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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH DDI_DMA_ADDR_BIND_HANDLE 9F "Jan 18, 2020" .SH NAME ddi_dma_addr_bind_handle \- binds an address to a DMA handle .SH SYNOPSIS .nf #include #include \fBint\fR \fBddi_dma_addr_bind_handle\fR(\fBddi_dma_handle_t\fR \fIhandle\fR, \fBstruct as *\fR\fIas\fR, \fBcaddr_t\fR \fIaddr\fR, \fBsize_t\fR \fIlen\fR, \fBuint_t\fR \fIflags\fR, \fBint (*\fR\fIcallback\fR) (caddr_t) , \fBcaddr_t\fR \fIarg\fR, \fBddi_dma_cookie_t *\fR\fIcookiep\fR, \fBuint_t *\fR\fIccountp\fR); .fi .SH INTERFACE LEVEL illumos DDI specific (illumos DDI). .SH PARAMETERS .ne 2 .na \fB\fIhandle\fR \fR .ad .RS 13n The \fBDMA\fR handle previously allocated by a call to \fBddi_dma_alloc_handle\fR(9F). .RE .sp .ne 2 .na \fB\fIas\fR \fR .ad .RS 13n A pointer to an address space structure. This parameter should be set to \fINULL\fR, which implies kernel address space. .RE .sp .ne 2 .na \fB\fIaddr\fR \fR .ad .RS 13n Virtual address of the memory object. .RE .sp .ne 2 .na \fB\fIlen\fR \fR .ad .RS 13n Length of the memory object in bytes. .RE .sp .ne 2 .na \fB\fIflags\fR \fR .ad .RS 13n Valid flags include: .sp .ne 2 .na \fB\fBDDI_DMA_WRITE\fR \fR .ad .RS 23n Transfer direction is from memory to I/O. .RE .sp .ne 2 .na \fB\fBDDI_DMA_READ\fR \fR .ad .RS 23n Transfer direction is from I/O to memory. .RE .sp .ne 2 .na \fB\fBDDI_DMA_RDWR\fR \fR .ad .RS 23n Both read and write. .RE .sp .ne 2 .na \fB\fBDDI_DMA_REDZONE\fR \fR .ad .RS 23n Establish an \fBMMU\fR redzone at end of the object. .RE .sp .ne 2 .na \fB\fBDDI_DMA_PARTIAL\fR \fR .ad .RS 23n Partial resource allocation. .RE .sp .ne 2 .na \fB\fBDDI_DMA_CONSISTENT\fR \fR .ad .RS 23n Nonsequential, random, and small block transfers. .RE .sp .ne 2 .na \fB\fBDDI_DMA_STREAMING\fR \fR .ad .RS 23n Sequential, unidirectional, block-sized, and block-aligned transfers. .RE .RE .sp .ne 2 .na \fB\fIcallback\fR \fR .ad .RS 13n The address of a function to call back later if resources are not currently available. The following special function addresses may also be used. .sp .ne 2 .na \fB\fBDDI_DMA_SLEEP\fR \fR .ad .RS 21n Wait until resources are available. .RE .sp .ne 2 .na \fB\fBDDI_DMA_DONTWAIT\fR \fR .ad .RS 21n Do not wait until resources are available and do not schedule a callback. .RE .RE .sp .ne 2 .na \fB\fIarg\fR \fR .ad .RS 13n Argument to be passed to the callback function, \fIcallback\fR, if such a function is specified. .RE .sp .ne 2 .na \fB\fIcookiep\fR \fR .ad .RS 13n A pointer to the first \fBddi_dma_cookie\fR(9S) structure. This should be left as \fBNULL\fR in new callers. .RE .sp .ne 2 .na \fB\fIccountp\fR \fR .ad .RS 13n Upon a successful return, \fIccountp\fR points to a value representing the number of cookies for this \fBDMA\fR object. This can be left as \fBNULL\fR in new callers. The cookie count can be obtained by calling \fBddi_dma_ncookies\fR(9F). .RE .SH DESCRIPTION \fBddi_dma_addr_bind_handle()\fR allocates \fBDMA\fR resources for a memory object such that a device can perform \fBDMA\fR to or from the object. \fBDMA\fR resources are allocated considering the device's \fBDMA\fR attributes as expressed by \fBddi_dma_attr\fR(9S) (see \fBddi_dma_alloc_handle\fR(9F)). .sp .LP \fBddi_dma_addr_bind_handle()\fR allocates and