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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 DEVMAP 9E "Jan 15, 1997" .SH NAME devmap \- validate and translate virtual mapping for memory mapped device .SH SYNOPSIS .LP .nf #include #include \fBint prefix\fR\fBdevmap\fR(\fBdev_t\fR \fIdev\fR, \fBdevmap_cookie_t\fR \fIdhp\fR, \fBoffset_t\fR \fIoff\fR, \fBsize_t\fR \fIlen\fR, \fBsize_t *\fR\fImaplen\fR, \fBuint_t\fR \fImodel\fR); .fi .SH INTERFACE LEVEL .sp .LP Solaris DDI specific (Solaris DDI). .SH PARAMETERS .sp .ne 2 .na \fB\fIdev\fR \fR .ad .RS 11n Device whose memory is to be mapped. .RE .sp .ne 2 .na \fB\fIdhp\fR \fR .ad .RS 11n An opaque mapping handle that the system uses to describe the mapping. .RE .sp .ne 2 .na \fB\fIoff\fR \fR .ad .RS 11n User offset within the logical device memory at which the mapping begins. .RE .sp .ne 2 .na \fB\fIlen\fR \fR .ad .RS 11n Length (in bytes) of the mapping to be mapped. .RE .sp .ne 2 .na \fB\fImaplen\fR \fR .ad .RS 11n Pointer to length (in bytes) of mapping that has been validated. \fImaplen\fR is less than or equal to \fIlen\fR. .RE .sp .ne 2 .na \fB\fImodel\fR \fR .ad .RS 11n The data model type of the current thread. .RE .SH DESCRIPTION .sp .LP \fBdevmap()\fR is a required entry point for character drivers supporting memory-mapped devices if the drivers use the devmap framework to set up the mapping. A memory mapped device has memory that can be mapped into a process's address space. The \fBmmap\fR(2) system call, when applied to a character special file, allows this device memory to be mapped into user space for direct access by the user applications. .sp .LP As a result of a \fBmmap\fR(2) system call, the system calls the \fBdevmap()\fR entry point during the mapping setup when \fBD_DEVMAP\fR is set in the \fBcb_flag\fR field of the \fBcb_ops\fR(9S) structure, and any of the following conditions apply: .RS +4 .TP .ie t \(bu .el o \fBddi_devmap_segmap\fR(9F) is used as the \fBsegmap\fR(9E) entry point. .RE .RS +4 .TP .ie t \(bu .el o \fBsegmap\fR(9E) entry point is set to \fINULL.\fR .RE .RS +4 .TP .ie t \(bu .el o \fBmmap\fR(9E) entry point is set to \fINULL.\fR .RE .sp .LP Otherwise \fBEINVAL\fR will be returned to \fBmmap\fR(2). .sp .LP Device drivers should use \fBdevmap()\fR to validate the user mappings to the device, to translate the logical offset, \fIoff\fR, to the corresponding physical offset within the device address space, and to pass the mapping information to the system for setting up the mapping. .sp .LP \fIdhp\fR is a device mapping handle that the system uses to describe a mapping to a memory that is either contiguous in physical address space or in kernel virtual address space. The system may create multiple mapping handles in one \fBmmap\fR(2) system call (for example, if the mapping contains multiple physically discontiguous memory regions). .sp .LP \fImodel\fR returns the C Language Type Model which the current thread expects. It is set to \fBDDI_MODEL_ILP32\fR if the current thread expects 32-bit ( \fIILP32\fR) semantics, or \fBDDI_MODEL_LP64\fR if the current thread expects 64-bit ( \fILP64\fR) semantics. \fImodel\fR is used in combination with \fBddi_model_convert_from\fR(9F) to determine whether there is a data model mismatch between the current thread and the device driver. The device driver might have to adjust the shape of data structures before exporting them to a user thread which supports a different data model. .sp .LP \fBdevmap()\fR should return \fBEINVAL\fR if the logical offset, \fIoff\fR, is out of the range of memory exported by the device to user space. If \fIoff\fR + \fIlen\fR exceeds the range of the contiguous memory, \fBdevmap()\fR should return the length from \fIoff\fR to the end of the contiguous memory region. The system will repeatedly call \fBdevmap()\fR until the original mapping length is satisfied. The driver sets \fI*maplen\fR to the validated length which must be either less than or equal to \fIlen\fR. .sp .LP The \fBdevmap()\fR entry point must initialize the mapping parameters before passing them to the system through either \fBdevmap_devmem_setup\fR(9F) (if the memory being mapped is device memory) or \fBdevmap_umem_setup\fR(9F) (if the memory being mapped is kernel memory). The \fBdevmap()\fR entry point initializes the mapping parameters by mapping the control callback structure (see \fBdevmap_callback_ctl\fR(9S)), the device access attributes, mapping length, maximum protection possible for the