drivers/mtd/ubi/misc.c
Source file repositories/reference/linux-study-clean/drivers/mtd/ubi/misc.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/mtd/ubi/misc.c- Extension
.c- Size
- 4844 bytes
- Lines
- 192
- Domain
- Driver Families
- Bucket
- drivers/mtd
- 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.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
ubi.h
Detected Declarations
function Copyrightfunction ubi_check_volumefunction ubi_update_reservedfunction ubi_calculate_reservedfunction ubi_check_patternfunction ubi_msgfunction ubi_warnfunction ubi_err
Annotated Snippet
if (err) {
if (mtd_is_eccerr(err))
err = 1;
break;
}
}
vfree(buf);
return err;
}
/**
* ubi_update_reserved - update bad eraseblock handling accounting data.
* @ubi: UBI device description object
*
* This function calculates the gap between current number of PEBs reserved for
* bad eraseblock handling and the required level of PEBs that must be
* reserved, and if necessary, reserves more PEBs to fill that gap, according
* to availability. Should be called with ubi->volumes_lock held.
*/
void ubi_update_reserved(struct ubi_device *ubi)
{
int need = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
if (need <= 0 || ubi->avail_pebs == 0)
return;
need = min_t(int, need, ubi->avail_pebs);
ubi->avail_pebs -= need;
ubi->rsvd_pebs += need;
ubi->beb_rsvd_pebs += need;
ubi_msg(ubi, "reserved more %d PEBs for bad PEB handling", need);
}
/**
* ubi_calculate_reserved - calculate how many PEBs must be reserved for bad
* eraseblock handling.
* @ubi: UBI device description object
*/
void ubi_calculate_reserved(struct ubi_device *ubi)
{
/*
* Calculate the actual number of PEBs currently needed to be reserved
* for future bad eraseblock handling.
*/
ubi->beb_rsvd_level = ubi->bad_peb_limit - ubi->bad_peb_count;
if (ubi->beb_rsvd_level < 0) {
ubi->beb_rsvd_level = 0;
ubi_warn(ubi, "number of bad PEBs (%d) is above the expected limit (%d), not reserving any PEBs for bad PEB handling, will use available PEBs (if any)",
ubi->bad_peb_count, ubi->bad_peb_limit);
}
}
/**
* ubi_check_pattern - check if buffer contains only a certain byte pattern.
* @buf: buffer to check
* @patt: the pattern to check
* @size: buffer size in bytes
*
* This function returns %1 in there are only @patt bytes in @buf, and %0 if
* something else was also found.
*/
int ubi_check_pattern(const void *buf, uint8_t patt, int size)
{
int i;
for (i = 0; i < size; i++)
if (((const uint8_t *)buf)[i] != patt)
return 0;
return 1;
}
/* Normal UBI messages */
void ubi_msg(const struct ubi_device *ubi, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
pr_notice(UBI_NAME_STR "%d: %pV\n", ubi->ubi_num, &vaf);
va_end(args);
}
/* UBI warning messages */
void ubi_warn(const struct ubi_device *ubi, const char *fmt, ...)
Annotation
- Immediate include surface: `ubi.h`.
- Detected declarations: `function Copyright`, `function ubi_check_volume`, `function ubi_update_reserved`, `function ubi_calculate_reserved`, `function ubi_check_pattern`, `function ubi_msg`, `function ubi_warn`, `function ubi_err`.
- Atlas domain: Driver Families / drivers/mtd.
- Implementation status: source implementation candidate.
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.