intel_driver.h

intel_driver.h位于src目录下，内容为：

#ifndef INTEL_DRIVER_H
#define INTEL_DRIVER_Hstruct xf86_platform_device;#define INTEL_VERSION 4000
#define INTEL_NAME "intel"
#define INTEL_DRIVER_NAME "intel"#define INTEL_VERSION_MAJOR PACKAGE_VERSION_MAJOR
#define INTEL_VERSION_MINOR PACKAGE_VERSION_MINOR
#define INTEL_VERSION_PATCH PACKAGE_VERSION_PATCHLEVEL#define PCI_CHIP_I810		0x7121
#define PCI_CHIP_I810_DC100	0x7123
#define PCI_CHIP_I810_E		0x7125
#define PCI_CHIP_I815		0x1132#define PCI_CHIP_I830_M		0x3577
#define PCI_CHIP_845_G		0x2562
#define PCI_CHIP_I854		0x358E
#define PCI_CHIP_I855_GM	0x3582
#define PCI_CHIP_I865_G		0x2572#define PCI_CHIP_I915_G		0x2582
#define PCI_CHIP_I915_GM	0x2592
#define PCI_CHIP_E7221_G	0x258A
#define PCI_CHIP_I945_G		0x2772
#define PCI_CHIP_I945_GM        0x27A2
#define PCI_CHIP_I945_GME	0x27AE
#define PCI_CHIP_PINEVIEW_M	0xA011
#define PCI_CHIP_PINEVIEW_G	0xA001
#define PCI_CHIP_Q35_G		0x29B2
#define PCI_CHIP_G33_G		0x29C2
#define PCI_CHIP_Q33_G		0x29D2#define PCI_CHIP_G35_G		0x2982
#define PCI_CHIP_I965_Q		0x2992
#define PCI_CHIP_I965_G		0x29A2
#define PCI_CHIP_I946_GZ	0x2972
#define PCI_CHIP_I965_GM        0x2A02
#define PCI_CHIP_I965_GME       0x2A12
#define PCI_CHIP_GM45_GM	0x2A42
#define PCI_CHIP_G45_E_G	0x2E02
#define PCI_CHIP_G45_G		0x2E22
#define PCI_CHIP_Q45_G		0x2E12
#define PCI_CHIP_G41_G		0x2E32
#define PCI_CHIP_B43_G		0x2E42
#define PCI_CHIP_B43_G1		0x2E92#define PCI_CHIP_IRONLAKE_D_G		0x0042
#define PCI_CHIP_IRONLAKE_M_G		0x0046#define PCI_CHIP_SANDYBRIDGE_GT1	0x0102
#define PCI_CHIP_SANDYBRIDGE_GT2	0x0112
#define PCI_CHIP_SANDYBRIDGE_GT2_PLUS	0x0122
#define PCI_CHIP_SANDYBRIDGE_M_GT1	0x0106
#define PCI_CHIP_SANDYBRIDGE_M_GT2	0x0116
#define PCI_CHIP_SANDYBRIDGE_M_GT2_PLUS	0x0126
#define PCI_CHIP_SANDYBRIDGE_S_GT	0x010A#define PCI_CHIP_IVYBRIDGE_M_GT1	0x0156
#define PCI_CHIP_IVYBRIDGE_M_GT2	0x0166
#define PCI_CHIP_IVYBRIDGE_D_GT1	0x0152
#define PCI_CHIP_IVYBRIDGE_D_GT2	0x0162
#define PCI_CHIP_IVYBRIDGE_S_GT1	0x015a
#define PCI_CHIP_IVYBRIDGE_S_GT2	0x016a#define PCI_CHIP_HASWELL_D_GT1		0x0402
#define PCI_CHIP_HASWELL_D_GT2		0x0412
#define PCI_CHIP_HASWELL_D_GT3		0x0422
#define PCI_CHIP_HASWELL_M_GT1		0x0406
#define PCI_CHIP_HASWELL_M_GT2		0x0416
#define PCI_CHIP_HASWELL_M_GT3		0x0426
#define PCI_CHIP_HASWELL_S_GT1		0x040A
#define PCI_CHIP_HASWELL_S_GT2		0x041A
#define PCI_CHIP_HASWELL_S_GT3		0x042A
#define PCI_CHIP_HASWELL_B_GT1		0x040B
#define PCI_CHIP_HASWELL_B_GT2		0x041B
