From c9e4f9c4cdbdf140d4de20021d07037f8d590bfd Mon Sep 17 00:00:00 2001 From: Theo de Raadt Date: Tue, 28 Nov 1995 16:43:58 +0000 Subject: i386 isa bounce buffers by hannken@eis.cs.tu-bs.de --- sys/arch/i386/isa/isa_machdep.h | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'sys/arch/i386/isa/isa_machdep.h') diff --git a/sys/arch/i386/isa/isa_machdep.h b/sys/arch/i386/isa/isa_machdep.h index a118e7fc17a..495653d9b65 100644 --- a/sys/arch/i386/isa/isa_machdep.h +++ b/sys/arch/i386/isa/isa_machdep.h @@ -97,17 +97,23 @@ struct intrhand { * XXX should be made partially machine- and bus-mapping-independent. * * DMA_BOUNCE is the number of pages of low-addressed physical memory - * to acquire for ISA bounce buffers. + * to acquire for ISA bounce buffers. If physical memory below 16 MB + * then DMA_BOUNCE_LOW will be used. * - * isaphysmem is the location of those bounce buffers. (They are currently - * assumed to be contiguous. + * isaphysmem is the address of this physical contiguous low memory. + * isaphysmempgs is the number of pages allocated. */ #ifndef DMA_BOUNCE -#define DMA_BOUNCE 8 /* one buffer per channel */ +#define DMA_BOUNCE 48 /* number of pages if memory > 16M */ +#endif + +#ifndef DMA_BOUNCE_LOW +#define DMA_BOUNCE_LOW 16 /* number of pages if memory <= 16M */ #endif extern vm_offset_t isaphysmem; +extern int isaphysmempgs; /* -- cgit v1.2.3