From 81965b139d171744e1a0d7a8e9aeace74c8a6103 Mon Sep 17 00:00:00 2001
From: Andreas Baumann <mail@andreasbaumann.cc>
Date: Tue, 1 Aug 2017 16:57:04 +0200
Subject: added function pci_enable_bus_mastering to enable DMA transfers on
 the PCI bus adapted interface of pci_device_get_driver to also take a pointer
 to the PCI controller the PCI descriptor of a device also contains bus,
 device and function now

---
 src/hardware/pci.c | 20 +++++++++++++++++---
 src/hardware/pci.h |  7 ++++++-
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/hardware/pci.c b/src/hardware/pci.c
index 6b622c1..30eca6f 100644
--- a/src/hardware/pci.c
+++ b/src/hardware/pci.c
@@ -14,6 +14,7 @@
 
 #define PCI_VENDOR_ID 0x00
 #define PCI_DEVICE_ID 0x02
+#define PCI_COMMAND 0x04
 #define PCI_REVISION 0x08
 #define PCI_INTERFACE 0x09
 #define PCI_SUBCLASS 0x0A
@@ -22,6 +23,9 @@
 #define PCI_BAR_BASE 0x10
 #define PCI_INTERRUPT 0x3C
 
+// commands for PCI_COMMAND register
+#define PCI_COMMAND_ENABLE_BUS_MASTERING 0x0004
+
 void pci_controller_init( pci_controller_t *controller )
 {
 	memset( controller, 0, sizeof( pci_controller_t ) );
@@ -116,7 +120,7 @@ void pci_controller_scan_and_register( pci_controller_t *controller, driver_mana
 					}
 				}
 
-				driver_t *driver = pci_device_get_driver( &device_descriptor, interrupt, context );
+				driver_t *driver = pci_device_get_driver( controller, &device_descriptor, interrupt, context );
 				if( driver ) {
 					driver_manager_add_driver( driver_manager, driver );
 				}
@@ -129,6 +133,9 @@ void pci_device_descriptor_init( pci_device_descriptor_t *descriptor, pci_contro
 {
 	memset( descriptor, 0, sizeof( pci_device_descriptor_t ) );
 
+	descriptor->bus = bus;
+	descriptor->device = device;
+	descriptor->function = function;
 	descriptor->vendor_id = pci_controller_read( controller, bus, device, function, PCI_VENDOR_ID );
 	descriptor->device_id = pci_controller_read( controller, bus, device, function, PCI_DEVICE_ID );
 	descriptor->class_id = pci_controller_read( controller, bus, device, function, PCI_CLASS );
@@ -171,7 +178,7 @@ void pci_base_address_register_init( pci_base_address_register_t *base_address_r
 	}
 }
 
-driver_t *pci_device_get_driver( pci_device_descriptor_t *descriptor, interrupt_t *interrupt, void *context )
+driver_t *pci_device_get_driver( pci_controller_t *pci, pci_device_descriptor_t *descriptor, interrupt_t *interrupt, void *context )
 {
 	driver_t *driver = NULL;
 	
@@ -181,7 +188,7 @@ driver_t *pci_device_get_driver( pci_device_descriptor_t *descriptor, interrupt_
 			switch( descriptor->device_id ) {
 				case 0x8139: // RTL8139
 					driver = (driver_t *)malloc( sizeof( rtl8139_t ) );
-					rtl8139_init( (rtl8139_t *)driver, descriptor, interrupt, context );
+					rtl8139_init( (rtl8139_t *)driver, pci, descriptor, interrupt, context );
 					break;
 			}
 			break;
@@ -210,3 +217,10 @@ driver_t *pci_device_get_driver( pci_device_descriptor_t *descriptor, interrupt_
 	
 	return driver;
 }
+
+void pci_enable_bus_mastering( pci_controller_t *controller, pci_device_descriptor_t *descriptor )
+{
+	uint16_t val = pci_controller_read( controller, descriptor->bus, descriptor->device, descriptor->function, PCI_COMMAND );
+	val |= PCI_COMMAND_ENABLE_BUS_MASTERING;
+	pci_controller_write( controller, descriptor->bus, descriptor->device, descriptor->function, PCI_COMMAND, val );
+}
diff --git a/src/hardware/pci.h b/src/hardware/pci.h
index 9bc29bb..ccfd20f 100644
--- a/src/hardware/pci.h
+++ b/src/hardware/pci.h
@@ -8,6 +8,9 @@
 #include "driver.h"
 
 typedef struct {
+	uint16_t bus;
+	uint16_t device;
+	uint16_t function;
 	uint16_t vendor_id;
 	uint16_t device_id;
 	uint8_t class_id;
@@ -45,6 +48,8 @@ void pci_device_descriptor_init( pci_device_descriptor_t *descriptor, pci_contro
 
 void pci_base_address_register_init( pci_base_address_register_t *base_address_register, pci_controller_t *controller, uint16_t bus, uint16_t device, uint16_t function, uint16_t bar );
 
-driver_t *pci_device_get_driver( pci_device_descriptor_t *descriptor, interrupt_t *interrupt, void *context );
+driver_t *pci_device_get_driver( pci_controller_t *pci, pci_device_descriptor_t *descriptor, interrupt_t *interrupt, void *context );
+
+void pci_enable_bus_mastering( pci_controller_t *controller, pci_device_descriptor_t *descriptor );
 
 #endif // PCI_H
-- 
cgit v1.2.3-54-g00ecf