ia64/linux-2.6.18-xen.hg

view drivers/serial/ip22zilog.h @ 897:329ea0ccb344

balloon: try harder to balloon up under memory pressure.

Currently if the balloon driver is unable to increase the guest's
reservation it assumes the failure was due to reaching its full
allocation, gives up on the ballooning operation and records the limit
it reached as the "hard limit". The driver will not try again until
the target is set again (even to the same value).

However it is possible that ballooning has in fact failed due to
memory pressure in the host and therefore it is desirable to keep
attempting to reach the target in case memory becomes available. The
most likely scenario is that some guests are ballooning down while
others are ballooning up and therefore there is temporary memory
pressure while things stabilise. You would not expect a well behaved
toolstack to ask a domain to balloon to more than its allocation nor
would you expect it to deliberately over-commit memory by setting
balloon targets which exceed the total host memory.

This patch drops the concept of a hard limit and causes the balloon
driver to retry increasing the reservation on a timer in the same
manner as when decreasing the reservation.

Also if we partially succeed in increasing the reservation
(i.e. receive less pages than we asked for) then we may as well keep
those pages rather than returning them to Xen.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Fri Jun 05 14:01:20 2009 +0100 (2009-06-05)
parents 831230e53067
children
line source
1 #ifndef _IP22_ZILOG_H
2 #define _IP22_ZILOG_H
4 #include <asm/byteorder.h>
6 struct zilog_channel {
7 #ifdef __BIG_ENDIAN
8 volatile unsigned char unused0[3];
9 volatile unsigned char control;
10 volatile unsigned char unused1[3];
11 volatile unsigned char data;
12 #else /* __LITTLE_ENDIAN */
13 volatile unsigned char control;
14 volatile unsigned char unused0[3];
15 volatile unsigned char data;
16 volatile unsigned char unused1[3];
17 #endif
18 };
20 struct zilog_layout {
21 struct zilog_channel channelB;
22 struct zilog_channel channelA;
23 };
25 #define NUM_ZSREGS 16
27 /* Conversion routines to/from brg time constants from/to bits
28 * per second.
29 */
30 #define BRG_TO_BPS(brg, freq) ((freq) / 2 / ((brg) + 2))
31 #define BPS_TO_BRG(bps, freq) ((((freq) + (bps)) / (2 * (bps))) - 2)
33 /* The Zilog register set */
35 #define FLAG 0x7e
37 /* Write Register 0 */
38 #define R0 0 /* Register selects */
39 #define R1 1
40 #define R2 2
41 #define R3 3
42 #define R4 4
43 #define R5 5
44 #define R6 6
45 #define R7 7
46 #define R8 8
47 #define R9 9
48 #define R10 10
49 #define R11 11
50 #define R12 12
51 #define R13 13
52 #define R14 14
53 #define R15 15
55 #define NULLCODE 0 /* Null Code */
56 #define POINT_HIGH 0x8 /* Select upper half of registers */
57 #define RES_EXT_INT 0x10 /* Reset Ext. Status Interrupts */
58 #define SEND_ABORT 0x18 /* HDLC Abort */
59 #define RES_RxINT_FC 0x20 /* Reset RxINT on First Character */
60 #define RES_Tx_P 0x28 /* Reset TxINT Pending */
61 #define ERR_RES 0x30 /* Error Reset */
62 #define RES_H_IUS 0x38 /* Reset highest IUS */
64 #define RES_Rx_CRC 0x40 /* Reset Rx CRC Checker */
65 #define RES_Tx_CRC 0x80 /* Reset Tx CRC Checker */
66 #define RES_EOM_L 0xC0 /* Reset EOM latch */
68 /* Write Register 1 */
70 #define EXT_INT_ENAB 0x1 /* Ext Int Enable */
71 #define TxINT_ENAB 0x2 /* Tx Int Enable */
72 #define PAR_SPEC 0x4 /* Parity is special condition */
74 #define RxINT_DISAB 0 /* Rx Int Disable */
75 #define RxINT_FCERR 0x8 /* Rx Int on First Character Only or Error */
76 #define INT_ALL_Rx 0x10 /* Int on all Rx Characters or error */
77 #define INT_ERR_Rx 0x18 /* Int on error only */
78 #define RxINT_MASK 0x18
