drivers/gpu/drm/amd/amdgpu/cik_ih.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/amd/amdgpu/cik_ih.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/amd/amdgpu/cik_ih.c
Extension
.c
Size
12544 bytes
Lines
463
Domain
Driver Families
Bucket
drivers/gpu
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.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/pci.h>

#include "amdgpu.h"
#include "amdgpu_ih.h"
#include "cikd.h"

#include "bif/bif_4_1_d.h"
#include "bif/bif_4_1_sh_mask.h"

#include "oss/oss_2_0_d.h"
#include "oss/oss_2_0_sh_mask.h"

/*
 * Interrupts
 * Starting with r6xx, interrupts are handled via a ring buffer.
 * Ring buffers are areas of GPU accessible memory that the GPU
 * writes interrupt vectors into and the host reads vectors out of.
 * There is a rptr (read pointer) that determines where the
 * host is currently reading, and a wptr (write pointer)
 * which determines where the GPU has written.  When the
 * pointers are equal, the ring is idle.  When the GPU
 * writes vectors to the ring buffer, it increments the
 * wptr.  When there is an interrupt, the host then starts
 * fetching commands and processing them until the pointers are
 * equal again at which point it updates the rptr.
 */

static void cik_ih_set_interrupt_funcs(struct amdgpu_device *adev);

/**
 * cik_ih_enable_interrupts - Enable the interrupt ring buffer
 *
 * @adev: amdgpu_device pointer
 *
 * Enable the interrupt ring buffer (CIK).
 */
static void cik_ih_enable_interrupts(struct amdgpu_device *adev)
{
	u32 ih_cntl = RREG32(mmIH_CNTL);
	u32 ih_rb_cntl = RREG32(mmIH_RB_CNTL);

	ih_cntl |= IH_CNTL__ENABLE_INTR_MASK;
	ih_rb_cntl |= IH_RB_CNTL__RB_ENABLE_MASK;
	WREG32(mmIH_CNTL, ih_cntl);
	WREG32(mmIH_RB_CNTL, ih_rb_cntl);
	adev->irq.ih.enabled = true;
}

/**
 * cik_ih_disable_interrupts - Disable the interrupt ring buffer
 *
 * @adev: amdgpu_device pointer
 *
 * Disable the interrupt ring buffer (CIK).
 */
static void cik_ih_disable_interrupts(struct amdgpu_device *adev)
{
	u32 ih_rb_cntl = RREG32(mmIH_RB_CNTL);
	u32 ih_cntl = RREG32(mmIH_CNTL);

	ih_rb_cntl &= ~IH_RB_CNTL__RB_ENABLE_MASK;
	ih_cntl &= ~IH_CNTL__ENABLE_INTR_MASK;
	WREG32(mmIH_RB_CNTL, ih_rb_cntl);
	WREG32(mmIH_CNTL, ih_cntl);
	/* set rptr, wptr to 0 */
	WREG32(mmIH_RB_RPTR, 0);
	WREG32(mmIH_RB_WPTR, 0);
	adev->irq.ih.enabled = false;
	adev->irq.ih.rptr = 0;
}

/**
 * cik_ih_irq_init - init and enable the interrupt ring
 *
 * @adev: amdgpu_device pointer
 *
 * Allocate a ring buffer for the interrupt controller,
 * enable the RLC, disable interrupts, enable the IH
 * ring buffer and enable it (CIK).
 * Called at device load and reume.
 * Returns 0 for success, errors for failure.
 */
static int cik_ih_irq_init(struct amdgpu_device *adev)
{
	struct amdgpu_ih_ring *ih = &adev->irq.ih;
	int rb_bufsz;
	u32 interrupt_cntl, ih_cntl, ih_rb_cntl;

	/* disable irqs */
	cik_ih_disable_interrupts(adev);

Annotation

Implementation Notes