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linux/drivers/net/wireless/ath/wil6210/interrupt.c
Vladimir Kondratiev e0287c4ab8 wil6210: use NAPI 
Introduce NAPI for Rx and Tx completion.

This fixes packet reordering that happens when Rx handled right in
the IRQ: netif_rx puts packet in 'percpu' queue, then network stack
fetches packets from 'percpu' queues for processing, with different
pattern of queue switching. As result, network stack see packets
in different order. This causes hard to understand TCP throughput
degradation in about 30min

Complete polling if only one packet was processed - this eliminates
empty polls that would be otherwise done at the end of each burst

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2013-05-22 15:08:35 -04:00

511 lines
13 KiB
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/*
* Copyright (c) 2012 Qualcomm Atheros, Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <linux/interrupt.h>
#include "wil6210.h"
#include "trace.h"
/**
* Theory of operation:
*
* There is ISR pseudo-cause register,
* dma_rgf->DMA_RGF.PSEUDO_CAUSE.PSEUDO_CAUSE
* Its bits represents OR'ed bits from 3 real ISR registers:
* TX, RX, and MISC.
*
* Registers may be configured to either "write 1 to clear" or
* "clear on read" mode
*
* When handling interrupt, one have to mask/unmask interrupts for the
* real ISR registers, or hardware may malfunction.
*
*/
#define WIL6210_IRQ_DISABLE (0xFFFFFFFFUL)
#define WIL6210_IMC_RX BIT_DMA_EP_RX_ICR_RX_DONE
#define WIL6210_IMC_TX (BIT_DMA_EP_TX_ICR_TX_DONE | \
BIT_DMA_EP_TX_ICR_TX_DONE_N(0))
#define WIL6210_IMC_MISC (ISR_MISC_FW_READY | \
ISR_MISC_MBOX_EVT | \
ISR_MISC_FW_ERROR)
#define WIL6210_IRQ_PSEUDO_MASK (u32)(~(BIT_DMA_PSEUDO_CAUSE_RX | \
BIT_DMA_PSEUDO_CAUSE_TX | \
BIT_DMA_PSEUDO_CAUSE_MISC))
#if defined(CONFIG_WIL6210_ISR_COR)
/* configure to Clear-On-Read mode */
#define WIL_ICR_ICC_VALUE (0xFFFFFFFFUL)
static inline void wil_icr_clear(u32 x, void __iomem *addr)
{
}
#else /* defined(CONFIG_WIL6210_ISR_COR) */
/* configure to Write-1-to-Clear mode */
#define WIL_ICR_ICC_VALUE (0UL)
static inline void wil_icr_clear(u32 x, void __iomem *addr)
{
iowrite32(x, addr);
}
#endif /* defined(CONFIG_WIL6210_ISR_COR) */
static inline u32 wil_ioread32_and_clear(void __iomem *addr)
{
u32 x = ioread32(addr);
wil_icr_clear(x, addr);
return x;
}
static void wil6210_mask_irq_tx(struct wil6210_priv *wil)
{
iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
HOSTADDR(RGF_DMA_EP_TX_ICR) +
offsetof(struct RGF_ICR, IMS));
}
static void wil6210_mask_irq_rx(struct wil6210_priv *wil)
{
iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
HOSTADDR(RGF_DMA_EP_RX_ICR) +
offsetof(struct RGF_ICR, IMS));
}
static void wil6210_mask_irq_misc(struct wil6210_priv *wil)
{
iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
HOSTADDR(RGF_DMA_EP_MISC_ICR) +
