/*
*
* Intel Management Engine Interface (Intel MEI) Linux driver
* Copyright (c) 2003-2012, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
*/
#include <linux/pci.h>
#include <linux/kthread.h>
#include <linux/interrupt.h>
#include "mei_dev.h"
#include "hw-me.h"
#include "hbm.h"
/**
* mei_me_reg_read - Reads 32bit data from the mei device
*
* @dev: the device structure
* @offset: offset from which to read the data
*
* returns register value (u32)
*/
static inline u32 mei_me_reg_read(const struct mei_me_hw *hw,
unsigned long offset)
{
return ioread32(hw->mem_addr + offset);
}
/**
* mei_me_reg_write - Writes 32bit data to the mei device
*
* @dev: the device structure
* @offset: offset from which to write the data
* @value: register value to write (u32)
*/
static inline void mei_me_reg_write(const struct mei_me_hw *hw,
unsigned long offset, u32 value)
{
iowrite32(value, hw->mem_addr + offset);
}
/**
* mei_me_mecbrw_read - Reads 32bit data from ME circular buffer
* read window register
*
* @dev: the device structure
*
* returns ME_CB_RW register value (u32)
*/
static u32 mei_me_mecbrw_read(const struct mei_device *dev)
{
return mei_me_reg_read(to_me_hw(dev), ME_CB_RW);
}
/**
* mei_me_mecsr_read - Reads 32bit data from the ME CSR
*
* @dev: the device structure
*
* returns ME_CSR_HA register value (u32)
*/
static inline u32 mei_me_mecsr_read(const struct mei_me_hw *hw)
{
return mei_me_reg_read(hw, ME_CSR_HA);
}
/**
* mei_hcsr_read - Reads 32bit data from the host CSR
*
* @dev: the device structure
*
* returns H_CSR register value (u32)
*/
static inline u32 mei_hcsr_read(const struct mei_me_hw *hw)
{
return mei_me_reg_read(hw, H_CSR);
}
/**
* mei_hcsr_set - writes H_CSR register to the mei device,
* and ignores the H_IS bit for it is write-one-to-zero.
*
* @dev: the device structure
*/
static inline void mei_hcsr_set(struct mei_me_hw *hw, u32 hcsr)
{
hcsr &= ~H_IS;
mei_me_reg_write(hw, H_CSR, hcsr);
}
/**
* me_hw_config - configure hw dependent settings
*
* @dev: mei device
*/
static void mei_me_hw_config(struct mei_device *dev)
{
u32 hcsr = mei_hcsr_read(to_me_hw(dev));
/* Doesn't change in runtime */
dev->hbuf_depth = (hcsr & H_CBD) >> 24;
}
/**
* mei_clear_interrupts - clear and stop interrupts
*
* @dev: the device structure
*/
static void mei_me_intr_clear(struct mei_device *dev)
{
struct mei_me_hw *hw = to_me_hw(dev);
u32 hcsr = mei_hcsr_read(hw);
if ((hcsr & H_IS) == H_IS)
mei_me_reg_write(hw, H_CSR, hcsr);
}
/**
* mei_me_intr_enable - enables mei device interrupts
*
* @dev: the device structure
*/
static void mei_me_intr_enable(struct mei_device *dev)
{
struct mei_me_hw *hw = to_me_hw(dev);
u32 hcsr = mei_hcsr_read(hw);
hcsr |= H_IE;
mei_hcsr_set(hw, hcsr);
}
/**
* mei_disable_interrupts - disables mei device interrupts
*
* @dev: the device structure
*/
static void mei_me_intr_disable(struct mei_device *dev)
{
struct mei_me_hw *hw = to_me_hw(dev);
u32 hcsr = mei_hcsr_read(hw);
hcsr &= ~H_IE;
mei_hcsr_set(hw, hcsr);
}
/**
* mei_me_hw_reset_release - release device from the reset
*
* @dev: the device structure
*/
static void mei_me_hw_reset_release(struct mei_device *dev)
{
struct mei_me_hw *hw = to_me_hw(dev);
u32 hcsr = mei_hcsr_read(hw);
hcsr |= H_IG;
hcsr &= ~H_RST;
mei_hcsr_set(hw, hcsr);
}
/**
* mei_me_hw_reset - resets fw via mei csr register.
