John Baldwin 254e4e5b77 Simplify swi for bus_dma.
When a DMA request using bounce pages completes, a swi is triggered to
schedule pending DMA requests using the just-freed bounce pages.  For
a long time this bus_dma swi has been tied to a "virtual memory" swi
(swi_vm).  However, all of the swi_vm implementations are the same and
consist of checking a flag (busdma_swi_pending) which is always true
and if set calling busdma_swi.  I suspect this dates back to the
pre-SMPng days and that the intention was for swi_vm to serve as a
mux.  However, in the current scheme there's no need for the mux.

Instead, remove swi_vm and vm_ih.  Each bus_dma implementation that
uses bounce pages is responsible for creating its own swi (busdma_ih)
which it now schedules directly.  This swi invokes busdma_swi directly
removing the need for busdma_swi_pending.

One consequence is that the swi now works on RISC-V which had previously
failed to invoke busdma_swi from swi_vm.

Reviewed by:	imp, kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D33447
2021-12-28 13:51:25 -08:00

75 lines
2.3 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1998 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
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* 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.
*
* $FreeBSD$
*/
#ifndef _MACHINE_MD_VAR_H_
#define _MACHINE_MD_VAR_H_
/*
* Miscellaneous machine-dependent declarations.
*/
extern char sigcode32[];
extern int szsigcode32;
#ifdef __powerpc64__
extern char sigcode64[], sigcode64_elfv2[];
extern int szsigcode64, szsigcode64_elfv2;
struct dumperinfo;
struct minidumpstate;
int cpu_minidumpsys(struct dumperinfo *, const struct minidumpstate *);
#endif
extern long Maxmem;
extern vm_offset_t kstack0;
extern vm_offset_t kstack0_phys;
extern int powerpc_pow_enabled;
extern int cacheline_size;
extern int hw_direct_map;
void __syncicache(void *, int);
int is_physical_memory(vm_offset_t addr);
int mem_valid(vm_offset_t addr, int len);
void decr_init(void);
void decr_ap_init(void);
void decr_tc_init(void);
void cpu_feature_setup(void);
void cpu_setup(u_int);
struct trapframe;
void powerpc_interrupt(struct trapframe *);
#endif /* !_MACHINE_MD_VAR_H_ */