offsetof(struct RGF_ICR, IMS));
}
static void wil6210_mask_irq_pseudo(struct wil6210_priv *wil)
{
wil_dbg_irq(wil, "%s()\n", __func__);
iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
HOSTADDR(RGF_DMA_PSEUDO_CAUSE_MASK_SW));
clear_bit(wil_status_irqen, &wil->status);
}
void wil6210_unmask_irq_tx(struct wil6210_priv *wil)
{
iowrite32(WIL6210_IMC_TX, wil->csr +
HOSTADDR(RGF_DMA_EP_TX_ICR) +
offsetof(struct RGF_ICR, IMC));
}
void wil6210_unmask_irq_rx(struct wil6210_priv *wil)
{
iowrite32(WIL6210_IMC_RX, wil->csr +
HOSTADDR(RGF_DMA_EP_RX_ICR) +
offsetof(struct RGF_ICR, IMC));
}
static void wil6210_unmask_irq_misc(struct wil6210_priv *wil)
{
iowrite32(WIL6210_IMC_MISC, wil->csr +
HOSTADDR(RGF_DMA_EP_MISC_ICR) +
offsetof(struct RGF_ICR, IMC));
}
static void wil6210_unmask_irq_pseudo(struct wil6210_priv *wil)
{
wil_dbg_irq(wil, "%s()\n", __func__);
set_bit(wil_status_irqen, &wil->status);
iowrite32(WIL6210_IRQ_PSEUDO_MASK, wil->csr +
HOSTADDR(RGF_DMA_PSEUDO_CAUSE_MASK_SW));
}
void wil6210_disable_irq(struct wil6210_priv *wil)
{
wil_dbg_irq(wil, "%s()\n", __func__);
wil6210_mask_irq_tx(wil);
wil6210_mask_irq_rx(wil);
wil6210_mask_irq_misc(wil);
wil6210_mask_irq_pseudo(wil);
}
void wil6210_enable_irq(struct wil6210_priv *wil)
{
wil_dbg_irq(wil, "%s()\n", __func__);
iowrite32(WIL_ICR_ICC_VALUE, wil->csr + HOSTADDR(RGF_DMA_EP_RX_ICR) +
offsetof(struct RGF_ICR, ICC));
iowrite32(WIL_ICR_ICC_VALUE, wil->csr + HOSTADDR(RGF_DMA_EP_TX_ICR) +
offsetof(struct RGF_ICR, ICC));
iowrite32(WIL_ICR_ICC_VALUE, wil->csr + HOSTADDR(RGF_DMA_EP_MISC_ICR) +
offsetof(struct RGF_ICR, ICC));
wil6210_unmask_irq_pseudo(wil);
wil6210_unmask_irq_tx(wil);
wil6210_unmask_irq_rx(wil);
wil6210_unmask_irq_misc(wil);
}
static irqreturn_t wil6210_irq_rx(int irq, void *cookie)
{
struct wil6210_priv *wil = cookie;
u32 isr = wil_ioread32_and_clear(wil->csr +
HOSTADDR(RGF_DMA_EP_RX_ICR) +
offsetof(struct RGF_ICR, ICR));
trace_wil6210_irq_rx(isr);
wil_dbg_irq(wil, "ISR RX 0x%08x\n", isr);
if (!isr) {
wil_err(wil, "spurious IRQ: RX\n");
return IRQ_NONE;
}
wil6210_mask_irq_rx(wil);
if (isr & BIT_DMA_EP_RX_ICR_RX_DONE) {
wil_dbg_irq(wil, "RX done\n");
isr &= ~BIT_DMA_EP_RX_ICR_RX_DONE;
wil_dbg_txrx(wil, "NAPI schedule\n");
napi_schedule(&wil->napi_rx);
}
if (isr)
wil_err(wil, "un-handled RX ISR bits 0x%08x\n", isr);
/* Rx IRQ will be enabled when NAPI processing finished */
return IRQ_HANDLED;
}
static irqreturn_t wil6210_irq_tx(int irq, void *cookie)
{
struct wil6210_priv *wil = cookie;
u32 isr = wil_ioread32_and_clear(wil->csr +
HOSTADDR(RGF_DMA_EP_TX_ICR) +
offsetof(struct RGF_ICR, ICR));
trace_wil6210_irq_tx(isr);
wil_dbg_irq(wil, "ISR TX 0x%08x\n", isr);
if (!isr) {
wil_err(wil, "spurious IRQ: TX\n");
return IRQ_NONE;
}
wil6210_mask_irq_tx(wil);
if (isr & BIT_DMA_EP_TX_ICR_TX_DONE) {
wil_dbg_irq(wil, "TX done\n");
