alistair23-linux/include/linux/mmc/ioctl.h
John Calixto cb87ea28ed mmc: core: Add mmc CMD+ACMD passthrough ioctl
Allows appropriately-privileged applications to send CMD (normal) and ACMD
(application-specific; preceded with CMD55) commands to cards/devices on
the mmc bus.  This is primarily useful for enabling the security
functionality built in to every SD card.

It can also be used as a generic passthrough (e.g. to enable virtual
machines to control mmc bus devices directly).  However, this use case has
not been tested rigorously.  Generic passthrough testing was only conducted
for a few non-security opcodes to prove the feasibility of the passthrough.

Since any opcode can be sent using this passthrough, it is very possible to
render the card/device unusable.  Applications that use this ioctl must
have CAP_SYS_RAWIO.

Security commands tested on TI PCIxx12 (SDHCI), Sigma Designs SMP8652 SoC,
TI OMAP3621/OMAP3630 SoC, Samsung S5PC110 SoC, Qualcomm MSM7200A SoC.

Signed-off-by: John Calixto <john.calixto@modsystems.com>
Reviewed-by: Andrei Warkentin <andreiw@motorola.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2011-05-24 21:02:54 -04:00

55 lines
1.6 KiB
C

#ifndef LINUX_MMC_IOCTL_H
#define LINUX_MMC_IOCTL_H
struct mmc_ioc_cmd {
/* Implies direction of data. true = write, false = read */
int write_flag;
/* Application-specific command. true = precede with CMD55 */
int is_acmd;
__u32 opcode;
__u32 arg;
__u32 response[4]; /* CMD response */
unsigned int flags;
unsigned int blksz;
unsigned int blocks;
/*
* Sleep at least postsleep_min_us useconds, and at most
* postsleep_max_us useconds *after* issuing command. Needed for
* some read commands for which cards have no other way of indicating
* they're ready for the next command (i.e. there is no equivalent of
* a "busy" indicator for read operations).
*/
unsigned int postsleep_min_us;
unsigned int postsleep_max_us;
/*
* Override driver-computed timeouts. Note the difference in units!
*/
unsigned int data_timeout_ns;
unsigned int cmd_timeout_ms;
/*
* For 64-bit machines, the next member, ``__u64 data_ptr``, wants to
* be 8-byte aligned. Make sure this struct is the same size when
* built for 32-bit.
*/
__u32 __pad;
/* DAT buffer */
__u64 data_ptr;
};
#define mmc_ioc_cmd_set_data(ic, ptr) ic.data_ptr = (__u64)(unsigned long) ptr
#define MMC_IOC_CMD _IOWR(MMC_BLOCK_MAJOR, 0, struct mmc_ioc_cmd)
/*
* Since this ioctl is only meant to enhance (and not replace) normal access
* to the mmc bus device, an upper data transfer limit of MMC_IOC_MAX_BYTES
* is enforced per ioctl call. For larger data transfers, use the normal
* block device operations.
*/
#define MMC_IOC_MAX_BYTES (512L * 256)
#endif /* LINUX_MMC_IOCTL_H */