*
* @dev: the device structure
* @interrupts_enabled: if interrupt should be enabled after reset.
*/
static void mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
{
struct mei_me_hw *hw = to_me_hw(dev);
u32 hcsr = mei_hcsr_read(hw);
dev_dbg(&dev->pdev->dev, "before reset HCSR = 0x%08x.\n", hcsr);
hcsr |= (H_RST | H_IG);
if (intr_enable)
hcsr |= H_IE;
else
hcsr |= ~H_IE;
mei_hcsr_set(hw, hcsr);
if (dev->dev_state == MEI_DEV_POWER_DOWN)
mei_me_hw_reset_release(dev);
dev_dbg(&dev->pdev->dev, "current HCSR = 0x%08x.\n", mei_hcsr_read(hw));
}
/**
* mei_me_host_set_ready - enable device
*
* @dev - mei device
* returns bool
*/
static void mei_me_host_set_ready(struct mei_device *dev)
{
struct mei_me_hw *hw = to_me_hw(dev);
hw->host_hw_state |= H_IE | H_IG | H_RDY;
mei_hcsr_set(hw, hw->host_hw_state);
}
/**
* mei_me_host_is_ready - check whether the host has turned ready
*
* @dev - mei device
* returns bool
*/
static bool mei_me_host_is_ready(struct mei_device *dev)
{
struct mei_me_hw *hw = to_me_hw(dev);
hw->host_hw_state = mei_hcsr_read(hw);
return (hw->host_hw_state & H_RDY) == H_RDY;
}
/**
* mei_me_hw_is_ready - check whether the me(hw) has turned ready
*
* @dev - mei device
* returns bool
*/
static bool mei_me_hw_is_ready(struct mei_device *dev)
{
struct mei_me_hw *hw = to_me_hw(dev);
hw->me_hw_state = mei_me_mecsr_read(hw);
return (hw->me_hw_state & ME_RDY_HRA) == ME_RDY_HRA;
}
static int mei_me_hw_ready_wait(struct mei_device *dev)
{
int err;
if (mei_me_hw_is_ready(dev))
return 0;
mutex_unlock(&dev->device_lock);
err = wait_event_interruptible_timeout(dev->wait_hw_ready,
dev->recvd_hw_ready, MEI_INTEROP_TIMEOUT);
mutex_lock(&dev->device_lock);
if (!err && !dev->recvd_hw_ready) {
dev_err(&dev->pdev->dev,
"wait hw ready failed. status = 0x%x\n", err);
return -ETIMEDOUT;
}
dev->recvd_hw_ready = false;
return 0;
}
static int mei_me_hw_start(struct mei_device *dev)
{
int ret = mei_me_hw_ready_wait(dev);
if (ret)
return ret;
dev_dbg(&dev->pdev->dev, "hw is ready\n");
mei_me_host_set_ready(dev);
return ret;
}
/**
* mei_hbuf_filled_slots - gets number of device filled buffer slots
*
* @dev: the device structure
*
* returns number of filled slots
*/
static unsigned char mei_hbuf_filled_slots(struct mei_device *dev)
{
struct mei_me_hw *hw = to_me_hw(dev);
char read_ptr, write_ptr;
hw->host_hw_state = mei_hcsr_read(hw);
read_ptr = (char) ((hw->host_hw_state & H_CBRP) >> 8);
write_ptr = (char) ((hw->host_hw_state & H_CBWP) >> 16);
return (unsigned char) (write_ptr - read_ptr);
}
/**
* mei_hbuf_is_empty - checks if host buffer is empty.
*
* @dev: the device structure
*
* returns true if empty, false - otherwise.
*/
static bool mei_me_hbuf_is_empty(struct mei_device *dev)
{
return mei_hbuf_filled_slots(dev) == 0;
}
/**
* mei_me_hbuf_empty_slots - counts write empty slots.
