cregit-Linux how code gets into the kernel

Release 4.14 drivers/misc/aspeed-lpc-ctrl.c

Directory: drivers/misc
/*
 * Copyright 2017 IBM Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/mfd/syscon.h>
#include <linux/miscdevice.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/poll.h>
#include <linux/regmap.h>

#include <linux/aspeed-lpc-ctrl.h>


#define DEVICE_NAME	"aspeed-lpc-ctrl"


#define HICR7 0x8

#define HICR8 0xc


struct aspeed_lpc_ctrl {
	
struct miscdevice	miscdev;
	
struct regmap		*regmap;
	
phys_addr_t		mem_base;
	
resource_size_t		mem_size;
	
u32		pnor_size;
	
u32		pnor_base;
};


static struct aspeed_lpc_ctrl *file_aspeed_lpc_ctrl(struct file *file) { return container_of(file->private_data, struct aspeed_lpc_ctrl, miscdev); }

Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur26100.00%1100.00%
Total26100.00%1100.00%


static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma) { struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); unsigned long vsize = vma->vm_end - vma->vm_start; pgprot_t prot = vma->vm_page_prot; if (vma->vm_pgoff + vsize > lpc_ctrl->mem_base + lpc_ctrl->mem_size) return -EINVAL; /* ast2400/2500 AHB accesses are not cache coherent */ prot = pgprot_noncached(prot); if (remap_pfn_range(vma, vma->vm_start, (lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff, vsize, prot)) return -EAGAIN; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur107100.00%2100.00%
Total107100.00%2100.00%


static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd, unsigned long param) { struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); void __user *p = (void __user *)param; struct aspeed_lpc_ctrl_mapping map; u32 addr; u32 size; long rc; if (copy_from_user(&map, p, sizeof(map))) return -EFAULT; if (map.flags != 0) return -EINVAL; switch (cmd) { case ASPEED_LPC_CTRL_IOCTL_GET_SIZE: /* The flash windows don't report their size */ if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY) return -EINVAL; /* Support more than one window id in the future */ if (map.window_id != 0) return -EINVAL; map.size = lpc_ctrl->mem_size; return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0; case ASPEED_LPC_CTRL_IOCTL_MAP: /* * The top half of HICR7 is the MSB of the BMC address of the * mapping. * The bottom half of HICR7 is the MSB of the HOST LPC * firmware space address of the mapping. * * The 1 bits in the top of half of HICR8 represent the bits * (in the requested address) that should be ignored and * replaced with those from the top half of HICR7. * The 1 bits in the bottom half of HICR8 represent the bits * (in the requested address) that should be kept and pass * into the BMC address space. */ /* * It doesn't make sense to talk about a size or offset with * low 16 bits set. Both HICR7 and HICR8 talk about the top 16 * bits of addresses and sizes. */ if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff)) return -EINVAL; /* * Because of the way the masks work in HICR8 offset has to * be a multiple of size. */ if (map.offset & (map.size - 1)) return -EINVAL; if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) { addr = lpc_ctrl->pnor_base; size = lpc_ctrl->pnor_size; } else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) { addr = lpc_ctrl->mem_base; size = lpc_ctrl->mem_size; } else { return -EINVAL; } /* Check overflow first! */ if (map.offset + map.size < map.offset || map.offset + map.size > size) return -EINVAL; if (map.size == 0 || map.size > size) return -EINVAL; addr += map.offset; /* * addr (host lpc address) is safe regardless of values. This * simply changes the address the host has to request on its * side of the LPC bus. This cannot impact the hosts own * memory space by surprise as LPC specific accessors are * required. The only strange thing that could be done is * setting the lower 16 bits but the shift takes care of that. */ rc = regmap_write(lpc_ctrl->regmap, HICR7, (addr | (map.addr >> 16))); if (rc) return rc; return regmap_write(lpc_ctrl->regmap, HICR8, (~(map.size - 1)) | ((map.size >> 16) - 1)); } return -EINVAL; }

Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur366100.00%1100.00%
Total366100.00%1100.00%

static const struct file_operations aspeed_lpc_ctrl_fops = { .owner = THIS_MODULE, .mmap = aspeed_lpc_ctrl_mmap, .unlocked_ioctl = aspeed_lpc_ctrl_ioctl, };
static int aspeed_lpc_ctrl_probe(struct platform_device *pdev) { struct aspeed_lpc_ctrl *lpc_ctrl; struct device_node *node; struct resource resm; struct device *dev; int rc; dev = &pdev->dev; lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL); if (!lpc_ctrl) return -ENOMEM; node = of_parse_phandle(dev->of_node, "flash", 0); if (!node) { dev_err(dev, "Didn't find host pnor flash node\n"); return -ENODEV; } rc = of_address_to_resource(node, 1, &resm); of_node_put(node); if (rc) { dev_err(dev, "Couldn't address to resource for flash\n"); return rc; } lpc_ctrl->pnor_size = resource_size(&resm); lpc_ctrl->pnor_base = resm.start; dev_set_drvdata(&pdev->dev, lpc_ctrl); node = of_parse_phandle(dev->of_node, "memory-region", 0); if (!node) { dev_err(dev, "Didn't find reserved memory\n"); return -EINVAL; } rc = of_address_to_resource(node, 0, &resm); of_node_put(node); if (rc) { dev_err(dev, "Couldn't address to resource for reserved memory\n"); return -ENOMEM; } lpc_ctrl->mem_size = resource_size(&resm); lpc_ctrl->mem_base = resm.start; lpc_ctrl->regmap = syscon_node_to_regmap( pdev->dev.parent->of_node); if (IS_ERR(lpc_ctrl->regmap)) { dev_err(dev, "Couldn't get regmap\n"); return -ENODEV; } lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR; lpc_ctrl->miscdev.name = DEVICE_NAME; lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops; lpc_ctrl->miscdev.parent = dev; rc = misc_register(&lpc_ctrl->miscdev); if (rc) dev_err(dev, "Unable to register device\n"); else dev_info(dev, "Loaded at %pr\n", &resm); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur34299.42%266.67%
Arnd Bergmann20.58%133.33%
Total344100.00%3100.00%


static int aspeed_lpc_ctrl_remove(struct platform_device *pdev) { struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev); misc_deregister(&lpc_ctrl->miscdev); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur35100.00%1100.00%
Total35100.00%1100.00%

static const struct of_device_id aspeed_lpc_ctrl_match[] = { { .compatible = "aspeed,ast2400-lpc-ctrl" }, { .compatible = "aspeed,ast2500-lpc-ctrl" }, { }, }; static struct platform_driver aspeed_lpc_ctrl_driver = { .driver = { .name = DEVICE_NAME, .of_match_table = aspeed_lpc_ctrl_match, }, .probe = aspeed_lpc_ctrl_probe, .remove = aspeed_lpc_ctrl_remove, }; module_platform_driver(aspeed_lpc_ctrl_driver); MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Cyril Bur <cyrilbur@gmail.com>"); MODULE_DESCRIPTION("Control for aspeed 2400/2500 LPC HOST to BMC mappings");

Overall Contributors

PersonTokensPropCommitsCommitProp
Cyril Bur104999.81%266.67%
Arnd Bergmann20.19%133.33%
Total1051100.00%3100.00%
Directory: drivers/misc
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.