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path: root/drivers/staging/kpc2000/kpc_dma/fileops.c
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Diffstat (limited to 'drivers/staging/kpc2000/kpc_dma/fileops.c')
-rw-r--r--drivers/staging/kpc2000/kpc_dma/fileops.c418
1 files changed, 418 insertions, 0 deletions
diff --git a/drivers/staging/kpc2000/kpc_dma/fileops.c b/drivers/staging/kpc2000/kpc_dma/fileops.c
new file mode 100644
index 000000000000..616658709bd9
--- /dev/null
+++ b/drivers/staging/kpc2000/kpc_dma/fileops.c
@@ -0,0 +1,418 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/kernel.h> /* printk() */
+#include <linux/slab.h> /* kmalloc() */
+#include <linux/fs.h> /* everything... */
+#include <linux/errno.h> /* error codes */
+#include <linux/types.h> /* size_t */
+#include <linux/cdev.h>
+#include <linux/uaccess.h> /* copy_*_user */
+#include <linux/aio.h> /* aio stuff */
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include "kpc_dma_driver.h"
+#include "uapi.h"
+
+/********** Helper Functions **********/
+static inline
+unsigned int count_pages(unsigned long iov_base, size_t iov_len)
+{
+ unsigned long first = (iov_base & PAGE_MASK) >> PAGE_SHIFT;
+ unsigned long last = ((iov_base+iov_len-1) & PAGE_MASK) >> PAGE_SHIFT;
+ return last - first + 1;
+}
+
+static inline
+unsigned int count_parts_for_sge(struct scatterlist *sg)
+{
+ unsigned int sg_length = sg_dma_len(sg);
+ sg_length += (0x80000-1);
+ return (sg_length / 0x80000);
+}
+
+/********** Transfer Helpers **********/
+static
+int kpc_dma_transfer(struct dev_private_data *priv, struct kiocb *kcb, unsigned long iov_base, size_t iov_len)
+{
+ unsigned int i = 0;
+ long rv = 0;
+ struct kpc_dma_device *ldev;
+ struct aio_cb_data *acd;
+ DECLARE_COMPLETION_ONSTACK(done);
+ u32 desc_needed = 0;
+ struct scatterlist *sg;
+ u32 num_descrs_avail;
+ struct kpc_dma_descriptor *desc;
+ unsigned int pcnt;
+ unsigned int p;
+ u64 card_addr;
+ u64 dma_addr;
+ u64 user_ctl;
+
+ BUG_ON(priv == NULL);
+ ldev = priv->ldev;
+ BUG_ON(ldev == NULL);
+
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_transfer(priv = [%p], kcb = [%p], iov_base = [%p], iov_len = %ld) ldev = [%p]\n", priv, kcb, (void*)iov_base, iov_len, ldev);
+
+ acd = (struct aio_cb_data *) kzalloc(sizeof(struct aio_cb_data), GFP_KERNEL);
+ if (!acd){
+ dev_err(&priv->ldev->pldev->dev, "Couldn't kmalloc space for for the aio data\n");
+ return -ENOMEM;
+ }
+ memset(acd, 0x66, sizeof(struct aio_cb_data));
+
+ acd->priv = priv;
+ acd->ldev = priv->ldev;
+ acd->cpl = &done;
+ acd->flags = 0;
+ acd->kcb = kcb;
+ acd->len = iov_len;
