[PATCH v1 4/4] s390x: Testing the Subchannel I/O read

Pierre Morel
2019-11-13T12:23:28Z

This simple test test the I/O reading by the SUB Channel by:
- initializing the Channel SubSystem with predefined CSSID:
0xfe000000 CSSID for a Virtual CCW
0x00090000 SSID for CCW-PONG
- initializing the ORB pointing to a single READ CCW
- starts the STSH command with the ORB
- Expect an interrupt
- writes the read data to output

The test implements lots of traces when DEBUG is on and
tests if memory above the stack is corrupted.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
lib/s390x/css.h | 244 +++++++++++++++++++++++++++++++++++++++++++++++++++
lib/s390x/css_dump.c | 141 +++++++++++++++++++++++++++++
s390x/Makefile | 2 +
s390x/css.c | 222 ++++++++++++++++++++++++++++++++++++++++++++++
s390x/unittests.cfg | 4 +
5 files changed, 613 insertions(+)
create mode 100644 lib/s390x/css.h
create mode 100644 lib/s390x/css_dump.c
create mode 100644 s390x/css.c

diff --git a/lib/s390x/css.h b/lib/s390x/css.h
new file mode 100644
index 0000000..a7c42fd
--- /dev/null
+++ b/lib/s390x/css.h
@@ -0,0 +1,244 @@
+/*
+ * CSS definitions
+ *
+ * Copyright IBM, Corp. 2019
+ * Author: Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#ifndef CSS_H
+#define CSS_H
+
+#define CCW_F_CD 0x80
+#define CCW_F_CC 0x40
+#define CCW_F_SLI 0x20
+#define CCW_F_SKP 0x10
+#define CCW_F_PCI 0x08
+#define CCW_F_IDA 0x04
+#define CCW_F_S 0x02
+#define CCW_F_MIDA 0x01
+
+#define CCW_C_NOP 0x03
+#define CCW_C_TIC 0x08
+
+struct ccw {
+ unsigned char code;
+ unsigned char flags;
+ unsigned short count;
+ unsigned int data;
+} __attribute__ ((aligned(4)));
+
+#define ORB_M_KEY 0xf0000000
+#define ORB_F_SUSPEND 0x08000000
+#define ORB_F_STREAMING 0x04000000
+#define ORB_F_MODIFCTRL 0x02000000
+#define ORB_F_SYNC 0x01000000
+#define ORB_F_FORMAT 0x00800000
+#define ORB_F_PREFETCH 0x00400000
+#define ORB_F_INIT_IRQ 0x00200000
+#define ORB_F_ADDRLIMIT 0x00100000
+#define ORB_F_SUSP_IRQ 0x00080000
+#define ORB_F_TRANSPORT 0x00040000
+#define ORB_F_IDAW2 0x00020000
+#define ORB_F_IDAW_2K 0x00010000
+#define ORB_M_LPM 0x0000ff00
+#define ORB_F_LPM_DFLT 0x00008000
+#define ORB_F_ILSM 0x00000080
+#define ORB_F_CCW_IND 0x00000040
+#define ORB_F_ORB_EXT 0x00000001
+struct orb {
+ unsigned int intparm;
+ unsigned int ctrl;
+ unsigned int cpa;
+ unsigned int prio;
+ unsigned int reserved[4];
+} __attribute__ ((aligned(4)));;
+
+struct scsw {
+ uint32_t ctrl;
+ uint32_t addr;
+ uint8_t devs;
+ uint8_t schs;
+ uint16_t count;
+};
+
+struct pmcw {
+ uint32_t intparm;
+ uint16_t flags;
+ uint16_t devnum;
+ uint8_t lpm;
+ uint8_t pnom;
+ uint8_t lpum;
+ uint8_t pim;
+ uint16_t mbi;
+ uint8_t pom;
+ uint8_t pam;
+ uint8_t chpid[8];
+ uint32_t flag2;
+};
+struct schib {
+ struct pmcw pmcw;
+ struct scsw scsw;
+ uint32_t md0;
+ uint32_t md1;
+ uint32_t md2;
+} __attribute__ ((aligned(4)));
+
+struct irb {
+ struct scsw scsw;
+ uint32_t esw[5];
+ uint32_t ecw[8];
+ uint32_t emw[8];
+} __attribute__ ((aligned(4)));;
