blob: 1abb9029f984c943ef7ed9db8d454cc1ee89f84c [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Service Call tests
*
* Copyright (c) 2020 IBM Corp
*
* Authors:
* Claudio Imbrenda <imbrenda@linux.ibm.com>
*/
#include <libcflat.h>
#include <asm/page.h>
#include <asm/asm-offsets.h>
#include <asm/interrupt.h>
#include <sclp.h>
#define PGM_NONE 1
#define PGM_BIT_SPEC (1ULL << PGM_INT_CODE_SPECIFICATION)
#define PGM_BIT_ADDR (1ULL << PGM_INT_CODE_ADDRESSING)
#define PGM_BIT_PRIV (1ULL << PGM_INT_CODE_PRIVILEGED_OPERATION)
#define MKPTR(x) ((void *)(uint64_t)(x))
#define LC_SIZE (2 * PAGE_SIZE)
static uint8_t pagebuf[LC_SIZE] __attribute__((aligned(LC_SIZE))); /* scratch pages used for some tests */
static uint8_t prefix_buf[LC_SIZE] __attribute__((aligned(LC_SIZE))); /* temporary lowcore for test_sccb_prefix */
/* SCCB template to be used */
static union {
uint8_t raw[PAGE_SIZE];
SCCBHeader header;
WriteEventData data;
} sccb_template;
static uint32_t valid_code; /* valid command code for READ SCP INFO */
/**
* Perform one service call, handling exceptions and interrupts.
*/
static int sclp_service_call_test(unsigned int command, void *sccb)
{
int cc;
sclp_mark_busy();
sclp_setup_int();
cc = servc(command, __pa(sccb));
if (lowcore.pgm_int_code) {
sclp_handle_ext();
return 0;
}
if (!cc)
sclp_wait_busy();
return cc;
}
/**
* Perform one test at the given address, optionally using the SCCB template,
* checking for the expected program interrupts and return codes.
*
* The parameter buf_len indicates the number of bytes of the template that
* should be copied to the test address, and should be 0 when the test
* address is invalid, in which case nothing is copied.
*
* The template is used to simplify tests where the same buffer content is
* used many times in a row, at different addresses.
*
* Returns true in case of success or false in case of failure
*/
static bool test_one_sccb(uint32_t cmd, uint8_t *addr, uint16_t buf_len, uint64_t exp_pgm, uint16_t exp_rc)
{
SCCBHeader *h = (SCCBHeader *)addr;
int res, pgm;
/* Copy the template to the test address if needed */
if (buf_len)
memcpy(addr, sccb_template.raw, buf_len);
if (exp_pgm != PGM_NONE)
expect_pgm_int();
/* perform the actual call */
res = sclp_service_call_test(cmd, h);
if (res) {
report_info("SCLP not ready (command %#x, address %p, cc %d)", cmd, addr, res);
return false;
}
pgm = clear_pgm_int();
/* Check if the program exception was one of the expected ones */
if (!((1ULL << pgm) & exp_pgm)) {
report_info("First failure at addr %p, buf_len %d, cmd %#x, pgm code %d",
addr, buf_len, cmd, pgm);
return false;
}
/* Check if the response code is the one expected */
if (exp_rc && exp_rc != h->response_code) {
report_info("First failure at addr %p, buf_len %d, cmd %#x, resp code %#x",
addr, buf_len, cmd, h->response_code);
return false;
}
return true;
}
/**
* Wrapper for test_one_sccb to be used when the template should not be
* copied and the memory address should not be touched.
*/
static bool test_one_ro(uint32_t cmd, uint8_t *addr, uint64_t exp_pgm, uint16_t exp_rc)
{
return test_one_sccb(cmd, addr, 0, exp_pgm, exp_rc);
}
/**
* Wrapper for test_one_sccb to set up a simple SCCB template.