+ acd->page_count = count_pages(iov_base, iov_len);
+
+ // Allocate an array of page pointers
+ acd->user_pages = kzalloc(sizeof(struct page *) * acd->page_count, GFP_KERNEL);
+ if (!acd->user_pages){
+ dev_err(&priv->ldev->pldev->dev, "Couldn't kmalloc space for for the page pointers\n");
+ rv = -ENOMEM;
+ goto err_alloc_userpages;
+ }
+
+ // Lock the user buffer pages in memory, and hold on to the page pointers (for the sglist)
+ down_read(&current->mm->mmap_sem); /* get memory map semaphore */
+ rv = get_user_pages(iov_base, acd->page_count, FOLL_TOUCH | FOLL_WRITE | FOLL_GET, acd->user_pages, NULL);
+ up_read(&current->mm->mmap_sem); /* release the semaphore */
+ if (rv != acd->page_count){
+ dev_err(&priv->ldev->pldev->dev, "Couldn't get_user_pages (%ld)\n", rv);
+ goto err_get_user_pages;
+ }
+
+ // Allocate and setup the sg_table (scatterlist entries)
+ rv = sg_alloc_table_from_pages(&acd->sgt, acd->user_pages, acd->page_count, iov_base & (PAGE_SIZE-1), iov_len, GFP_KERNEL);
+ if (rv){
+ dev_err(&priv->ldev->pldev->dev, "Couldn't alloc sg_table (%ld)\n", rv);
+ goto err_alloc_sg_table;
+ }
+
+ // Setup the DMA mapping for all the sg entries
+ acd->mapped_entry_count = dma_map_sg(&ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, ldev->dir);
+ if (acd->mapped_entry_count <= 0){
+ dev_err(&priv->ldev->pldev->dev, "Couldn't dma_map_sg (%d)\n", acd->mapped_entry_count);
+ goto err_dma_map_sg;
+ }
+
+ // Calculate how many descriptors are actually needed for this transfer.
+ for_each_sg(acd->sgt.sgl, sg, acd->mapped_entry_count, i){
+ desc_needed += count_parts_for_sge(sg);
+ }
+
+ lock_engine(ldev);
+
+ // Figoure out how many descriptors are available and return an error if there aren't enough
+ num_descrs_avail = count_descriptors_available(ldev);
+ dev_dbg(&priv->ldev->pldev->dev, " mapped_entry_count = %d num_descrs_needed = %d num_descrs_avail = %d\n", acd->mapped_entry_count, desc_needed, num_descrs_avail);
+ if (desc_needed >= ldev->desc_pool_cnt){
+ dev_warn(&priv->ldev->pldev->dev, " mapped_entry_count = %d num_descrs_needed = %d num_descrs_avail = %d TOO MANY to ever complete!\n", acd->mapped_entry_count, desc_needed, num_descrs_avail);
+ rv = -EAGAIN;
+ goto err_descr_too_many;
+ }
+ if (desc_needed > num_descrs_avail){
+ dev_warn(&priv->ldev->pldev->dev, " mapped_entry_count = %d num_descrs_needed = %d num_descrs_avail = %d Too many to complete right now.\n", acd->mapped_entry_count, desc_needed, num_descrs_avail);
+ rv = -EMSGSIZE;
+ goto err_descr_too_many;
+ }
+
+ // Loop through all the sg table entries and fill out a descriptor for each one.
