/*
* 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 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
* parmeters ("+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[];
/*
* 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 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;
}
#endif /* !__ASSEMBLY__ */
#endif /* _EPAPR_HCALLS_H */