*
* @dev: the device structure
*
* returns -1(ESLOTS_OVERFLOW) if overflow, otherwise empty slots count
*/
static int mei_me_hbuf_empty_slots(struct mei_device *dev)
{
unsigned char filled_slots, empty_slots;
filled_slots = mei_hbuf_filled_slots(dev);
empty_slots = dev->hbuf_depth - filled_slots;
/* check for overflow */
if (filled_slots > dev->hbuf_depth)
return -EOVERFLOW;
return empty_slots;
}
static size_t mei_me_hbuf_max_len(const struct mei_device *dev)
{
return dev->hbuf_depth * sizeof(u32) - sizeof(struct mei_msg_hdr);
}
/**
* mei_write_message - writes a message to mei device.
*
* @dev: the device structure
* @header: mei HECI header of message
* @buf: message payload will be written
*
* This function returns -EIO if write has failed
*/
static int mei_me_write_message(struct mei_device *dev,
struct mei_msg_hdr *header,
unsigned char *buf)
{
struct mei_me_hw *hw = to_me_hw(dev);
unsigned long rem;
unsigned long length = header->length;
u32 *reg_buf = (u32 *)buf;
u32 hcsr;
u32 dw_cnt;
int i;
int empty_slots;
dev_dbg(&dev->pdev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));
empty_slots = mei_hbuf_empty_slots(dev);
dev_dbg(&dev->pdev->dev, "empty slots = %hu.\n", empty_slots);
dw_cnt = mei_data2slots(length);
if (empty_slots < 0 || dw_cnt > empty_slots)
return -EIO;
mei_me_reg_write(hw, H_CB_WW, *((u32 *) header));
for (i = 0; i < length / 4; i++)
mei_me_reg_write(hw, H_CB_WW, reg_buf[i]);
rem = length & 0x3;
if (rem > 0) {
u32 reg = 0;
memcpy(®, &buf[length - rem], rem);
mei_me_reg_write(hw, H_CB_WW, reg);
}
hcsr = mei_hcsr_read(hw) | H_IG;
mei_hcsr_set(hw, hcsr);
if (!mei_me_hw_is_ready(dev))
return -EIO;
return 0;
}
/**
* mei_me_count_full_read_slots - counts read full slots.
*
* @dev: the device structure
*
* returns -1(ESLOTS_OVERFLOW) if overflow, otherwise filled slots count
*/
static int mei_me_count_full_read_slots(struct mei_device *dev)
{
struct mei_me_hw *hw = to_me_hw(dev);
char read_ptr, write_ptr;
unsigned char buffer_depth, filled_slots;
hw->me_hw_state = mei_me_mecsr_read(hw);
buffer_depth = (unsigned char)((hw->me_hw_state & ME_CBD_HRA) >> 24);
read_ptr = (char) ((hw->me_hw_state & ME_CBRP_HRA) >> 8);
write_ptr = (char) ((hw->me_hw_state & ME_CBWP_HRA) >> 16);
filled_slots = (unsigned char) (write_ptr - read_ptr);
/* check for overflow */
if (filled_slots > buffer_depth)
return -EOVERFLOW;
dev_dbg(&dev->pdev->dev, "filled_slots =%08x\n", filled_slots);
return (int)filled_slots;
}
/**
* mei_me_read_slots - reads a message from mei device.
*
* @dev: the device structure
* @buffer: message buffer will be written
* @buffer_length: message size will be read
*/
static int mei_me_read_slots(struct mei_device *dev, unsigned char *buffer,
unsigned long buffer_length)
{
struct mei_me_hw *hw = to_me_hw(dev);
u32 *reg_buf = (u32 *)buffer;
u32 hcsr;
for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
*reg_buf++ = mei_me_mecbrw_read(dev);
if (buffer_length > 0) {
u32 reg = mei_me_mecbrw_read(dev);
memcpy(reg_buf, ®, buffer_length);
}
hcsr = mei_hcsr_read(hw) | H_IG;
mei_hcsr_set(hw, hcsr);
return 0;
}
/**
* mei_me_irq_quick_handler - The ISR of the MEI device
*
* @irq: The irq number
* @dev_id: pointer to the device structure
*
* returns irqreturn_t
*/
irqreturn_t mei_me_irq_quick_handler(int irq, void *dev_id)
{
struct mei_device *dev = (struct mei_device *) dev_id;
struct mei_me_hw *hw = to_me_hw(dev);
u32 csr_reg = mei_hcsr_read(hw);
if ((csr_reg & H_IS) != H_IS)
return IRQ_NONE;
/* clear H_IS bit in H_CSR */
mei_me_reg_write(hw, H_CSR, csr_reg);
return IRQ_WAKE_THREAD;
}
/**
* mei_me_irq_thread_handler - function called after ISR to handle the interrupt
* processing.
