diff options
author | Rafa Bilski <rafalbilski@interia.pl> | 2007-02-08 18:56:04 +0100 |
---|---|---|
committer | Dave Jones <davej@redhat.com> | 2007-02-10 20:05:50 -0500 |
commit | 348f31ed2bd18391fe5903aa0ad7bfcda6d8ca0b (patch) | |
tree | 1752aedc8f7780cef02688e4df386a93188c700b /arch/i386/kernel/cpu/cpufreq/longhaul.c | |
parent | e57501c15f48d6b7a8fe2b023be8f4779484482d (diff) | |
download | lwn-348f31ed2bd18391fe5903aa0ad7bfcda6d8ca0b.tar.gz lwn-348f31ed2bd18391fe5903aa0ad7bfcda6d8ca0b.zip |
[CPUFREQ] Longhaul - Separate frequency and voltage transition
This change should make Longhaul more compatible with
both ver. 2 and Powersaver processors. Voltage transitions
will be done before or after frequency transition. That depends
on direction of change. I don't know how to force conservative
governor when voltage scaling is enabled, so there is only
a warning for user. Minimal voltage is calculated in different
way now because in this way more power is saved at lower
multipliers.
Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'arch/i386/kernel/cpu/cpufreq/longhaul.c')
-rw-r--r-- | arch/i386/kernel/cpu/cpufreq/longhaul.c | 109 |
1 files changed, 93 insertions, 16 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/i386/kernel/cpu/cpufreq/longhaul.c index fc9afbb7c1fc..8f40cb47720e 100644 --- a/arch/i386/kernel/cpu/cpufreq/longhaul.c +++ b/arch/i386/kernel/cpu/cpufreq/longhaul.c @@ -65,7 +65,8 @@ static unsigned int fsb; static struct mV_pos *vrm_mV_table; static unsigned char *mV_vrm_table; struct f_msr { - unsigned char vrm; + u8 vrm; + u8 pos; }; static struct f_msr f_msr_table[32]; @@ -75,6 +76,7 @@ static int can_scale_voltage; static struct acpi_processor *pr = NULL; static struct acpi_processor_cx *cx = NULL; static u8 longhaul_flags; +static u8 longhaul_pos; /* Module parameters */ static int scale_voltage; @@ -165,26 +167,47 @@ static void do_longhaul1(unsigned int clock_ratio_index) static void do_powersaver(int cx_address, unsigned int clock_ratio_index) { union msr_longhaul longhaul; + u8 dest_pos; u32 t; + dest_pos = f_msr_table[clock_ratio_index].pos; + rdmsrl(MSR_VIA_LONGHAUL, longhaul.val); + /* Setup new frequency */ longhaul.bits.RevisionKey = longhaul.bits.RevisionID; longhaul.bits.SoftBusRatio = clock_ratio_index & 0xf; longhaul.bits.SoftBusRatio4 = (clock_ratio_index & 0x10) >> 4; - longhaul.bits.EnableSoftBusRatio = 1; - - if (can_scale_voltage) { + /* Setup new voltage */ + if (can_scale_voltage) longhaul.bits.SoftVID = f_msr_table[clock_ratio_index].vrm; + /* Sync to timer tick */ + safe_halt(); + /* Raise voltage if necessary */ + if (can_scale_voltage && longhaul_pos < dest_pos) { longhaul.bits.EnableSoftVID = 1; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + /* Change voltage */ + if (!cx_address) { + ACPI_FLUSH_CPU_CACHE(); + halt(); + } else { + ACPI_FLUSH_CPU_CACHE(); + /* Invoke C3 */ + inb(cx_address); + /* Dummy op - must do something useless after P_LVL3 + * read */ + t = inl(acpi_fadt.xpm_tmr_blk.address); + } + longhaul.bits.EnableSoftVID = 0; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + longhaul_pos = dest_pos; } - /* Sync to timer tick */ - safe_halt(); /* Change frequency on next halt or sleep */ + longhaul.bits.EnableSoftBusRatio = 1; wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); if (!cx_address) { ACPI_FLUSH_CPU_CACHE(); - /* Invoke C1 */ halt(); } else { ACPI_FLUSH_CPU_CACHE(); @@ -194,12 +217,29 @@ static void do_powersaver(int cx_address, unsigned int clock_ratio_index) t = inl(acpi_fadt.xpm_tmr_blk.address); } /* Disable bus ratio bit */ - local_irq_disable(); - longhaul.bits.RevisionKey = longhaul.bits.RevisionID; longhaul.bits.EnableSoftBusRatio = 0; - longhaul.bits.EnableSoftBSEL = 0; - longhaul.bits.EnableSoftVID = 0; wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + + /* Reduce voltage if necessary */ + if (can_scale_voltage && longhaul_pos > dest_pos) { + longhaul.bits.EnableSoftVID = 1; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + /* Change voltage */ + if (!cx_address) { + ACPI_FLUSH_CPU_CACHE(); + halt(); + } else { + ACPI_FLUSH_CPU_CACHE(); + /* Invoke C3 */ + inb(cx_address); + /* Dummy op - must do something useless after P_LVL3 + * read */ + t = inl(acpi_fadt.xpm_tmr_blk.address); + } + longhaul.bits.EnableSoftVID = 0; + wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); + longhaul_pos = dest_pos; + } } /** @@ -420,6 +460,7 @@ static void __init longhaul_setup_voltagescaling(void) union msr_longhaul longhaul; struct mV_pos minvid, maxvid; unsigned int j, speed, pos, kHz_step, numvscales; + int min_vid_speed; rdmsrl(MSR_VIA_LONGHAUL, longhaul.val); if (!(longhaul.bits.RevisionID & 1)) { @@ -439,8 +480,6 @@ static void __init longhaul_setup_voltagescaling(void) minvid = vrm_mV_table[longhaul.bits.MinimumVID]; maxvid = vrm_mV_table[longhaul.bits.MaximumVID]; - numvscales = maxvid.pos - minvid.pos + 1; - kHz_step = (highest_speed - lowest_speed) / numvscales; if (minvid.mV == 0 || maxvid.mV == 0 || minvid.mV > maxvid.mV) { printk (KERN_INFO PFX "Bogus values Min:%d.%03d Max:%d.%03d. " @@ -456,20 +495,58 @@ static void __init longhaul_setup_voltagescaling(void) return; } - printk(KERN_INFO PFX "Max VID=%d.%03d Min VID=%d.%03d, %d possible voltage scales\n", + /* How many voltage steps */ + numvscales = maxvid.pos - minvid.pos + 1; + printk(KERN_INFO PFX + "Max VID=%d.%03d " + "Min VID=%d.%03d, " + "%d possible voltage scales\n", maxvid.mV/1000, maxvid.mV%1000, minvid.mV/1000, minvid.mV%1000, numvscales); - + + /* Calculate max frequency at min voltage */ + j = longhaul.bits.MinMHzBR; + if (longhaul.bits.MinMHzBR4) + j += 16; + min_vid_speed = eblcr_table[j]; + if (min_vid_speed == -1) + return; + switch (longhaul.bits.MinMHzFSB) { + case 0: + min_vid_speed *= 13333; + break; + case 1: + min_vid_speed *= 10000; + break; + case 3: + min_vid_speed *= 6666; + break; + default: + return; + break; + } + if (min_vid_speed >= highest_speed) + return; + /* Calculate kHz for one voltage step */ + kHz_step = (highest_speed - min_vid_speed) / numvscales; + j = 0; while (longhaul_table[j].frequency != CPUFREQ_TABLE_END) { speed = longhaul_table[j].frequency; - pos = (speed - lowest_speed) / kHz_step + minvid.pos; + if (speed > min_vid_speed) + pos = (speed - min_vid_speed) / kHz_step + minvid.pos; + else + pos = minvid.pos; f_msr_table[longhaul_table[j].index].vrm = mV_vrm_table[pos]; + f_msr_table[longhaul_table[j].index].pos = pos; j++; } + longhaul_pos = maxvid.pos; can_scale_voltage = 1; + printk(KERN_INFO PFX "Voltage scaling enabled. " + "Use of \"conservative\" governor is highly recommended.\n"); } |