+ desc = ldev->desc_next;
+ card_addr = acd->priv->card_addr;
+ for_each_sg(acd->sgt.sgl, sg, acd->mapped_entry_count, i){
+ pcnt = count_parts_for_sge(sg);
+ for (p = 0 ; p < pcnt ; p++){
+ // Fill out the descriptor
+ BUG_ON(desc == NULL);
+ clear_desc(desc);
+ if (p != pcnt-1){
+ desc->DescByteCount = 0x80000;
+ } else {
+ desc->DescByteCount = sg_dma_len(sg) - (p * 0x80000);
+ }
+ desc->DescBufferByteCount = desc->DescByteCount;
+
+ desc->DescControlFlags |= DMA_DESC_CTL_IRQONERR;
+ if (i == 0 && p == 0)
+ desc->DescControlFlags |= DMA_DESC_CTL_SOP;
+ if (i == acd->mapped_entry_count-1 && p == pcnt-1)
+ desc->DescControlFlags |= DMA_DESC_CTL_EOP | DMA_DESC_CTL_IRQONDONE;
+
+ desc->DescCardAddrLS = (card_addr & 0xFFFFFFFF);
+ desc->DescCardAddrMS = (card_addr >> 32) & 0xF;
+ card_addr += desc->DescByteCount;
+
+ dma_addr = sg_dma_address(sg) + (p * 0x80000);
+ desc->DescSystemAddrLS = (dma_addr & 0x00000000FFFFFFFF) >> 0;
+ desc->DescSystemAddrMS = (dma_addr & 0xFFFFFFFF00000000) >> 32;
+
+ user_ctl = acd->priv->user_ctl;
+ if (i == acd->mapped_entry_count-1 && p == pcnt-1){
+ user_ctl = acd->priv->user_ctl_last;
+ }
+ desc->DescUserControlLS = (user_ctl & 0x00000000FFFFFFFF) >> 0;
+ desc->DescUserControlMS = (user_ctl & 0xFFFFFFFF00000000) >> 32;
+
+ if (i == acd->mapped_entry_count-1 && p == pcnt-1)
+ desc->acd = acd;
+
+ dev_dbg(&priv->ldev->pldev->dev, " Filled descriptor %p (acd = %p)\n", desc, desc->acd);
+
+ ldev->desc_next = desc->Next;
+ desc = desc->Next;
+ }
+ }
+
+ // Send the filled descriptors off to the hardware to process!
+ SetEngineSWPtr(ldev, ldev->desc_next);
+
+ unlock_engine(ldev);
+
+ // If this is a synchronous kiocb, we need to put the calling process to sleep until the transfer is complete
+ if (kcb == NULL || is_sync_kiocb(kcb)){
+ rv = wait_for_completion_interruptible(&done);
+ // If the user aborted (rv == -ERESTARTSYS), we're no longer responsible for cleaning up the acd
+ if (rv == -ERESTARTSYS){
+ acd->cpl = NULL;
+ }
+ if (rv == 0){
+ rv = acd->len;
+ kfree(acd);
+ }
+ return rv;
+ }
+
+ return -EIOCBQUEUED;
+
+ err_descr_too_many:
+ unlock_engine(ldev);
+ dma_unmap_sg(&ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, ldev->dir);
+ sg_free_table(&acd->sgt);
+ err_dma_map_sg:
+ err_alloc_sg_table:
+ for (i = 0 ; i < acd->page_count ; i++){
+ put_page(acd->user_pages[i]);
+ }
+ err_get_user_pages:
+ kfree(acd->user_pages);
+ err_alloc_userpages:
+ kfree(acd);
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_transfer returning with error %ld\n", rv);
+ return rv;
+}
+
+void transfer_complete_cb(struct aio_cb_data *acd, size_t xfr_count, u32 flags)
+{
+ unsigned int i;
+
+ BUG_ON(acd == NULL);
+ BUG_ON(acd->user_pages == NULL);
+ BUG_ON(acd->sgt.sgl == NULL);
+ BUG_ON(acd->ldev == NULL);
+ BUG_ON(acd->ldev->pldev == NULL);
+
+ dev_dbg(&acd->ldev->pldev->dev, "transfer_complete_cb(acd = [%p])\n", acd);
+
+ for (i = 0 ; i < acd->page_count ; i++){
+ if (!PageReserved(acd->user_pages[i])){
+ set_page_dirty(acd->user_pages[i]);
+ }
+ }
+
+ dma_unmap_sg(&acd->ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, acd->ldev->dir);
