drivers/dma/qcom/hidma.h
Source file repositories/reference/linux-study-clean/drivers/dma/qcom/hidma.h
File Facts
- System
- Linux kernel
- Corpus path
drivers/dma/qcom/hidma.h- Extension
.h- Size
- 5285 bytes
- Lines
- 161
- Domain
- Driver Families
- Bucket
- drivers/dma
- Inferred role
- Driver Families: implementation source
- Status
- source implementation candidate
Why This File Exists
Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/kfifo.hlinux/interrupt.hlinux/dmaengine.h
Detected Declarations
struct hidma_trestruct hidma_lldevstruct hidma_descstruct hidma_chanstruct hidma_devenum tre_type
Annotated Snippet
struct hidma_tre {
atomic_t allocated; /* if this channel is allocated */
bool queued; /* flag whether this is pending */
u16 status; /* status */
u32 idx; /* index of the tre */
u32 dma_sig; /* signature of the tre */
const char *dev_name; /* name of the device */
void (*callback)(void *data); /* requester callback */
void *data; /* Data associated with this channel*/
struct hidma_lldev *lldev; /* lldma device pointer */
u32 tre_local[HIDMA_TRE_SIZE / sizeof(u32) + 1]; /* TRE local copy */
u32 tre_index; /* the offset where this was written*/
u32 int_flags; /* interrupt flags */
u8 err_info; /* error record in this transfer */
u8 err_code; /* completion code */
};
struct hidma_lldev {
bool msi_support; /* flag indicating MSI support */
bool initialized; /* initialized flag */
u8 trch_state; /* trch_state of the device */
u8 evch_state; /* evch_state of the device */
u8 chidx; /* channel index in the core */
u32 nr_tres; /* max number of configs */
spinlock_t lock; /* reentrancy */
struct hidma_tre *trepool; /* trepool of user configs */
struct device *dev; /* device */
void __iomem *trca; /* Transfer Channel address */
void __iomem *evca; /* Event Channel address */
struct hidma_tre
**pending_tre_list; /* Pointers to pending TREs */
atomic_t pending_tre_count; /* Number of TREs pending */
void *tre_ring; /* TRE ring */
dma_addr_t tre_dma; /* TRE ring to be shared with HW */
u32 tre_ring_size; /* Byte size of the ring */
u32 tre_processed_off; /* last processed TRE */
void *evre_ring; /* EVRE ring */
dma_addr_t evre_dma; /* EVRE ring to be shared with HW */
u32 evre_ring_size; /* Byte size of the ring */
u32 evre_processed_off; /* last processed EVRE */
u32 tre_write_offset; /* TRE write location */
struct tasklet_struct task; /* task delivering notifications */
DECLARE_KFIFO_PTR(handoff_fifo,
struct hidma_tre *); /* pending TREs FIFO */
};
struct hidma_desc {
struct dma_async_tx_descriptor desc;
/* link list node for this channel*/
struct list_head node;
u32 tre_ch;
};
struct hidma_chan {
bool paused;
bool allocated;
char dbg_name[16];
u32 dma_sig;
dma_cookie_t last_success;
/*
* active descriptor on this channel
* It is used by the DMA complete notification to
* locate the descriptor that initiated the transfer.
*/
struct hidma_dev *dmadev;
struct hidma_desc *running;
struct dma_chan chan;
struct list_head free;
struct list_head prepared;
struct list_head queued;
struct list_head active;
struct list_head completed;
/* Lock for this structure */
spinlock_t lock;
};
struct hidma_dev {
int irq;
int chidx;
u32 nr_descriptors;
int msi_virqbase;
struct hidma_lldev *lldev;
void __iomem *dev_trca;
Annotation
- Immediate include surface: `linux/kfifo.h`, `linux/interrupt.h`, `linux/dmaengine.h`.
- Detected declarations: `struct hidma_tre`, `struct hidma_lldev`, `struct hidma_desc`, `struct hidma_chan`, `struct hidma_dev`, `enum tre_type`.
- Atlas domain: Driver Families / drivers/dma.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
- IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.