napi_schedule(&wil->napi_tx);
isr &= ~BIT_DMA_EP_TX_ICR_TX_DONE;
/* clear also all VRING interrupts */
isr &= ~(BIT(25) - 1UL);
}
if (isr)
wil_err(wil, "un-handled TX ISR bits 0x%08x\n", isr);
/* Tx IRQ will be enabled when NAPI processing finished */
return IRQ_HANDLED;
}
static void wil_notify_fw_error(struct wil6210_priv *wil)
{
struct device *dev = &wil_to_ndev(wil)->dev;
char *envp[3] = {
[0] = "SOURCE=wil6210",
[1] = "EVENT=FW_ERROR",
[2] = NULL,
};
kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
}
static void wil_cache_mbox_regs(struct wil6210_priv *wil)
{
/* make shadow copy of registers that should not change on run time */
wil_memcpy_fromio_32(&wil->mbox_ctl, wil->csr + HOST_MBOX,
sizeof(struct wil6210_mbox_ctl));
wil_mbox_ring_le2cpus(&wil->mbox_ctl.rx);
wil_mbox_ring_le2cpus(&wil->mbox_ctl.tx);
}
static irqreturn_t wil6210_irq_misc(int irq, void *cookie)
{
struct wil6210_priv *wil = cookie;
u32 isr = wil_ioread32_and_clear(wil->csr +
HOSTADDR(RGF_DMA_EP_MISC_ICR) +
offsetof(struct RGF_ICR, ICR));
trace_wil6210_irq_misc(isr);
wil_dbg_irq(wil, "ISR MISC 0x%08x\n", isr);
if (!isr) {
wil_err(wil, "spurious IRQ: MISC\n");
return IRQ_NONE;
}
wil6210_mask_irq_misc(wil);
if (isr & ISR_MISC_FW_ERROR) {
wil_err(wil, "Firmware error detected\n");
clear_bit(wil_status_fwready, &wil->status);
/*
* do not clear @isr here - we do 2-nd part in thread
* there, user space get notified, and it should be done
* in non-atomic context
*/
}
if (isr & ISR_MISC_FW_READY) {
wil_dbg_irq(wil, "IRQ: FW ready\n");
wil_cache_mbox_regs(wil);
set_bit(wil_status_reset_done, &wil->status);
/**
* Actual FW ready indicated by the
* WMI_FW_READY_EVENTID
*/
isr &= ~ISR_MISC_FW_READY;
}
wil->isr_misc = isr;
if (isr) {
return IRQ_WAKE_THREAD;
} else {
wil6210_unmask_irq_misc(wil);
return IRQ_HANDLED;
}
}
static irqreturn_t wil6210_irq_misc_thread(int irq, void *cookie)
{
struct wil6210_priv *wil = cookie;
u32 isr = wil->isr_misc;
trace_wil6210_irq_misc_thread(isr);
wil_dbg_irq(wil, "Thread ISR MISC 0x%08x\n", isr);
if (isr & ISR_MISC_FW_ERROR) {
wil_notify_fw_error(wil);
isr &= ~ISR_MISC_FW_ERROR;
}
if (isr & ISR_MISC_MBOX_EVT) {
wil_dbg_irq(wil, "MBOX event\n");
wmi_recv_cmd(wil);
isr &= ~ISR_MISC_MBOX_EVT;
}
if (isr)
wil_err(wil, "un-handled MISC ISR bits 0x%08x\n", isr);
wil->isr_misc = 0;
wil6210_unmask_irq_misc(wil);
return IRQ_HANDLED;
}
/**
* thread IRQ handler
*/
static irqreturn_t wil6210_thread_irq(int irq, void *cookie)
{
struct wil6210_priv *wil = cookie;
wil_dbg_irq(wil, "Thread IRQ\n");
/* Discover real IRQ cause */
if (wil->isr_misc)
wil6210_irq_misc_thread(irq, cookie);
wil6210_unmask_irq_pseudo(wil);
return IRQ_HANDLED;
}
/* DEBUG
* There is subtle bug in hardware that causes IRQ to raise when it should be
* masked. It is quite rare and hard to debug.
*
* Catch irq issue if it happens and print all I can.