associates a number of \fBDMA\fR cookies with \fIhandle\fR. To get the total number of cookies, callers should use the \fBddi_dma_ncookies\fR(9F) function. To get all of the cookies, callers should use the \fBddi_dma_cookie_iter\fR(9F) or \fBddi_dma_cookie_get\fR(9F) functions. Callers should pass \fBNULL\fR for \fIcookiep\fR and \fIccountp\fR. These values are required if using the deprecated \fBddi_dma_nextcookie\fR(9F) interface, in which case \fIcookiep\fR is filled in with the first \fBddi_dma_cookie\fR(9S) structure. .sp .LP When a \fBDMA\fR transfer completes, the driver frees up system \fBDMA\fR resources by calling \fBddi_dma_unbind_handle\fR(9F). .sp .LP The \fIflags\fR argument contains information for mapping routines. .sp .ne 2 .na \fB\fBDDI_DMA_WRITE\fR, \fBDDI_DMA_READ\fR, \fBDDI_DMA_RDWR\fR\fR .ad .sp .6 .RS 4n These flags describe the intended direction of the \fBDMA\fR transfer. .RE .sp .ne 2 .na \fB\fBDDI_DMA_STREAMING\fR \fR .ad .sp .6 .RS 4n This flag should be set if the device is doing sequential, unidirectional, block-sized, and block-aligned transfers to or from memory. The alignment and padding constraints specified by the \fBminxfer\fR and \fBburstsizes\fR fields in the \fBDMA\fR attribute structure, \fBddi_dma_attr\fR(9S) (see \fBddi_dma_alloc_handle\fR(9F)) is used to allocate the most effective hardware support for large transfers. .RE .sp .ne 2 .na \fB\fBDDI_DMA_CONSISTENT\fR \fR .ad .sp .6 .RS 4n This flag should be set if the device accesses memory randomly, or if synchronization steps using \fBddi_dma_sync\fR(9F) need to be as efficient as possible. I/O parameter blocks used for communication between a device and a driver should be allocated using \fBDDI_DMA_CONSISTENT\fR. .RE .sp .ne 2 .na \fB\fBDDI_DMA_REDZONE\fR \fR .ad .sp .6 .RS 4n If this flag is set, the system attempts to establish a protected red zone after the object. The \fBDMA\fR resource allocation functions do not guarantee the success of this request as some implementations may not have the hardware ability to support a red zone. .RE .sp .ne 2 .na \fB\fBDDI_DMA_PARTIAL\fR \fR .ad .sp .6 .RS 4n Setting this flag indicates the caller can accept resources for part of the object. That is, if the size of the object exceeds the resources available, only resources for a portion of the object are allocated. The system indicates this condition by returning status \fBDDI_DMA_PARTIAL_MAP\fR. At a later point, the caller can use \fBddi_dma_getwin\fR(9F) to change the valid portion of the object for which resources are allocated. If resources were allocated for only part of the object, \fBddi_dma_addr_bind_handle()\fR returns resources for the first \fBDMA\fRwindow. Even when \fBDDI_DMA_PARTIAL\fR is set, the system may decide to allocate resources for the entire object (less overhead) in which case \fBDDI_DMA_MAPPED\fR is returned. .RE .sp .LP The callback function \fIcallback\fR indicates how a caller wants to handle the possibility of resources not being available. If \fIcallback\fR is set to \fBDDI_DMA_DONTWAIT\fR, the caller does not care if the allocation fails, and can handle an allocation failure appropriately. If \fIcallback\fR is set to \fBDDI_DMA_SLEEP\fR, the caller wishes to have the allocation routines wait for resources to become available. If