZE, GFP_KERNEL);773	if (!src)774		return -ENOMEM;775 776	dest = kzalloc(PAGE_SIZE, GFP_KERNEL);777	if (!dest) {778		kfree(src);779		return -ENOMEM;780	}781 782	/* Fill in src buffer */783	for (i = 0; i < PAGE_SIZE; i++)784		((u8 *) src)[i] = (u8)i;785 786	dma_chan = &mv_chan->dmachan;787	if (mv_xor_alloc_chan_resources(dma_chan) < 1) {788		err = -ENODEV;789		goto out;790	}791 792	unmap = dmaengine_get_unmap_data(dma_chan->device->dev, 2, GFP_KERNEL);793	if (!unmap) {794		err = -ENOMEM;795		goto free_resources;796	}797 798	src_dma = dma_map_page(dma_chan->device->dev, virt_to_page(src),799			       offset_in_page(src), PAGE_SIZE,800			       DMA_TO_DEVICE);801	unmap->addr[0] = src_dma;802 803	ret = dma_mapping_error(dma_chan->device->dev, src_dma);804	if (ret) {805		err = -ENOMEM;806		goto free_resources;807	}808	unmap->to_cnt = 1;809 810	dest_dma = dma_map_page(dma_chan->device->dev, virt_to_page(dest),811				offset_in_page(dest), PAGE_SIZE,812				DMA_FROM_DEVICE);813	unmap->addr[1] = dest_dma;814 815	ret = dma_mapping_error(dma_chan->device->dev, dest_dma);816	if (ret) {817		err = -ENOMEM;818		goto free_resources;819	}820	unmap->from_cnt = 1;821	unmap->len = PAGE_SIZE;822 823	tx = mv_xor_prep_dma_memcpy(dma_chan, dest_dma, src_dma,824				    PAGE_SIZE, 0);825	if (!tx) {826		dev_err(dma_chan->device->dev,827			"Self-test cannot prepare operation, disabling\n");828		err = -ENODEV;829		goto free_resources;830	}831 832	cookie = mv_xor_tx_submit(tx);833	if (dma_submit_error(cookie)) {834		dev_err(dma_chan->device->dev,835			"Self-test submit error, disabling\n");836		err = -ENODEV;837		goto free_resources;838	}839 840	mv_xor_issue_pending(dma_chan);841	async_tx_ack(tx);842	msleep(1);843 844	if (mv_xor_status(dma_chan, cookie, NULL) !=845	    DMA_COMPLETE) {846		dev_err(dma_chan->device->dev,847			"Self-test copy timed out, disabling\n");848		err = -ENODEV;849		goto free_resources;850	}851 852	dma_sync_single_for_cpu(dma_chan->device->dev, dest_dma,853				PAGE_SIZE, DMA_FROM_DEVICE);854	if (memcmp(src, dest, PAGE_SIZE)) {855		dev_err(dma_chan->device->dev,856			"Self-test copy failed compare, disabling\n");857		err = -ENODEV;858		goto free_resources;859	}860 861free_resources:862	dmaengine_unmap_put(unmap);863	mv_xor_free_chan_resources(dma_chan);864out:865	kfree(src);866	kfree(dest);867	return err;868}869 870#define MV_XOR_NUM_SRC_TEST 4 /* must be <= 15 */871static int872mv_chan_xor_self_test(struct mv_xor_chan *mv_chan)873{874	int i, src_idx, ret;875	struct page *dest;876	struct page *xor_srcs[MV_XOR_NUM_SRC_TEST];877	dma_addr_t dma_srcs[MV_XOR_NUM_SRC_TEST];878	dma_addr_t dest_dma;879	struct dma_async_tx_descriptor *tx;880	struct dmaengine_unmap_data *unmap;881	struct dma_chan *dma_chan;882	dma_cookie_t cookie;883	u8 cmp_byte = 0;884	u32 cmp_word;885	int err = 0;886	int src_count = MV_XOR_NUM_SRC_TEST;887 888	for (src_idx = 0; src_idx < src_count; src_idx++) {889		xor_srcs[src_idx] = alloc_page(GFP_KERNEL);890		if (!xor_srcs[src_idx]) {891			while (src_idx--)892				__free_page(xor_srcs[src_idx]);893			return -ENOMEM;894		}895	}896 897	dest = alloc_page(GFP_KERNEL);898	if (!dest) {899		while (src_idx--)900			__free_page(xor_srcs[src_idx]);901		return -ENOMEM;902	}903 904	/* Fill in src buffers */905	for (src_idx = 0; src_idx < src_count; src_idx++) {906		u8 *ptr = page_address(xor_srcs[src_idx]);907		for (i = 0; i < PAGE_SIZE; i++)908			ptr[i] = (1 << src_idx);909	}910 911	for (src_idx = 0; src_idx < src_count; src_idx++)912		cmp_byte ^= (u8) (1 << src_idx);913 914	cmp_word = (cmp_byte << 24) | (cmp_byte << 16) |915		(cmp_byte << 8) | cmp_byte;916 917	memset(page_address(dest), 0, PAGE_SIZE);918 919	dma_chan = &mv_chan->dmachan;920	if (mv_xor_alloc_chan_resources(dma_chan) < 1) {921		err = -ENODEV;922		goto out;923	}924 925	unmap = dmaengine_get_unmap_data(dma_chan->device->dev, src_count + 1,926					 GFP_KERNEL);927	if (!unmap) {928		err = -ENOMEM;929		goto free_resources;930	}931 932	/* test xor */933	for (i = 0; i < src_count; i++) {934		unmap->addr[i] = dma_map_page(dma_chan->device->dev, xor_srcs[i],935					      0, PAGE_SIZE, DMA_TO_DEVICE);936		dma_srcs[i] = unmap->addr[i];937		ret = dma_mapping_error(dma_chan->device->dev, unmap->addr[i]);938		if (ret) {939			err = -ENOMEM;940			goto free_resources;941		}942		unmap->to_cnt++;943	}944 945	unmap->addr[src_count] = dma_map_page(dma_chan->device->dev, dest, 0, PAGE_SIZE,946				      DMA_FROM_DEVICE);947	dest_dma = unmap->addr[src_count];948	ret = dma_mapping_error(dma_chan->device->dev, unmap->addr[src_count]);949	if (ret) {950		err = -ENOMEM;951		goto free_resources;952	}953	unmap->from_cnt = 1;954	unmap->len = PAGE_SIZE;955 956	tx = mv_xor_prep_dma_xor(dma_chan, dest_dma, dma_srcs,957				 src_count, PAGE_SIZE, 0);958	if (!tx) {959		dev_err(dma_chan->device->dev,960			"Self-test cannot prepare operation, disabling\n");961		err = -ENODEV;962		goto free_resources;963	}964 965	cookie = mv_xor_tx_submit(tx);966	if (dma_submit_error(cookie)) {967		dev_err(dma_chan->device->dev,968			"Self-test submit error, disabling\n");969		err = -ENODEV;970		goto free_resources;971	}972 973	mv_xor_issue_pending(dma_chan);974	async_tx_ack(tx);975	msleep(8);976 977	if (mv_xor_status(dma_chan, cookie, NULL) !=978	    DMA_COMPLETE) {979		dev_err(dma_chan->device->dev,980			"Self-test xor timed out, disabling\n");981		err = -ENODEV;982		goto free_resources;983	}984 985	dma_sync_single_for_cpu(dma_chan->device->dev, dest_dma,986				PAGE_SIZE, DMA_FROM_DEVICE);987	for (i = 0; i < (PAGE_SIZE / sizeof(u32)); i++) {988		u32 *ptr = page_address(dest);989		if (ptr[i] != cmp_word) {990			dev_err(dma_chan->device->dev,991				"Self-test xor failed compare, disabling. index %d, data %x, expected %x\n",992				i, ptr[i], cmp_word);993			err = -ENODEV;994			goto free_resources;995		}996	}997 998free_resources:999	dmaengine_unmap_put(unmap);1000	mv_xor_free_chan_resources(dma_chan);1001out:1002	src_idx = src_count;1003	while (src_idx--)1004		__free_page(xor_srcs[src_idx]);1005	__free_page(dest);1006	return err;1007}1008 1009static int mv_xor_channel_remove(struct mv_xor_chan *mv_chan)1010{1011	struct dma_chan *chan, *_chan;1012	struct device *dev = mv_chan->dmadev.dev;1013 1014	dma_async_device_unregister(&mv_chan->dmadev);1015 1016	dma_free_coherent(dev, MV_XOR_POOL_SIZE,1017			  mv_chan->dma_desc_pool_virt, mv_chan->dma_desc_pool);1018	dma_unmap_single(dev, mv_chan->dummy_src_addr,1019			 MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE);1020	dma_unmap_single(dev, mv_chan->dummy_dst_addr,1021			 MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE);1022 1023	list_for_each_entry_safe(chan, _chan, &mv_chan->dmadev.channels,1024				 