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/*
* Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
* Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org)
* Copyright (C) 2000 SiByte, Inc.
*
* Written by Justin Carlson of SiByte, Inc.
* and Kip Walker of Broadcom Corp.
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <asm/io.h>
#include <asm/sibyte/sb1250.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_dma.h>
#ifdef CONFIG_SB1_PASS_1_WORKAROUNDS
#define SB1_PREF_LOAD_STREAMED_HINT "0"
#define SB1_PREF_STORE_STREAMED_HINT "1"
#else
#define SB1_PREF_LOAD_STREAMED_HINT "4"
#define SB1_PREF_STORE_STREAMED_HINT "5"
#endif
#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
static inline void clear_page_cpu(void *page)
#else
void clear_page(void *page)
#endif
{
unsigned char *addr = (unsigned char *) page;
unsigned char *end = addr + PAGE_SIZE;
/*
* JDCXXX - This should be bottlenecked by the write buffer, but these
* things tend to be mildly unpredictable...should check this on the
* performance model
*
* We prefetch 4 lines ahead. We're also "cheating" slightly here...
* since we know we're on an SB1, we force the assembler to take
* 64-bit operands to speed things up
*/
do {
__asm__ __volatile__(
" .set mips4 \n"
#ifdef CONFIG_CPU_HAS_PREFETCH
" pref " SB1_PREF_STORE_STREAMED_HINT ", 0(%0) \n" /* Prefetch the first 4 lines */
" pref " SB1_PREF_STORE_STREAMED_HINT ", 32(%0) \n"
" pref " SB1_PREF_STORE_STREAMED_HINT ", 64(%0) \n"
" pref " SB1_PREF_STORE_STREAMED_HINT ", 96(%0) \n"
#endif
"1: sd $0, 0(%0) \n" /* Throw out a cacheline of 0's */
" sd $0, 8(%0) \n"
" sd $0, 16(%0) \n"
" sd $0, 24(%0) \n"
#ifdef CONFIG_CPU_HAS_PREFETCH
" pref " SB1_PREF_STORE_STREAMED_HINT ",128(%0) \n" /* Prefetch 4 lines ahead */
#endif
" .set mips0 \n"
:
: "r" (addr)
: "memory");
addr += 32;
} while (addr != end);
}
#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
static inline void copy_page_cpu(void *to, void *from)
#else
void copy_page(void *to, void *from)
#endif
{
unsigned char *src = from;
unsigned char *dst = to;
unsigned char *end = src + PAGE_SIZE;
/*
* This should be optimized in assembly...can't use ld/sd, though,
* because the top 32 bits could be nuked if we took an interrupt
* during the routine. And this is not a good place to be cli()'ing
*
* The pref's used here are using "streaming" hints, which cause the
* copied data to be kicked out of the cache sooner. A page copy often
* ends up copying a lot more data than is commonly used, so this seems
* to make sense in terms of reducing cache pollution, but I've no real
* performance data to back this up
*/
do {
__asm__ __volatile__(
" .set mips4 \n"
#ifdef CONFIG_CPU_HAS_PREFETCH
" pref " SB1_PREF_LOAD_STREAMED_HINT ", 0(%0)\n" /* Prefetch the first 3 lines */
" pref " SB1_PREF_STORE_STREAMED_HINT ", 0(%1)\n"
" pref " SB1_PREF_LOAD_STREAMED_HINT ", 32(%0)\n"
" pref " SB1_PREF_STORE_STREAMED_HINT ", 32(%1)\n"
" pref " SB1_PREF_LOAD_STREAMED_HINT ", 64(%0)\n"
" pref " SB1_PREF_STORE_STREAMED_HINT ", 64(%1)\n"
#endif
"1: lw $2, 0(%0) \n" /* Block copy a cacheline */
" lw $3, 4(%0) \n"
" lw $4, 8(%0) \n"
" lw $5, 12(%0) \n"
" lw $6, 16(%0) \n"
" lw $7, 20(%0) \n"
" lw $8, 24(%0) \n"
" lw $9, 28(%0) \n"
#ifdef CONFIG_CPU_HAS_PREFETCH
" pref " SB1_PREF_LOAD_STREAMED_HINT ", 96(%0) \n" /* Prefetch ahead */
" pref " SB1_PREF_STORE_STREAMED_HINT ", 96(%1) \n"
#endif
" sw $2, 0(%1) \n"
" sw $3, 4(%1) \n"
" sw $4, 8(%1) \n"
" sw $5, 12(%1) \n"
" sw $6, 16(%1) \n"
" sw $7, 20(%1) \n"
" sw $8, 24(%1) \n"
" sw $9, 28(%1) \n"
" .set mips0 \n"
:
: "r" (src), "r" (dst)
: "$2","$3","$4","$5","$6","$7","$8","$9","memory");
src += 32;
dst += 32;
} while (src != end);
}
#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
/*
* Pad descriptors to cacheline, since each is exclusively owned by a
* particular CPU.
*/
typedef struct dmadscr_s {
uint64_t dscr_a;
uint64_t dscr_b;
uint64_t pad_a;
uint64_t pad_b;
} dmadscr_t;
static dmadscr_t page_descr[NR_CPUS] __attribute__((aligned(SMP_CACHE_BYTES)));
void sb1_dma_init(void)
{
int cpu = smp_processor_id();
uint64_t base_val = PHYSADDR(&page_descr[cpu]) | V_DM_DSCR_BASE_RINGSZ(1);
__raw_writeq(base_val,
IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
__raw_writeq(base_val | M_DM_DSCR_BASE_RESET,
IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
__raw_writeq(base_val | M_DM_DSCR_BASE_ENABL,
IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
}
void clear_page(void *page)
{
int cpu = smp_processor_id();
/* if the page is above Kseg0, use old way */
if (KSEGX(page) != CAC_BASE)
return clear_page_cpu(page);
page_descr[cpu].dscr_a = PHYSADDR(page) | M_DM_DSCRA_ZERO_MEM | M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
/*
* Don't really want to do it this way, but there's no
* reliable way to delay completion detection.
*/
while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)) & M_DM_DSCR_BASE_INTERRUPT)))
;
__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
}
void copy_page(void *to, void *from)
{
unsigned long from_phys = PHYSADDR(from);
unsigned long to_phys = PHYSADDR(to);
int cpu = smp_processor_id();
/* if either page is above Kseg0, use old way */
if ((KSEGX(to) != CAC_BASE) || (KSEGX(from) != CAC_BASE))
return copy_page_cpu(to, from);
page_descr[cpu].dscr_a = PHYSADDR(to_phys) | M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
page_descr[cpu].dscr_b = PHYSADDR(from_phys) | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
/*
* Don't really want to do it this way, but there's no
* reliable way to delay completion detection.
*/
while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)) & M_DM_DSCR_BASE_INTERRUPT)))
;
__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
}
#endif
EXPORT_SYMBOL(clear_page);
EXPORT_SYMBOL(copy_page);