#define PCI_CHIP_HASWELL_B_GT3		0x042B
#define PCI_CHIP_HASWELL_E_GT1		0x040E
#define PCI_CHIP_HASWELL_E_GT2		0x041E
#define PCI_CHIP_HASWELL_E_GT3		0x042E#define PCI_CHIP_HASWELL_ULT_D_GT1	0x0A02
#define PCI_CHIP_HASWELL_ULT_D_GT2	0x0A12
#define PCI_CHIP_HASWELL_ULT_D_GT3	0x0A22
#define PCI_CHIP_HASWELL_ULT_M_GT1	0x0A06
#define PCI_CHIP_HASWELL_ULT_M_GT2	0x0A16
#define PCI_CHIP_HASWELL_ULT_M_GT3	0x0A26
#define PCI_CHIP_HASWELL_ULT_S_GT1	0x0A0A
#define PCI_CHIP_HASWELL_ULT_S_GT2	0x0A1A
#define PCI_CHIP_HASWELL_ULT_S_GT3	0x0A2A
#define PCI_CHIP_HASWELL_ULT_B_GT1	0x0A0B
#define PCI_CHIP_HASWELL_ULT_B_GT2	0x0A1B
#define PCI_CHIP_HASWELL_ULT_B_GT3	0x0A2B
#define PCI_CHIP_HASWELL_ULT_E_GT1	0x0A0E
#define PCI_CHIP_HASWELL_ULT_E_GT2	0x0A1E
#define PCI_CHIP_HASWELL_ULT_E_GT3	0x0A2E#define PCI_CHIP_HASWELL_CRW_D_GT1	0x0D02
#define PCI_CHIP_HASWELL_CRW_D_GT2	0x0D12
#define PCI_CHIP_HASWELL_CRW_D_GT3	0x0D22
#define PCI_CHIP_HASWELL_CRW_M_GT1	0x0D06
#define PCI_CHIP_HASWELL_CRW_M_GT2	0x0D16
#define PCI_CHIP_HASWELL_CRW_M_GT3	0x0D26
#define PCI_CHIP_HASWELL_CRW_S_GT1	0x0D0A
#define PCI_CHIP_HASWELL_CRW_S_GT2	0x0D1A
#define PCI_CHIP_HASWELL_CRW_S_GT3	0x0D2A
#define PCI_CHIP_HASWELL_CRW_B_GT1	0x0D0B
#define PCI_CHIP_HASWELL_CRW_B_GT2	0x0D1B
#define PCI_CHIP_HASWELL_CRW_B_GT3	0x0D2B
#define PCI_CHIP_HASWELL_CRW_E_GT1	0x0D0E
#define PCI_CHIP_HASWELL_CRW_E_GT2	0x0D1E
#define PCI_CHIP_HASWELL_CRW_E_GT3	0x0D2Estruct intel_device_info {int gen;
};
struct intel_device;int intel_entity_get_devid(int index);int intel_open_device(int entity_num,const struct pci_device *pci,struct xf86_platform_device *dev);
void intel_close_device(int entity_num);
int __intel_peek_fd(ScrnInfoPtr scrn);
struct intel_device *intel_get_device(ScrnInfoPtr scrn, int *fd);
int intel_has_render_node(struct intel_device *dev);
const char *intel_get_master_name(struct intel_device *dev);
const char *intel_get_client_name(struct intel_device *dev);
int intel_get_client_fd(struct intel_device *dev);
int intel_get_device_id(struct intel_device *dev);
int intel_get_master(struct intel_device *dev);
int intel_put_master(struct intel_device *dev);
void intel_put_device(struct intel_device *dev);void intel_detect_chipset(ScrnInfoPtr scrn, struct intel_device *dev);#define IS_DEFAULT_ACCEL_METHOD(x) ({ \enum { NOACCEL, SNA, UXA } default_accel_method__ = DEFAULT_ACCEL_METHOD; \default_accel_method__ == x; \
})#define hosted() (0)#endif /* INTEL_DRIVER_H */