device_node) {1025		list_del(&chan->device_node);1026	}1027 1028	free_irq(mv_chan->irq, mv_chan);1029 1030	return 0;1031}1032 1033static struct mv_xor_chan *1034mv_xor_channel_add(struct mv_xor_device *xordev,1035		   struct platform_device *pdev,1036		   int idx, dma_cap_mask_t cap_mask, int irq)1037{1038	int ret = 0;1039	struct mv_xor_chan *mv_chan;1040	struct dma_device *dma_dev;1041 1042	mv_chan = devm_kzalloc(&pdev->dev, sizeof(*mv_chan), GFP_KERNEL);1043	if (!mv_chan)1044		return ERR_PTR(-ENOMEM);1045 1046	mv_chan->idx = idx;1047	mv_chan->irq = irq;1048	if (xordev->xor_type == XOR_ORION)1049		mv_chan->op_in_desc = XOR_MODE_IN_REG;1050	else1051		mv_chan->op_in_desc = XOR_MODE_IN_DESC;1052 1053	dma_dev = &mv_chan->dmadev;1054	dma_dev->dev = &pdev->dev;1055	mv_chan->xordev = xordev;1056 1057	/*1058	 * These source and destination dummy buffers are used to implement1059	 * a DMA_INTERRUPT operation as a minimum-sized XOR operation.1060	 * Hence, we only need to map the buffers at initialization-time.1061	 */1062	mv_chan->dummy_src_addr = dma_map_single(dma_dev->dev,1063		mv_chan->dummy_src, MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE);1064	mv_chan->dummy_dst_addr = dma_map_single(dma_dev->dev,1065		mv_chan->dummy_dst, MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE);1066 1067	/* allocate coherent memory for hardware descriptors1068	 * note: writecombine gives slightly better performance, but1069	 * requires that we explicitly flush the writes1070	 */1071	mv_chan->dma_desc_pool_virt =1072	  dma_alloc_wc(&pdev->dev, MV_XOR_POOL_SIZE, &mv_chan->dma_desc_pool,1073		       GFP_KERNEL);1074	if (!mv_chan->dma_desc_pool_virt)1075		return ERR_PTR(-ENOMEM);1076 1077	/* discover transaction capabilities from the platform data */1078	dma_dev->cap_mask = cap_mask;1079 1080	INIT_LIST_HEAD(&dma_dev->channels);1081 1082	/* set base routines */1083	dma_dev->device_alloc_chan_resources = mv_xor_alloc_chan_resources;1084	dma_dev->device_free_chan_resources = mv_xor_free_chan_resources;1085	dma_dev->device_tx_status = mv_xor_status;1086	dma_dev->device_issue_pending = mv_xor_issue_pending;1087 1088	/* set prep routines based on capability */1089	if (dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask))1090		dma_dev->device_prep_dma_interrupt = mv_xor_prep_dma_interrupt;1091	if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask))1092		dma_dev->device_prep_dma_memcpy = mv_xor_prep_dma_memcpy;1093	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {1094		dma_dev->max_xor = 8;1095		dma_dev->device_prep_dma_xor = mv_xor_prep_dma_xor;1096	}1097 1098	mv_chan->mmr_base = xordev->xor_base;1099	mv_chan->mmr_high_base = xordev->xor_high_base;1100	tasklet_setup(&mv_chan->irq_tasklet, mv_xor_tasklet);1101 1102	/* clear errors before enabling interrupts */1103	mv_chan_clear_err_status(mv_chan);1104 1105	ret = request_irq(mv_chan->irq, mv_xor_interrupt_handler,1106			  0, dev_name(&pdev->dev), mv_chan);1107	if (ret)1108		goto err_free_dma;1109 1110	mv_chan_unmask_interrupts(mv_chan);1111 1112	if (mv_chan->op_in_desc == XOR_MODE_IN_DESC)1113		mv_chan_set_mode(mv_chan, XOR_OPERATION_MODE_IN_DESC);1114	else1115		mv_chan_set_mode(mv_chan, XOR_OPERATION_MODE_XOR);1116 1117	spin_lock_init(&mv_chan->lock);1118	INIT_LIST_HEAD(&mv_chan->chain);1119	