text: /*
   * ePAPR hcall interface
   *
   * Copyright 2008-2011 Freescale Semiconductor, Inc.
   *
   * Author: Timur Tabi <timur@freescale.com>
   *
   * This file is provided under a dual BSD/GPL license.  When using or
   * redistributing this file, you may do so under either license.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above copyright
   *       notice, this list of conditions and the following disclaimer in the
   *       documentation and/or other materials provided with the distribution.
   *     * Neither the name of Freescale Semiconductor nor the
   *       names of its contributors may be used to endorse or promote products
   *       derived from this software without specific prior written permission.
   *
   *
   * ALTERNATIVELY, this software may be distributed under the terms of the
   * GNU General Public License ("GPL") as published by the Free Software
   * Foundation, either version 2 of that License or (at your option) any
   * later version.
   *
   * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  /* A "hypercall" is an "sc 1" instruction.  This header file provides C
   * wrapper functions for the ePAPR hypervisor interface.  It is inteded
   * for use by Linux device drivers and other operating systems.
   *
   * The hypercalls are implemented as inline assembly, rather than assembly
   * language functions in a .S file, for optimization.  It allows
   * the caller to issue the hypercall instruction directly, improving both
   * performance and memory footprint.
   */
  
  #ifndef _EPAPR_HCALLS_H
  #define _EPAPR_HCALLS_H
  
  #include <uapi/asm/epapr_hcalls.h>
  
  #ifndef __ASSEMBLY__
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <asm/byteorder.h>
  
  /*
   * Hypercall register clobber list
   *
   * These macros are used to define the list of clobbered registers during a
   * hypercall.  Technically, registers r0 and r3-r12 are always clobbered,
   * but the gcc inline assembly syntax does not allow us to specify registers
   * on the clobber list that are also on the input/output list.  Therefore,
   * the lists of clobbered registers depends on the number of register
   * parameters ("+r" and "=r") passed to the hypercall.
   *
   * Each assembly block should use one of the HCALL_CLOBBERSx macros.  As a
   * general rule, 'x' is the number of parameters passed to the assembly
   * block *except* for r11.
   *
   * If you're not sure, just use the smallest value of 'x' that does not
   * generate a compilation error.  Because these are static inline functions,
   * the compiler will only check the clobber list for a function if you
   * compile code that calls that function.
   *
   * r3 and r11 are not included in any clobbers list because they are always
   * listed as output registers.
   *
   * XER, CTR, and LR are currently listed as clobbers because it's uncertain
   * whether they will be clobbered.
   *
   * Note that r11 can be used as an output parameter.
   *
   * The "memory" clobber is only necessary for hcalls where the Hypervisor
   * will read or write guest memory. However, we add it to all hcalls because
   * the impact is minimal, and we want to ensure that it's present for the
   * hcalls that need it.
  */
  
  /* List of common clobbered registers.  Do not use this macro. */
  #define EV_HCALL_CLOBBERS "r0", "r12", "xer", "ctr", "lr", "cc", "memory"
  
  #define EV_HCALL_CLOBBERS8 EV_HCALL_CLOBBERS
  #define EV_HCALL_CLOBBERS7 EV_HCALL_CLOBBERS8, "r10"
  #define EV_HCALL_CLOBBERS6 EV_HCALL_CLOBBERS7, "r9"
  #define EV_HCALL_CLOBBERS5 EV_HCALL_CLOBBERS6, "r8"
  #define EV_HCALL_CLOBBERS4 EV_HCALL_CLOBBERS5, "r7"
  #define EV_HCALL_CLOBBERS3 EV_HCALL_CLOBBERS4, "r6"
  #define EV_HCALL_CLOBBERS2 EV_HCALL_CLOBBERS3, "r5"
  #define EV_HCALL_CLOBBERS1 EV_HCALL_CLOBBERS2, "r4"
  
  extern bool epapr_paravirt_enabled;
  extern u32 epapr_hypercall_start[];
  
  #ifdef CONFIG_EPAPR_PARAVIRT
  int __init epapr_paravirt_early_init(void);
  #else
  static inline int epapr_paravirt_early_init(void) { return 0; }
  #endif
  
