From 361356b08003f5e3c606e16eeb6a17fe02ff2726 Mon Sep 17 00:00:00 2001
From: Moritz Fischer <moritzf@google.com>
Date: Mon, 8 Mar 2021 12:02:33 -0800
Subject: Add pci_device_disable() function

This implements a pci_device_disable() function, currently only for
the linux_sysfs() backend.

This mirrors the implementation for pci_device_enable()

Signed-off-by: Moritz Fischer <moritzf@google.com>
---
 include/pciaccess.h     |  1 +
 src/common_interface.c  | 10 ++++++++++
 src/linux_sysfs.c       | 15 +++++++++++++--
 src/pciaccess_private.h |  1 +
 4 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/include/pciaccess.h b/include/pciaccess.h
index 3865fe1..829e04c 100644
--- a/include/pciaccess.h
+++ b/include/pciaccess.h
@@ -143,6 +143,7 @@ const char *pci_device_get_vendor_name(const struct pci_device *dev);
 const char *pci_device_get_subvendor_name(const struct pci_device *dev);
 
 void pci_device_enable(struct pci_device *dev);
+void pci_device_disable(struct pci_device *dev);
 
 int pci_device_cfg_read    (struct pci_device *dev, void *data,
     pciaddr_t offset, pciaddr_t size, pciaddr_t *bytes_read);
diff --git a/src/common_interface.c b/src/common_interface.c
index a4439b6..6dbaa6b 100644
--- a/src/common_interface.c
+++ b/src/common_interface.c
@@ -676,6 +676,16 @@ pci_device_enable(struct pci_device *dev)
 	pci_sys->methods->enable(dev);
 }
 
+void
+pci_device_disable(struct pci_device *dev)
+{
+	if (dev == NULL)
+		return;
+
+	if (pci_sys->methods->disable)
+		pci_sys->methods->disable(dev);
+}
+
 /**
  * Map the legacy memory space for the PCI domain containing \c dev.
  *
diff --git a/src/linux_sysfs.c b/src/linux_sysfs.c
index 1b4051b..d62f48c 100644
--- a/src/linux_sysfs.c
+++ b/src/linux_sysfs.c
@@ -742,7 +742,7 @@ pci_device_linux_sysfs_unmap_range(struct pci_device *dev,
     return err;
 }
 
-static void pci_device_linux_sysfs_enable(struct pci_device *dev)
+static void pci_device_linux_sysfs_set_enable(struct pci_device *dev, int enable)
 {
     char name[256];
     int fd;
@@ -758,10 +758,20 @@ static void pci_device_linux_sysfs_enable(struct pci_device *dev)
     if (fd == -1)
        return;
 
-    write( fd, "1", 1 );
+    write( fd, enable ? "1" : "0" , 1 );
     close(fd);
 }
 
+static void pci_device_linux_sysfs_enable(struct pci_device *dev)
+{
+	return pci_device_linux_sysfs_set_enable(dev, 1);
+}
+
+static void pci_device_linux_sysfs_disable(struct pci_device *dev)
+{
+	return pci_device_linux_sysfs_set_enable(dev, 0);
+}
+
 static int pci_device_linux_sysfs_boot_vga(struct pci_device *dev)
 {
     char name[256];
@@ -1042,6 +1052,7 @@ static const struct pci_system_methods linux_sysfs_methods = {
 
     .fill_capabilities = pci_fill_capabilities_generic,
     .enable = pci_device_linux_sysfs_enable,
+    .disable = pci_device_linux_sysfs_disable,
     .boot_vga = pci_device_linux_sysfs_boot_vga,
     .has_kernel_driver = pci_device_linux_sysfs_has_kernel_driver,
 
diff --git a/src/pciaccess_private.h b/src/pciaccess_private.h
index d3b68d4..be5d15d 100644
--- a/src/pciaccess_private.h
+++ b/src/pciaccess_private.h
@@ -76,6 +76,7 @@ struct pci_system_methods {
 
     int (*fill_capabilities)( struct pci_device * dev );
     void (*enable)( struct pci_device *dev );
+    void (*disable)( struct pci_device *dev );
     int (*boot_vga)( struct pci_device *dev );
     int (*has_kernel_driver)( struct pci_device *dev );
     struct pci_io_handle *(*open_device_io)( struct pci_io_handle *handle,
-- 
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