INIT_LIST_HEAD(&mv_chan->completed_slots);1120	INIT_LIST_HEAD(&mv_chan->free_slots);1121	INIT_LIST_HEAD(&mv_chan->allocated_slots);1122	mv_chan->dmachan.device = dma_dev;1123	dma_cookie_init(&mv_chan->dmachan);1124 1125	list_add_tail(&mv_chan->dmachan.device_node, &dma_dev->channels);1126 1127	if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) {1128		ret = mv_chan_memcpy_self_test(mv_chan);1129		dev_dbg(&pdev->dev, "memcpy self test returned %d\n", ret);1130		if (ret)1131			goto err_free_irq;1132	}1133 1134	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {1135		ret = mv_chan_xor_self_test(mv_chan);1136		dev_dbg(&pdev->dev, "xor self test returned %d\n", ret);1137		if (ret)1138			goto err_free_irq;1139	}1140 1141	dev_info(&pdev->dev, "Marvell XOR (%s): ( %s%s%s)\n",1142		 mv_chan->op_in_desc ? "Descriptor Mode" : "Registers Mode",1143		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "xor " : "",1144		 dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "cpy " : "",1145		 dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask) ? "intr " : "");1146 1147	ret = dma_async_device_register(dma_dev);1148	if (ret)1149		goto err_free_irq;1150 1151	return mv_chan;1152 1153err_free_irq:1154	free_irq(mv_chan->irq, mv_chan);1155err_free_dma:1156	dma_free_coherent(&pdev->dev, MV_XOR_POOL_SIZE,1157			  mv_chan->dma_desc_pool_virt, mv_chan->dma_desc_pool);1158	return ERR_PTR(ret);1159}1160 1161static void1162mv_xor_conf_mbus_windows(struct mv_xor_device *xordev,1163			 const struct mbus_dram_target_info *dram)1164{1165	void __iomem *base = xordev->xor_high_base;1166	u32 win_enable = 0;1167	int i;1168 1169	for (i = 0; i < 8; i++) {1170		writel(0, base + WINDOW_BASE(i));1171		writel(0, base + WINDOW_SIZE(i));1172		if (i < 4)1173			writel(0, base + WINDOW_REMAP_HIGH(i));1174	}1175 1176	for (i = 0; i < dram->num_cs; i++) {1177		const struct mbus_dram_window *cs = dram->cs + i;1178 1179		writel((cs->base & 0xffff0000) |1180		       (cs->mbus_attr << 8) |1181		       dram->mbus_dram_target_id, base + WINDOW_BASE(i));1182		writel((cs->size - 1) & 0xffff0000, base + WINDOW_SIZE(i));1183 1184		/* Fill the caching variables for later use */1185		xordev->win_start[i] = cs->base;1186		xordev->win_end[i] = cs->base + cs->size - 1;1187 1188		win_enable |= (1 << i);1189		win_enable |= 3 << (16 + (2 * i));1190	}1191 1192	writel(win_enable, base + WINDOW_BAR_ENABLE(0));1193	writel(win_enable, base + WINDOW_BAR_ENABLE(1));1194	writel(0, base + WINDOW_OVERRIDE_CTRL(0));1195	writel(0, base + WINDOW_OVERRIDE_CTRL(1));1196}1197 1198static void1199mv_xor_conf_mbus_windows_a3700(struct mv_xor_device *xordev)1200{1201	void __iomem *base = xordev->xor_high_base;1202	u32 win_enable = 0;1203	int i;1204 1205	for (i = 0; i < 8; i++) {1206		writel(0, base + WINDOW_BASE(i));1207		writel(0, base + WINDOW_SIZE(i));1208		if (i < 4)1209			writel(0, base + WINDOW_REMAP_HIGH(i));1210	}1211	/*1212	 * For Armada3700 open default 4GB Mbus window. The dram1213	 * related configuration are done at AXIS level.1214	 */1215	writel(0xffff0000, base + WINDOW_SIZE(0));1216	win_enable |= 1;1217	win_enable |= 3 << 16;1218 1219	writel(win_enable, base + WINDOW_BAR_ENABLE(0));1220	writel(win_enable, base + WINDOW_BAR_ENABLE(1));1221	writel(0, base + WINDOW_OVERRIDE_CTRL(0));1222	writel(0, base + WINDOW_OVERRIDE_CTRL(1));1223}1224 