*
* The parameter sccb_len indicates the value that will be saved in the SCCB
* length field of the SCCB, buf_len indicates the number of bytes of
* template that need to be copied to the actual test address. In many cases
* it's enough to clear/copy the first 8 bytes of the buffer, while the SCCB
* itself can be larger.
*
* Returns true in case of success or false in case of failure
*/
static bool test_one_simple(uint32_t cmd, uint8_t *addr, uint16_t sccb_len,
uint16_t buf_len, uint64_t exp_pgm, uint16_t exp_rc)
{
memset(sccb_template.raw, 0, sizeof(sccb_template.raw));
sccb_template.header.length = sccb_len;
return test_one_sccb(cmd, addr, buf_len, exp_pgm, exp_rc);
}
/**
* Test SCCB lengths < 8.
*/
static void test_sccb_too_short(void)
{
int len;
for (len = 0; len < 8; len++)
if (!test_one_simple(valid_code, pagebuf, len, 8, PGM_BIT_SPEC, 0))
break;
report(len == 8, "SCCB too short");
}
/**
* Test SCCBs that are not 64-bit aligned.
*/
static void test_sccb_unaligned(void)
{
int offset;
for (offset = 1; offset < 8; offset++)
if (!test_one_simple(valid_code, offset + pagebuf, 8, 8, PGM_BIT_SPEC, 0))
break;
report(offset == 8, "SCCB unaligned");
}
/**
* Test SCCBs whose address is in the lowcore or prefix area.
*/
static void test_sccb_prefix(void)
{
uint8_t scratch[LC_SIZE];
uint32_t prefix, new_prefix;
int offset;
/*
* copy the current lowcore to the future new location, otherwise we
* will not have a valid lowcore after setting the new prefix.
*/
memcpy(prefix_buf, 0, LC_SIZE);
/* save the current prefix (it's probably going to be 0) */
prefix = get_prefix();
/*
* save the current content of absolute pages 0 and 1, so we can
* restore them after we trash them later on
*/
memcpy(scratch, (void *)(intptr_t)prefix, LC_SIZE);
/* set the new prefix to prefix_buf */
new_prefix = (uint32_t)(intptr_t)prefix_buf;
set_prefix(new_prefix);
/*
* testing with SCCB addresses in the lowcore; since we can't
* actually trash the lowcore (unsurprisingly, things break if we
* do), this will be a read-only test.
*/
for (offset = 0; offset < LC_SIZE; offset += 8)
if (!test_one_ro(valid_code, MKPTR(offset), PGM_BIT_SPEC, 0))
break;
report(offset == LC_SIZE, "SCCB low pages");
/*
* the SCLP should not even touch the memory, but we will write the
* SCCBs all over the two pages starting at absolute address 0, thus
* trashing them; we will need to restore them later.
*/
for (offset = 0; offset < LC_SIZE; offset += 8)
if (!test_one_simple(valid_code, MKPTR(new_prefix + offset), 8, 8, PGM_BIT_SPEC, 0))
break;
report(offset == LC_SIZE, "SCCB prefix pages");
/* restore the previous contents of absolute pages 0 and 1 */
memcpy(prefix_buf, 0, LC_SIZE);
/* restore the prefix to the original value */
set_prefix(prefix);
}
/**
* Test SCCBs that are above 2GB. If outside of memory, an addressing
* exception is also allowed.
