include/asm/epapr_hcalls.h

0001 /*
0002  * ePAPR hcall interface
0003  *
0004  * Copyright 2008-2011 Freescale Semiconductor, Inc.
0005  *
0006  * Author: Timur Tabi <timur@freescale.com>
0007  *
0008  * This file is provided under a dual BSD/GPL license.  When using or
0009  * redistributing this file, you may do so under either license.
0010  *
0011  * Redistribution and use in source and binary forms, with or without
0012  * modification, are permitted provided that the following conditions are met:
0013  *     * Redistributions of source code must retain the above copyright
0014  *       notice, this list of conditions and the following disclaimer.
0015  *     * Redistributions in binary form must reproduce the above copyright
0016  *       notice, this list of conditions and the following disclaimer in the
0017  *       documentation and/or other materials provided with the distribution.
0018  *     * Neither the name of Freescale Semiconductor nor the
0019  *       names of its contributors may be used to endorse or promote products
0020  *       derived from this software without specific prior written permission.
0021  *
0022  *
0023  * ALTERNATIVELY, this software may be distributed under the terms of the
0024  * GNU General Public License ("GPL") as published by the Free Software
0025  * Foundation, either version 2 of that License or (at your option) any
0026  * later version.
0027  *
0028  * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
0029  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
0030  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
0031  * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
0032  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
0033  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
0034  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
0035  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
0036  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
0037  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
0038  */
0039
0040 /* A "hypercall" is an "sc 1" instruction.  This header file provides C
0041  * wrapper functions for the ePAPR hypervisor interface.  It is inteded
0042  * for use by Linux device drivers and other operating systems.
0043  *
0044  * The hypercalls are implemented as inline assembly, rather than assembly
0045  * language functions in a .S file, for optimization.  It allows
0046  * the caller to issue the hypercall instruction directly, improving both
0047  * performance and memory footprint.
0048  */
0049
0050 #ifndef _EPAPR_HCALLS_H
0051 #define _EPAPR_HCALLS_H
0052
0053 #include <uapi/asm/epapr_hcalls.h>
0054
0055 #ifndef __ASSEMBLY__
0056 #include <linux/types.h>
0057 #include <linux/errno.h>
0058 #include <asm/byteorder.h>
0059
0060 /*
0061  * Hypercall register clobber list
0062  *
0063  * These macros are used to define the list of clobbered registers during a
0064  * hypercall.  Technically, registers r0 and r3-r12 are always clobbered,
0065  * but the gcc inline assembly syntax does not allow us to specify registers
0066  * on the clobber list that are also on the input/output list.  Therefore,
0067  * the lists of clobbered registers depends on the number of register
0068  * parameters ("+r" and "=r") passed to the hypercall.
0069  *
0070  * Each assembly block should use one of the HCALL_CLOBBERSx macros.  As a
0071  * general rule, 'x' is the number of parameters passed to the assembly
0072  * block *except* for r11.
0073  *
0074  * If you're not sure, just use the smallest value of 'x' that does not
0075  * generate a compilation error.  Because these are static inline functions,
0076  * the compiler will only check the clobber list for a function if you
0077  * compile code that calls that function.
0078  *
0079  * r3 and r11 are not included in any clobbers list because they are always
0080  * listed as output registers.
0081  *
0082  * XER, CTR, and LR are currently listed as clobbers because it's uncertain
0083  * whether they will be clobbered.
0084  *
0085  * Note that r11 can be used as an output parameter.
0086  *
0087  * The "memory" clobber is only necessary for hcalls where the Hypervisor
0088  * will read or write guest memory. However, we add it to all hcalls because
0089  * the impact is minimal, and we want to ensure that it's present for the
0090  * hcalls that need it.