mapping, and optional mapping flags. See \fBdevmap_devmem_setup\fR(9F) and \fBdevmap_umem_setup\fR(9F) for further information on initializing the mapping parameters. .sp .LP The system will copy the driver's \fBdevmap_callback_ctl\fR(9S) data into its private memory so the drivers do not need to keep the data structure after the return from either \fBdevmap_devmem_setup\fR(9F) or \fBdevmap_umem_setup\fR(9F). .sp .LP For device mappings, the system establishes the mapping to the physical address that corresponds to \fIoff\fR by passing the register number and the offset within the register address space to \fBdevmap_devmem_setup\fR(9F). .sp .LP For kernel memory mapping, the system selects a user virtual address that is aligned with the kernel address being mapped for cache coherence. .SH RETURN VALUES .sp .ne 2 .na \fB\fB0\fR \fR .ad .RS 12n Successful completion. .RE .sp .ne 2 .na \fBNon-zero\fR .ad .RS 12n An error occurred. .RE .SH EXAMPLES .LP \fBExample 1 \fRImplementing the \fBdevmap()\fR Entry Point .sp .LP The following is an example of the implementation for the \fBdevmap()\fR entry point. For mapping device memory, \fBdevmap()\fR calls \fBdevmap_devmem_setup\fR(9F) with the register number, \fIrnumber\fR, and the offset within the register, \fIroff\fR. For mapping kernel memory, the driver must first allocate the kernel memory using \fBddi_umem_alloc\fR(9F). For example, \fBddi_umem_alloc\fR(9F) can be called in the \fBattach\fR(9E) routine. The resulting kernel memory cookie is stored in the driver soft state structure, which is accessible from the \fBdevmap()\fR entry point. See \fBddi_soft_state\fR(9F). \fBdevmap()\fR passes the cookie obtained from \fBddi_umem_alloc\fR(9F) and the offset within the allocated kernel memory to \fBdevmap_umem_setup\fR(9F). The corresponding \fBddi_umem_free\fR(9F) can be made in the \fBdetach\fR(9E) routine to free up the kernel memory. .sp .in +2 .nf \&.\|.\|. #define MAPPING_SIZE 0x2000 /* size of the mapping */ #define MAPPING_START 0x70000000 /* logical offset at beginning of the mapping */ static struct devmap_callback_ctl xxmap_ops = { DEVMAP_OPS_REV, /* devmap_ops version number */ xxmap_map, /* devmap_ops map routine */ xxmap_access, /* devmap_ops access routine */ xxmap_dup, /* devmap_ops dup routine */ xxmap_unmap, /* devmap_ops unmap routine */ }; static int xxdevmap(dev_t dev, devmap_cookie_t dhp, offset_t off, size_t len, size_t *maplen, uint_t model) { int instance; struct xxstate *xsp; struct ddi_device_acc_attr *endian_attr; struct devmap_callback_ctl *callbackops = NULL; ddi_umem_cookie_t cookie; dev_info_t *dip; offset_t roff; offset_t koff; uint_t rnumber; uint_t maxprot; uint_t flags = 0; size_t length; int err; /* get device soft state */ instance = getminor(dev); xsp = ddi_get_soft_state(statep, instance); if (xsp == NULL) return (-1); dip = xsp->dip; /* check for a valid offset */ if ( \fIoff is invalid\fR ) return (-1); /* check if len is within the range of contiguous memory */ if ( \fB(\fR\fIoff\fR\fB + \fR\fIlen\fR\fB)\fR \fIis contiguous\fR\fB\&.)\fR length = len; else length = MAPPING_START + MAPPING_SIZE - off; /* device access attributes */ endian_attr = xsp->endian_attr; if ( \fI off is referring to a device memory. \fR ) { /* assign register related parameters */ rnumber = XXX; /* index to register set at off */ roff = XXX; /* offset of rnumber at local bus */ callbackops = &xxmap_ops; /* do all callbacks for this mapping */ maxprot = PROT_ALL; /* allowing all access */ if ((err = devmap_devmem_setup(dhp, dip, callbackops, rnumber, roff, length, maxprot, flags, endian_attr)) < 0) return (err); } else if (\fI off is referring to a kernel memory.\fR) { cookie = xsp->cookie; /* cookie is obtained from ddi_umem_alloc(9F) */ koff = XXX; /* offset within the kernel memory. */ callbackops = NULL; /* don't do callback for this mapping */ maxprot = PROT_ALL; /* allowing all access */ if ((err = devmap_umem_setup(dhp, dip, callbackops, cookie, koff, length, maxprot, flags, endian_attr)) < 0) return (err); } *maplen = length; return (0); } .fi .in -2 .SH SEE ALSO .sp .LP \fBmmap\fR(2), \fBattach\fR(9E), \fBdetach\fR(9E), \fBmmap\fR(9E), \fBsegmap\fR(9E), \fBddi_devmap_segmap\fR(9F), \fBddi_model_convert_from\fR(9F), \fBddi_soft_state\fR(9F), \fBddi_umem_alloc\fR(9F), \fBddi_umem_free\fR(9F), \fBdevmap_devmem_setup\fR(9F), \fBdevmap_setup\fR(9F), \fBdevmap_umem_setup\fR(9F), \fBcb_ops\fR(9S), \fBdevmap_callback_ctl\fR(9S) .sp .LP \fIWriting Device Drivers\fR