diff options
Diffstat (limited to 'drivers/s390/char/diag_ftp.c')
| -rw-r--r-- | drivers/s390/char/diag_ftp.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/drivers/s390/char/diag_ftp.c b/drivers/s390/char/diag_ftp.c new file mode 100644 index 000000000..36bbd6b6e --- /dev/null +++ b/drivers/s390/char/diag_ftp.c @@ -0,0 +1,241 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DIAGNOSE X'2C4' instruction based HMC FTP services, useable on z/VM + * + * Copyright IBM Corp. 2013 + * Author(s): Ralf Hoppe (rhoppe@de.ibm.com) + * + */ + +#define KMSG_COMPONENT "hmcdrv" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/irq.h> +#include <linux/wait.h> +#include <linux/string.h> +#include <asm/asm-extable.h> +#include <asm/ctl_reg.h> +#include <asm/diag.h> + +#include "hmcdrv_ftp.h" +#include "diag_ftp.h" + +/* DIAGNOSE X'2C4' return codes in Ry */ +#define DIAG_FTP_RET_OK 0 /* HMC FTP started successfully */ +#define DIAG_FTP_RET_EBUSY 4 /* HMC FTP service currently busy */ +#define DIAG_FTP_RET_EIO 8 /* HMC FTP service I/O error */ +/* and an artificial extension */ +#define DIAG_FTP_RET_EPERM 2 /* HMC FTP service privilege error */ + +/* FTP service status codes (after INTR at guest real location 133) */ +#define DIAG_FTP_STAT_OK 0U /* request completed successfully */ +#define DIAG_FTP_STAT_PGCC 4U /* program check condition */ +#define DIAG_FTP_STAT_PGIOE 8U /* paging I/O error */ +#define DIAG_FTP_STAT_TIMEOUT 12U /* timeout */ +#define DIAG_FTP_STAT_EBASE 16U /* base of error codes from SCLP */ +#define DIAG_FTP_STAT_LDFAIL (DIAG_FTP_STAT_EBASE + 1U) /* failed */ +#define DIAG_FTP_STAT_LDNPERM (DIAG_FTP_STAT_EBASE + 2U) /* not allowed */ +#define DIAG_FTP_STAT_LDRUNS (DIAG_FTP_STAT_EBASE + 3U) /* runs */ +#define DIAG_FTP_STAT_LDNRUNS (DIAG_FTP_STAT_EBASE + 4U) /* not runs */ + +/** + * struct diag_ftp_ldfpl - load file FTP parameter list (LDFPL) + * @bufaddr: real buffer address (at 4k boundary) + * @buflen: length of buffer + * @offset: dir/file offset + * @intparm: interruption parameter (unused) + * @transferred: bytes transferred + * @fsize: file size, filled on GET + * @failaddr: failing address + * @spare: padding + * @fident: file name - ASCII + */ +struct diag_ftp_ldfpl { + u64 bufaddr; + u64 buflen; + u64 offset; + u64 intparm; + u64 transferred; + u64 fsize; + u64 failaddr; + u64 spare; + u8 fident[HMCDRV_FTP_FIDENT_MAX]; +} __packed; + +static DECLARE_COMPLETION(diag_ftp_rx_complete); +static int diag_ftp_subcode; + +/** + * diag_ftp_handler() - FTP services IRQ handler + * @extirq: external interrupt (sub-) code + * @param32: 32-bit interruption parameter from &struct diag_ftp_ldfpl + * @param64: unused (for 64-bit interrupt parameters) + */ +static void diag_ftp_handler(struct ext_code extirq, + unsigned int param32, + unsigned long param64) +{ + if ((extirq.subcode >> 8) != 8) + return; /* not a FTP services sub-code */ + + inc_irq_stat(IRQEXT_FTP); + diag_ftp_subcode = extirq.subcode & 0xffU; + complete(&diag_ftp_rx_complete); +} + +/** + * diag_ftp_2c4() - DIAGNOSE X'2C4' service call + * @fpl: pointer to prepared LDFPL + * @cmd: FTP command to be executed + * + * Performs a DIAGNOSE X'2C4' call with (input/output) FTP parameter list + * @fpl and FTP function code @cmd. In case of an error the function does + * nothing and returns an (negative) error code. + * + * Notes: + * 1. This function only initiates a transfer, so the caller