0091 */
0092
0093 /* List of common clobbered registers.  Do not use this macro. */
0094 #define EV_HCALL_CLOBBERS "r0", "r12", "xer", "ctr", "lr", "cc", "memory"
0095
0096 #define EV_HCALL_CLOBBERS8 EV_HCALL_CLOBBERS
0097 #define EV_HCALL_CLOBBERS7 EV_HCALL_CLOBBERS8, "r10"
0098 #define EV_HCALL_CLOBBERS6 EV_HCALL_CLOBBERS7, "r9"
0099 #define EV_HCALL_CLOBBERS5 EV_HCALL_CLOBBERS6, "r8"
0100 #define EV_HCALL_CLOBBERS4 EV_HCALL_CLOBBERS5, "r7"
0101 #define EV_HCALL_CLOBBERS3 EV_HCALL_CLOBBERS4, "r6"
0102 #define EV_HCALL_CLOBBERS2 EV_HCALL_CLOBBERS3, "r5"
0103 #define EV_HCALL_CLOBBERS1 EV_HCALL_CLOBBERS2, "r4"
0104
0105 extern bool epapr_paravirt_enabled;
0106 extern u32 epapr_hypercall_start[];
0107
0108 #ifdef CONFIG_EPAPR_PARAVIRT
0109 int __init epapr_paravirt_early_init(void);
0110 #else
0111 static inline int epapr_paravirt_early_init(void) { return 0; }
0112 #endif
0113
0114 /*
0115  * We use "uintptr_t" to define a register because it's guaranteed to be a
0116  * 32-bit integer on a 32-bit platform, and a 64-bit integer on a 64-bit
0117  * platform.
0118  *
0119  * All registers are either input/output or output only.  Registers that are
0120  * initialized before making the hypercall are input/output.  All
0121  * input/output registers are represented with "+r".  Output-only registers
0122  * are represented with "=r".  Do not specify any unused registers.  The
0123  * clobber list will tell the compiler that the hypercall modifies those
0124  * registers, which is good enough.
0125  */
0126
0127 /**
0128  * ev_int_set_config - configure the specified interrupt
0129  * @interrupt: the interrupt number
0130  * @config: configuration for this interrupt
0131  * @priority: interrupt priority
0132  * @destination: destination CPU number
0133  *
0134  * Returns 0 for success, or an error code.
0135  */
0136 static inline unsigned int ev_int_set_config(unsigned int interrupt,
0137     uint32_t config, unsigned int priority, uint32_t destination)
0138 {
0139     register uintptr_t r11 __asm__("r11");
0140     register uintptr_t r3 __asm__("r3");
0141     register uintptr_t r4 __asm__("r4");
0142     register uintptr_t r5 __asm__("r5");
0143     register uintptr_t r6 __asm__("r6");
0144
0145     r11 = EV_HCALL_TOKEN(EV_INT_SET_CONFIG);
0146     r3  = interrupt;
0147     r4  = config;
0148     r5  = priority;
0149     r6  = destination;
0150
0151     asm volatile("bl    epapr_hypercall_start"
0152         : "+r" (r11), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6)
0153         : : EV_HCALL_CLOBBERS4
0154     );
0155
0156     return r3;
0157 }
0158
0159 /**
0160  * ev_int_get_config - return the config of the specified interrupt
0161  * @interrupt: the interrupt number
0162  * @config: returned configuration for this interrupt
0163  * @priority: returned interrupt priority
0164  * @destination: returned destination CPU number
0165  *
0166  * Returns 0 for success, or an error code.
0167  */
0168 static inline unsigned int ev_int_get_config(unsigned int interrupt,
0169     uint32_t *config, unsigned int *priority, uint32_t *destination)
0170 {
0171     register uintptr_t r11 __asm__("r11");
0172     register uintptr_t r3 __asm__("r3");
0173     register uintptr_t r4 __asm__("r4");
0174     register uintptr_t r5 __asm__("r5");
0175     register uintptr_t r6 __asm__("r6");
0176
0177     r11 = EV_HCALL_TOKEN(EV_INT_GET_CONFIG);
0178     r3 = interrupt;
0179
0180     asm volatile("bl    epapr_hypercall_start"
0181         : "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5), "=r" (r6)
0182         : : EV_HCALL_CLOBBERS4
0183     );
0184
0185     *config = r4;
0186     *priority = r5;
0187     *destination = r6;
0188
0189     return r3;
0190 }
0191
0192 /**
0193  * ev_int_set_mask - sets the mask for the specified interrupt source
0194  * @interrupt: the interrupt number
0195  * @mask: 0=enable interrupts, 1=disable interrupts
0196  *
0197  * Returns 0 for success, or an error code.
0198  */
0199 static inline unsigned int ev_int_set_mask(unsigned int interrupt,
0200     unsigned int mask)
0201 {
0202     register uintptr_t r11 __asm__("r11");
0203     register uintptr_t r3 __asm__("r3");
0204     register uintptr_t r4 __asm__("r4");
0205
0206     r11 = EV_HCALL_TOKEN(EV_INT_SET_MASK);
0207     r3 = interrupt;
0208     r4 = mask;
0209
0210     asm volatile("bl    epapr_hypercall_start"
0211         : "+r" (r11), "+r" (r3), "+r" (r4)
0212         : : EV_HCALL_CLOBBERS2
0213     );
0214
0215     return r3;
0216 }
0217
0218 /**
0219  * ev_int_get_mask - returns the mask for the specified interrupt source
0220  * @interrupt: the interrupt number
0221  * @mask: returned mask for this interrupt (0=enabled, 1=disabled)
0222  *
0223  * Returns 0 for success, or an error code.
