kernel-fxtec-pro1x/arch/s390/pci/pci_insn.c
Sebastian Ott b170bad40d s390/pci: do not read data after failed load
If a pci load instruction fails the content of the register where the
data is stored is possibly unchanged. Fix the inline assembly wrapper
__pcilg to not return stale data. Additionally fix the callers of this
function who access uninitialized variables.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-04-17 14:07:38 +02:00

202 lines
4.3 KiB
C

/*
* s390 specific pci instructions
*
* Copyright IBM Corp. 2013
*/
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <asm/pci_insn.h>
#include <asm/processor.h>
#define ZPCI_INSN_BUSY_DELAY 1 /* 1 microsecond */
/* Modify PCI Function Controls */
static inline u8 __mpcifc(u64 req, struct zpci_fib *fib, u8 *status)
{
u8 cc;
asm volatile (
" .insn rxy,0xe300000000d0,%[req],%[fib]\n"
" ipm %[cc]\n"
" srl %[cc],28\n"
: [cc] "=d" (cc), [req] "+d" (req), [fib] "+Q" (*fib)
: : "cc");
*status = req >> 24 & 0xff;
return cc;
}
int s390pci_mod_fc(u64 req, struct zpci_fib *fib)
{
u8 cc, status;
do {
cc = __mpcifc(req, fib, &status);
if (cc == 2)
msleep(ZPCI_INSN_BUSY_DELAY);
} while (cc == 2);
if (cc)
printk_once(KERN_ERR "%s: error cc: %d status: %d\n",
__func__, cc, status);
return (cc) ? -EIO : 0;
}
/* Refresh PCI Translations */
static inline u8 __rpcit(u64 fn, u64 addr, u64 range, u8 *status)
{
register u64 __addr asm("2") = addr;
register u64 __range asm("3") = range;
u8 cc;
asm volatile (
" .insn rre,0xb9d30000,%[fn],%[addr]\n"
" ipm %[cc]\n"
" srl %[cc],28\n"
: [cc] "=d" (cc), [fn] "+d" (fn)
: [addr] "d" (__addr), "d" (__range)
: "cc");
*status = fn >> 24 & 0xff;
return cc;
}
int s390pci_refresh_trans(u64 fn, u64 addr, u64 range)
{
u8 cc, status;
do {
cc = __rpcit(fn, addr, range, &status);
if (cc == 2)
udelay(ZPCI_INSN_BUSY_DELAY);
} while (cc == 2);
if (cc)
printk_once(KERN_ERR "%s: error cc: %d status: %d dma_addr: %Lx size: %Lx\n",
__func__, cc, status, addr, range);
return (cc) ? -EIO : 0;
}
/* Set Interruption Controls */
void set_irq_ctrl(u16 ctl, char *unused, u8 isc)
{
asm volatile (
" .insn rsy,0xeb00000000d1,%[ctl],%[isc],%[u]\n"
: : [ctl] "d" (ctl), [isc] "d" (isc << 27), [u] "Q" (*unused));
}
/* PCI Load */
static inline int __pcilg(u64 *data, u64 req, u64 offset, u8 *status)
{
register u64 __req asm("2") = req;
register u64 __offset asm("3") = offset;
int cc = -ENXIO;
u64 __data;
asm volatile (
" .insn rre,0xb9d20000,%[data],%[req]\n"
"0: ipm %[cc]\n"
" srl %[cc],28\n"
"1:\n"
EX_TABLE(0b, 1b)
: [cc] "+d" (cc), [data] "=d" (__data), [req] "+d" (__req)
: "d" (__offset)
: "cc");
*status = __req >> 24 & 0xff;
if (!cc)
*data = __data;
return cc;
}
int s390pci_load(u64 *data, u64 req, u64 offset)
{
u8 status;
int cc;
do {
cc = __pcilg(data, req, offset, &status);
if (cc == 2)
udelay(ZPCI_INSN_BUSY_DELAY);
} while (cc == 2);
if (cc)
printk_once(KERN_ERR "%s: error cc: %d status: %d req: %Lx offset: %Lx\n",
__func__, cc, status, req, offset);
return (cc > 0) ? -EIO : cc;
}
EXPORT_SYMBOL_GPL(s390pci_load);
/* PCI Store */
static inline int __pcistg(u64 data, u64 req, u64 offset, u8 *status)
{
register u64 __req asm("2") = req;
register u64 __offset asm("3") = offset;
int cc = -ENXIO;
asm volatile (
" .insn rre,0xb9d00000,%[data],%[req]\n"
"0: ipm %[cc]\n"
" srl %[cc],28\n"
"1:\n"
EX_TABLE(0b, 1b)
: [cc] "+d" (cc), [req] "+d" (__req)
: "d" (__offset), [data] "d" (data)
: "cc");
*status = __req >> 24 & 0xff;
return cc;
}
int s390pci_store(u64 data, u64 req, u64 offset)
{
u8 status;
int cc;
do {
cc = __pcistg(data, req, offset, &status);
if (cc == 2)
udelay(ZPCI_INSN_BUSY_DELAY);
} while (cc == 2);
if (cc)
printk_once(KERN_ERR "%s: error cc: %d status: %d req: %Lx offset: %Lx\n",
__func__, cc, status, req, offset);
return (cc > 0) ? -EIO : cc;
}
EXPORT_SYMBOL_GPL(s390pci_store);
/* PCI Store Block */
static inline int __pcistb(const u64 *data, u64 req, u64 offset, u8 *status)
{
int cc = -ENXIO;
asm volatile (
" .insn rsy,0xeb00000000d0,%[req],%[offset],%[data]\n"
"0: ipm %[cc]\n"
" srl %[cc],28\n"
"1:\n"
EX_TABLE(0b, 1b)
: [cc] "+d" (cc), [req] "+d" (req)
: [offset] "d" (offset), [data] "Q" (*data)
: "cc");
*status = req >> 24 & 0xff;
return cc;
}
int s390pci_store_block(const u64 *data, u64 req, u64 offset)
{
u8 status;
int cc;
do {
cc = __pcistb(data, req, offset, &status);
if (cc == 2)
udelay(ZPCI_INSN_BUSY_DELAY);
} while (cc == 2);
if (cc)
printk_once(KERN_ERR "%s: error cc: %d status: %d req: %Lx offset: %Lx\n",
__func__, cc, status, req, offset);
return (cc > 0) ? -EIO : cc;
}
EXPORT_SYMBOL_GPL(s390pci_store_block);