From a2d05131f0515e5c53c12c26549f5be2ef7777e7 Mon Sep 17 00:00:00 2001
From: Marcin Chrzanowski <marcin.j.chrzanowski@gmail.com>
Date: Wed, 23 May 2018 21:24:03 +0200
Subject: Implement draw columns

---
 char.c | 139 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 138 insertions(+), 1 deletion(-)

(limited to 'char.c')

diff --git a/char.c b/char.c
index a4ba095..54fd8a3 100644
--- a/char.c
+++ b/char.c
@@ -1,10 +1,13 @@
 #include "char.h"
 
+#include <linux/anon_inodes.h>
 #include <linux/cdev.h>
 #include <linux/device.h>
 #include <linux/fs.h>
+#include <asm/uaccess.h>
 
 #include "doomdev.h"
+#include "harddoom.h"
 #include "util.h"
 #include "pci.h"
 #include "surface.h"
@@ -24,9 +27,143 @@ long doom_create_surface(struct file *filp, unsigned long arg)
 	return new_surface(filp, params);
 }
 
+void free_texture(struct texture_data *texture_data);
+int texture_release(struct inode *inode, struct file *filp)
+{
+	struct texture_data *texture_data;
+
+	texture_data = filp->private_data;
+
+	free_texture(texture_data);
+
+	kfree(texture_data);
+
+	return 0;
+}
+
+struct file_operations texture_fops = {
+	.owner = THIS_MODULE,
+	.release = texture_release
+
+};
+
+int verify_texture_params(struct doomdev_ioctl_create_texture *params)
+{
+	if (params->size > 4 * 1024 * 1024) {
+		return -EOVERFLOW;
+	}
+
+	if (params->height > 1023) {
+		return -EOVERFLOW;
+	}
+
+	return 0;
+}
+
+int alloc_texture(struct doomdev_ioctl_create_texture *params,
+	       struct texture_data *texture_data)
+{
+	int err;
+	int i;
+	int not_written;
+	int pages_needed;
+
+	texture_data->size = params->size;
+	texture_data->height = params->height;
+
+	pages_needed = (params->size / HARDDOOM_PAGE_SIZE);
+	if (params->size % HARDDOOM_PAGE_SIZE != 0) {
+		pages_needed += 1;
+	}
+
+	texture_data->pages = pages_needed;
+	texture_data->texture_cpu =
+		dma_alloc_coherent(texture_data->doom_data->pci_device,
+				params->size, &texture_data->texture_dev,
+				GFP_KERNEL);
+	ORFAIL_NULL(texture_data->texture_cpu, -ENOMEM, error_texture);
+
+	texture_data->page_table_cpu = 
+		dma_alloc_coherent(texture_data->doom_data->pci_device,
+				pages_needed * 4, &texture_data->page_table_dev,
+				GFP_KERNEL);
+	ORFAIL_NULL(texture_data->page_table_cpu, -ENOMEM, error_pt);
+
+	for (i = 0; i < pages_needed; i++) {
+		texture_data->page_table_cpu[i] =
+			(HARDDOOM_PTE_PHYS_MASK &
+			 (texture_data->texture_dev + HARDDOOM_PAGE_SIZE * i)) |
+			HARDDOOM_PTE_VALID;
+	}
+
+	not_written = copy_from_user(texture_data->texture_cpu,
+			(void __user *) params->data_ptr,
+			params->size);
+
+
+	if (not_written) {
+		err = -EFAULT;
+		goto error_copy;
+	}
+
+	return 0;
+
+error_copy:
+	dma_free_coherent(texture_data->doom_data->pci_device,
+			texture_data->pages * 4, texture_data->page_table_cpu,
+			texture_data->page_table_dev);
+error_pt:
+	dma_free_coherent(texture_data->doom_data->pci_device,
+			texture_data->size, texture_data->texture_cpu,
+			texture_data->texture_dev);
+error_texture:
+	return err;
+}
+
+void free_texture(struct texture_data *texture_data)
+{
+	dma_free_coherent(texture_data->doom_data->pci_device,
+			texture_data->pages * 4, texture_data->page_table_cpu,
+			texture_data->page_table_dev);
+
+	dma_free_coherent(texture_data->doom_data->pci_device,
+			texture_data->size, texture_data->texture_cpu,
+			texture_data->texture_dev);
+}
+
 long doom_create_texture(struct file *filp, unsigned long arg)
 {
-	return -1;
+	int err;
+	struct doomdev_ioctl_create_texture *params;
+	struct texture_data *texture_data;
+	int fd;
+	struct doom_data *doom_data;
+
+	params = (struct doomdev_ioctl_create_texture *) arg;
+
+	err = verify_texture_params(params);
+	if (err < 0) {
+		return err;
+	}
+
+	texture_data = kmalloc(sizeof(*texture_data), GFP_KERNEL);
+	ORFAIL_NULL(texture_data, -ENOMEM, error_data);
+	doom_data = container_of(filp->f_inode->i_cdev, struct doom_data, cdev);
+	texture_data->doom_data = doom_data;
+	
+	ORFAIL(alloc_texture(params, texture_data), error_texture);
+
+	fd = anon_inode_getfd("doom_texture", &texture_fops, texture_data, 0);
+	ORFAIL(fd, error_inode);
+
+	return fd;
+
+error_inode:
+	free_texture(texture_data);
+error_texture:
+	kfree(texture_data);
+error_data:
+	return err;
 }
 
 long doom_create_flat(struct file *filp, unsigned long arg)
-- 
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