0224  */
0225 static inline unsigned int ev_int_get_mask(unsigned int interrupt,
0226     unsigned int *mask)
0227 {
0228     register uintptr_t r11 __asm__("r11");
0229     register uintptr_t r3 __asm__("r3");
0230     register uintptr_t r4 __asm__("r4");
0231
0232     r11 = EV_HCALL_TOKEN(EV_INT_GET_MASK);
0233     r3 = interrupt;
0234
0235     asm volatile("bl    epapr_hypercall_start"
0236         : "+r" (r11), "+r" (r3), "=r" (r4)
0237         : : EV_HCALL_CLOBBERS2
0238     );
0239
0240     *mask = r4;
0241
0242     return r3;
0243 }
0244
0245 /**
0246  * ev_int_eoi - signal the end of interrupt processing
0247  * @interrupt: the interrupt number
0248  *
0249  * This function signals the end of processing for the specified
0250  * interrupt, which must be the interrupt currently in service. By
0251  * definition, this is also the highest-priority interrupt.
0252  *
0253  * Returns 0 for success, or an error code.
0254  */
0255 static inline unsigned int ev_int_eoi(unsigned int interrupt)
0256 {
0257     register uintptr_t r11 __asm__("r11");
0258     register uintptr_t r3 __asm__("r3");
0259
0260     r11 = EV_HCALL_TOKEN(EV_INT_EOI);
0261     r3 = interrupt;
0262
0263     asm volatile("bl    epapr_hypercall_start"
0264         : "+r" (r11), "+r" (r3)
0265         : : EV_HCALL_CLOBBERS1
0266     );
0267
0268     return r3;
0269 }
0270
0271 /**
0272  * ev_byte_channel_send - send characters to a byte stream
0273  * @handle: byte stream handle
0274  * @count: (input) num of chars to send, (output) num chars sent
0275  * @buffer: pointer to a 16-byte buffer
0276  *
0277  * @buffer must be at least 16 bytes long, because all 16 bytes will be
0278  * read from memory into registers, even if count < 16.
0279  *
0280  * Returns 0 for success, or an error code.
0281  */
0282 static inline unsigned int ev_byte_channel_send(unsigned int handle,
0283     unsigned int *count, const char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
0284 {
0285     register uintptr_t r11 __asm__("r11");
0286     register uintptr_t r3 __asm__("r3");
0287     register uintptr_t r4 __asm__("r4");
0288     register uintptr_t r5 __asm__("r5");
0289     register uintptr_t r6 __asm__("r6");
0290     register uintptr_t r7 __asm__("r7");
0291     register uintptr_t r8 __asm__("r8");
0292     const uint32_t *p = (const uint32_t *) buffer;
0293
0294     r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_SEND);
0295     r3 = handle;
0296     r4 = *count;
0297     r5 = be32_to_cpu(p[0]);
0298     r6 = be32_to_cpu(p[1]);
0299     r7 = be32_to_cpu(p[2]);
0300     r8 = be32_to_cpu(p[3]);
0301
0302     asm volatile("bl    epapr_hypercall_start"
0303         : "+r" (r11), "+r" (r3),
0304           "+r" (r4), "+r" (r5), "+r" (r6), "+r" (r7), "+r" (r8)
0305         : : EV_HCALL_CLOBBERS6
0306     );
0307
0308     *count = r4;
0309
0310     return r3;
0311 }
0312
0313 /**
0314  * ev_byte_channel_receive - fetch characters from a byte channel
0315  * @handle: byte channel handle
0316  * @count: (input) max num of chars to receive, (output) num chars received
0317  * @buffer: pointer to a 16-byte buffer
0318  *
0319  * The size of @buffer must be at least 16 bytes, even if you request fewer
0320  * than 16 characters, because we always write 16 bytes to @buffer.  This is
0321  * for performance reasons.
0322  *
0323  * Returns 0 for success, or an error code.