*/
static void test_sccb_high(void)
{
SCCBHeader *h = (SCCBHeader *)pagebuf;
uintptr_t a[33 * 4 * 2 + 2]; /* for the list of addresses to test */
uint64_t maxram;
int i, pgm, len = 0;
h->length = 8;
/* addresses with 1 bit set in the first 33 bits */
for (i = 0; i < 33; i++)
a[len++] = 1UL << (i + 31);
/* addresses with 2 consecutive bits set in the first 33 bits */
for (i = 0; i < 33; i++)
a[len++] = 3UL << (i + 31);
/* addresses with all bits set in bits 0..N */
for (i = 0; i < 33; i++)
a[len++] = 0xffffffff80000000UL << i;
/* addresses with all bits set in bits N..33 */
a[len++] = 0x80000000;
for (i = 1; i < 33; i++, len++)
a[len] = a[len - 1] | (1UL << (i + 31));
/* all the addresses above, but adding the offset of a valid buffer */
for (i = 0; i < len; i++)
a[len + i] = a[i] + (intptr_t)h;
len += i;
/* two more hand-crafted addresses */
a[len++] = 0xdeadbeef00000000;
a[len++] = 0xdeaddeadbeef0000;
maxram = get_ram_size();
for (i = 0; i < len; i++) {
pgm = PGM_BIT_SPEC | (a[i] >= maxram ? PGM_BIT_ADDR : 0);
if (!test_one_ro(valid_code, (void *)a[i], pgm, 0))
break;
}
report(i == len, "SCCB high addresses");
}
/**
* Test invalid commands, both invalid command detail codes and valid
* ones with invalid command class code.
*/
static void test_inval(void)
{
const uint16_t res = SCLP_RC_INVALID_SCLP_COMMAND;
uint32_t cmd;
int i;
report_prefix_push("Invalid command");
for (i = 0; i < 65536; i++) {
cmd = 0xdead0000 | i;
if (!test_one_simple(cmd, pagebuf, PAGE_SIZE, PAGE_SIZE, PGM_NONE, res))
break;
}
report(i == 65536, "Command detail code");
for (i = 0; i < 256; i++) {
cmd = (valid_code & ~0xff) | i;
if (cmd == valid_code)
continue;
if (!test_one_simple(cmd, pagebuf, PAGE_SIZE, PAGE_SIZE, PGM_NONE, res))
break;
}
report(i == 256, "Command class code");
report_prefix_pop();
}
/**
* Test short SCCBs (but larger than 8).
*/
static void test_short(void)
{
const uint16_t res = SCLP_RC_INSUFFICIENT_SCCB_LENGTH;
int len;
for (len = 8; len < 144; len++)
if (!test_one_simple(valid_code, pagebuf, len, len, PGM_NONE, res))
break;
report(len == 144, "Insufficient SCCB length (Read SCP info)");
for (len = 8; len < 40; len++)
if (!test_one_simple(SCLP_READ_CPU_INFO, pagebuf, len, len, PGM_NONE, res))
break;
report(len == 40, "Insufficient SCCB length (Read CPU info)");
}
/**
* Test SCCB page boundary violations.
*/
static void test_boundary(void)
{
const uint32_t cmd = SCLP_CMD_WRITE_EVENT_DATA;
const uint16_t res = SCLP_RC_SCCB_BOUNDARY_VIOLATION;
WriteEventData *sccb = &sccb_template.data;
int len, offset;
memset(sccb_template.raw, 0, sizeof(sccb_template.raw));
sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
for (len = 32; len <= 4096; len++) {
offset = len & 7 ? len & ~7 : len - 8;
for (offset = 4096 - offset; offset < 4096; offset += 8) {
sccb->h.length = len;
if (!test_one_sccb(cmd, offset + pagebuf, len, PGM_NONE, res))
goto out;
}
}
out:
report(len > 4096 && offset == 4096, "SCCB page boundary violation");
}
/**
* Test excessively long SCCBs.
*/
static void test_toolong(void)
{
const uint32_t cmd = SCLP_CMD_WRITE_EVENT_DATA;
const uint16_t res = SCLP_RC_SCCB_BOUNDARY_VIOLATION;
WriteEventData *sccb = &sccb_template.data;
int len;
memset(sccb_template.raw, 0, sizeof(sccb_template.raw));
sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
for (len = 4097; len < 8192; len++) {
sccb->h.length = len;
if (!test_one_sccb(cmd, pagebuf, PAGE_SIZE, PGM_NONE, res))
break;
}
report(len == 8192, "SCCB bigger than 4k");
}
/**
* Test privileged operation.
