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上一篇引出了radeon_driver_load_kms这个函数，这篇文章开始详细解析这个函数。
radeon_driver_load_kms函数是所有和GPU初始化相关的内容的起始点，调用radeon_device_init()来初始化芯片的非显示部分(asic init, CP, writeback等），调用radeon_modeset_init()来初始化显示部分（CRTC、connector、encoder、hotplug detect等）。 源码如下：
drivers/gpu/drm/radeon/radeon_kms.c
/**
* radeon_driver_load_kms - Main load function for KMS.
*
* @dev: drm dev pointer
* @flags: device flags
*
* This is the main load function for KMS (all asics).
* It calls radeon_device_init() to set up the non-display
* parts of the chip (asic init, CP, writeback, etc.), and
* radeon_modeset_init() to set up the display parts
* (crtcs, encoders, hotplug detect, etc.).
* Returns 0 on success, error on failure.
*/
int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
{
struct radeon_device *rdev;
int r, acpi_status;
#ifdef CONFIG_CPU_LOONGSON3
turn_off_lvds();
#endif
rdev = kzalloc(sizeof(struct radeon_device), GFP_KERNEL);
if (rdev == NULL) {
return -ENOMEM;
}
dev->dev_private = (void *)rdev;
/* update BUS flag */
if (pci_find_capability(dev->pdev, PCI_CAP_ID_AGP)) {
flags |= RADEON_IS_AGP;
} else if (pci_is_pcie(dev->pdev)) {
flags |= RADEON_IS_PCIE;
} else {
flags |= RADEON_IS_PCI;
}
if ((radeon_runtime_pm != 0) &&
radeon_has_atpx() &&
((flags & RADEON_IS_IGP) == 0) &&
!pci_is_thunderbolt_attached(dev->pdev))
flags |= RADEON_IS_PX;
/* radeon_device_init should report only fatal error
* like memory allocation failure or iomapping failure,
* or memory manager initialization failure, it must
* properly initialize the GPU MC controller and permit
* VRAM allocation
*/
r = radeon_device_init(rdev, dev, dev->pdev, flags);
if (r) {
dev_err(&dev->pdev->dev, "Fatal error during GPU init\n");
goto out;
}
/* Again modeset_init should fail only on fatal error
* otherwise it should provide enough functionalities
* for shadowfb to run
*/
r = radeon_modeset_init(rdev);
if (r)
dev_err(&dev->pdev->dev, "Fatal error during modeset init\n");
#ifdef CONFIG_CPU_LOONGSON3
turn_on_lvds();
#endif
/* Call ACPI methods: require modeset init
* but failure is not fatal
*/
if (!r) {
acpi_status = radeon_acpi_init(rdev);
if (acpi_status)
dev_dbg(&dev->pdev->dev,
"Error during ACPI methods call\n");
}
if (radeon_is_px(dev)) {
dev_pm_set_driver_flags(dev->dev, DPM_FLAG_NEVER_SKIP);
pm_runtime_use_autosuspend(dev->dev);
pm_runtime_set_autosuspend_delay(dev->dev, 5000);
pm_runtime_set_active(dev->dev);
pm_runtime_allow(dev->dev);
pm_runtime_mark_last_busy(dev->dev);
pm_runtime_put_autosuspend(dev->dev);
}
out:
if (r)
radeon_driver_unload_kms(dev);
return r;
}
函数一开始先分配struct radeon_device结构体实例，即新建了一个struct radeon_device 设备。
struct radeon_device的定义如下：
drivers/gpu/drm/radeon/radeon.h
/*
* Core structure, functions and helpers.
