From: Len Brown Date: Mon, 22 Apr 2013 12:00:16 +0000 (+0200) Subject: x86/mwait_idle: stop using driver_data for static flags X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~6975 X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=4e96e50c36fe32aa3e5d5da370f58da89fd35cb3;p=xen.git x86/mwait_idle: stop using driver_data for static flags The (Linux) commit 4202735e8ab6ecfb0381631a0d0b58fefe0bd4e2 (cpuidle: Split cpuidle_state structure and move per-cpu statistics fields) observed that the MWAIT flags for Cn on every processor to date were the same, and created get_driver_data() to supply them. Unfortunately, that assumption is false, going forward. So here we restore the MWAIT flags to the cpuidle_state table. However, instead restoring the old "driver_data" field, we put the flags into the existing "flags" field, where they probalby should have lived all along. This patch does not change any operation. Signed-off-by: Len Brown Signed-off-by: Jan Beulich Acked-by: George Dunlap --- diff --git a/xen/arch/x86/cpu/mwait-idle.c b/xen/arch/x86/cpu/mwait-idle.c index 21447e1754..111c14906b 100644 --- a/xen/arch/x86/cpu/mwait-idle.c +++ b/xen/arch/x86/cpu/mwait-idle.c @@ -107,6 +107,16 @@ static const struct cpuidle_state { */ #define CPUIDLE_FLAG_TLB_FLUSHED 0x10000 +/* + * MWAIT takes an 8-bit "hint" in EAX "suggesting" + * the C-state (top nibble) and sub-state (bottom nibble) + * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc. + * + * We store the hint at the top of our "flags" for each state. + */ +#define flg2MWAIT(flags) (((flags) >> 24) & 0xFF) +#define MWAIT2flg(eax) ((eax & 0xFF) << 24) + /* * States are indexed by the cstate number, * which is also the index into the MWAIT hint array. @@ -116,18 +126,19 @@ static const struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = { { /* MWAIT C0 */ }, { /* MWAIT C1 */ .name = "C1-NHM", + .flags = MWAIT2flg(0x00), .exit_latency = 3, .target_residency = 6, }, { /* MWAIT C2 */ .name = "C3-NHM", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 20, .target_residency = 80, }, { /* MWAIT C3 */ .name = "C6-NHM", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 200, .target_residency = 800, } @@ -137,24 +148,25 @@ static const struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = { { /* MWAIT C0 */ }, { /* MWAIT C1 */ .name = "C1-SNB", + .flags = MWAIT2flg(0x00), .exit_latency = 1, .target_residency = 1, }, { /* MWAIT C2 */ .name = "C3-SNB", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 80, .target_residency = 211, }, { /* MWAIT C3 */ .name = "C6-SNB", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 104, .target_residency = 345, }, { /* MWAIT C4 */ .name = "C7-SNB", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 109, .target_residency = 345, } @@ -164,24 +176,25 @@ static const struct cpuidle_state ivb_cstates[MWAIT_MAX_NUM_CSTATES] = { { /* MWAIT C0 */ }, { /* MWAIT C1 */ .name = "C1-IVB", + .flags = MWAIT2flg(0x00), .exit_latency = 1, .target_residency = 1, }, { /* MWAIT C2 */ .name = "C3-IVB", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 59, .target_residency = 156, }, { /* MWAIT C3 */ .name = "C6-IVB", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 80, .target_residency = 300, }, { /* MWAIT C4 */ .name = "C7-IVB", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 87, .target_residency = 300, } @@ -191,44 +204,32 @@ static const struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = { { /* MWAIT C0 */ }, { /* MWAIT C1 */ .name = "C1-ATM", + .flags = MWAIT2flg(0x00), .exit_latency = 1, .target_residency = 4, }, { /* MWAIT C2 */ .name = "C2-ATM", + .flags = MWAIT2flg(0x10), .exit_latency = 20, .target_residency = 80, }, { /* MWAIT C3 */ }, { /* MWAIT C4 */ .name = "C4-ATM", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 100, .target_residency = 400, }, { /* MWAIT C5 */ }, { /* MWAIT C6 */ .name = "C6-ATM", - .flags = CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED, .exit_latency = 140, .target_residency = 560, } }; -static u32 get_driver_data(unsigned int cstate) -{ - static const u32 driver_data[] = { - [1] /* MWAIT C1 */ = 0x00, - [2] /* MWAIT C2 */ = 0x10, - [3] /* MWAIT C3 */ = 0x20, - [4] /* MWAIT C4 */ = 0x30, - [5] /* MWAIT C5 */ = 0x40, - [6] /* MWAIT C6 */ = 0x52, - }; - - return driver_data[cstate < ARRAY_SIZE(driver_data) ? cstate : 0]; -} - static void mwait_idle(void) { unsigned int cpu = smp_processor_id(); @@ -477,7 +478,7 @@ static int mwait_idle_cpu_init(struct notifier_block *nfb, cx = dev->states + dev->count; cx->type = cstate; - cx->address = get_driver_data(cstate); + cx->address = flg2MWAIT(cpuidle_state_table[cstate].flags); cx->entry_method = ACPI_CSTATE_EM_FFH; cx->latency = cpuidle_state_table[cstate].exit_latency; cx->target_residency =