iwlagn: move ICT code into separate file

All the ICT ISR code is iwlagn specific, and doesn't
need to be in iwlcore. So create a new iwl-agn.h
header file that will hold agn specific function
declarations etc., and move the ICT code into a new
iwl-agn-ict.c file that is linked into iwlagn. This
also gets rid of exporting those symbols.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

1 files changed, 303 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-ict.c b/drivers/net/wireless/iwlwifi/iwl-agn-ict.c
new file mode 100644
index 000000000000..d6b028b1b6ef
--- /dev/null
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-ict.c
@@ -0,0 +1,303 @@
+/******************************************************************************
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2008 - 2010 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
+ * USA
+ *
+ * The full GNU General Public License is included in this distribution
+ * in the file called LICENSE.GPL.
+ *
+ * Contact Information:
+ *  Intel Linux Wireless <ilw@linux.intel.com>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *****************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/etherdevice.h>
+#include <linux/sched.h>
+#include <net/mac80211.h>
+
+#include "iwl-dev.h"
+#include "iwl-core.h"
+#include "iwl-agn.h"
+#include "iwl-helpers.h"
+
+#define ICT_COUNT (PAGE_SIZE/sizeof(u32))
+
+/* Free dram table */
+void iwl_free_isr_ict(struct iwl_priv *priv)
+{
+	if (priv->ict_tbl_vir) {
+		dma_free_coherent(&priv->pci_dev->dev,
+				  (sizeof(u32) * ICT_COUNT) + PAGE_SIZE,
+				  priv->ict_tbl_vir, priv->ict_tbl_dma);
+		priv->ict_tbl_vir = NULL;
+	}
+}
+
+
+/* allocate dram shared table it is a PAGE_SIZE aligned
+ * also reset all data related to ICT table interrupt.
+ */
+int iwl_alloc_isr_ict(struct iwl_priv *priv)
+{
+
+	if (priv->cfg->use_isr_legacy)
+		return 0;
+	/* allocate shrared data table */
+	priv->ict_tbl_vir = dma_alloc_coherent(&priv->pci_dev->dev,
+					       (sizeof(u32) * ICT_COUNT) + PAGE_SIZE,
+					       &priv->ict_tbl_dma, GFP_KERNEL);
+	if (!priv->ict_tbl_vir)
+		return -ENOMEM;
+
+	/* align table to PAGE_SIZE boundry */
+	priv->aligned_ict_tbl_dma = ALIGN(priv->ict_tbl_dma, PAGE_SIZE);
+
+	IWL_DEBUG_ISR(priv, "ict dma addr %Lx dma aligned %Lx diff %d\n",
+			     (unsigned long long)priv->ict_tbl_dma,
+			     (unsigned long long)priv->aligned_ict_tbl_dma,
+			(int)(priv->aligned_ict_tbl_dma - priv->ict_tbl_dma));
+
+	priv->ict_tbl =  priv->ict_tbl_vir +
+			  (priv->aligned_ict_tbl_dma - priv->ict_tbl_dma);
+
+	IWL_DEBUG_ISR(priv, "ict vir addr %p vir aligned %p diff %d\n",
+			     priv->ict_tbl, priv->ict_tbl_vir,
+			(int)(priv->aligned_ict_tbl_dma - priv->ict_tbl_dma));
+
+	/* reset table and index to all 0 */
+	memset(priv->ict_tbl_vir,0, (sizeof(u32) * ICT_COUNT) + PAGE_SIZE);
+	priv->ict_index = 0;
+
+	/* add periodic RX interrupt */
+	priv->inta_mask |= CSR_INT_BIT_RX_PERIODIC;
+	return 0;
+}
+
+/* Device is going up inform it about using ICT interrupt table,
+ * also we need to tell the driver to start using ICT interrupt.