*/
typedef uint32_t (*radeon_rreg_t)(struct radeon_device*, uint32_t);
typedef void (*radeon_wreg_t)(struct radeon_device*, uint32_t, uint32_t);
struct radeon_device {
struct device *dev;
struct drm_device *ddev;
struct pci_dev *pdev;
struct rw_semaphore exclusive_lock;
/* ASIC */
union radeon_asic_config config;
enum radeon_family family;
unsigned long flags;
int usec_timeout;
enum radeon_pll_errata pll_errata;
int num_gb_pipes;
int num_z_pipes;
int disp_priority;
/* BIOS */
uint8_t *bios;
bool is_atom_bios;
uint16_t bios_header_start;
struct radeon_bo *stolen_vga_memory;
/* Register mmio */
resource_size_t rmmio_base;
resource_size_t rmmio_size;
/* protects concurrent MM_INDEX/DATA based register access */
spinlock_t mmio_idx_lock;
/* protects concurrent SMC based register access */
spinlock_t smc_idx_lock;
/* protects concurrent PLL register access */
spinlock_t pll_idx_lock;
/* protects concurrent MC register access */
spinlock_t mc_idx_lock;
/* protects concurrent PCIE register access */
spinlock_t pcie_idx_lock;
/* protects concurrent PCIE_PORT register access */
spinlock_t pciep_idx_lock;
/* protects concurrent PIF register access */
spinlock_t pif_idx_lock;
/* protects concurrent CG register access */
spinlock_t cg_idx_lock;
/* protects concurrent UVD register access */
spinlock_t uvd_idx_lock;
/* protects concurrent RCU register access */
spinlock_t rcu_idx_lock;
/* protects concurrent DIDT register access */
spinlock_t didt_idx_lock;
/* protects concurrent ENDPOINT (audio) register access */
spinlock_t end_idx_lock;
void __iomem *rmmio;
radeon_rreg_t mc_rreg;
radeon_wreg_t mc_wreg;
radeon_rreg_t pll_rreg;
radeon_wreg_t pll_wreg;
uint32_t pcie_reg_mask;
radeon_rreg_t pciep_rreg;
radeon_wreg_t pciep_wreg;
/* io port */
void __iomem *rio_mem;
resource_size_t rio_mem_size;
struct radeon_clock clock;
struct radeon_mc mc;
struct radeon_gart gart;
struct radeon_mode_info mode_info;
struct radeon_scratch scratch;
struct radeon_doorbell doorbell;
struct radeon_mman mman;
struct radeon_fence_driver fence_drv[RADEON_NUM_RINGS];
wait_queue_head_t fence_queue;
u64 fence_context;
struct mutex ring_lock;
struct radeon_ring ring[RADEON_NUM_RINGS];
bool ib_pool_ready;
struct radeon_sa_manager ring_tmp_bo;
struct radeon_irq irq;
struct radeon_asic *asic;
struct radeon_gem gem;
struct radeon_pm pm;
struct radeon_uvd uvd;
struct radeon_vce vce;
uint32_t bios_scratch[RADEON_BIOS_NUM_SCRATCH];
struct radeon_wb wb;
struct radeon_dummy_page dummy_page;
bool shutdown;
bool need_dma32;
bool need_swiotlb;
bool accel_working;
bool fastfb_working; /* IGP feature*/
bool needs_reset, in_reset;
struct radeon_surface_reg surface_regs[RADEON_GEM_MAX_SURFACES];
const struct firmware *me_fw; /* all family ME firmware */
const struct firmware *pfp_fw; /* r6/700 PFP firmware */
const struct firmware *rlc_fw; /* r6/700 RLC firmware */
const struct firmware *mc_fw; /* NI MC firmware */
const struct firmware *ce_fw; /* SI CE firmware */
const struct firmware *mec_fw; /* CIK MEC firmware */
const struct firmware *mec2_fw; /* KV MEC2 firmware */
const struct firmware *sdma_fw; /* CIK SDMA firmware */
const struct firmware *smc_fw; /* SMC firmware */
const struct firmware *uvd_fw; /* UVD firmware */
const struct firmware *vce_fw; /* VCE firmware */
bool new_fw;
struct r600_vram_scratch vram_scratch;
int msi_enabled; /* msi enabled */
struct r600_ih ih; /* r6/700 interrupt ring */
struct radeon_rlc rlc;
struct radeon_mec mec;
struct delayed_work hotplug_work;
struct work_struct dp_work;
struct work_struct audio_work;
int need_recover;
struct delayed_work recover_work;
int num_crtc; /* number of crtcs */
struct mutex dc_hw_i2c_mutex; /* display controller hw i2c mutex */
bool has_uvd;
bool has_vce;
struct r600_audio audio; /* audio stuff */
struct notifier_block acpi_nb;
/* only one userspace can use Hyperz features or CMASK at a time */
struct drm_file *hyperz_filp;
struct drm_file *cmask_filp;
/* i2c buses */
struct radeon_i2c_chan *i2c_bus[RADEON_MAX_I2C_BUS];
/* debugfs */
struct radeon_debugfs debugfs[RADEON_DEBUGFS_MAX_COMPONENTS];
unsigned debugfs_count;
/* virtual memory */
struct radeon_vm_manager vm_manager;
struct mutex gpu_clock_mutex;
/* memory stats */
atomic64_t vram_usage;
atomic64_t gtt_usage;
atomic64_t num_bytes_moved;
atomic_t gpu_reset_counter;
/* ACPI interface */
struct radeon_atif atif;
struct radeon_atcs atcs;
/* srbm instance registers */
struct mutex srbm_mutex;
/* clock, powergating flags */
u32 cg_flags;
u32 pg_flags;
struct dev_pm_domain vga_pm_domain;
bool have_disp_power_ref;
u32 px_quirk_flags;
/* tracking pinned memory */
u64 vram_pin_size;
u64 gart_pin_size;
struct mutex mn_lock;
DECLARE_HASHTABLE(mn_hash, 7);
};
分配内存之后，紧接着就是dev->dev_private = (void *)rdev;
这句程序完成了struct drm_device和struct radeon_device的衔接。
