This lets an application open a suitable DRM device and pass the file
descriptor to the mode setting driver through an X server command line
option, '-masterfd'.
There's a companion application, xlease, which creates a DRM master by
leasing an output from another X server. That is available at
git clone git://people.freedesktop.org/~keithp/xlease
Signed-off-by: Keith Packard <[email protected]>
---
hw/xfree86/common/xf86Globals.c | 2 ++
hw/xfree86/common/xf86Priv.h | 1 +
hw/xfree86/drivers/modesetting/driver.c | 26 +++++++++++++++++++++++++-
hw/xfree86/drivers/modesetting/driver.h | 1 +
hw/xfree86/os-support/linux/lnx_init.c | 22 ++++++++++++++++++++++
5 files changed, 51 insertions(+), 1 deletion(-)
diff --git a/hw/xfree86/common/xf86Globals.c b/hw/xfree86/common/xf86Globals.c
index e890f05c2..7cc7401a2 100644
--- a/hw/xfree86/common/xf86Globals.c
+++ b/hw/xfree86/common/xf86Globals.c
@@ -53,6 +53,8 @@ DevPrivateKeyRec xf86ScreenKeyRec;
ScrnInfoPtr *xf86Screens = NULL; /* List of ScrnInfos */
ScrnInfoPtr *xf86GPUScreens = NULL; /* List of ScrnInfos */
+int xf86DRMMasterFd = -1; /* Command line argument for DRM master file
descriptor */
+
const unsigned char byte_reversed[256] = {
0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
diff --git a/hw/xfree86/common/xf86Priv.h b/hw/xfree86/common/xf86Priv.h
index 4fe2b5f33..393af3900 100644
--- a/hw/xfree86/common/xf86Priv.h
+++ b/hw/xfree86/common/xf86Priv.h
@@ -93,6 +93,7 @@ extern _X_EXPORT int xf86LogVerbose; /* log file verbosity
level */
extern ScrnInfoPtr *xf86GPUScreens; /* List of pointers to ScrnInfoRecs */
extern int xf86NumGPUScreens;
+extern _X_EXPORT int xf86DRMMasterFd; /* Command line argument
for DRM master file descriptor */
#ifndef DEFAULT_VERBOSE
#define DEFAULT_VERBOSE 0
#endif
diff --git a/hw/xfree86/drivers/modesetting/driver.c
b/hw/xfree86/drivers/modesetting/driver.c
index ec2aa9a27..1d84e113d 100644
--- a/hw/xfree86/drivers/modesetting/driver.c
+++ b/hw/xfree86/drivers/modesetting/driver.c
@@ -36,6 +36,7 @@
#include <unistd.h>
#include <fcntl.h>
#include "xf86.h"
+#include "xf86Priv.h"
#include "xf86_OSproc.h"
#include "compiler.h"
#include "xf86Pci.h"
@@ -194,11 +195,24 @@ modesettingEntPtr ms_ent_priv(ScrnInfoPtr scrn)
return pPriv->ptr;
}
+static int
+get_passed_fd(void)
+{
+ if (xf86DRMMasterFd >= 0) {
+ xf86DrvMsg(-1, X_INFO, "Using passed DRM master file descriptor %d\n",
xf86DRMMasterFd);
+ return dup(xf86DRMMasterFd);
+ }
+ return -1;
+}
+
static int
open_hw(const char *dev)
{
int fd;
+ if ((fd = get_passed_fd()) != -1)
+ return fd;
+
if (dev)
fd = open(dev, O_RDWR, 0);
else {
@@ -822,6 +836,12 @@ ms_get_drm_master_fd(ScrnInfoPtr pScrn)
return TRUE;
}
+ ms->fd_passed = FALSE;
+ if ((ms->fd = get_passed_fd()) >= 0) {
+ ms->fd_passed = TRUE;
+ return TRUE;
+ }
+
#ifdef XSERVER_PLATFORM_BUS
if (pEnt->location.type == BUS_PLATFORM) {
if (pEnt->location.id.plat->flags & XF86_PDEV_SERVER_FD)
@@ -1495,6 +1515,9 @@ SetMaster(ScrnInfoPtr pScrn)
(ms->pEnt->location.id.plat->flags & XF86_PDEV_SERVER_FD))
return TRUE;
+ if (ms->fd_passed)
+ return TRUE;
+
ret = drmSetMaster(ms->fd);
if (ret)
xf86DrvMsg(pScrn->scrnIndex, X_ERROR, "drmSetMaster failed: %s\n",
@@ -1746,7 +1769,8 @@ LeaveVT(ScrnInfoPtr pScrn)
(ms->pEnt->location.id.plat->flags & XF86_PDEV_SERVER_FD))
return;
- drmDropMaster(ms->fd);
+ if (!ms->fd_passed)
+ drmDropMaster(ms->fd);
}
/*
diff --git a/hw/xfree86/drivers/modesetting/driver.h
b/hw/xfree86/drivers/modesetting/driver.h
index fe835918b..6be51e01b 100644
--- a/hw/xfree86/drivers/modesetting/driver.h
+++ b/hw/xfree86/drivers/modesetting/driver.h
@@ -84,6 +84,7 @@ struct ms_drm_queue {
typedef struct _modesettingRec {
int fd;
+ Bool fd_passed;
int Chipset;
EntityInfoPtr pEnt;
diff --git a/hw/xfree86/os-support/linux/lnx_init.c
b/hw/xfree86/os-support/linux/lnx_init.c
index 9e5ddcd50..b654f7618 100644
--- a/hw/xfree86/os-support/linux/lnx_init.c
+++ b/hw/xfree86/os-support/linux/lnx_init.c
@@ -356,6 +356,13 @@ xf86CloseConsole(void)
close(xf86Info.consoleFd); /* make the vt-manager happy */
}
+#define CHECK_FOR_REQUIRED_ARGUMENT() \
+ if (((i + 1) >= argc) || (!argv[i + 1])) {
\
+ ErrorF("Required argument to %s not specified\n", argv[i]); \
+ UseMsg(); \
+ FatalError("Required argument to %s not specified\n", argv[i]); \
+ }
+
int
xf86ProcessArgument(int argc, char *argv[], int i)
{
@@ -376,6 +383,19 @@ xf86ProcessArgument(int argc, char *argv[], int i)
}
return 1;
}
+
+ if (!strcmp(argv[i], "-masterfd")) {
+ CHECK_FOR_REQUIRED_ARGUMENT();
+ if (xf86PrivsElevated())
+ FatalError("\nCannot specify -masterfd when server is
setuid/setgid\n");
+ if (sscanf(argv[++i], "%d", &xf86DRMMasterFd) != 1) {
+ UseMsg();
+ xf86DRMMasterFd = -1;
+ return 0;
+ }
+ return 2;
+ }
+
return 0;
}
@@ -385,4 +405,6 @@ xf86UseMsg(void)
ErrorF("vtXX use the specified VT number\n");
ErrorF("-keeptty ");
ErrorF("don't detach controlling tty (for debugging only)\n");
+ if (!xf86PrivsElevated())
+ ErrorF("-masterfd <fd> use the specified fd as the DRM master
fd\n");
}
--
2.15.1
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