1225/*1226 * Since this XOR driver is basically used only for RAID5, we don't1227 * need to care about synchronizing ->suspend with DMA activity,1228 * because the DMA engine will naturally be quiet due to the block1229 * devices being suspended.1230 */1231static int mv_xor_suspend(struct platform_device *pdev, pm_message_t state)1232{1233	struct mv_xor_device *xordev = platform_get_drvdata(pdev);1234	int i;1235 1236	for (i = 0; i < MV_XOR_MAX_CHANNELS; i++) {1237		struct mv_xor_chan *mv_chan = xordev->channels[i];1238 1239		if (!mv_chan)1240			continue;1241 1242		mv_chan->saved_config_reg =1243			readl_relaxed(XOR_CONFIG(mv_chan));1244		mv_chan->saved_int_mask_reg =1245			readl_relaxed(XOR_INTR_MASK(mv_chan));1246	}1247 1248	return 0;1249}1250 1251static int mv_xor_resume(struct platform_device *dev)1252{1253	struct mv_xor_device *xordev = platform_get_drvdata(dev);1254	const struct mbus_dram_target_info *dram;1255	int i;1256 1257	for (i = 0; i < MV_XOR_MAX_CHANNELS; i++) {1258		struct mv_xor_chan *mv_chan = xordev->channels[i];1259 1260		if (!mv_chan)1261			continue;1262 1263		writel_relaxed(mv_chan->saved_config_reg,1264			       XOR_CONFIG(mv_chan));1265		writel_relaxed(mv_chan->saved_int_mask_reg,1266			       XOR_INTR_MASK(mv_chan));1267	}1268 1269	if (xordev->xor_type == XOR_ARMADA_37XX) {1270		mv_xor_conf_mbus_windows_a3700(xordev);1271		return 0;1272	}1273 1274	dram = mv_mbus_dram_info();1275	if (dram)1276		mv_xor_conf_mbus_windows(xordev, dram);1277 1278	return 0;1279}1280 1281static const struct of_device_id mv_xor_dt_ids[] = {1282	{ .compatible = "marvell,orion-xor", .data = (void *)XOR_ORION },1283	{ .compatible = "marvell,armada-380-xor", .data = (void *)XOR_ARMADA_38X },1284	{ .compatible = "marvell,armada-3700-xor", .data = (void *)XOR_ARMADA_37XX },1285	{},1286};1287 1288static unsigned int mv_xor_engine_count;1289 1290static int mv_xor_probe(struct platform_device *pdev)1291{1292	const struct mbus_dram_target_info *dram;1293	struct mv_xor_device *xordev;1294	struct mv_xor_platform_data *pdata = dev_get_platdata(&pdev->dev);1295	struct resource *res;1296	unsigned int max_engines, max_channels;1297	int i, ret;1298 1299	dev_notice(&pdev->dev, "Marvell shared XOR driver\n");1300 1301	xordev = devm_kzalloc(&pdev->dev, sizeof(*xordev), GFP_KERNEL);1302	if (!xordev)1303		return -ENOMEM;1304 1305	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);1306	if (!res)1307		return -ENODEV;1308 1309	xordev->xor_base = devm_ioremap(&pdev->dev, res->start,1310					resource_size(res));1311	if (!xordev->xor_base)1312		return -EBUSY;1313 1314	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);1315	if (!res)1316		return -ENODEV;1317 1318	xordev->xor_high_base = devm_ioremap(&pdev->dev, res->start,1319					     resource_size(res));1320	if (!xordev->xor_high_base)1321		return -EBUSY;1322 1323	platform_set_drvdata(pdev, xordev);1324 1325 1326	/*1327	 * We need to know which type of XOR device we use before1328	 * setting up. In non-dt case it can only be the legacy one.1329	 */1330	xordev->xor_type = XOR_ORION;1331	if (pdev->dev.of_node)1332		xordev->xor_type = (uintptr_t)device_get_match_data(&pdev->dev);1333 1334	/*1335	 * (Re-)program MBUS remapping windows if we are asked to.1336	 */1337	if (xordev->xor_type == XOR_ARMADA_37XX) {1338		