+
+/* CSS low level access functions */
+
+static inline int ssch(unsigned long schid, struct orb *addr)
+{
+ register long long reg1 asm("1") = schid;
+ int ccode = -1;
+
+ asm volatile(
+ " ssch 0(%2)\n"
+ "0: ipm %0\n"
+ " srl %0,28\n"
+ "1:\n"
+ : "+d" (ccode)
+ : "d" (reg1), "a" (addr), "m" (*addr)
+ : "cc", "memory");
+ return ccode;
+}
+
+static inline int stsch(unsigned long schid, struct schib *addr)
+{
+ register unsigned long reg1 asm ("1") = schid;
+ int ccode;
+
+ asm volatile(
+ " stsch 0(%3)\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=d" (ccode), "=m" (*addr)
+ : "d" (reg1), "a" (addr)
+ : "cc");
+ return ccode;
+}
+
+static inline int msch(unsigned long schid, struct schib *addr)
+{
+ register unsigned long reg1 asm ("1") = schid;
+ int ccode;
+
+ asm volatile(
+ " msch 0(%3)\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=d" (ccode), "=m" (*addr)
+ : "d" (reg1), "a" (addr)
+ : "cc");
+ return ccode;
+}
+
+static inline int tsch(unsigned long schid, struct irb *addr)
+{
+ register unsigned long reg1 asm ("1") = schid;
+ int ccode;
+
+ asm volatile(
+ " tsch 0(%3)\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=d" (ccode), "=m" (*addr)
+ : "d" (reg1), "a" (addr)
+ : "cc");
+ return ccode;
+}
+
+static inline int hsch(unsigned long schid)
+{
+ register unsigned long reg1 asm("1") = schid;
+ int ccode;
+
+ asm volatile(
+ " hsch\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=d" (ccode)
+ : "d" (reg1)
+ : "cc");
+ return ccode;
+}
+
+static inline int xsch(unsigned long schid)
+{
+ register unsigned long reg1 asm("1") = schid;
+ int ccode;
+
+ asm volatile(
+ " xsch\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=d" (ccode)
+ : "d" (reg1)
+ : "cc");
+ return ccode;
+}
+
+static inline int csch(unsigned long schid)
+{
+ register unsigned long reg1 asm("1") = schid;
+ int ccode;
+
+ asm volatile(
+ " csch\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=d" (ccode)
+ : "d" (reg1)
+ : "cc");
+ return ccode;
+}
+
+static inline int rsch(unsigned long schid)
+{
+ register unsigned long reg1 asm("1") = schid;
+ int ccode;
+
+ asm volatile(
+ " rsch\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=d" (ccode)
+ : "d" (reg1)
+ : "cc");
+ return ccode;
+}
+
+static inline int rchp(unsigned long chpid)
+{
+ register unsigned long reg1 asm("1") = chpid;
+ int ccode;
+
+ asm volatile(
+ " rchp\n"
+ " ipm %0\n"
+ " srl %0,28"
+ : "=d" (ccode)
+ : "d" (reg1)
+ : "cc");
+ return ccode;
+}
+
+void dump_scsw(struct scsw *);
+void dump_irb(struct irb *irbp);
+void dump_pmcw_flags(uint16_t f);
+void dump_pmcw(struct pmcw *p);
+void dump_schib(struct schib *sch);
+struct ccw *dump_ccw(struct ccw *cp);
+void dump_orb(struct orb *op);
+
+extern unsigned long stacktop;
+#endif
diff --git a/lib/s390x/css_dump.c b/lib/s390x/css_dump.c
new file mode 100644
index 0000000..4f6b628
--- /dev/null
+++ b/lib/s390x/css_dump.c
@@ -0,0 +1,141 @@
+/*
+ * Channel Sub-System structures dumping
+ *
+ * Copyright (c) 2019 IBM Corp.