intel_driver.h中声明了intel_device.c中实现的函数，虽然名字一个叫driver、一个叫device。其中内容在下边分析inter_device.c的时候再做讲解。

intel_device.c

intel_device.c位于src目录下，文件内容较长（将近850行），因此在此不全部列出，而是一个函数一个函数来分析。

• intel_open_device

int intel_open_device(int entity_num,const struct pci_device *pci,struct xf86_platform_device *platform)
{struct intel_device *dev;char *path;int fd, master_count;if (intel_device_key == -1)intel_device_key = xf86AllocateEntityPrivateIndex();if (intel_device_key == -1)return -1;dev = xf86GetEntityPrivate(entity_num, intel_device_key)->ptr;if (dev)return dev->fd;path = get_path(platform);master_count = 1; /* DRM_MASTER is managed by Xserver */fd = get_fd(platform);if (fd == -1) {fd = __intel_open_device(pci, path);if (fd == -1)goto err_path;master_count = 0;}if (path == NULL) {path = find_master_node(fd);if (path == NULL)goto err_close;}if (!__intel_check_device(fd))goto err_close;dev = malloc(sizeof(*dev));if (dev == NULL)goto err_close;/* If hosted under a system compositor, just pretend to be master */if (hosted())master_count++;/* Non-root user holding MASTER, don't let go */if (geteuid() && is_master(fd))master_count++;if (pci)dev->device_id = pci->device_id;elsedev->device_id = __intel_get_device_id(fd);dev->idx = entity_num;dev->fd = fd;dev->open_count = master_count;dev->master_count = master_count;dev->master_node = path;dev->render_node = find_render_node(fd);if (dev->render_node == NULL)dev->render_node = dev->master_node;xf86GetEntityPrivate(entity_num, intel_device_key)->ptr = dev;return fd;err_close:if (master_count == 0) /* Don't close server-fds */close(fd);
err_path:free(path);return -1;
}

这个函数本身也不短，分块来分析。先看第1段：

    if (intel_device_key == -1)intel_device_key = xf86AllocateEntityPrivateIndex();if (intel_device_key == -1)return -1;

intel_device_key在同文件中定义，为静态全局变量：

static int intel_device_key = -1;

初始时intel_device_key的值为-1，必定会调用xf86AllocateEntityPrivateIndex()。xf86AllocateEntityPrivateIndex函数在xorg-server源码的hw/xfree86/common/xf86Bus.c中，代码如下：

/** Allocate a private in the entities.*/int
xf86AllocateEntityPrivateIndex(void)
{int idx, i;EntityPtr pEnt;DevUnion *nprivs;idx = xf86EntityPrivateCount++;for (i = 0; i < xf86NumEntities; i++) {pEnt = xf86Entities[i];nprivs = xnfreallocarray(pEnt->entityPrivates,xf86EntityPrivateCount, sizeof(DevUnion));/* Zero the new private */memset(&nprivs[idx], 0, sizeof(DevUnion));pEnt->entityPrivates = nprivs;}return idx;
}

再来看第2段：

    dev = xf86GetEntityPrivate(entity_num, intel_device_key)->ptr;if (dev)return dev->fd;

xf86GetEntityPrivate函数同在xorg-server源码的hw/xfree86/common/xf86Bus.c中，就在xf86AllocateEntityPrivateIndex函数实现的下边，代码如下：

DevUnion *
xf86GetEntityPrivate(int entityIndex, int privIndex)
{if (entityIndex >= xf86NumEntities || privIndex >= xf86EntityPrivateCount)return NULL;return &(xf86Entities[entityIndex]->entityPrivates[privIndex]);
}

接下来看第3段：

path = get_path(platform);

path是函数内部定义的局部变量：char *path;。

这段代码的意思是根据intel_open_device函数的入参struct xf86_platform_device *platform即平台设备指针获得相应的路径。

get_path函数在同文件中实现，代码如下：

#if defined(ODEV_ATTRIB_PATH)
static char *get_path(struct xf86_platform_device *dev)
{const char *path;if (dev == NULL)return NULL;path = xf86_get_platform_device_attrib(dev, ODEV_ATTRIB_PATH);if (path == NULL)return NULL;return strdup(path);
}#elsestatic char *get_path(struct xf86_platform_device *dev)
{return NULL;
}
#endif

接下来看第4段：

    master_count = 1; /* DRM_MASTER is managed by Xserver */fd = get_fd(platform);if (fd == -1) {fd = __intel_open_device(pci, path);if (fd == -1)goto err_path;master_count = 0;}

这段代码的意思是根据intel_open_device函数的入参struct xf86_platform_device *platform即平台设备指针获得相应的文件描述符。如果获取不到，则调用__intel_open_device函数根据intel_open_device函数的入参pci打开设备。

get_path函数在同文件中实现，代码如下：

#if defined(ODEV_ATTRIB_FD)
static int get_fd(struct xf86_platform_device *dev)
{if (dev == NULL)return -1;return xf86_get_platform_device_int_attrib(dev, ODEV_ATTRIB_FD, -1);
}#elsestatic int get_fd(struct xf86_platform_device *dev)
{return -1;
}
#endif

__intel_open_device函数在同文件中实现，代码如下：

static int __intel_open_device(const struct pci_device *pci, const char *path)
{int fd;if (path == NULL) {if (pci == NULL)return -1;fd = __intel_open_device__pci(pci);if (fd == -1)fd = __intel_open_device__legacy(pci);} elsefd = open_cloexec(path);return fd;
}

__intel_open_device函数中包含的2个函数都比较大，我们在下一篇文章中进行分析。