From 42dc62e5db80994c51e0e62d6c264ce71c655c58 Mon Sep 17 00:00:00 2001
From: Marcin Chrzanowski <marcin.j.chrzanowski@gmail.com>
Date: Wed, 23 May 2018 00:16:05 +0200
Subject: Add synchronization and irq

---
 pci.c          | 41 +++++++++++++++++++++++++++++++++++++++++
 private_data.h |  6 ++++++
 2 files changed, 47 insertions(+)

diff --git a/pci.c b/pci.c
index e747118..0402647 100644
--- a/pci.c
+++ b/pci.c
@@ -2,6 +2,7 @@
 
 #include <linux/kernel.h>
 #include <linux/pci.h>
+#include <linux/interrupt.h>
 
 #include "char.h"
 #include "harddoom.h"
@@ -9,6 +10,34 @@
 #include "harddoomdev.h"
 #include "private_data.h"
 
+void handle_pong_sync(struct doom_data *doom_data)
+{
+	up(&doom_data->pong_sem);
+}
+
+irqreturn_t doom_irq(int irq, void *dev)
+{
+	uint32_t interrupts;
+	struct doom_data *doom_data;
+
+
+	doom_data = dev;
+
+	interrupts = get_interrupts(doom_data->iomem);
+	if (!interrupts) {
+		return IRQ_NONE;
+	}
+
+	if (interrupts & HARDDOOM_INTR_PONG_SYNC) {
+		handle_pong_sync(doom_data);
+		interrupts &= ~HARDDOOM_INTR_PONG_SYNC;
+	}
+
+	deactivate_intr(doom_data->iomem, HARDDOOM_INTR_MASK);
+
+	return IRQ_HANDLED;
+}
+
 int init_pci(struct pci_dev *dev)
 {
 	struct doom_data *doom_data;
@@ -30,8 +59,19 @@ int init_pci(struct pci_dev *dev)
 	pci_set_dma_mask(dev, DMA_BIT_MASK(32));
 	pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(32));
 
+	mutex_init(&doom_data->mutex);
+	sema_init(&doom_data->ping_sem, 1);
+	sema_init(&doom_data->pong_sem, 0);
+
+	ORFAIL(request_irq(dev->irq, doom_irq, IRQF_SHARED,
+			"doom", doom_data), error_irq);
+
 	return 0;
 
+error_irq:
+	pci_clear_master(dev);
+	pci_iounmap(dev, doom_data->iomem);
+	kfree(doom_data);
 error_kmalloc:
 	pci_release_regions(dev);
 error_regions:
@@ -46,6 +86,7 @@ void cleanup_pci(struct pci_dev *dev)
 
 	doom_data = pci_get_drvdata(dev);
 
+	free_irq(dev->irq, doom_data);
 	pci_clear_master(dev);
 	pci_iounmap(dev, doom_data->iomem);
 	kfree(doom_data);
diff --git a/private_data.h b/private_data.h
index 38148bd..39ceba8 100644
--- a/private_data.h
+++ b/private_data.h
@@ -9,13 +9,19 @@ struct doom_data {
 	struct device *device;
 	struct device *pci_device;
 	void __iomem *iomem;
+	struct mutex mutex;
+	struct semaphore ping_sem;
+	struct semaphore pong_sem;
 };
 
 struct surface_data {
 	struct doom_data *doom_data;
 
 	int surface_size;
+	int width;
+	int height;
 	int pages;
+	int total_bytes;
 
 	uint8_t *surface_cpu;
 	uint32_t *page_table_cpu;
-- 
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