*/
static void test_priv(void)
{
SCCBHeader *h = (SCCBHeader *)pagebuf;
report_prefix_push("Privileged operation");
h->length = 8;
expect_pgm_int();
enter_pstate();
servc(valid_code, __pa(h));
check_pgm_int_code(PGM_INT_CODE_PRIVILEGED_OPERATION);
report_prefix_pop();
}
/**
* Test addressing exceptions. We need to test SCCB addresses between the
* end of available memory and 2GB, because after 2GB a specification
* exception is also allowed.
* Only applicable if the VM has less than 2GB of memory
*/
static void test_addressing(void)
{
unsigned long i, maxram = get_ram_size();
/* the VM has more than 2GB of memory */
if (maxram >= 0x80000000) {
report_skip("Invalid SCCB address");
return;
}
/* test all possible valid addresses immediately after the end of memory
* up to 64KB after the end of memory
*/
for (i = 0; i < 0x10000 && i + maxram < 0x80000000; i += 8)
if (!test_one_ro(valid_code, MKPTR(i + maxram), PGM_BIT_ADDR, 0))
goto out;
/* test more addresses until we reach 1MB after end of memory;
* increment by a prime number (times 8) in order to test all
* possible valid offsets inside pages
*/
for (; i < 0x100000 && i + maxram < 0x80000000 ; i += 808)
if (!test_one_ro(valid_code, MKPTR(i + maxram), PGM_BIT_ADDR, 0))
goto out;
/* test the remaining addresses until we reach address 2GB;
* increment by a prime number (times 8) in order to test all
* possible valid offsets inside pages
*/
for (; i + maxram < 0x80000000; i += 800024)
if (!test_one_ro(valid_code, MKPTR(i + maxram), PGM_BIT_ADDR, 0))
goto out;
out:
report(i + maxram >= 0x80000000, "Invalid SCCB address");
}
/**
* Test some bits in the instruction format that are specified to be ignored.
*/
static void test_instbits(void)
{
SCCBHeader *h = (SCCBHeader *)pagebuf;
int cc;
sclp_mark_busy();
h->length = 8;
sclp_setup_int();
asm volatile(
" .insn rre,0xb2204200,%1,%2\n" /* servc %1,%2 */
" ipm %0\n"
" srl %0,28"
: "=&d" (cc) : "d" (valid_code), "a" (__pa(pagebuf))
: "cc", "memory");
/* No exception, but also no command accepted, so no interrupt is
* expected. We need to clear the flag manually otherwise we will
* loop forever when we try to report failure.
*/
if (cc)
sclp_handle_ext();
else
sclp_wait_busy();
report(cc == 0, "Instruction format ignored bits");
}
/**
* Find a valid READ INFO command code; not all codes are always allowed, and
* probing should be performed in the right order.
*/
static void find_valid_sclp_code(void)
{
const unsigned int commands[] = { SCLP_CMDW_READ_SCP_INFO_FORCED,
SCLP_CMDW_READ_SCP_INFO };
SCCBHeader *h = (SCCBHeader *)pagebuf;
int i, cc;
for (i = 0; i < ARRAY_SIZE(commands); i++) {
sclp_mark_busy();
memset(h, 0, sizeof(*h));
h->length = 4096;
valid_code = commands[i];
cc = sclp_service_call(commands[i], h);
if (cc)
break;
if (h->response_code == SCLP_RC_NORMAL_READ_COMPLETION)
return;
if (h->response_code != SCLP_RC_INVALID_SCLP_COMMAND)
break;
}
report_abort("READ_SCP_INFO failed");
}
int main(void)
{
report_prefix_push("sclp");
find_valid_sclp_code();
/* Test some basic things */
test_instbits();
test_priv();
test_addressing();
/* Test the specification exceptions */
test_sccb_too_short();
test_sccb_unaligned();
test_sccb_prefix();
test_sccb_high();
/* Test the expected response codes */
test_inval();
test_short();
test_boundary();
test_toolong();
return report_summary();
}