  /*
   * We use "uintptr_t" to define a register because it's guaranteed to be a
   * 32-bit integer on a 32-bit platform, and a 64-bit integer on a 64-bit
   * platform.
   *
   * All registers are either input/output or output only.  Registers that are
   * initialized before making the hypercall are input/output.  All
   * input/output registers are represented with "+r".  Output-only registers
   * are represented with "=r".  Do not specify any unused registers.  The
   * clobber list will tell the compiler that the hypercall modifies those
   * registers, which is good enough.
   */
  
  /**
   * ev_int_set_config - configure the specified interrupt
   * @interrupt: the interrupt number
   * @config: configuration for this interrupt
   * @priority: interrupt priority
   * @destination: destination CPU number
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_int_set_config(unsigned int interrupt,
  	uint32_t config, unsigned int priority, uint32_t destination)
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  	register uintptr_t r4 __asm__("r4");
  	register uintptr_t r5 __asm__("r5");
  	register uintptr_t r6 __asm__("r6");
  
  	r11 = EV_HCALL_TOKEN(EV_INT_SET_CONFIG);
  	r3  = interrupt;
  	r4  = config;
  	r5  = priority;
  	r6  = destination;
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6)
  		: : EV_HCALL_CLOBBERS4
  	);
  
  	return r3;
  }
  
  /**
   * ev_int_get_config - return the config of the specified interrupt
   * @interrupt: the interrupt number
   * @config: returned configuration for this interrupt
   * @priority: returned interrupt priority
   * @destination: returned destination CPU number
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_int_get_config(unsigned int interrupt,
  	uint32_t *config, unsigned int *priority, uint32_t *destination)
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  	register uintptr_t r4 __asm__("r4");
  	register uintptr_t r5 __asm__("r5");
  	register uintptr_t r6 __asm__("r6");
  
  	r11 = EV_HCALL_TOKEN(EV_INT_GET_CONFIG);
  	r3 = interrupt;
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5), "=r" (r6)
  		: : EV_HCALL_CLOBBERS4
  	);
  
  	*config = r4;
  	*priority = r5;
  	*destination = r6;
  
  	return r3;
  }
  
  /**
   * ev_int_set_mask - sets the mask for the specified interrupt source
   * @interrupt: the interrupt number
   * @mask: 0=enable interrupts, 1=disable interrupts
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_int_set_mask(unsigned int interrupt,
  	unsigned int mask)
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  	register uintptr_t r4 __asm__("r4");
  
  	r11 = EV_HCALL_TOKEN(EV_INT_SET_MASK);
  	r3 = interrupt;
  	r4 = mask;
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3), "+r" (r4)
  		: : EV_HCALL_CLOBBERS2
  	);
  
  	return r3;
  }
  
  /**
   * ev_int_get_mask - returns the mask for the specified interrupt source
   * @interrupt: the interrupt number
   * @mask: returned mask for this interrupt (0=enabled, 1=disabled)
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_int_get_mask(unsigned int interrupt,
  	unsigned int *mask)
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  	register uintptr_t r4 __asm__("r4");
  
  	r11 = EV_HCALL_TOKEN(EV_INT_GET_MASK);
  	r3 = interrupt;
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3), "=r" (r4)
  		: : EV_HCALL_CLOBBERS2
  	);
  
  	*mask = r4;
  
  	return r3;
  }
  
  /**
   * ev_int_eoi - signal the end of interrupt processing
   * @interrupt: the interrupt number
   *
   * This function signals the end of processing for the specified
   * interrupt, which must be the interrupt currently in service. By
   * definition, this is also the highest-priority interrupt.
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_int_eoi(unsigned int interrupt)
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  
  	r11 = EV_HCALL_TOKEN(EV_INT_EOI);
  	r3 = interrupt;
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3)
  		: : EV_HCALL_CLOBBERS1
  	);
  
  	return r3;
  }
  
  /**
   * ev_byte_channel_send - send characters to a byte stream
   * @handle: byte stream handle
   * @count: (input) num of chars to send, (output) num chars sent
   * @buffer: pointer to a 16-byte buffer
   *
   * @buffer must be at least 16 bytes long, because all 16 bytes will be
   * read from memory into registers, even if count < 16.
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_byte_channel_send(unsigned int handle,
  	unsigned int *count, const char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  	register uintptr_t r4 __asm__("r4");
  	register uintptr_t r5 __asm__("r5");
  	register uintptr_t r6 __asm__("r6");
  	register uintptr_t r7 __asm__("r7");
  	register uintptr_t r8 __asm__("r8");
  	const uint32_t *p = (const uint32_t *) buffer;
  