+ *
+ * Authors:
+ * Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Library General Public License version 2.
+ *
+ * Description:
+ * Provides the dumping functions for various structures used by subchannels:
+ * - ORB : Operation request block, describe the I/O operation and point to
+ * a CCW chain
+ * - CCW : Channel Command Word, describe the data and flow control
+ * - IRB : Interuption response Block, describe the result of an operation
+ * hold a SCSW and several channel type dependent fields.
+ * - SCHIB: SubChannel Information Block composed of:
+ * - SCSW: SubChannel Status Word, status of the channel as a result of an
+ * operation when in IRB.
+ * - PMCW: Path Management Control Word
+ * You need the QEMU ccw-pong device in QEMU to answer the I/O transfers.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <css.h>
+
+static const char *scsw_str = "kkkkslccfpixuzen";
+static const char *scsw_str2 = "1SHCrshcsdsAIPSs";
+
+void dump_scsw(struct scsw *s)
+{
+ int i;
+ uint32_t scsw = s->ctrl;
+ char line[64] = {};
+
+ for (i = 0; i < 16; i++) {
+ if ((scsw << i) & 0x80000000)
+ line[i] = scsw_str[i];
+ else
+ line[i] = '_';
+ }
+ line[i] = ' ';
+ for (; i < 32; i++) {
+ if ((scsw << i) & 0x80000000)
+ line[i + 1] = scsw_str2[i - 16];
+ else
+ line[i + 1] = '_';
+ }
+ printf("scsw->flags: %s\n", line);
+ printf("scsw->addr : %08x\n", s->addr);
+ printf("scsw->devs : %02x\n", s->devs);
+ printf("scsw->schs : %02x\n", s->schs);
+ printf("scsw->count: %04x\n", s->count);
+
+}
+
+void dump_irb(struct irb *irbp)
+{
+ int i;
+ uint32_t *p = (uint32_t *)irbp;
+
+ dump_scsw(&irbp->scsw);
+ for (i = 0; i < sizeof(*irbp)/sizeof(*p); i++, p++)
+ printf("irb[%02x] : %08x\n", i, *p);
+}
+
+static const char *pmcw_str = "11iii111ellmmdtv";
+void dump_pmcw_flags(uint16_t f)
+{
+ int i;
+ char line[32] = {};
+
+ for (i = 0; i < 16; i++) {
+ if ((f << i) & 0x8000)
+ line[i] = pmcw_str[i];
+ else
+ line[i] = '_';
+ }
+ printf("pmcw->pmcw flgs: %s\n", line);
+}
+
+void dump_pmcw(struct pmcw *p)
+{
+ int i;
+
+ printf("pmcw->intparm : %08x\n", p->intparm);
+ printf("pmcw->flags : %04x\n", p->flags);
+ dump_pmcw_flags(p->flags);
+ printf("pmcw->devnum : %04x\n", p->devnum);
+ printf("pmcw->lpm : %02x\n", p->lpm);
+ printf("pmcw->pnom : %02x\n", p->pnom);
+ printf("pmcw->lpum : %02x\n", p->lpum);
+ printf("pmcw->pim : %02x\n", p->pim);
+ printf("pmcw->mbi : %04x\n", p->mbi);
+ printf("pmcw->pom : %02x\n", p->pom);
+ printf("pmcw->pam : %02x\n", p->pam);
+ printf("pmcw->mbi : %04x\n", p->mbi);
+ for (i = 0; i < 8; i++)
+ printf("pmcw->chpid[%d]: %02x\n", i, p->chpid[i]);
+ printf("pmcw->flags2 : %08x\n", p->flag2);
+}
+
+void dump_schib(struct schib *sch)
+{
+ struct pmcw *p = &sch->pmcw;
+ struct scsw *s = &sch->scsw;
+
+ printf("--SCHIB--\n");
+ dump_pmcw(p);
+ dump_scsw(s);
+}