+ */
+int iwl_reset_ict(struct iwl_priv *priv)
+{
+	u32 val;
+	unsigned long flags;
+
+	if (!priv->ict_tbl_vir)
+		return 0;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	iwl_disable_interrupts(priv);
+
+	memset(&priv->ict_tbl[0], 0, sizeof(u32) * ICT_COUNT);
+
+	val = priv->aligned_ict_tbl_dma >> PAGE_SHIFT;
+
+	val |= CSR_DRAM_INT_TBL_ENABLE;
+	val |= CSR_DRAM_INIT_TBL_WRAP_CHECK;
+
+	IWL_DEBUG_ISR(priv, "CSR_DRAM_INT_TBL_REG =0x%X "
+			"aligned dma address %Lx\n",
+			val, (unsigned long long)priv->aligned_ict_tbl_dma);
+
+	iwl_write32(priv, CSR_DRAM_INT_TBL_REG, val);
+	priv->use_ict = true;
+	priv->ict_index = 0;
+	iwl_write32(priv, CSR_INT, priv->inta_mask);
+	iwl_enable_interrupts(priv);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+/* Device is going down disable ict interrupt usage */
+void iwl_disable_ict(struct iwl_priv *priv)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->use_ict = false;
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static irqreturn_t iwl_isr(int irq, void *data)
+{
+	struct iwl_priv *priv = data;
+	u32 inta, inta_mask;
+#ifdef CONFIG_IWLWIFI_DEBUG
+	u32 inta_fh;
+#endif
+	if (!priv)
+		return IRQ_NONE;
+
+	spin_lock(&priv->lock);
+
+	/* Disable (but don't clear!) interrupts here to avoid
+	 *    back-to-back ISRs and sporadic interrupts from our NIC.
+	 * If we have something to service, the tasklet will re-enable ints.
+	 * If we *don't* have something, we'll re-enable before leaving here. */
+	inta_mask = iwl_read32(priv, CSR_INT_MASK);  /* just for debug */
+	iwl_write32(priv, CSR_INT_MASK, 0x00000000);
+
+	/* Discover which interrupts are active/pending */
+	inta = iwl_read32(priv, CSR_INT);
+
+	/* Ignore interrupt if there's nothing in NIC to service.
+	 * This may be due to IRQ shared with another device,
+	 * or due to sporadic interrupts thrown from our NIC. */
+	if (!inta) {
+		IWL_DEBUG_ISR(priv, "Ignore interrupt, inta == 0\n");
+		goto none;
+	}
+
+	if ((inta == 0xFFFFFFFF) || ((inta & 0xFFFFFFF0) == 0xa5a5a5a0)) {
+		/* Hardware disappeared. It might have already raised
+		 * an interrupt */
+		IWL_WARN(priv, "HARDWARE GONE?? INTA == 0x%08x\n", inta);
+		goto unplugged;
+	}
+
+#ifdef CONFIG_IWLWIFI_DEBUG
+	if (iwl_get_debug_level(priv) & (IWL_DL_ISR)) {
+		inta_fh = iwl_read32(priv, CSR_FH_INT_STATUS);
+		IWL_DEBUG_ISR(priv, "ISR inta 0x%08x, enabled 0x%08x, "
+			      "fh 0x%08x\n", inta, inta_mask, inta_fh);
+	}
+#endif
+
+	priv->inta |= inta;
+	/* iwl_irq_tasklet() will service interrupts and re-enable them */
+	if (likely(inta))
+		tasklet_schedule(&priv->irq_tasklet);
+	else if (test_bit(STATUS_INT_ENABLED, &priv->status) && !priv->inta)
+		iwl_enable_interrupts(priv);
+
+ unplugged:
+	spin_unlock(&priv->lock);
+	return IRQ_HANDLED;
+
+ none:
+	/* re-enable interrupts here since we don't have anything to service. */
+	/* only Re-enable if diabled by irq  and no schedules tasklet. */
+	if (test_bit(STATUS_INT_ENABLED, &priv->status) && !priv->inta)
+		iwl_enable_interrupts(priv);
+
+	spin_unlock(&priv->lock);
+	return IRQ_NONE;
+}
+
+/* interrupt handler using ict table, with this interrupt driver will
+ * stop using INTA register to get device's interrupt, reading this register
+ * is expensive, device will write interrupts in ICT dram table, increment
+ * index then will fire interrupt to driver, driver will OR all ICT table
+ * entries from current index up to table entry with 0 value. the result is
+ * the interrupt we need to service, driver will set the entries back to 0 and
+ * set index.