0324  */
0325 static inline unsigned int ev_byte_channel_receive(unsigned int handle,
0326     unsigned int *count, char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
0327 {
0328     register uintptr_t r11 __asm__("r11");
0329     register uintptr_t r3 __asm__("r3");
0330     register uintptr_t r4 __asm__("r4");
0331     register uintptr_t r5 __asm__("r5");
0332     register uintptr_t r6 __asm__("r6");
0333     register uintptr_t r7 __asm__("r7");
0334     register uintptr_t r8 __asm__("r8");
0335     uint32_t *p = (uint32_t *) buffer;
0336
0337     r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_RECEIVE);
0338     r3 = handle;
0339     r4 = *count;
0340
0341     asm volatile("bl    epapr_hypercall_start"
0342         : "+r" (r11), "+r" (r3), "+r" (r4),
0343           "=r" (r5), "=r" (r6), "=r" (r7), "=r" (r8)
0344         : : EV_HCALL_CLOBBERS6
0345     );
0346
0347     *count = r4;
0348     p[0] = cpu_to_be32(r5);
0349     p[1] = cpu_to_be32(r6);
0350     p[2] = cpu_to_be32(r7);
0351     p[3] = cpu_to_be32(r8);
0352
0353     return r3;
0354 }
0355
0356 /**
0357  * ev_byte_channel_poll - returns the status of the byte channel buffers
0358  * @handle: byte channel handle
0359  * @rx_count: returned count of bytes in receive queue
0360  * @tx_count: returned count of free space in transmit queue
0361  *
0362  * This function reports the amount of data in the receive queue (i.e. the
0363  * number of bytes you can read), and the amount of free space in the transmit
0364  * queue (i.e. the number of bytes you can write).
0365  *
0366  * Returns 0 for success, or an error code.
0367  */
0368 static inline unsigned int ev_byte_channel_poll(unsigned int handle,
0369     unsigned int *rx_count, unsigned int *tx_count)
0370 {
0371     register uintptr_t r11 __asm__("r11");
0372     register uintptr_t r3 __asm__("r3");
0373     register uintptr_t r4 __asm__("r4");
0374     register uintptr_t r5 __asm__("r5");
0375
0376     r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_POLL);
0377     r3 = handle;
0378
0379     asm volatile("bl    epapr_hypercall_start"
0380         : "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5)
0381         : : EV_HCALL_CLOBBERS3
0382     );
0383
0384     *rx_count = r4;
0385     *tx_count = r5;
0386
0387     return r3;
0388 }
0389
0390 /**
0391  * ev_int_iack - acknowledge an interrupt
0392  * @handle: handle to the target interrupt controller
0393  * @vector: returned interrupt vector
0394  *
0395  * If handle is zero, the function returns the next interrupt source
0396  * number to be handled irrespective of the hierarchy or cascading
0397  * of interrupt controllers. If non-zero, specifies a handle to the
0398  * interrupt controller that is the target of the acknowledge.
0399  *
0400  * Returns 0 for success, or an error code.
0401  */
0402 static inline unsigned int ev_int_iack(unsigned int handle,
0403     unsigned int *vector)
0404 {
0405     register uintptr_t r11 __asm__("r11");
0406     register uintptr_t r3 __asm__("r3");
0407     register uintptr_t r4 __asm__("r4");
0408
0409     r11 = EV_HCALL_TOKEN(EV_INT_IACK);
0410     r3 = handle;
0411
0412     asm volatile("bl    epapr_hypercall_start"
0413         : "+r" (r11), "+r" (r3), "=r" (r4)
0414         : : EV_HCALL_CLOBBERS2
0415     );
0416
0417     *vector = r4;
0418
0419     return r3;
0420 }
0421
0422 /**
0423  * ev_doorbell_send - send a doorbell to another partition
0424  * @handle: doorbell send handle
0425  *
0426  * Returns 0 for success, or an error code.
0427  */
0428 static inline unsigned int ev_doorbell_send(unsigned int handle)
0429 {
0430     register uintptr_t r11 __asm__("r11");
0431     register uintptr_t r3 __asm__("r3");
0432
0433     r11 = EV_HCALL_TOKEN(EV_DOORBELL_SEND);
0434     r3 = handle;
0435
0436     asm volatile("bl    epapr_hypercall_start"
0437         : "+r" (r11), "+r" (r3)
0438         : : EV_HCALL_CLOBBERS1
0439     );
0440
0441     return r3;
0442 }
0443
0444 /**
0445  * ev_idle -- wait for next interrupt on this core
0446  *
0447  * Returns 0 for success, or an error code.