*/
static int wil6210_debug_irq_mask(struct wil6210_priv *wil, u32 pseudo_cause)
{
if (!test_bit(wil_status_irqen, &wil->status)) {
u32 icm_rx = wil_ioread32_and_clear(wil->csr +
HOSTADDR(RGF_DMA_EP_RX_ICR) +
offsetof(struct RGF_ICR, ICM));
u32 icr_rx = wil_ioread32_and_clear(wil->csr +
HOSTADDR(RGF_DMA_EP_RX_ICR) +
offsetof(struct RGF_ICR, ICR));
u32 imv_rx = ioread32(wil->csr +
HOSTADDR(RGF_DMA_EP_RX_ICR) +
offsetof(struct RGF_ICR, IMV));
u32 icm_tx = wil_ioread32_and_clear(wil->csr +
HOSTADDR(RGF_DMA_EP_TX_ICR) +
offsetof(struct RGF_ICR, ICM));
u32 icr_tx = wil_ioread32_and_clear(wil->csr +
HOSTADDR(RGF_DMA_EP_TX_ICR) +
offsetof(struct RGF_ICR, ICR));
u32 imv_tx = ioread32(wil->csr +
HOSTADDR(RGF_DMA_EP_TX_ICR) +
offsetof(struct RGF_ICR, IMV));
u32 icm_misc = wil_ioread32_and_clear(wil->csr +
HOSTADDR(RGF_DMA_EP_MISC_ICR) +
offsetof(struct RGF_ICR, ICM));
u32 icr_misc = wil_ioread32_and_clear(wil->csr +
HOSTADDR(RGF_DMA_EP_MISC_ICR) +
offsetof(struct RGF_ICR, ICR));
u32 imv_misc = ioread32(wil->csr +
HOSTADDR(RGF_DMA_EP_MISC_ICR) +
offsetof(struct RGF_ICR, IMV));
wil_err(wil, "IRQ when it should be masked: pseudo 0x%08x\n"
"Rx icm:icr:imv 0x%08x 0x%08x 0x%08x\n"
"Tx icm:icr:imv 0x%08x 0x%08x 0x%08x\n"
"Misc icm:icr:imv 0x%08x 0x%08x 0x%08x\n",
pseudo_cause,
icm_rx, icr_rx, imv_rx,
icm_tx, icr_tx, imv_tx,
icm_misc, icr_misc, imv_misc);
return -EINVAL;
}
return 0;
}
static irqreturn_t wil6210_hardirq(int irq, void *cookie)
{
irqreturn_t rc = IRQ_HANDLED;
struct wil6210_priv *wil = cookie;
u32 pseudo_cause = ioread32(wil->csr + HOSTADDR(RGF_DMA_PSEUDO_CAUSE));
/**
* pseudo_cause is Clear-On-Read, no need to ACK
*/
if ((pseudo_cause == 0) || ((pseudo_cause & 0xff) == 0xff))
return IRQ_NONE;
/* FIXME: IRQ mask debug */
if (wil6210_debug_irq_mask(wil, pseudo_cause))
return IRQ_NONE;
trace_wil6210_irq_pseudo(pseudo_cause);
wil_dbg_irq(wil, "Pseudo IRQ 0x%08x\n", pseudo_cause);
wil6210_mask_irq_pseudo(wil);
/* Discover real IRQ cause
* There are 2 possible phases for every IRQ:
* - hard IRQ handler called right here
* - threaded handler called later
*
* Hard IRQ handler reads and clears ISR.
*
* If threaded handler requested, hard IRQ handler
* returns IRQ_WAKE_THREAD and saves ISR register value
* for the threaded handler use.
*
* voting for wake thread - need at least 1 vote
*/
if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_RX) &&
(wil6210_irq_rx(irq, cookie) == IRQ_WAKE_THREAD))
rc = IRQ_WAKE_THREAD;
if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_TX) &&
(wil6210_irq_tx(irq, cookie) == IRQ_WAKE_THREAD))
rc = IRQ_WAKE_THREAD;
if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_MISC) &&
(wil6210_irq_misc(irq, cookie) == IRQ_WAKE_THREAD))
rc = IRQ_WAKE_THREAD;
/* if thread is requested, it will unmask IRQ */
if (rc != IRQ_WAKE_THREAD)
wil6210_unmask_irq_pseudo(wil);
return rc;
}
static int wil6210_request_3msi(struct wil6210_priv *wil, int irq)
{
int rc;
/*
* IRQ's are in the following order:
* - Tx
* - Rx
* - Misc
*/
rc = request_irq(irq, wil6210_irq_tx, IRQF_SHARED,
WIL_NAME"_tx", wil);
if (rc)
return rc;
rc = request_irq(irq + 1, wil6210_irq_rx, IRQF_SHARED,
WIL_NAME"_rx", wil);
if (rc)
goto free0;
rc = request_threaded_irq(irq + 2, wil6210_irq_misc,
wil6210_irq_misc_thread,
IRQF_SHARED, WIL_NAME"_misc", wil);
if (rc)
goto free1;
return 0;
/* error branch */
free1:
free_irq(irq + 1, wil);
free0:
free_irq(irq, wil);
return rc;
}
int wil6210_init_irq(struct wil6210_priv *wil, int irq)
{
int rc;
if (wil->n_msi == 3)
rc = wil6210_request_3msi(wil, irq);
else
rc = request_threaded_irq(irq, wil6210_hardirq,
wil6210_thread_irq,
wil->n_msi ? 0 : IRQF_SHARED,
WIL_NAME, wil);
if (rc)
return rc;
wil6210_enable_irq(wil);
return 0;
}
void wil6210_fini_irq(struct wil6210_priv *wil, int irq)
{
wil6210_disable_irq(wil);
free_irq(irq, wil);
if (wil->n_msi == 3) {
free_irq(irq + 1, wil);
free_irq(irq + 2, wil);
}
}
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