*
* @irq: The irq number
* @dev_id: pointer to the device structure
*
* returns irqreturn_t
*
*/
irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
{
struct mei_device *dev = (struct mei_device *) dev_id;
struct mei_cl_cb complete_list;
s32 slots;
int rets;
dev_dbg(&dev->pdev->dev, "function called after ISR to handle the interrupt processing.\n");
/* initialize our complete list */
mutex_lock(&dev->device_lock);
mei_io_list_init(&complete_list);
/* Ack the interrupt here
* In case of MSI we don't go through the quick handler */
if (pci_dev_msi_enabled(dev->pdev))
mei_clear_interrupts(dev);
/* check if ME wants a reset */
if (!mei_hw_is_ready(dev) &&
dev->dev_state != MEI_DEV_RESETTING &&
dev->dev_state != MEI_DEV_INITIALIZING) {
dev_dbg(&dev->pdev->dev, "FW not ready.\n");
mei_reset(dev, 1);
mutex_unlock(&dev->device_lock);
return IRQ_HANDLED;
}
/* check if we need to start the dev */
if (!mei_host_is_ready(dev)) {
if (mei_hw_is_ready(dev)) {
dev_dbg(&dev->pdev->dev, "we need to start the dev.\n");
dev->recvd_hw_ready = true;
wake_up_interruptible(&dev->wait_hw_ready);
mutex_unlock(&dev->device_lock);
return IRQ_HANDLED;
} else {
dev_dbg(&dev->pdev->dev, "Reset Completed.\n");
mei_me_hw_reset_release(dev);
mutex_unlock(&dev->device_lock);
return IRQ_HANDLED;
}
}
/* check slots available for reading */
slots = mei_count_full_read_slots(dev);
while (slots > 0) {
/* we have urgent data to send so break the read */
if (dev->wr_ext_msg.hdr.length)
break;
dev_dbg(&dev->pdev->dev, "slots =%08x\n", slots);
dev_dbg(&dev->pdev->dev, "call mei_irq_read_handler.\n");
rets = mei_irq_read_handler(dev, &complete_list, &slots);
if (rets)
goto end;
}
rets = mei_irq_write_handler(dev, &complete_list);
end:
dev_dbg(&dev->pdev->dev, "end of bottom half function.\n");
dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
mutex_unlock(&dev->device_lock);
mei_irq_compl_handler(dev, &complete_list);
return IRQ_HANDLED;
}
static const struct mei_hw_ops mei_me_hw_ops = {
.host_is_ready = mei_me_host_is_ready,
.hw_is_ready = mei_me_hw_is_ready,
.hw_reset = mei_me_hw_reset,
.hw_config = mei_me_hw_config,
.hw_start = mei_me_hw_start,
.intr_clear = mei_me_intr_clear,
.intr_enable = mei_me_intr_enable,
.intr_disable = mei_me_intr_disable,
.hbuf_free_slots = mei_me_hbuf_empty_slots,
.hbuf_is_ready = mei_me_hbuf_is_empty,
.hbuf_max_len = mei_me_hbuf_max_len,
.write = mei_me_write_message,
.rdbuf_full_slots = mei_me_count_full_read_slots,
.read_hdr = mei_me_mecbrw_read,
.read = mei_me_read_slots
};
/**
* init_mei_device - allocates and initializes the mei device structure
*
* @pdev: The pci device structure
*
* returns The mei_device_device pointer on success, NULL on failure.
*/
struct mei_device *mei_me_dev_init(struct pci_dev *pdev)
{
struct mei_device *dev;
dev = kzalloc(sizeof(struct mei_device) +
sizeof(struct mei_me_hw), GFP_KERNEL);
if (!dev)
return NULL;
mei_device_init(dev);
dev->ops = &mei_me_hw_ops;
dev->pdev = pdev;
return dev;
}