+
+struct ccw *dump_ccw(struct ccw *cp)
+{
+ printf("CCW: code: %02x flags: %02x count: %04x data: %08x\n", cp->code,
+ cp->flags, cp->count, cp->data);
+
+ if (cp->code == CCW_C_TIC)
+ return (struct ccw *)(long)cp->data;
+
+ return (cp->flags & CCW_F_CC) ? cp + 1 : NULL;
+}
+
+void dump_orb(struct orb *op)
+{
+ struct ccw *cp;
+
+ printf("ORB: intparm : %08x\n", op->intparm);
+ printf("ORB: ctrl : %08x\n", op->ctrl);
+ printf("ORB: prio : %08x\n", op->prio);
+ cp = (struct ccw *)(long) (op->cpa);
+ while (cp)
+ cp = dump_ccw(cp);
+}
+
diff --git a/s390x/Makefile b/s390x/Makefile
index 3744372..9ebbb84 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -16,6 +16,7 @@ tests += $(TEST_DIR)/diag288.elf
tests += $(TEST_DIR)/stsi.elf
tests += $(TEST_DIR)/skrf.elf
tests += $(TEST_DIR)/smp.elf
+tests += $(TEST_DIR)/css.elf
tests_binary = $(patsubst %.elf,%.bin,$(tests))

all: directories test_cases test_cases_binary
@@ -50,6 +51,7 @@ cflatobjs += lib/s390x/sclp-console.o
cflatobjs += lib/s390x/interrupt.o
cflatobjs += lib/s390x/mmu.o
cflatobjs += lib/s390x/smp.o
+cflatobjs += lib/s390x/css_dump.o

OBJDIRS += lib/s390x

diff --git a/s390x/css.c b/s390x/css.c
new file mode 100644
index 0000000..6cdaf61
--- /dev/null
+++ b/s390x/css.c
@@ -0,0 +1,222 @@
+/*
+ * Channel Sub-System tests
+ *
+ * Copyright (c) 2019 IBM Corp
+ *
+ * Authors:
+ * Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#include <libcflat.h>
+#include <alloc_phys.h>
+#include <asm/page.h>
+#include <string.h>
+#include <asm/interrupt.h>
+#include <asm/arch_def.h>
+
+#include <css.h>
+
+#define PSW_PRG_MASK (PSW_MASK_IO | PSW_MASK_EA | PSW_MASK_BA)
+
+#define DEBUG 1
+#ifdef DEBUG
+#define DBG(format, arg...) \
+ printf("KT_%s:%d " format "\n", __func__, __LINE__, ##arg)
+#else
+#define DBG(format, arg...) do {} while (0)
+#endif
+
+#define CSSID_PONG (0xfe000000 | 0x00090000)
+
+struct lowcore *lowcore = (void *)0x0;
+
+#define NB_CCW 100
+static struct ccw ccw[NB_CCW];
+
+#define NB_ORB 100
+static struct orb orb[NB_ORB];
+
+static struct irb irb;
+static struct schib schib;
+
+static char buffer[4096];
+
+static void delay(int d)
+{
+ int i, j;
+
+ while (d--)
+ for (i = 1000000; i; i--)
+ for (j = 1000000; j; j--)
+ ;
+}
+
+static void set_io_irq_subclass_mask(uint64_t const new_mask)
+{
+ asm volatile (
+ "lctlg %%c6, %%c6, %[source]\n"
+ : /* No outputs */
+ : [source] "R" (new_mask));
+}
+
+static void set_system_mask(uint8_t new_mask)
+{
+ asm volatile (
+ "ssm %[source]\n"
+ : /* No outputs */
+ : [source] "R" (new_mask));
+}
+
+static void enable_io_irq(void)
+{
+ set_io_irq_subclass_mask(0x00000000ff000000);
+ set_system_mask(PSW_PRG_MASK >> 56);
+}
+
+void handle_io_int(sregs_t *regs)
+{
+ int ret = 0;
+
+ DBG("IO IRQ: subsys_id_word=%08x", lowcore->subsys_id_word);
+ DBG("......: io_int_parm =%08x", lowcore->io_int_param);