+ */
+irqreturn_t iwl_isr_ict(int irq, void *data)
+{
+	struct iwl_priv *priv = data;
+	u32 inta, inta_mask;
+	u32 val = 0;
+
+	if (!priv)
+		return IRQ_NONE;
+
+	/* dram interrupt table not set yet,
+	 * use legacy interrupt.
+	 */
+	if (!priv->use_ict)
+		return iwl_isr(irq, data);
+
+	spin_lock(&priv->lock);
+
+	/* Disable (but don't clear!) interrupts here to avoid
+	 * back-to-back ISRs and sporadic interrupts from our NIC.
+	 * If we have something to service, the tasklet will re-enable ints.
+	 * If we *don't* have something, we'll re-enable before leaving here.
+	 */
+	inta_mask = iwl_read32(priv, CSR_INT_MASK);  /* just for debug */
+	iwl_write32(priv, CSR_INT_MASK, 0x00000000);
+
+
+	/* Ignore interrupt if there's nothing in NIC to service.
+	 * This may be due to IRQ shared with another device,
+	 * or due to sporadic interrupts thrown from our NIC. */
+	if (!priv->ict_tbl[priv->ict_index]) {
+		IWL_DEBUG_ISR(priv, "Ignore interrupt, inta == 0\n");
+		goto none;
+	}
+
+	/* read all entries that not 0 start with ict_index */
+	while (priv->ict_tbl[priv->ict_index]) {
+
+		val |= le32_to_cpu(priv->ict_tbl[priv->ict_index]);
+		IWL_DEBUG_ISR(priv, "ICT index %d value 0x%08X\n",
+				priv->ict_index,
+				le32_to_cpu(priv->ict_tbl[priv->ict_index]));
+		priv->ict_tbl[priv->ict_index] = 0;
+		priv->ict_index = iwl_queue_inc_wrap(priv->ict_index,
+						     ICT_COUNT);
+
+	}
+
+	/* We should not get this value, just ignore it. */
+	if (val == 0xffffffff)
+		val = 0;
+
+	/*
+	 * this is a w/a for a h/w bug. the h/w bug may cause the Rx bit
+	 * (bit 15 before shifting it to 31) to clear when using interrupt
+	 * coalescing. fortunately, bits 18 and 19 stay set when this happens
+	 * so we use them to decide on the real state of the Rx bit.
+	 * In order words, bit 15 is set if bit 18 or bit 19 are set.
+	 */
+	if (val & 0xC0000)
+		val |= 0x8000;
+
+	inta = (0xff & val) | ((0xff00 & val) << 16);
+	IWL_DEBUG_ISR(priv, "ISR inta 0x%08x, enabled 0x%08x ict 0x%08x\n",
+			inta, inta_mask, val);
+
+	inta &= priv->inta_mask;
+	priv->inta |= inta;
+
+	/* iwl_irq_tasklet() will service interrupts and re-enable them */
+	if (likely(inta))
+		tasklet_schedule(&priv->irq_tasklet);
+	else if (test_bit(STATUS_INT_ENABLED, &priv->status) && !priv->inta) {
+		/* Allow interrupt if was disabled by this handler and
+		 * no tasklet was schedules, We should not enable interrupt,
+		 * tasklet will enable it.
+		 */
+		iwl_enable_interrupts(priv);
+	}
+
+	spin_unlock(&priv->lock);
+	return IRQ_HANDLED;
+
+ none:
+	/* re-enable interrupts here since we don't have anything to service.
+	 * only Re-enable if disabled by irq.
+	 */
+	if (test_bit(STATUS_INT_ENABLED, &priv->status) && !priv->inta)
+		iwl_enable_interrupts(priv);
+
+	spin_unlock(&priv->lock);
+	return IRQ_NONE;
+}