/******************************************************************************
*
* 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 <linux/gfp.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->_agn.ict_tbl_vir) {
dma_free_coherent(&priv->pci_dev->dev,
(sizeof(u32) * ICT_COUNT) + PAGE_SIZE,
priv->_agn.ict_tbl_vir,
priv->_agn.ict_tbl_dma);
priv->_agn.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->base_params->use_isr_legacy)
return 0;
/* allocate shrared data table */
priv->_agn.ict_tbl_vir =
dma_alloc_coherent(&priv->pci_dev->dev,
(sizeof(u32) * ICT_COUNT) + PAGE_SIZE,
&priv->_agn.ict_tbl_dma, GFP_KERNEL);
if (!priv->_agn.ict_tbl_vir)
return -ENOMEM;
/* align table to PAGE_SIZE boundry */
priv->_agn.aligned_ict_tbl_dma = ALIGN(priv->_agn.ict_tbl_dma, PAGE_SIZE);
IWL_DEBUG_ISR(priv, "ict dma addr %Lx dma aligned %Lx diff %d\n",
(unsigned long long)priv->_agn.ict_tbl_dma,
(unsigned long long)priv->_agn.aligned_ict_tbl_dma,
(int)(priv->_agn.aligned_ict_tbl_dma - priv->_agn.ict_tbl_dma));
priv->_agn.ict_tbl = priv->_agn.ict_tbl_vir +
(priv->_agn.aligned_ict_tbl_dma - priv->_agn.ict_tbl_dma);
IWL_DEBUG_ISR(priv, "ict vir addr %p vir aligned %p diff %d\n",
priv->_agn.ict_tbl, priv->_agn.ict_tbl_vir,
(int)(priv->_agn.aligned_ict_tbl_dma - priv->_agn.ict_tbl_dma));
/* reset table and index to all 0 */
memset(priv->_agn.ict_tbl_vir,0, (sizeof(u32) * ICT_COUNT) + PAGE_SIZE);
priv->_agn.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->_agn.ict_tbl_vir)
return 0;
spin_lock_irqsave(&priv->lock, flags);
iwl_disable_interrupts(priv);
memset(&priv->_agn.ict_tbl[0], 0, sizeof(u32) * ICT_COUNT);
val = priv->_agn.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->_agn.aligned_ict_tbl_dma);
iwl_write32(priv, CSR_DRAM_INT_TBL_REG, val);
priv->_agn.use_ict = true;
priv->_agn.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->_agn.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;
unsigned long flags;
#ifdef CONFIG_IWLWIFI_DEBUG
u32 inta_fh;
#endif
if (!priv)
return IRQ_NONE;
spin_lock_irqsave(&priv->lock, flags);
/* 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->_agn.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->_agn.inta)
iwl_enable_interrupts(priv);
unplugged:
spin_unlock_irqrestore(&priv->lock, flags);
return IRQ_HANDLED;
none:
/* re-enable interrupts here since we don't have anything to service. */
/* only Re-enable if disabled by irq and no schedules tasklet. */
if (test_bit(STATUS_INT_ENABLED, &priv->status) && !priv->_agn.inta)
iwl_enable_interrupts(priv);
spin_unlock_irqrestore(&priv->lock, flags);
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;
unsigned long flags;
if (!priv)
return IRQ_NONE;
/* dram interrupt table not set yet,
* use legacy interrupt.
*/
if (!priv->_agn.use_ict)
return iwl_isr(irq, data);
spin_lock_irqsave(&priv->lock, flags);
/* 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->_agn.ict_tbl[priv->_agn.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->_agn.ict_tbl[priv->_agn.ict_index]) {
val |= le32_to_cpu(priv->_agn.ict_tbl[priv->_agn.ict_index]);
IWL_DEBUG_ISR(priv, "ICT index %d value 0x%08X\n",
priv->_agn.ict_index,
le32_to_cpu(priv->_agn.ict_tbl[priv->_agn.ict_index]));
priv->_agn.ict_tbl[priv->_agn.ict_index] = 0;
priv->_agn.ict_index = iwl_queue_inc_wrap(priv->_agn.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->_agn.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->_agn.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_irqrestore(&priv->lock, flags);
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->_agn.inta)
iwl_enable_interrupts(priv);
spin_unlock_irqrestore(&priv->lock, flags);
return IRQ_NONE;
}