0448  */
0449 static inline unsigned int ev_idle(void)
0450 {
0451     register uintptr_t r11 __asm__("r11");
0452     register uintptr_t r3 __asm__("r3");
0453
0454     r11 = EV_HCALL_TOKEN(EV_IDLE);
0455
0456     asm volatile("bl    epapr_hypercall_start"
0457         : "+r" (r11), "=r" (r3)
0458         : : EV_HCALL_CLOBBERS1
0459     );
0460
0461     return r3;
0462 }
0463
0464 #ifdef CONFIG_EPAPR_PARAVIRT
0465 static inline unsigned long epapr_hypercall(unsigned long *in,
0466                 unsigned long *out,
0467                 unsigned long nr)
0468 {
0469     register unsigned long r0 asm("r0");
0470     register unsigned long r3 asm("r3") = in[0];
0471     register unsigned long r4 asm("r4") = in[1];
0472     register unsigned long r5 asm("r5") = in[2];
0473     register unsigned long r6 asm("r6") = in[3];
0474     register unsigned long r7 asm("r7") = in[4];
0475     register unsigned long r8 asm("r8") = in[5];
0476     register unsigned long r9 asm("r9") = in[6];
0477     register unsigned long r10 asm("r10") = in[7];
0478     register unsigned long r11 asm("r11") = nr;
0479     register unsigned long r12 asm("r12");
0480
0481     asm volatile("bl    epapr_hypercall_start"
0482              : "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
0483                "=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
0484                "=r"(r12)
0485              : "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "r"(r8),
0486                "r"(r9), "r"(r10), "r"(r11)
0487              : "memory", "cc", "xer", "ctr", "lr");
0488
0489     out[0] = r4;
0490     out[1] = r5;
0491     out[2] = r6;
0492     out[3] = r7;
0493     out[4] = r8;
0494     out[5] = r9;
0495     out[6] = r10;
0496     out[7] = r11;
0497
0498     return r3;
0499 }
0500 #else
0501 static unsigned long epapr_hypercall(unsigned long *in,
0502                    unsigned long *out,
0503                    unsigned long nr)
0504 {
0505     return EV_UNIMPLEMENTED;
0506 }
0507 #endif
0508
0509 static inline long epapr_hypercall0_1(unsigned int nr, unsigned long *r2)
0510 {
0511     unsigned long in[8] = {0};
0512     unsigned long out[8];
0513     unsigned long r;
0514
0515     r = epapr_hypercall(in, out, nr);
0516     *r2 = out[0];
0517
0518     return r;
0519 }
0520
0521 static inline long epapr_hypercall0(unsigned int nr)
0522 {
0523     unsigned long in[8] = {0};
0524     unsigned long out[8];
0525
0526     return epapr_hypercall(in, out, nr);
0527 }
0528
0529 static inline long epapr_hypercall1(unsigned int nr, unsigned long p1)
0530 {
0531     unsigned long in[8] = {0};
0532     unsigned long out[8];
0533
0534     in[0] = p1;
0535     return epapr_hypercall(in, out, nr);
0536 }
0537
0538 static inline long epapr_hypercall2(unsigned int nr, unsigned long p1,
0539                     unsigned long p2)
0540 {
0541     unsigned long in[8] = {0};
0542     unsigned long out[8];
0543
0544     in[0] = p1;
0545     in[1] = p2;
0546     return epapr_hypercall(in, out, nr);
0547 }
0548
0549 static inline long epapr_hypercall3(unsigned int nr, unsigned long p1,
0550                     unsigned long p2, unsigned long p3)
0551 {
0552     unsigned long in[8] = {0};
0553     unsigned long out[8];
0554
0555     in[0] = p1;
0556     in[1] = p2;
0557     in[2] = p3;
0558     return epapr_hypercall(in, out, nr);
0559 }
0560
0561 static inline long epapr_hypercall4(unsigned int nr, unsigned long p1,
0562                     unsigned long p2, unsigned long p3,
0563                     unsigned long p4)
0564 {
0565     unsigned long in[8] = {0};
0566     unsigned long out[8];
0567
0568     in[0] = p1;
0569     in[1] = p2;
0570     in[2] = p3;
0571     in[3] = p4;
0572     return epapr_hypercall(in, out, nr);
0573 }
0574 #endif /* !__ASSEMBLY__ */
0575 #endif /* _EPAPR_HCALLS_H */