freebsd-dev/sys/powerpc/ofw/rtas.c
Nathan Whitehorn f70dd52fe6 Allow use of a pre-instantiated RTAS as well as a self-instantiated one. This
lets the kernel boot on RTAS-based systems by being kexec'ed from Linux.
2015-01-22 22:04:43 +00:00

273 lines
6.7 KiB
C

/*-
* Copyright (c) 2011 Nathan Whitehorn
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/pmap.h>
#include <machine/bus.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/pmap.h>
#include <machine/rtas.h>
#include <machine/stdarg.h>
#include <dev/ofw/openfirm.h>
static MALLOC_DEFINE(M_RTAS, "rtas", "Run Time Abstraction Service");
static vm_offset_t rtas_bounce_phys;
static caddr_t rtas_bounce_virt;
static off_t rtas_bounce_offset;
static size_t rtas_bounce_size;
static uintptr_t rtas_private_data;
static struct mtx rtas_mtx;
static phandle_t rtas;
/* From ofwcall.S */
int rtascall(vm_offset_t callbuffer, uintptr_t rtas_privdat);
extern uintptr_t rtas_entry;
extern register_t rtasmsr;
int setfault(faultbuf); /* defined in locore.S */
/*
* After the VM is up, allocate RTAS memory and instantiate it
*/
static void rtas_setup(void *);
SYSINIT(rtas_setup, SI_SUB_KMEM, SI_ORDER_ANY, rtas_setup, NULL);
static void
rtas_setup(void *junk)
{
ihandle_t rtasi;
cell_t rtas_size = 0, rtas_ptr;
char path[31];
int result;
rtas = OF_finddevice("/rtas");
if (rtas == -1) {
rtas = 0;
return;
}
OF_package_to_path(rtas, path, sizeof(path));
mtx_init(&rtas_mtx, "RTAS", NULL, MTX_SPIN);
/* RTAS must be called with everything turned off in MSR */
rtasmsr = mfmsr();
rtasmsr &= ~(PSL_IR | PSL_DR | PSL_EE | PSL_SE);
#ifdef __powerpc64__
rtasmsr &= ~PSL_SF;
#endif
/*
* Allocate rtas_size + one page of contiguous, wired physical memory
* that can fit into a 32-bit address space and accessed from real mode.
* This is used both to bounce arguments and for RTAS private data.
*
* It must be 4KB-aligned and not cross a 256 MB boundary.
*/
OF_getencprop(rtas, "rtas-size", &rtas_size, sizeof(rtas_size));
rtas_size = round_page(rtas_size);
rtas_bounce_virt = contigmalloc(rtas_size + PAGE_SIZE, M_RTAS, 0, 0,
ulmin(platform_real_maxaddr(), BUS_SPACE_MAXADDR_32BIT),
4096, 256*1024*1024);
rtas_private_data = vtophys(rtas_bounce_virt);
rtas_bounce_virt += rtas_size; /* Actual bounce area */
rtas_bounce_phys = vtophys(rtas_bounce_virt);
rtas_bounce_size = PAGE_SIZE;
/*
* Instantiate RTAS. We always use the 32-bit version.
*/
if (OF_hasprop(rtas, "linux,rtas-entry") &&
OF_hasprop(rtas, "linux,rtas-base")) {
OF_getencprop(rtas, "linux,rtas-base", &rtas_ptr,
sizeof(rtas_ptr));
rtas_private_data = rtas_ptr;
OF_getencprop(rtas, "linux,rtas-entry", &rtas_ptr,
sizeof(rtas_ptr));
} else {
rtasi = OF_open(path);
if (rtasi == 0) {
rtas = 0;
printf("Error initializing RTAS: could not open "
"node\n");
return;
}
result = OF_call_method("instantiate-rtas", rtasi, 1, 1,
(cell_t)rtas_private_data, &rtas_ptr);
OF_close(rtasi);
if (result != 0) {
rtas = 0;
rtas_ptr = 0;
printf("Error initializing RTAS (%d)\n", result);
return;
}
}
rtas_entry = (uintptr_t)(rtas_ptr);
}
static cell_t
rtas_real_map(const void *buf, size_t len)
{
cell_t phys;
mtx_assert(&rtas_mtx, MA_OWNED);
/*
* Make sure the bounce page offset satisfies any reasonable
* alignment constraint.
*/
rtas_bounce_offset += sizeof(register_t) -
(rtas_bounce_offset % sizeof(register_t));
if (rtas_bounce_offset + len > rtas_bounce_size) {
panic("Oversize RTAS call!");
return 0;
}
if (buf != NULL)
memcpy(rtas_bounce_virt + rtas_bounce_offset, buf, len);
else
return (0);
phys = rtas_bounce_phys + rtas_bounce_offset;
rtas_bounce_offset += len;
return (phys);
}
static void
rtas_real_unmap(cell_t physaddr, void *buf, size_t len)
{
mtx_assert(&rtas_mtx, MA_OWNED);
if (physaddr == 0)
return;
memcpy(buf, rtas_bounce_virt + (physaddr - rtas_bounce_phys), len);
}
/* Check if we have RTAS */
int
rtas_exists(void)
{
return (rtas != 0);
}
/* Call an RTAS method by token */
int
rtas_call_method(cell_t token, int nargs, int nreturns, ...)
{
vm_offset_t argsptr;
faultbuf env, *oldfaultbuf;
va_list ap;
struct {
cell_t token;
cell_t nargs;
cell_t nreturns;
cell_t args_n_results[12];
} args;
int n, result;
if (!rtas_exists() || nargs + nreturns > 12)
return (-1);
args.token = token;
va_start(ap, nreturns);
mtx_lock_spin(&rtas_mtx);
rtas_bounce_offset = 0;
args.nargs = nargs;
args.nreturns = nreturns;
for (n = 0; n < nargs; n++)
args.args_n_results[n] = va_arg(ap, cell_t);
argsptr = rtas_real_map(&args, sizeof(args));
/* Get rid of any stale machine checks that have been waiting. */
__asm __volatile ("sync; isync");
oldfaultbuf = curthread->td_pcb->pcb_onfault;
if (!setfault(env)) {
__asm __volatile ("sync");
result = rtascall(argsptr, rtas_private_data);
__asm __volatile ("sync; isync");
} else {
result = RTAS_HW_ERROR;
}
curthread->td_pcb->pcb_onfault = oldfaultbuf;
__asm __volatile ("sync");
rtas_real_unmap(argsptr, &args, sizeof(args));
mtx_unlock_spin(&rtas_mtx);
if (result < 0)
return (result);
for (n = nargs; n < nargs + nreturns; n++)
*va_arg(ap, cell_t *) = args.args_n_results[n];
return (result);
}
/* Look up an RTAS token */
cell_t
rtas_token_lookup(const char *method)
{
cell_t token;
if (!rtas_exists())
return (-1);
if (OF_getencprop(rtas, method, &token, sizeof(token)) == -1)
return (-1);
return (token);
}