+
+ for (i = 0 ; i < acd->page_count ; i++){
+ put_page(acd->user_pages[i]);
+ }
+
+ sg_free_table(&acd->sgt);
+
+ kfree(acd->user_pages);
+
+ acd->flags = flags;
+
+ if (acd->kcb == NULL || is_sync_kiocb(acd->kcb)){
+ if (acd->cpl){
+ complete(acd->cpl);
+ } else {
+ // There's no completion, so we're responsible for cleaning up the acd
+ kfree(acd);
+ }
+ } else {
+#ifdef CONFIG_KPC_DMA_AIO
+ aio_complete(acd->kcb, acd->len, acd->flags);
+#endif
+ kfree(acd);
+ }
+}
+
+/********** Fileops **********/
+static
+int kpc_dma_open(struct inode *inode, struct file *filp)
+{
+ struct dev_private_data *priv;
+ struct kpc_dma_device *ldev = kpc_dma_lookup_device(iminor(inode));
+ if (ldev == NULL)
+ return -ENODEV;
+
+ if (! atomic_dec_and_test(&ldev->open_count)){
+ atomic_inc(&ldev->open_count);
+ return -EBUSY; /* already open */
+ }
+
+ priv = kzalloc(sizeof(struct dev_private_data), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->ldev = ldev;
+ filp->private_data = priv;
+
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_open(inode = [%p], filp = [%p]) priv = [%p] ldev = [%p]\n", inode, filp, priv, priv->ldev);
+ return 0;
+}
+
+static
+int kpc_dma_close(struct inode *inode, struct file *filp)
+{
+ struct kpc_dma_descriptor *cur;
+ struct dev_private_data *priv = (struct dev_private_data *)filp->private_data;
+ struct kpc_dma_device *eng = priv->ldev;
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_close(inode = [%p], filp = [%p]) priv = [%p], ldev = [%p]\n", inode, filp, priv, priv->ldev);
+
+ lock_engine(eng);
+
+ stop_dma_engine(eng);
+
+ cur = eng->desc_completed->Next;
+ while (cur != eng->desc_next){
+ dev_dbg(&eng->pldev->dev, "Aborting descriptor %p (acd = %p)\n", cur, cur->acd);
+ if (cur->DescControlFlags & DMA_DESC_CTL_EOP){
+ if (cur->acd)
+ transfer_complete_cb(cur->acd, 0, ACD_FLAG_ABORT);
+ }
+
+ clear_desc(cur);
+ eng->desc_completed = cur;
+
+ cur = cur->Next;
+ }
+
+ start_dma_engine(eng);
+
+ unlock_engine(eng);
+
+ atomic_inc(&priv->ldev->open_count); /* release the device */
+ kfree(priv);
+ return 0;
+}
+
+#ifdef CONFIG_KPC_DMA_AIO
+static
+int kpc_dma_aio_cancel(struct kiocb *kcb)
+{
+ struct dev_private_data *priv = (struct dev_private_data *)kcb->ki_filp->private_data;
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_aio_cancel(kcb = [%p]) priv = [%p], ldev = [%p]\n", kcb, priv, priv->ldev);
+ return 0;
+}
+
+static
+ssize_t kpc_dma_aio_read(struct kiocb *kcb, const struct iovec *iov, unsigned long iov_count, loff_t pos)
+{
+ struct dev_private_data *priv = (struct dev_private_data *)kcb->ki_filp->private_data;
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_aio_read(kcb = [%p], iov = [%p], iov_count = %ld, pos = %lld) priv = [%p], ldev = [%p]\n", kcb, iov, iov_count, pos, priv, priv->ldev);
+
+ if (priv->ldev->dir != DMA_FROM_DEVICE)
+ return -EMEDIUMTYPE;
+
+ if (iov_count != 1){
+ dev_err(&priv->ldev->pldev->dev, "kpc_dma_aio_read() called with iov_count > 1!\n");
+ return -EFAULT;
+ }
+
+ if (!is_sync_kiocb(kcb))
