drivers/s390/char/sclp_ap.c

Source file repositories/reference/linux-study-clean/drivers/s390/char/sclp_ap.c

File Facts

System
Linux kernel
Corpus path
drivers/s390/char/sclp_ap.c
Extension
.c
Size
1330 bytes
Lines
63
Domain
Driver Families
Bucket
drivers/s390
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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

struct ap_cfg_sccb {
	struct sccb_header header;
} __packed;

static int do_ap_configure(sclp_cmdw_t cmd, u32 apid)
{
	struct ap_cfg_sccb *sccb;
	int rc;

	if (!SCLP_HAS_AP_RECONFIG)
		return -EOPNOTSUPP;

	sccb = (struct ap_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!sccb)
		return -ENOMEM;

	sccb->header.length = PAGE_SIZE;
	cmd |= (apid & 0xFF) << 8;
	rc = sclp_sync_request(cmd, sccb);
	if (rc)
		goto out;
	switch (sccb->header.response_code) {
	case 0x0020: case 0x0120: case 0x0440: case 0x0450:
		break;
	default:
		pr_warn("configure AP adapter %u failed: cmd=0x%08x response=0x%04x\n",
			apid, cmd, sccb->header.response_code);
		rc = -EIO;
		break;
	}
out:
	free_page((unsigned long) sccb);
	return rc;
}

int sclp_ap_configure(u32 apid)
{
	return do_ap_configure(SCLP_CMDW_CONFIGURE_AP, apid);
}
EXPORT_SYMBOL(sclp_ap_configure);

int sclp_ap_deconfigure(u32 apid)
{
	return do_ap_configure(SCLP_CMDW_DECONFIGURE_AP, apid);
}
EXPORT_SYMBOL(sclp_ap_deconfigure);

Annotation

Implementation Notes