any other value is set and a \fBDMA\fR resource allocation fails, this value is assumed to be the address of a function to be called when resources become available. When the specified function is called, \fIarg\fR is passed to it as an argument. The specified callback function must return either \fBDDI_DMA_CALLBACK_RUNOUT\fR or \fBDDI_DMA_CALLBACK_DONE\fR. \fBDDI_DMA_CALLBACK_RUNOUT\fR indicates that the callback function attempted to allocate \fBDMA\fR resources but failed. In this case, the callback function is put back on a list to be called again later. \fBDDI_DMA_CALLBACK_DONE\fR indicates that either the allocation of \fBDMA\fR resources was successful or the driver no longer wishes to retry. .sp .LP The callback function is called in interrupt context. Therefore, only system functions accessible from interrupt context are be available. The callback function must take whatever steps are necessary to protect its critical resources, data structures, queues, and so on. .SH RETURN VALUES \fBddi_dma_addr_bind_handle()\fR returns: .sp .ne 2 .na \fB\fBDDI_DMA_MAPPED\fR \fR .ad .RS 24n Successfully allocated resources for the entire object. .RE .sp .ne 2 .na \fB\fBDDI_DMA_PARTIAL_MAP\fR \fR .ad .RS 24n Successfully allocated resources for a part of the object. This is acceptable when partial transfers are permitted by setting the \fBDDI_DMA_PARTIAL\fR flag in \fIflags\fR. .RE .sp .ne 2 .na \fB\fBDDI_DMA_INUSE\fR \fR .ad .RS 24n Another I/O transaction is using the \fBDMA\fR handle. .RE .sp .ne 2 .na \fB\fBDDI_DMA_NORESOURCES\fR \fR .ad .RS 24n No resources are available at the present time. .RE .sp .ne 2 .na \fB\fBDDI_DMA_NOMAPPING\fR \fR .ad .RS 24n The object cannot be reached by the device requesting the resources. .RE .sp .ne 2 .na \fB\fBDDI_DMA_TOOBIG\fR \fR .ad .RS 24n The object is too big. A request of this size can never be satisfied on this particular system. The maximum size varies depending on machine and configuration. .RE .SH CONTEXT \fBddi_dma_addr_bind_handle()\fR can be called from user, kernel, or interrupt context, except when \fIcallback\fR is set to \fBDDI_DMA_SLEEP\fR, in which case it can only be called from user or kernel context. .SH SEE ALSO \fBddi_dma_alloc_handle\fR(9F), \fBddi_dma_cookie_get\fR(9F), \fBddi_dma_cookie_iter\fR(9F), \fBddi_dma_free_handle\fR(9F), \fBddi_dma_getwin\fR(9F), \fBddi_dma_mem_alloc\fR(9F), \fBddi_dma_mem_free\fR(9F), \fBddi_dma_ncookies\fR(9F), \fBddi_dma_sync\fR(9F), \fBddi_dma_unbind_handle\fR(9F), \fBddi_umem_iosetup\fR(9F), \fBddi_dma_attr\fR(9S), \fBddi_dma_cookie\fR(9S) .sp .LP \fIWriting Device Drivers\fR .SH NOTES If the driver permits partial mapping with the \fBDDI_DMA_PARTIAL\fR flag, the number of cookies in each window may exceed the size of the device's scatter/gather list as specified in the \fBdma_attr_sgllen\fR field in the \fBddi_dma_attr\fR(9S) structure. In this case, each set of cookies comprising a \fBDMA\fR window will satisfy the \fBDMA\fR attributes as described in the \fBddi_dma_attr\fR(9S) structure in all aspects. The driver should set up its \fBDMA\fR engine and perform one transfer for each set of cookies sufficient for its scatter/gather list, up to the number of cookies for this window, before advancing to the next window using \fBddi_dma_getwin\fR(9F).