It is possible while waiting for multiple types of external interrupts that we might have pending irqs remaining between irq consumption and irq-type disabling. Those interrupts could potentially propagate to the guest after IPL completes and cause unwanted behavior. As it is today, the SCLP will only recognize write events that are enabled by the control program's send and receive masks. To limit the window for, and prevent further irqs from, ASCII console events (specifically keystrokes), we should only enable the control program's receive mask when we need it. While we're at it, remove assignment of the (non control program) send and receive masks, as those are actually set by the SCLP. Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
139 lines
3.7 KiB
C
139 lines
3.7 KiB
C
/*
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* SCLP ASCII access driver
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*
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* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or (at
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* your option) any later version. See the COPYING file in the top-level
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* directory.
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*/
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#include "libc.h"
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#include "s390-ccw.h"
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#include "sclp.h"
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long write(int fd, const void *str, size_t len);
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static char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
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const unsigned char ebc2asc[256] =
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/* 0123456789abcdef0123456789abcdef */
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"................................" /* 1F */
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"................................" /* 3F */
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" ...........<(+|&.........!$*);." /* 5F first.chr.here.is.real.space */
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"-/.........,%_>?.........`:#@'=\""/* 7F */
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".abcdefghi.......jklmnopqr......" /* 9F */
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"..stuvwxyz......................" /* BF */
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".ABCDEFGHI.......JKLMNOPQR......" /* DF */
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"..STUVWXYZ......0123456789......";/* FF */
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/* Perform service call. Return 0 on success, non-zero otherwise. */
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static int sclp_service_call(unsigned int command, void *sccb)
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{
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int cc;
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asm volatile(
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" .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */
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" ipm %0\n"
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" srl %0,28"
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: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
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: "cc", "memory");
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consume_sclp_int();
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if (cc == 3)
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return -EIO;
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if (cc == 2)
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return -EBUSY;
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return 0;
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}
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void sclp_set_write_mask(uint32_t receive_mask, uint32_t send_mask)
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{
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WriteEventMask *sccb = (void *)_sccb;
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sccb->h.length = sizeof(WriteEventMask);
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sccb->mask_length = sizeof(unsigned int);
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sccb->cp_receive_mask = receive_mask;
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sccb->cp_send_mask = send_mask;
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sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
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}
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void sclp_setup(void)
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{
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sclp_set_write_mask(0, SCLP_EVENT_MASK_MSG_ASCII);
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}
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long write(int fd, const void *str, size_t len)
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{
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WriteEventData *sccb = (void *)_sccb;
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const char *p = str;
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size_t data_len = 0;
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size_t i;
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if (fd != 1 && fd != 2) {
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return -EIO;
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}
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for (i = 0; i < len; i++) {
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if ((data_len + 1) >= SCCB_DATA_LEN) {
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/* We would overflow the sccb buffer, abort early */
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len = i;
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break;
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}
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if (*p == '\n') {
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/* Terminal emulators might need \r\n, so generate it */
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sccb->data[data_len++] = '\r';
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}
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sccb->data[data_len++] = *p;
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p++;
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}
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sccb->h.length = sizeof(WriteEventData) + data_len;
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sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
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sccb->ebh.length = sizeof(EventBufferHeader) + data_len;
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sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
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sccb->ebh.flags = 0;
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sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
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return len;
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}
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void sclp_print(const char *str)
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{
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write(1, str, strlen(str));
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}
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void sclp_get_loadparm_ascii(char *loadparm)
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{
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ReadInfo *sccb = (void *)_sccb;
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memset((char *)_sccb, 0, sizeof(ReadInfo));
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sccb->h.length = sizeof(ReadInfo);
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if (!sclp_service_call(SCLP_CMDW_READ_SCP_INFO, sccb)) {
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ebcdic_to_ascii((char *) sccb->loadparm, loadparm, 8);
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}
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}
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int sclp_read(char *str, size_t count)
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{
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ReadEventData *sccb = (void *)_sccb;
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char *buf = (char *)(&sccb->ebh) + 7;
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/* If count exceeds max buffer size, then restrict it to the max size */
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if (count > SCCB_SIZE - 8) {
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count = SCCB_SIZE - 8;
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}
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sccb->h.length = SCCB_SIZE;
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sccb->h.function_code = SCLP_UNCONDITIONAL_READ;
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sclp_service_call(SCLP_CMD_READ_EVENT_DATA, sccb);
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memcpy(str, buf, count);
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return sccb->ebh.length - 7;
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}
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