80 #define WT_RDY_RT 0x20 /* Wait/Ready on R/T */
81 #define WT_FN_RDYFN 0x40 /* Wait/FN/Ready FN */
82 #define WT_RDY_ENAB 0x80 /* Wait/Ready Enable */
84 /* Write Register #2 (Interrupt Vector) */
86 /* Write Register 3 */
88 #define RxENAB 0x1 /* Rx Enable */
89 #define SYNC_L_INH 0x2 /* Sync Character Load Inhibit */
90 #define ADD_SM 0x4 /* Address Search Mode (SDLC) */
91 #define RxCRC_ENAB 0x8 /* Rx CRC Enable */
92 #define ENT_HM 0x10 /* Enter Hunt Mode */
93 #define AUTO_ENAB 0x20 /* Auto Enables */
94 #define Rx5 0x0 /* Rx 5 Bits/Character */
95 #define Rx7 0x40 /* Rx 7 Bits/Character */
96 #define Rx6 0x80 /* Rx 6 Bits/Character */
97 #define Rx8 0xc0 /* Rx 8 Bits/Character */
98 #define RxN_MASK 0xc0
100 /* Write Register 4 */
102 #define PAR_ENAB 0x1 /* Parity Enable */
103 #define PAR_EVEN 0x2 /* Parity Even/Odd* */
105 #define SYNC_ENAB 0 /* Sync Modes Enable */
106 #define SB1 0x4 /* 1 stop bit/char */
107 #define SB15 0x8 /* 1.5 stop bits/char */
108 #define SB2 0xc /* 2 stop bits/char */
110 #define MONSYNC 0 /* 8 Bit Sync character */
111 #define BISYNC 0x10 /* 16 bit sync character */
112 #define SDLC 0x20 /* SDLC Mode (01111110 Sync Flag) */
113 #define EXTSYNC 0x30 /* External Sync Mode */
115 #define X1CLK 0x0 /* x1 clock mode */
116 #define X16CLK 0x40 /* x16 clock mode */
117 #define X32CLK 0x80 /* x32 clock mode */
118 #define X64CLK 0xC0 /* x64 clock mode */
119 #define XCLK_MASK 0xC0
121 /* Write Register 5 */
123 #define TxCRC_ENAB 0x1 /* Tx CRC Enable */
124 #define RTS 0x2 /* RTS */
125 #define SDLC_CRC 0x4 /* SDLC/CRC-16 */
126 #define TxENAB 0x8 /* Tx Enable */
127 #define SND_BRK 0x10 /* Send Break */
128 #define Tx5 0x0 /* Tx 5 bits (or less)/character */
129 #define Tx7 0x20 /* Tx 7 bits/character */
130 #define Tx6 0x40 /* Tx 6 bits/character */
131 #define Tx8 0x60 /* Tx 8 bits/character */
132 #define TxN_MASK 0x60
133 #define DTR 0x80 /* DTR */
135 /* Write Register 6 (Sync bits 0-7/SDLC Address Field) */
137 /* Write Register 7 (Sync bits 8-15/SDLC 01111110) */
139 /* Write Register 8 (transmit buffer) */
141 /* Write Register 9 (Master interrupt control) */
142 #define VIS 1 /* Vector Includes Status */
143 #define NV 2 /* No Vector */
144 #define DLC 4 /* Disable Lower Chain */
145 #define MIE 8 /* Master Interrupt Enable */
146 #define STATHI 0x10 /* Status high */
147 #define NORESET 0 /* No reset on write to R9 */
148 #define CHRB 0x40 /* Reset channel B */
149 #define CHRA 0x80 /* Reset channel A */
150 #define FHWRES 0xc0 /* Force hardware reset */
152 /* Write Register 10 (misc control bits) */
153 #define BIT6 1 /* 6 bit/8bit sync */
154 #define LOOPMODE 2 /* SDLC Loop mode */
155 #define ABUNDER 4 /* Abort/flag on SDLC xmit underrun */
156 #define MARKIDLE 8 /* Mark/flag on idle */
157 #define GAOP 0x10 /* Go active on poll */
158 #define NRZ 0 /* NRZ mode */
159 #define NRZI 0x20 /* NRZI mode */
160 #define FM1 0x40 /* FM1 (transition = 1) */
161 #define FM0 0x60 /* FM0 (transition = 0) */
162 #define CRCPS 0x80 /* CRC Preset I/O */
164 /* Write Register 11 (Clock Mode control) */
165 #define TRxCXT 0 /* TRxC = Xtal output */
166 #define TRxCTC 1 /* TRxC = Transmit clock */
167 #define TRxCBR 2 /* TRxC = BR Generator Output */
168 #define TRxCDP 3 /* TRxC = DPLL output */
169 #define TRxCOI 4 /* TRxC O/I */
170 #define TCRTxCP 0 /* Transmit clock = RTxC pin */
171 #define TCTRxCP 8 /* Transmit clock = TRxC pin */
172 #define TCBR 0x10 /* Transmit clock = BR Generator output */
173 #define TCDPLL 0x18 /* Transmit clock = DPLL output */
174 #define RCRTxCP 0 /* Receive clock = RTxC pin */
175 #define RCTRxCP 0x20 /* Receive clock = TRxC pin */
176 #define RCBR 0x40 /* Receive clock = BR Generator output */