  	r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_SEND);
  	r3 = handle;
  	r4 = *count;
  	r5 = be32_to_cpu(p[0]);
  	r6 = be32_to_cpu(p[1]);
  	r7 = be32_to_cpu(p[2]);
  	r8 = be32_to_cpu(p[3]);
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3),
  		  "+r" (r4), "+r" (r5), "+r" (r6), "+r" (r7), "+r" (r8)
  		: : EV_HCALL_CLOBBERS6
  	);
  
  	*count = r4;
  
  	return r3;
  }
  
  /**
   * ev_byte_channel_receive - fetch characters from a byte channel
   * @handle: byte channel handle
   * @count: (input) max num of chars to receive, (output) num chars received
   * @buffer: pointer to a 16-byte buffer
   *
   * The size of @buffer must be at least 16 bytes, even if you request fewer
   * than 16 characters, because we always write 16 bytes to @buffer.  This is
   * for performance reasons.
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_byte_channel_receive(unsigned int handle,
  	unsigned int *count, char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  	register uintptr_t r4 __asm__("r4");
  	register uintptr_t r5 __asm__("r5");
  	register uintptr_t r6 __asm__("r6");
  	register uintptr_t r7 __asm__("r7");
  	register uintptr_t r8 __asm__("r8");
  	uint32_t *p = (uint32_t *) buffer;
  
  	r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_RECEIVE);
  	r3 = handle;
  	r4 = *count;
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3), "+r" (r4),
  		  "=r" (r5), "=r" (r6), "=r" (r7), "=r" (r8)
  		: : EV_HCALL_CLOBBERS6
  	);
  
  	*count = r4;
  	p[0] = cpu_to_be32(r5);
  	p[1] = cpu_to_be32(r6);
  	p[2] = cpu_to_be32(r7);
  	p[3] = cpu_to_be32(r8);
  
  	return r3;
  }
  
  /**
   * ev_byte_channel_poll - returns the status of the byte channel buffers
   * @handle: byte channel handle
   * @rx_count: returned count of bytes in receive queue
   * @tx_count: returned count of free space in transmit queue
   *
   * This function reports the amount of data in the receive queue (i.e. the
   * number of bytes you can read), and the amount of free space in the transmit
   * queue (i.e. the number of bytes you can write).
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_byte_channel_poll(unsigned int handle,
  	unsigned int *rx_count,	unsigned int *tx_count)
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  	register uintptr_t r4 __asm__("r4");
  	register uintptr_t r5 __asm__("r5");
  
  	r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_POLL);
  	r3 = handle;
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5)
  		: : EV_HCALL_CLOBBERS3
  	);
  
  	*rx_count = r4;
  	*tx_count = r5;
  
  	return r3;
  }
  
  /**
   * ev_int_iack - acknowledge an interrupt
   * @handle: handle to the target interrupt controller
   * @vector: returned interrupt vector
   *
   * If handle is zero, the function returns the next interrupt source
   * number to be handled irrespective of the hierarchy or cascading
   * of interrupt controllers. If non-zero, specifies a handle to the
   * interrupt controller that is the target of the acknowledge.
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_int_iack(unsigned int handle,
  	unsigned int *vector)
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  	register uintptr_t r4 __asm__("r4");
  
  	r11 = EV_HCALL_TOKEN(EV_INT_IACK);
  	r3 = handle;
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3), "=r" (r4)
  		: : EV_HCALL_CLOBBERS2
  	);
  
