freebsd-dev/sys/ia64/pci/pci_cfgreg.c
Marcel Moolenaar cc7a041c2b Disable interrupts when calling into SAL for PCI configuration
cycles. This serves 2 purposes:
1.  It prevents preemption and CPU migration while running SAL code.
2.  It reduces the chance of stack overflows: we're supposed to enter
    SAL with at least 16KB of either memory- or register stack space,
    which we can't do without switching to a different stack.
2010-03-22 03:06:11 +00:00

105 lines
2.9 KiB
C

/*-
* Copyright (c) 2010 Marcel Moolenaar
* Copyright (c) 2001 Doug Rabson
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <machine/cpufunc.h>
#include <machine/pci_cfgreg.h>
#include <machine/sal.h>
static u_long
pci_sal_address(int dom, int bus, int slot, int func, int reg)
{
u_long addr;
addr = ~0ul;
if (dom >= 0 && dom <= 255 && bus >= 0 && bus <= 255 &&
slot >= 0 && slot <= 31 && func >= 0 && func <= 7 &&
reg >= 0 && reg <= 255) {
addr = ((u_long)dom << 24) | ((u_long)bus << 16) |
((u_long)slot << 11) | ((u_long)func << 8) | (u_long)reg;
}
return (addr);
}
static int
pci_valid_access(int reg, int len)
{
int ok;
ok = ((len == 1 || len == 2 || len == 4) && (reg & (len - 1)) == 0)
? 1 : 0;
return (ok);
}
int
pci_cfgregopen(void)
{
return (1);
}
uint32_t
pci_cfgregread(int bus, int slot, int func, int reg, int len)
{
struct ia64_sal_result res;
register_t is;
u_long addr;
addr = pci_sal_address(0, bus, slot, func, reg);
if (addr == ~0ul)
return (~0);
if (!pci_valid_access(reg, len))
return (~0);
is = intr_disable();
res = ia64_sal_entry(SAL_PCI_CONFIG_READ, addr, len, 0, 0, 0, 0, 0);
intr_restore(is);
return ((res.sal_status < 0) ? ~0 : res.sal_result[0]);
}
void
pci_cfgregwrite(int bus, int slot, int func, int reg, uint32_t data, int len)
{
struct ia64_sal_result res;
register_t is;
u_long addr;
addr = pci_sal_address(0, bus, slot, func, reg);
if (addr == ~0ul)
return;
if (!pci_valid_access(reg, len))
return;
is = intr_disable();
res = ia64_sal_entry(SAL_PCI_CONFIG_WRITE, addr, len, data, 0, 0, 0, 0);
intr_restore(is);
}