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alistair23-linux/drivers/misc/mei/hw-me.c

387 lines
8.5 KiB
C

/*
*
* 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/mei.h>
#include "mei_dev.h"
#include "hw-me.h"
/**
* mei_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_reg_read(const struct mei_device *dev,
unsigned long offset)
{
return ioread32(dev->mem_addr + offset);
}
/**
* mei_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_reg_write(const struct mei_device *dev,
unsigned long offset, u32 value)
{
iowrite32(value, dev->mem_addr + offset);
}
/**
* mei_mecbrw_read - Reads 32bit data from ME circular buffer
* read window register
*
* @dev: the device structure
*
* returns ME_CB_RW register value (u32)
*/
u32 mei_mecbrw_read(const struct mei_device *dev)
{
return mei_reg_read(dev, ME_CB_RW);
}
/**
* mei_mecsr_read - Reads 32bit data from the ME CSR
*
* @dev: the device structure
*
* returns ME_CSR_HA register value (u32)
*/
static inline u32 mei_mecsr_read(const struct mei_device *dev)
{
return mei_reg_read(dev, 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_device *dev)
{
return mei_reg_read(dev, 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_device *dev, u32 hcsr)
{
hcsr &= ~H_IS;
mei_reg_write(dev, H_CSR, hcsr);
}
/**
* me_hw_config - configure hw dependent settings
*
* @dev: mei device
*/
void mei_hw_config(struct mei_device *dev)
{
u32 hcsr = mei_hcsr_read(dev);
/* Doesn't change in runtime */
dev->hbuf_depth = (hcsr & H_CBD) >> 24;
}
/**
* mei_clear_interrupts - clear and stop interrupts
*
* @dev: the device structure
*/
void mei_clear_interrupts(struct mei_device *dev)
{
u32 hcsr = mei_hcsr_read(dev);
if ((hcsr & H_IS) == H_IS)
mei_reg_write(dev, H_CSR, hcsr);
}
/**
* mei_enable_interrupts - enables mei device interrupts
*
* @dev: the device structure
*/
void mei_enable_interrupts(struct mei_device *dev)
{
u32 hcsr = mei_hcsr_read(dev);
hcsr |= H_IE;
mei_hcsr_set(dev, hcsr);
}
/**
* mei_disable_interrupts - disables mei device interrupts
*
* @dev: the device structure
*/
void mei_disable_interrupts(struct mei_device *dev)
{
u32 hcsr = mei_hcsr_read(dev);
hcsr &= ~H_IE;
mei_hcsr_set(dev, hcsr);
}
/**
* mei_hw_reset - resets fw via mei csr register.
*
* @dev: the device structure
* @interrupts_enabled: if interrupt should be enabled after reset.
*/
void mei_hw_reset(struct mei_device *dev, bool intr_enable)
{
u32 hcsr = mei_hcsr_read(dev);
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(dev, hcsr);
hcsr = mei_hcsr_read(dev) | H_IG;
hcsr &= ~H_RST;
mei_hcsr_set(dev, hcsr);
hcsr = mei_hcsr_read(dev);
dev_dbg(&dev->pdev->dev, "current HCSR = 0x%08x.\n", hcsr);
}
/**
* mei_host_set_ready - enable device
*
* @dev - mei device
* returns bool
*/
void mei_host_set_ready(struct mei_device *dev)
{
dev->host_hw_state |= H_IE | H_IG | H_RDY;
mei_hcsr_set(dev, dev->host_hw_state);
}
/**
* mei_host_is_ready - check whether the host has turned ready
*
* @dev - mei device
* returns bool
*/
bool mei_host_is_ready(struct mei_device *dev)
{
dev->host_hw_state = mei_hcsr_read(dev);
return (dev->host_hw_state & H_RDY) == H_RDY;
}
/**
* mei_me_is_ready - check whether the me has turned ready
*
* @dev - mei device
* returns bool
*/
bool mei_me_is_ready(struct mei_device *dev)
{
dev->me_hw_state = mei_mecsr_read(dev);
return (dev->me_hw_state & ME_RDY_HRA) == ME_RDY_HRA;
}
/**
* mei_interrupt_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_interrupt_quick_handler(int irq, void *dev_id)
{
struct mei_device *dev = (struct mei_device *) dev_id;
u32 csr_reg = mei_hcsr_read(dev);
if ((csr_reg & H_IS) != H_IS)
return IRQ_NONE;
/* clear H_IS bit in H_CSR */
mei_reg_write(dev, H_CSR, csr_reg);
return IRQ_WAKE_THREAD;
}
/**
* mei_hbuf_filled_slots - gets number of device filled buffer slots
*
* @device: the device structure
*
* returns number of filled slots
*/
static unsigned char mei_hbuf_filled_slots(struct mei_device *dev)
{
char read_ptr, write_ptr;
dev->host_hw_state = mei_hcsr_read(dev);
read_ptr = (char) ((dev->host_hw_state & H_CBRP) >> 8);
write_ptr = (char) ((dev->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.
*/
bool mei_hbuf_is_empty(struct mei_device *dev)
{
return mei_hbuf_filled_slots(dev) == 0;
}
/**
* mei_hbuf_empty_slots - counts write empty slots.
*
* @dev: the device structure
*
* returns -1(ESLOTS_OVERFLOW) if overflow, otherwise empty slots count
*/
int mei_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;
}
/**
* mei_write_message - writes a message to mei device.
*
* @dev: the device structure
* @hader: mei HECI header of message
* @buf: message payload will be written
*
* This function returns -EIO if write has failed
*/
int mei_write_message(struct mei_device *dev, struct mei_msg_hdr *header,
unsigned char *buf)
{
unsigned long rem, dw_cnt;
unsigned long length = header->length;
u32 *reg_buf = (u32 *)buf;
u32 hcsr;
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_reg_write(dev, H_CB_WW, *((u32 *) header));
for (i = 0; i < length / 4; i++)
mei_reg_write(dev, H_CB_WW, reg_buf[i]);
rem = length & 0x3;
if (rem > 0) {
u32 reg = 0;
memcpy(&reg, &buf[length - rem], rem);
mei_reg_write(dev, H_CB_WW, reg);
}
hcsr = mei_hcsr_read(dev) | H_IG;
mei_hcsr_set(dev, hcsr);
if (!mei_me_is_ready(dev))
return -EIO;
return 0;
}
/**
* mei_count_full_read_slots - counts read full slots.
*
* @dev: the device structure
*
* returns -1(ESLOTS_OVERFLOW) if overflow, otherwise filled slots count
*/
int mei_count_full_read_slots(struct mei_device *dev)
{
char read_ptr, write_ptr;
unsigned char buffer_depth, filled_slots;
dev->me_hw_state = mei_mecsr_read(dev);
buffer_depth = (unsigned char)((dev->me_hw_state & ME_CBD_HRA) >> 24);
read_ptr = (char) ((dev->me_hw_state & ME_CBRP_HRA) >> 8);
write_ptr = (char) ((dev->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_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
*/
void mei_read_slots(struct mei_device *dev, unsigned char *buffer,
unsigned long buffer_length)
{
u32 *reg_buf = (u32 *)buffer;
u32 hcsr;
for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
*reg_buf++ = mei_mecbrw_read(dev);
if (buffer_length > 0) {
u32 reg = mei_mecbrw_read(dev);
memcpy(reg_buf, &reg, buffer_length);
}
hcsr = mei_hcsr_read(dev) | H_IG;
mei_hcsr_set(dev, hcsr);
}