mv_xor_conf_mbus_windows_a3700(xordev);1339	} else {1340		dram = mv_mbus_dram_info();1341		if (dram)1342			mv_xor_conf_mbus_windows(xordev, dram);1343	}1344 1345	/* Not all platforms can gate the clock, so it is not1346	 * an error if the clock does not exists.1347	 */1348	xordev->clk = clk_get(&pdev->dev, NULL);1349	if (!IS_ERR(xordev->clk))1350		clk_prepare_enable(xordev->clk);1351 1352	/*1353	 * We don't want to have more than one channel per CPU in1354	 * order for async_tx to perform well. So we limit the number1355	 * of engines and channels so that we take into account this1356	 * constraint. Note that we also want to use channels from1357	 * separate engines when possible.  For dual-CPU Armada 37001358	 * SoC with single XOR engine allow using its both channels.1359	 */1360	max_engines = num_present_cpus();1361	if (xordev->xor_type == XOR_ARMADA_37XX)1362		max_channels =	num_present_cpus();1363	else1364		max_channels = min_t(unsigned int,1365				     MV_XOR_MAX_CHANNELS,1366				     DIV_ROUND_UP(num_present_cpus(), 2));1367 1368	if (mv_xor_engine_count >= max_engines)1369		return 0;1370 1371	if (pdev->dev.of_node) {1372		struct device_node *np;1373		int i = 0;1374 1375		for_each_child_of_node(pdev->dev.of_node, np) {1376			struct mv_xor_chan *chan;1377			dma_cap_mask_t cap_mask;1378			int irq;1379 1380			if (i >= max_channels)1381				continue;1382 1383			dma_cap_zero(cap_mask);1384			dma_cap_set(DMA_MEMCPY, cap_mask);1385			dma_cap_set(DMA_XOR, cap_mask);1386			dma_cap_set(DMA_INTERRUPT, cap_mask);1387 1388			irq = irq_of_parse_and_map(np, 0);1389			if (!irq) {1390				ret = -ENODEV;1391				goto err_channel_add;1392			}1393 1394			chan = mv_xor_channel_add(xordev, pdev, i,1395						  cap_mask, irq);1396			if (IS_ERR(chan)) {1397				ret = PTR_ERR(chan);1398				irq_dispose_mapping(irq);1399				goto err_channel_add;1400			}1401 1402			xordev->channels[i] = chan;1403			i++;1404		}1405	} else if (pdata && pdata->channels) {1406		for (i = 0; i < max_channels; i++) {1407			struct mv_xor_channel_data *cd;1408			struct mv_xor_chan *chan;1409			int irq;1410 1411			cd = &pdata->channels[i];1412			irq = platform_get_irq(pdev, i);1413			if (irq < 0) {1414				ret = irq;1415				goto err_channel_add;1416			}1417 1418			chan = mv_xor_channel_add(xordev, pdev, i,1419						  cd->cap_mask, irq);1420			if (IS_ERR(chan)) {1421				ret = PTR_ERR(chan);1422				goto err_channel_add;1423			}1424 1425			xordev->channels[i] = chan;1426		}1427	}1428 1429	return 0;1430 1431err_channel_add:1432	for (i = 0; i < MV_XOR_MAX_CHANNELS; i++)1433		if (xordev->channels[i]) {1434			mv_xor_channel_remove(xordev->channels[i]);1435			if (pdev->dev.of_node)1436				irq_dispose_mapping(xordev->channels[i]->irq);1437		}1438 1439	if (!IS_ERR(xordev->clk)) {1440		clk_disable_unprepare(xordev->clk);1441		clk_put(xordev->clk);1442	}1443 1444	return ret;1445}1446 1447static struct platform_driver mv_xor_driver = {1448	.probe		= mv_xor_probe,1449	.suspend        = mv_xor_suspend,1450	.resume         = mv_xor_resume,1451	.driver		= {1452		.name	        = MV_XOR_NAME,1453		.of_match_table = mv_xor_dt_ids,1454	},1455};1456 1457builtin_platform_driver(mv_xor_driver);1458 1459/*1460MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");1461MODULE_DESCRIPTION("DMA engine driver for Marvell's XOR engine");1462MODULE_LICENSE("GPL");1463*/1464