| /* |
| * Transactional Memory Unit Tests |
| * |
| * Copyright 2016 Suraj Jitindar Singh, IBM. |
| * |
| * This work is licensed under the terms of the GNU LGPL, version 2. |
| */ |
| #include <libcflat.h> |
| #include <asm/hcall.h> |
| #include <asm/processor.h> |
| #include <asm/time.h> |
| #include <asm/handlers.h> |
| #include <asm/smp.h> |
| #include <asm/setup.h> |
| #include <devicetree.h> |
| |
| /* Check "ibm,pa-features" property of a CPU node for the TM flag */ |
| static void cpu_has_tm(int fdtnode, u64 regval __unused, void *ptr) |
| { |
| const struct fdt_property *prop; |
| int plen; |
| |
| prop = fdt_get_property(dt_fdt(), fdtnode, "ibm,pa-features", &plen); |
| if (!prop) /* No features means TM is also not available */ |
| return; |
| /* Sanity check for the property layout (first two bytes are header) */ |
| assert(plen >= 8 && prop->data[1] == 0 && prop->data[0] <= plen - 2); |
| |
| /* |
| * The "Transactional Memory Category Support" flags are at byte |
| * offset 22 and 23 of the attribute type 0, so when adding the |
| * two bytes for the header, we've got to look at offset 24 for |
| * the TM support bit. |
| */ |
| if (prop->data[0] >= 24 && (prop->data[24] & 0x80) != 0) |
| *(int *)ptr += 1; |
| } |
| |
| /* Check amount of CPUs nodes that have the TM flag */ |
| static int count_cpus_with_tm(void) |
| { |
| int ret; |
| int available = 0; |
| |
| ret = dt_for_each_cpu_node(cpu_has_tm, &available); |
| if (ret < 0) |
| return ret; |
| |
| return available; |
| } |
| |
| /* |
| * Enable transactional memory |
| * Returns: FALSE - Failure |
| * TRUE - Success |
| */ |
| static bool enable_tm(void) |
| { |
| uint64_t msr = 0; |
| |
| asm volatile ("mfmsr %[msr]" : [msr] "=r" (msr)); |
| |
| msr |= (((uint64_t) 1) << 32); |
| |
| asm volatile ("mtmsrd %[msr]\n\t" |
| "mfmsr %[msr]" : [msr] "+r" (msr)); |
| |
| return !!(msr & (((uint64_t) 1) << 32)); |
| } |
| |
| /* |
| * Test H_CEDE call while transactional memory transaction is suspended |
| * |
| * WARNING: This tests for a known vulnerability in which the host may go down. |
| * Probably best not to run this if your host going down is going to cause |
| * problems. |
| * |
| * If the test passes then your kernel probably has the necessary patch. |
| * If the test fails then the H_CEDE call was unsuccessful and the |
| * vulnerability wasn't tested. |
| * If the test hits the vulnerability then it will never complete or report and |
| * the qemu process will block indefinitely. RCU stalls will be detected on the |
| * cpu and any process scheduled on the lost cpu will also block indefinitely. |
| */ |
| static void test_h_cede_tm(int argc, char **argv) |
| { |
| int i; |
| |
| if (argc > 2) |
| report_abort("Unsupported argument: '%s'", argv[2]); |
| |
| if (!start_all_cpus(halt, 0)) |
| report_abort("Failed to start secondary cpus"); |
| |
| if (!enable_tm()) |
| report_abort("Failed to enable tm"); |
| |
| /* |
| * Begin a transaction and guarantee we are in the suspend state |
| * before continuing |
| */ |
| asm volatile ("1: .long 0x7c00051d\n\t" /* tbegin. */ |
| "beq 2f\n\t" |
| ".long 0x7c0005dd\n\t" /* tsuspend. */ |
| "2: .long 0x7c00059c\n\t" /* tcheck cr0 */ |
| "bf 2,1b" : : : "cr0"); |
| |
| for (i = 0; i < 500; i++) { |
| msleep(10); |
| mdelay(5); |
| } |
| |
| report(i == 500, "H_CEDE TM"); |
| } |
| |
| struct { |
| const char *name; |
| void (*func)(int argc, char **argv); |
| } hctests[] = { |
| { "h_cede_tm", test_h_cede_tm }, |
| { NULL, NULL } |
| }; |
| |
| int main(int argc, char **argv) |
| { |
| bool all; |
| int i, cpus_with_tm; |
| |
| report_prefix_push("tm"); |
| |
| cpus_with_tm = count_cpus_with_tm(); |
| if (cpus_with_tm == 0) { |
| report_skip("TM is not available"); |
| goto done; |
| } |
| report(cpus_with_tm == nr_cpus, |
| "TM available in all 'ibm,pa-features' properties"); |
| |
| all = argc == 1 || !strcmp(argv[1], "all"); |
| |
| for (i = 0; hctests[i].name != NULL; i++) { |
| if (all || strcmp(argv[1], hctests[i].name) == 0) { |
| report_prefix_push(hctests[i].name); |
| hctests[i].func(argc, argv); |
| report_prefix_pop(); |
| } |
| } |
| |
| done: |
| report_prefix_pop(); |
| return report_summary(); |
| } |