177 #define RCDPLL 0x60 /* Receive clock = DPLL output */
178 #define RTxCX 0x80 /* RTxC Xtal/No Xtal */
180 /* Write Register 12 (lower byte of baud rate generator time constant) */
182 /* Write Register 13 (upper byte of baud rate generator time constant) */
184 /* Write Register 14 (Misc control bits) */
185 #define BRENAB 1 /* Baud rate generator enable */
186 #define BRSRC 2 /* Baud rate generator source */
187 #define DTRREQ 4 /* DTR/Request function */
188 #define AUTOECHO 8 /* Auto Echo */
189 #define LOOPBAK 0x10 /* Local loopback */
190 #define SEARCH 0x20 /* Enter search mode */
191 #define RMC 0x40 /* Reset missing clock */
192 #define DISDPLL 0x60 /* Disable DPLL */
193 #define SSBR 0x80 /* Set DPLL source = BR generator */
194 #define SSRTxC 0xa0 /* Set DPLL source = RTxC */
195 #define SFMM 0xc0 /* Set FM mode */
196 #define SNRZI 0xe0 /* Set NRZI mode */
198 /* Write Register 15 (external/status interrupt control) */
199 #define ZCIE 2 /* Zero count IE */
200 #define DCDIE 8 /* DCD IE */
201 #define SYNCIE 0x10 /* Sync/hunt IE */
202 #define CTSIE 0x20 /* CTS IE */
203 #define TxUIE 0x40 /* Tx Underrun/EOM IE */
204 #define BRKIE 0x80 /* Break/Abort IE */
207 /* Read Register 0 */
208 #define Rx_CH_AV 0x1 /* Rx Character Available */
209 #define ZCOUNT 0x2 /* Zero count */
210 #define Tx_BUF_EMP 0x4 /* Tx Buffer empty */
211 #define DCD 0x8 /* DCD */
212 #define SYNC 0x10 /* Sync/hunt */
213 #define CTS 0x20 /* CTS */
214 #define TxEOM 0x40 /* Tx underrun */
215 #define BRK_ABRT 0x80 /* Break/Abort */
217 /* Read Register 1 */
218 #define ALL_SNT 0x1 /* All sent */
219 /* Residue Data for 8 Rx bits/char programmed */
220 #define RES3 0x8 /* 0/3 */
221 #define RES4 0x4 /* 0/4 */
222 #define RES5 0xc /* 0/5 */
223 #define RES6 0x2 /* 0/6 */
224 #define RES7 0xa /* 0/7 */
225 #define RES8 0x6 /* 0/8 */
226 #define RES18 0xe /* 1/8 */
227 #define RES28 0x0 /* 2/8 */
228 /* Special Rx Condition Interrupts */
229 #define PAR_ERR 0x10 /* Parity error */
230 #define Rx_OVR 0x20 /* Rx Overrun Error */
231 #define CRC_ERR 0x40 /* CRC/Framing Error */
232 #define END_FR 0x80 /* End of Frame (SDLC) */
234 /* Read Register 2 (channel b only) - Interrupt vector */
235 #define CHB_Tx_EMPTY 0x00
236 #define CHB_EXT_STAT 0x02
237 #define CHB_Rx_AVAIL 0x04
238 #define CHB_SPECIAL 0x06
239 #define CHA_Tx_EMPTY 0x08
240 #define CHA_EXT_STAT 0x0a
241 #define CHA_Rx_AVAIL 0x0c
242 #define CHA_SPECIAL 0x0e
243 #define STATUS_MASK 0x0e
245 /* Read Register 3 (interrupt pending register) ch a only */
246 #define CHBEXT 0x1 /* Channel B Ext/Stat IP */
247 #define CHBTxIP 0x2 /* Channel B Tx IP */
248 #define CHBRxIP 0x4 /* Channel B Rx IP */
249 #define CHAEXT 0x8 /* Channel A Ext/Stat IP */
250 #define CHATxIP 0x10 /* Channel A Tx IP */
251 #define CHARxIP 0x20 /* Channel A Rx IP */
253 /* Read Register 8 (receive data register) */
255 /* Read Register 10 (misc status bits) */
256 #define ONLOOP 2 /* On loop */
257 #define LOOPSEND 0x10 /* Loop sending */
258 #define CLK2MIS 0x40 /* Two clocks missing */
259 #define CLK1MIS 0x80 /* One clock missing */
261 /* Read Register 12 (lower byte of baud rate generator constant) */
263 /* Read Register 13 (upper byte of baud rate generator constant) */
265 /* Read Register 15 (value of WR 15) */
267 /* Misc macros */
268 #define ZS_CLEARERR(channel) do { writeb(ERR_RES, &channel->control); \
269 udelay(5); } while(0)
271 #define ZS_CLEARSTAT(channel) do { writeb(RES_EXT_INT, &channel->control); \
272 udelay(5); } while(0)
274 #define ZS_CLEARFIFO(channel) do { readb(&channel->data); \
275 udelay(2); \
276 readb(&channel->data); \
277 udelay(2); \
278 readb(&channel->data); \
279 udelay(2); } while(0)
281 #endif /* _IP22_ZILOG_H */