must wait + * for completion (asynchronous execution). + * 2. The FTP parameter list @fpl must be aligned to a double-word boundary. + * 3. fpl->bufaddr must be a real address, 4k aligned + */ +static int diag_ftp_2c4(struct diag_ftp_ldfpl *fpl, + enum hmcdrv_ftp_cmdid cmd) +{ + int rc; + + diag_stat_inc(DIAG_STAT_X2C4); + asm volatile( + " diag %[addr],%[cmd],0x2c4\n" + "0: j 2f\n" + "1: la %[rc],%[err]\n" + "2:\n" + EX_TABLE(0b, 1b) + : [rc] "=d" (rc), "+m" (*fpl) + : [cmd] "0" (cmd), [addr] "d" (virt_to_phys(fpl)), + [err] "i" (DIAG_FTP_RET_EPERM) + : "cc"); + + switch (rc) { + case DIAG_FTP_RET_OK: + return 0; + case DIAG_FTP_RET_EBUSY: + return -EBUSY; + case DIAG_FTP_RET_EPERM: + return -EPERM; + case DIAG_FTP_RET_EIO: + default: + return -EIO; + } +} + +/** + * diag_ftp_cmd() - executes a DIAG X'2C4' FTP command, targeting a HMC + * @ftp: pointer to FTP command specification + * @fsize: return of file size (or NULL if undesirable) + * + * Attention: Notice that this function is not reentrant - so the caller + * must ensure locking. + * + * Return: number of bytes read/written or a (negative) error code + */ +ssize_t diag_ftp_cmd(const struct hmcdrv_ftp_cmdspec *ftp, size_t *fsize) +{ + struct diag_ftp_ldfpl *ldfpl; + ssize_t len; +#ifdef DEBUG + unsigned long start_jiffies; + + pr_debug("starting DIAG X'2C4' on '%s', requesting %zd bytes\n", + ftp->fname, ftp->len); + start_jiffies = jiffies; +#endif + init_completion(&diag_ftp_rx_complete); + + ldfpl = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); + if (!ldfpl) { + len = -ENOMEM; + goto out; + } + + len = strlcpy(ldfpl->fident, ftp->fname, sizeof(ldfpl->fident)); + if (len >= HMCDRV_FTP_FIDENT_MAX) { + len = -EINVAL; + goto out_free; + } + + ldfpl->transferred = 0; + ldfpl->fsize = 0; + ldfpl->offset = ftp->ofs; + ldfpl->buflen = ftp->len; + ldfpl->bufaddr = virt_to_phys(ftp->buf); + + len = diag_ftp_2c4(ldfpl, ftp->id); + if (len) + goto out_free; + + /* + * There is no way to cancel the running diag X'2C4', the code + * needs to wait unconditionally until the transfer is complete. + */ + wait_for_completion(&diag_ftp_rx_complete); + +#ifdef DEBUG + pr_debug("completed DIAG X'2C4' after %lu ms\n", + (jiffies - start_jiffies) * 1000 / HZ); + pr_debug("status of DIAG X'2C4' is %u, with %lld/%lld bytes\n", + diag_ftp_subcode, ldfpl->transferred, ldfpl->fsize); +#endif + + switch (diag_ftp_subcode) { + case DIAG_FTP_STAT_OK: /* success */ + len = ldfpl->transferred; + if (fsize) + *fsize = ldfpl->fsize; + break; + case DIAG_FTP_STAT_LDNPERM: + len = -EPERM; + break; + case DIAG_FTP_STAT_LDRUNS: + len = -EBUSY; + break; + case DIAG_FTP_STAT_LDFAIL: + len = -ENOENT; /* no such file or media */ + break; + default: + len = -EIO; + break; + } + +out_free: + free_page((unsigned long) ldfpl); +out: + return len; +} + +/** + * diag_ftp_startup() - startup of FTP services, when running on z/VM + * + * Return: 0 on success, else an (negative) error code + */ +int diag_ftp_startup(void) +{ + int rc; + + rc = register_external_irq(EXT_IRQ_CP_SERVICE, diag_ftp_handler); + if (rc) + return rc; + + irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); + return 0; +} + +/** + * diag_ftp_shutdown() - shutdown of FTP services, when running on z/VM + */ +void diag_ftp_shutdown(void) +{ + irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL); + unregister_external_irq(EXT_IRQ_CP_SERVICE, diag_ftp_handler); +} |