+ kiocb_set_cancel_fn(kcb, kpc_dma_aio_cancel);
+ return kpc_dma_transfer(priv, kcb, (unsigned long)iov->iov_base, iov->iov_len);
+}
+
+static
+ssize_t kpc_dma_aio_write(struct kiocb *kcb, const struct iovec *iov, unsigned long iov_count, loff_t pos)
+{
+ struct dev_private_data *priv = (struct dev_private_data *)kcb->ki_filp->private_data;
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_aio_write(kcb = [%p], iov = [%p], iov_count = %ld, pos = %lld) priv = [%p], ldev = [%p]\n", kcb, iov, iov_count, pos, priv, priv->ldev);
+
+ if (priv->ldev->dir != DMA_TO_DEVICE)
+ return -EMEDIUMTYPE;
+
+ if (iov_count != 1){
+ dev_err(&priv->ldev->pldev->dev, "kpc_dma_aio_write() called with iov_count > 1!\n");
+ return -EFAULT;
+ }
+
+ if (!is_sync_kiocb(kcb))
+ kiocb_set_cancel_fn(kcb, kpc_dma_aio_cancel);
+ return kpc_dma_transfer(priv, kcb, (unsigned long)iov->iov_base, iov->iov_len);
+}
+#endif
+
+static
+ssize_t kpc_dma_read( struct file *filp, char __user *user_buf, size_t count, loff_t *ppos)
+{
+ struct dev_private_data *priv = (struct dev_private_data *)filp->private_data;
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_read(filp = [%p], user_buf = [%p], count = %zu, ppos = [%p]) priv = [%p], ldev = [%p]\n", filp, user_buf, count, ppos, priv, priv->ldev);
+
+ if (priv->ldev->dir != DMA_FROM_DEVICE)
+ return -EMEDIUMTYPE;
+
+ return kpc_dma_transfer(priv, (struct kiocb *)NULL, (unsigned long)user_buf, count);
+}
+
+static
+ssize_t kpc_dma_write(struct file *filp, const char __user *user_buf, size_t count, loff_t *ppos)
+{
+ struct dev_private_data *priv = (struct dev_private_data *)filp->private_data;
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_write(filp = [%p], user_buf = [%p], count = %zu, ppos = [%p]) priv = [%p], ldev = [%p]\n", filp, user_buf, count, ppos, priv, priv->ldev);
+
+ if (priv->ldev->dir != DMA_TO_DEVICE)
+ return -EMEDIUMTYPE;
+
+ return kpc_dma_transfer(priv, (struct kiocb *)NULL, (unsigned long)user_buf, count);
+}
+
+static
+long kpc_dma_ioctl(struct file *filp, unsigned int ioctl_num, unsigned long ioctl_param)
+{
+ struct dev_private_data *priv = (struct dev_private_data *)filp->private_data;
+ dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_ioctl(filp = [%p], ioctl_num = 0x%x, ioctl_param = 0x%lx) priv = [%p], ldev = [%p]\n", filp, ioctl_num, ioctl_param, priv, priv->ldev);
+
+ switch (ioctl_num){
+ case KND_IOCTL_SET_CARD_ADDR: priv->card_addr = ioctl_param; return priv->card_addr;
+ case KND_IOCTL_SET_USER_CTL: priv->user_ctl = ioctl_param; return priv->user_ctl;
+ case KND_IOCTL_SET_USER_CTL_LAST: priv->user_ctl_last = ioctl_param; return priv->user_ctl_last;
+ case KND_IOCTL_GET_USER_STS: return priv->user_sts;
+ }
+
+ return -ENOTTY;
+}
+
+
+struct file_operations kpc_dma_fops = {
+ .owner = THIS_MODULE,
+ .open = kpc_dma_open,
+ .release = kpc_dma_close,
+ .read = kpc_dma_read,
+ .write = kpc_dma_write,
+#ifdef CONFIG_KPC_DMA_AIO
+ .aio_read = kpc_dma_aio_read,
+ .aio_write = kpc_dma_aio_write,
+#endif
+ .unlocked_ioctl = kpc_dma_ioctl,
+};
+
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.