drivers/net/ipa/ipa_mem.c

Source file repositories/reference/linux-study-clean/drivers/net/ipa/ipa_mem.c

File Facts

System
Linux kernel
Corpus path
drivers/net/ipa/ipa_mem.c
Extension
.c
Size
18398 bytes
Lines
706
Domain
Driver Families
Bucket
drivers/net
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

if (__test_and_set_bit(mem->id, regions)) {
			dev_err(dev, "duplicate memory region %u\n", mem->id);
			return false;
		}

		/* Defined regions have non-zero size and/or canary count */
		if (!ipa_mem_valid_one(ipa, mem))
			return false;
	}

	/* Now see if any required regions are not defined */
	for_each_clear_bit(mem_id, regions, IPA_MEM_COUNT) {
		if (ipa_mem_id_required(ipa, mem_id))
			dev_err(dev, "required memory region %u missing\n",
				mem_id);
	}

	return true;
}

/* Do all memory regions fit within the IPA local memory? */
static bool ipa_mem_size_valid(struct ipa *ipa)
{
	struct device *dev = ipa->dev;
	u32 limit = ipa->mem_size;
	u32 i;

	for (i = 0; i < ipa->mem_count; i++) {
		const struct ipa_mem *mem = &ipa->mem[i];

		if (mem->offset + mem->size <= limit)
			continue;

		dev_err(dev, "region %u ends beyond memory limit (0x%08x)\n",
			mem->id, limit);

		return false;
	}

	return true;
}

/**
 * ipa_mem_config() - Configure IPA shared memory
 * @ipa:	IPA pointer
 *
 * Return:	0 if successful, or a negative error code
 */
int ipa_mem_config(struct ipa *ipa)
{
	struct device *dev = ipa->dev;
	const struct ipa_mem *mem;
	const struct reg *reg;
	dma_addr_t addr;
	u32 mem_size;
	void *virt;
	u32 val;
	u32 i;

	/* Check the advertised location and size of the shared memory area */
	reg = ipa_reg(ipa, SHARED_MEM_SIZE);
	val = ioread32(ipa->reg_virt + reg_offset(reg));

	/* The fields in the register are in 8 byte units */
	ipa->mem_offset = 8 * reg_decode(reg, MEM_BADDR, val);

	/* Make sure the end is within the region's mapped space */
	mem_size = 8 * reg_decode(reg, MEM_SIZE, val);

	/* If the sizes don't match, issue a warning */
	if (ipa->mem_offset + mem_size < ipa->mem_size) {
		dev_warn(dev, "limiting IPA memory size to 0x%08x\n",
			 mem_size);
		ipa->mem_size = mem_size;
	} else if (ipa->mem_offset + mem_size > ipa->mem_size) {
		dev_dbg(dev, "ignoring larger reported memory size: 0x%08x\n",
			mem_size);
	}

	/* We know our memory size; make sure regions are all in range */
	if (!ipa_mem_size_valid(ipa))
		return -EINVAL;

	/* Prealloc DMA memory for zeroing regions */
	virt = dma_alloc_coherent(dev, IPA_MEM_MAX, &addr, GFP_KERNEL);
	if (!virt)
		return -ENOMEM;
	ipa->zero_addr = addr;
	ipa->zero_virt = virt;
	ipa->zero_size = IPA_MEM_MAX;

Annotation

Implementation Notes