+ DBG("......: io_int_word =%08x", lowcore->io_int_word);
+ ret = tsch(lowcore->subsys_id_word, &irb);
+ dump_irb(&irb);
+ if (ret)
+ DBG("......: tsch retval %d", ret);
+ DBG("IO IRQ: END");
+}
+
+static void set_schib(struct schib *sch)
+{
+ struct pmcw *p = &sch->pmcw;
+
+ p->intparm = 0xdeadbeef;
+ p->devnum = 0xc0ca;
+ p->lpm = 0x80;
+ p->flags = 0x3081;
+ p->chpid[7] = 0x22;
+ p->pim = 0x0f;
+ p->pam = 0x0f;
+ p->pom = 0x0f;
+ p->lpm = 0x0f;
+ p->lpum = 0xaa;
+ p->pnom = 0xf0;
+ p->mbi = 0xaa;
+ p->mbi = 0xaaaa;
+}
+
+static void css_enable(void)
+{
+ int ret;
+
+ ret = stsch(CSSID_PONG, &schib);
+ if (ret)
+ DBG("stsch: %x\n", ret);
+ dump_schib(&schib);
+ set_schib(&schib);
+ dump_schib(&schib);
+ ret = msch(CSSID_PONG, &schib);
+ if (ret)
+ DBG("msch : %x\n", ret);
+}
+
+/* These two definitions are part of the QEMU PONG interface */
+#define PONG_WRITE 0x21
+#define PONG_READ 0x22
+
+static int css_run(int fake)
+{
+ struct orb *p = orb;
+ int cc;
+
+ if (fake)
+ return 0;
+ css_enable();
+
+ enable_io_irq();
+
+ ccw[0].code = PONG_READ;
+ ccw[0].flags = CCW_F_PCI;
+ ccw[0].count = 80;
+ ccw[0].data = (unsigned int)(unsigned long) &buffer;
+
+ p->intparm = 0xcafec0ca;
+ p->ctrl = ORB_F_INIT_IRQ|ORB_F_FORMAT|ORB_F_LPM_DFLT;
+ p->cpa = (unsigned int) (unsigned long)&ccw[0];
+
+ printf("ORB AT %p\n", orb);
+ dump_orb(p);
+ cc = ssch(CSSID_PONG, p);
+ if (cc) {
+ DBG("cc: %x\n", cc);
+ return cc;
+ }
+
+ delay(1);
+
+ stsch(CSSID_PONG, &schib);
+ dump_schib(&schib);
+ DBG("got: %s\n", buffer);
+
+ return 0;
+}
+
+#define MAX_ERRORS 10
+static int checkmem(phys_addr_t start, phys_addr_t end)
+{
+ phys_addr_t curr;
+ int err = 0;
+
+ for (curr = start; curr != end; curr += PAGE_SIZE)
+ if (memcmp((void *)start, (void *)curr, PAGE_SIZE)) {
+ report("memcmp failed %lx", true, curr);
+ if (err++ > MAX_ERRORS)
+ break;
+ }
+ return err;
+}
+
+extern unsigned long bss_end;
+
+int main(int argc, char *argv[])
+{
+ phys_addr_t base, top;
+ int check_mem = 0;
+ int err = 0;
+
+ if (argc == 2 && !strcmp(argv[1], "-i"))
+ check_mem = 1;
+
+ report_prefix_push("css");
+ phys_alloc_get_unused(&base, &top);
+
+ top = 0x08000000; /* 128MB Need to be updated */
+ base = (phys_addr_t)&stacktop;
+
+ if (check_mem)
+ memset((void *)base, 0x00, top - base);
+
+ if (check_mem)
+ err = checkmem(base, top);
+ if (err)
+ goto out;
+
+ err = css_run(0);
+ if (err)
+ goto out;
+
+ if (check_mem)
+ err = checkmem(base, top);
+
+out:
+ if (err)
+ report("Tested", 0);
+ else
+ report("Tested", 1);
+
+ return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index f1b07cd..1755d9e 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -75,3 +75,7 @@ file = stsi.elf
[smp]
file = smp.elf
extra_params =-smp 2
+
+[css]
+file = css.elf
+extra_params =-device ccw-pong
--
2.7.4