#if defined(__i386__) || defined(__x86_64__) #include #include #include #include #include "helpers/helpers.h" /* Intel specific MSRs */ #define MSR_IA32_PERF_STATUS 0x198 #define MSR_IA32_MISC_ENABLES 0x1a0 #define MSR_IA32_ENERGY_PERF_BIAS 0x1b0 #define MSR_NEHALEM_TURBO_RATIO_LIMIT 0x1ad /* * read_msr * * Will return 0 on success and -1 on failure. * Possible errno values could be: * EFAULT -If the read/write did not fully complete * EIO -If the CPU does not support MSRs * ENXIO -If the CPU does not exist */ int read_msr(int cpu, unsigned int idx, unsigned long long *val) { int fd; char msr_file_name[64]; sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu); fd = open(msr_file_name, O_RDONLY); if (fd < 0) return -1; if (lseek(fd, idx, SEEK_CUR) == -1) goto err; if (read(fd, val, sizeof *val) != sizeof *val) goto err; close(fd); return 0; err: close(fd); return -1; } /* * write_msr * * Will return 0 on success and -1 on failure. * Possible errno values could be: * EFAULT -If the read/write did not fully complete * EIO -If the CPU does not support MSRs * ENXIO -If the CPU does not exist */ int write_msr(int cpu, unsigned int idx, unsigned long long val) { int fd; char msr_file_name[64]; sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu); fd = open(msr_file_name, O_WRONLY); if (fd < 0) return -1; if (lseek(fd, idx, SEEK_CUR) == -1) goto err; if (write(fd, &val, sizeof val) != sizeof val) goto err; close(fd); return 0; err: close(fd); return -1; } int msr_intel_get_perf_bias(unsigned int cpu) { unsigned long long val; int ret; if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS)) return -1; ret = read_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, &val); if (ret) return ret; return val; } int msr_intel_set_perf_bias(unsigned int cpu, unsigned int val) { int ret; if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS)) return -1; ret = write_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, val); if (ret) return ret; return 0; } unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu) { unsigned long long val; int ret; if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_HAS_TURBO_RATIO)) return -1; ret = read_msr(cpu, MSR_NEHALEM_TURBO_RATIO_LIMIT, &val); if (ret) return ret; return val; } #endif diff
path: root/drivers/usb/host/uhci-debug.c
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authorDexuan Cui <decui@microsoft.com>2017-01-28 11:46:02 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-31 10:59:48 +0100
commit433e19cf33d34bb6751c874a9c00980552fe508c (patch)
treece6547ef2987fbb289fa28f03536328a42781651 /drivers/usb/host/uhci-debug.c
parent191e885a2e130e639bb0c8ee350d7047294f2ce6 (diff)
Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") added the proper mb(), but removed the test "prev_write_sz < pending_sz" when making the signal decision. As a result, the guest can signal the host unnecessarily, and then the host can throttle the guest because the host thinks the guest is buggy or malicious; finally the user running stress test can perceive intermittent freeze of the guest. This patch brings back the test, and properly handles the in-place consumption APIs used by NetVSC (see get_next_pkt_raw(), put_pkt_raw() and commit_rd_index()). Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") Signed-off-by: Dexuan Cui <decui@microsoft.com> Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Tested-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/uhci-debug.c')