  	*vector = r4;
  
  	return r3;
  }
  
  /**
   * ev_doorbell_send - send a doorbell to another partition
   * @handle: doorbell send handle
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_doorbell_send(unsigned int handle)
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  
  	r11 = EV_HCALL_TOKEN(EV_DOORBELL_SEND);
  	r3 = handle;
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "+r" (r3)
  		: : EV_HCALL_CLOBBERS1
  	);
  
  	return r3;
  }
  
  /**
   * ev_idle -- wait for next interrupt on this core
   *
   * Returns 0 for success, or an error code.
   */
  static inline unsigned int ev_idle(void)
  {
  	register uintptr_t r11 __asm__("r11");
  	register uintptr_t r3 __asm__("r3");
  
  	r11 = EV_HCALL_TOKEN(EV_IDLE);
  
  	asm volatile("bl	epapr_hypercall_start"
  		: "+r" (r11), "=r" (r3)
  		: : EV_HCALL_CLOBBERS1
  	);
  
  	return r3;
  }
  
  #ifdef CONFIG_EPAPR_PARAVIRT
  static inline unsigned long epapr_hypercall(unsigned long *in,
  			    unsigned long *out,
  			    unsigned long nr)
  {
  	register unsigned long r0 asm("r0");
  	register unsigned long r3 asm("r3") = in[0];
  	register unsigned long r4 asm("r4") = in[1];
  	register unsigned long r5 asm("r5") = in[2];
  	register unsigned long r6 asm("r6") = in[3];
  	register unsigned long r7 asm("r7") = in[4];
  	register unsigned long r8 asm("r8") = in[5];
  	register unsigned long r9 asm("r9") = in[6];
  	register unsigned long r10 asm("r10") = in[7];
  	register unsigned long r11 asm("r11") = nr;
  	register unsigned long r12 asm("r12");
  
  	asm volatile("bl	epapr_hypercall_start"
  		     : "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
  		       "=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
  		       "=r"(r12)
  		     : "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "r"(r8),
  		       "r"(r9), "r"(r10), "r"(r11)
  		     : "memory", "cc", "xer", "ctr", "lr");
  
  	out[0] = r4;
  	out[1] = r5;
  	out[2] = r6;
  	out[3] = r7;
  	out[4] = r8;
  	out[5] = r9;
  	out[6] = r10;
  	out[7] = r11;
  
  	return r3;
  }
  #else
  static unsigned long epapr_hypercall(unsigned long *in,
  				   unsigned long *out,
  				   unsigned long nr)
  {
  	return EV_UNIMPLEMENTED;
  }
  #endif
  
  static inline long epapr_hypercall0_1(unsigned int nr, unsigned long *r2)
  {
  	unsigned long in[8] = {0};
  	unsigned long out[8];
  	unsigned long r;
  
  	r = epapr_hypercall(in, out, nr);
  	*r2 = out[0];
  
  	return r;
  }
  
  static inline long epapr_hypercall0(unsigned int nr)
  {
  	unsigned long in[8] = {0};
  	unsigned long out[8];
  
  	return epapr_hypercall(in, out, nr);
  }
  
  static inline long epapr_hypercall1(unsigned int nr, unsigned long p1)
  {
  	unsigned long in[8] = {0};
  	unsigned long out[8];
  
  	in[0] = p1;
  	return epapr_hypercall(in, out, nr);
  }
  
  static inline long epapr_hypercall2(unsigned int nr, unsigned long p1,
  				    unsigned long p2)
  {
  	unsigned long in[8] = {0};
  	unsigned long out[8];
  
  	in[0] = p1;
  	in[1] = p2;
  	return epapr_hypercall(in, out, nr);
  }
  
  static inline long epapr_hypercall3(unsigned int nr, unsigned long p1,
  				    unsigned long p2, unsigned long p3)
  {
  	unsigned long in[8] = {0};
  	unsigned long out[8];
  
  	in[0] = p1;
  	in[1] = p2;
  	in[2] = p3;
  	return epapr_hypercall(in, out, nr);
  }
  
  static inline long epapr_hypercall4(unsigned int nr, unsigned long p1,
  				    unsigned long p2, unsigned long p3,
  				    unsigned long p4)
  {
  	unsigned long in[8] = {0};
  	unsigned long out[8];
  
  	in[0] = p1;
  	in[1] = p2;
  	in[2] = p3;
  	in[3] = p4;
  	return epapr_hypercall(in, out, nr);
  }
  #endif /* !__ASSEMBLY__ */
  #endif /* _EPAPR_HCALLS_H */
  