diff options
Diffstat (limited to 'driver/dev.c')
| -rw-r--r-- | driver/dev.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/driver/dev.c b/driver/dev.c new file mode 100644 index 0000000..2a047a4 --- /dev/null +++ b/driver/dev.c @@ -0,0 +1,196 @@ +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/cdev.h> +#include <linux/sysfs.h> +#include <asm/atomic.h> +#include <linux/pagemap.h> +#include <linux/spinlock.h> +#include <linux/list.h> +#include <asm/scatterlist.h> +#include <linux/vmalloc.h> +#include <linux/stat.h> +#include <linux/interrupt.h> +#include <linux/wait.h> + +#include "base.h" + + +/** + * + * Called when an application open()s a /dev/fpga*, attaches the private data + * with the file pointer. + * + */ +static int pcidriver_open(struct inode *inode, struct file *filp) +{ + pcidriver_privdata_t *privdata; + + /* Set the private data area for the file */ + privdata = container_of( inode->i_cdev, pcidriver_privdata_t, cdev); + filp->private_data = privdata; + + pcidriver_module_get(privdata); + + return 0; +} + +/** + * + * Called when the application close()s the file descriptor. Does nothing at + * the moment. + * + */ +static int pcidriver_release(struct inode *inode, struct file *filp) +{ + pcidriver_privdata_t *privdata; + + /* Get the private data area */ + privdata = filp->private_data; + + pcidriver_module_put(privdata); + + return 0; +} + + +/*************************************************************************/ +/* Internal driver functions */ +static int pcidriver_mmap_bar(pcidriver_privdata_t *privdata, struct vm_area_struct *vmap, int bar) +{ +#ifdef PCIDRIVER_DUMMY_DEVICE + return -ENXIO; +#else /* PCIDRIVER_DUMMY_DEVICE */ + int ret = 0; + unsigned long bar_addr; + unsigned long bar_length, vma_size; + unsigned long bar_flags; + + mod_info_dbg("Entering mmap_pci\n"); + + + /* Get info of the BAR to be mapped */ + bar_addr = pci_resource_start(privdata->pdev, bar); + bar_length = pci_resource_len(privdata->pdev, bar); + bar_flags = pci_resource_flags(privdata->pdev, bar); + + /* Check sizes */ + vma_size = (vmap->vm_end - vmap->vm_start); + + if ((vma_size != bar_length) && + ((bar_length < PAGE_SIZE) && (vma_size != PAGE_SIZE))) { + mod_info( "mmap size is not correct! bar: %lu - vma: %lu\n", bar_length, vma_size ); + return -EINVAL; + } + + if (bar_flags & IORESOURCE_IO) { + /* Unlikely case, we will mmap a IO region */ + + /* IO regions are never cacheable */ + vmap->vm_page_prot = pgprot_noncached(vmap->vm_page_prot); + + /* Map the BAR */ + ret = io_remap_pfn_range(vmap, vmap->vm_start, (bar_addr >> PAGE_SHIFT), bar_length, vmap->vm_page_prot); + } else { + /* Normal case, mmap a memory region */ + + /* Ensure this VMA is non-cached, if it is not flaged as prefetchable. + * If it is prefetchable, caching is allowed and will give better performance. + * This should be set properly by the BIOS, but we want to be sure. */ + /* adapted from drivers/char/mem.c, mmap function. */ + + /* Setting noncached disables MTRR registers, and we want to use them. + * So we take this code out. This can lead to caching problems if and only if + * the System BIOS set something wrong. Check LDDv3, page 425. + */ + +// if (!(bar_flags & IORESOURCE_PREFETCH)) +// vmap->vm_page_prot = pgprot_noncached(vmap->vm_page_prot); + + + /* Map the BAR */ + ret = remap_pfn_range(vmap, vmap->vm_start, (bar_addr >> PAGE_SHIFT), bar_length, vmap->vm_page_prot); + } + + if (ret) { + mod_info("remap_pfn_range failed\n"); + return -EAGAIN; + } + + return 0; /* success */ +#endif /* PCIDRIVER_DUMMY_DEVICE */ +} + +/** + * + * This function is the entry point for mmap() and calls either pcidriver_mmap_bar + * or pcidriver_mmap_kmem + * + * @see pcidriver_mmap_bar + * @see pcidriver_mmap_kmem + * + */ +static int pcidriver_mmap(struct file *filp, struct vm_area_struct *vma) +{ + pcidriver_privdata_t *privdata; + int ret = 0, bar; + + mod_info_dbg("Entering mmap\n"); + + /* Get the private data area */ + privdata = filp->private_data; + + /* Check the current mmap mode */ + switch (privdata->mmap_mode) { + case PCIDRIVER_MMAP_PCI: + bar = privdata->mmap_area; + if ((bar < 0)||(bar > 5)) { + mod_info("Attempted to mmap a PCI area with the wrong mmap_area value: %d\n",privdata->mmap_area); + return -EINVAL; + } + ret = pcidriver_mmap_bar(privdata, vma, bar); + break; + case PCIDRIVER_MMAP_KMEM: + ret = pcidriver_mmap_kmem(privdata, vma); + break; + default: + mod_info( "Invalid mmap_mode value (%d)\n",privdata->mmap_mode ); + return -EINVAL; /* Invalid parameter (mode) */ + } + + return ret; +} + +static struct file_operations pcidriver_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = pcidriver_ioctl, + .mmap = pcidriver_mmap, + .open = pcidriver_open, + .release = pcidriver_release, +}; + +const struct file_operations *pcidriver_get_fops(void) +{ + return &pcidriver_fops; +} + + +void pcidriver_module_get(pcidriver_privdata_t *privdata) { + atomic_inc(&(privdata->refs)); +// mod_info("Ref: %i\n", atomic_read(&(privdata->refs))); +} + +void pcidriver_module_put(pcidriver_privdata_t *privdata) { + if (atomic_add_negative(-1, &(privdata->refs))) { + atomic_inc(&(privdata->refs)); + mod_info("Reference counting error..."); + } else { +// mod_info("Unref: %i\n", atomic_read(&(privdata->refs))); + } +} |