126 lines
5.3 KiB
C
126 lines
5.3 KiB
C
/* The system call implemented in this file:
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* m_type: SYS_VDEVIO
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*
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* The parameters for this system call are:
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* m2_i3: DIO_REQUEST (request input or output)
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* m2_i1: DIO_TYPE (flag indicating byte, word, or long)
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* m2_p1: DIO_VEC_ADDR (pointer to port/ value pairs)
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* m2_i2: DIO_VEC_SIZE (number of ports to read or write)
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*
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* Author:
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* Jorrit N. Herder <jnherder@cs.vu.nl>
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*/
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#include "../kernel.h"
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#include "../system.h"
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#include <minix/devio.h>
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/* Buffer for SYS_VDEVIO to copy (port,value)-pairs from/ to user. */
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PRIVATE char vdevio_pv_buf[VDEVIO_BUF_SIZE];
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/* SYS_VDEVIO sends a pointer to a (port,value)-pairs vector at the caller.
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* Define the maximum number of (port,value)-pairs that can be handled in a
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* in a single SYS_VDEVIO system call based on the struct definitions.
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*/
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#define MAX_PVB_PAIRS ((VDEVIO_BUF_SIZE * sizeof(char)) / sizeof(pvb_pair_t))
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#define MAX_PVW_PAIRS ((VDEVIO_BUF_SIZE * sizeof(char)) / sizeof(pvw_pair_t))
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#define MAX_PVL_PAIRS ((VDEVIO_BUF_SIZE * sizeof(char)) / sizeof(pvl_pair_t))
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/*===========================================================================*
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* do_vdevio *
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*===========================================================================*/
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PUBLIC int do_vdevio(m_ptr)
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register message *m_ptr; /* pointer to request message */
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{
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/* Perform a series of device I/O on behalf of a non-kernel process. The
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* I/O addresses and I/O values are fetched from and returned to some buffer
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* in user space. The actual I/O is wrapped by lock() and unlock() to prevent
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* that I/O batch from being interrrupted.
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* This is the counterpart of do_devio, which performs a single device I/O.
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*/
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pvb_pair_t *pvb_pairs; /* needed for byte values */
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pvw_pair_t *pvw_pairs; /* needed for word values */
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pvl_pair_t *pvl_pairs; /* needed for long values */
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int i;
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pid_t caller_pid; /* process id of caller */
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size_t bytes; /* # bytes to be copied */
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vir_bytes caller_vir; /* virtual address at caller */
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phys_bytes caller_phys; /* physical address at caller */
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phys_bytes kernel_phys; /* physical address in kernel */
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/* Check if nr of ports is ok and get size of (port,value) data. */
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if (m_ptr->DIO_VEC_SIZE <= 0) return(EINVAL);
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switch(m_ptr->DIO_TYPE) {
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case DIO_BYTE:
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if (m_ptr->DIO_VEC_SIZE > MAX_PVB_PAIRS) return(EINVAL);
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bytes = (size_t) (m_ptr->DIO_VEC_SIZE * sizeof(pvb_pair_t));
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break;
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case DIO_WORD:
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if (m_ptr->DIO_VEC_SIZE > MAX_PVW_PAIRS) return(EINVAL);
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bytes = (size_t) (m_ptr->DIO_VEC_SIZE * sizeof(pvw_pair_t));
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break;
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case DIO_LONG:
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if (m_ptr->DIO_VEC_SIZE > MAX_PVL_PAIRS) return(EINVAL);
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bytes = (size_t) (m_ptr->DIO_VEC_SIZE * sizeof(pvl_pair_t));
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break;
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default: /* this once and for all checks for a correct type */
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return(EINVAL);
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}
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/* Calculate physical addresses and copy (port,value)-pairs from user. */
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caller_pid = (pid_t) m_ptr->m_source;
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caller_vir = (vir_bytes) m_ptr->DIO_VEC_ADDR;
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caller_phys = umap_local(proc_addr(caller_pid), D, caller_vir, bytes);
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if (0 == caller_phys) return EFAULT;
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kernel_phys = vir2phys(vdevio_pv_buf);
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phys_copy(caller_phys, kernel_phys, (phys_bytes) bytes);
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/* Perform actual device I/O for byte, word, and long values. Note that
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* the entire switch is wrapped in lock() and unlock() to prevent the I/O
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* batch from being interrupted. It may be cleaner to do this just around
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* the for loops, but this results in rather lenghty code.
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*/
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lock();
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switch (m_ptr->DIO_TYPE) {
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case DIO_BYTE: /* byte values */
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pvb_pairs = (pvb_pair_t *) vdevio_pv_buf;
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if (DIO_INPUT == m_ptr->DIO_REQUEST) {
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for (i=0; i < m_ptr->DIO_VEC_SIZE; i++)
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pvb_pairs[i].value = inb(pvb_pairs[i].port);
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} else {
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for (i=0; i < m_ptr->DIO_VEC_SIZE; i++)
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outb(pvb_pairs[i].port, pvb_pairs[i].value);
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}
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break;
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case DIO_WORD: /* word values */
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pvw_pairs = (pvw_pair_t *) vdevio_pv_buf;
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if (DIO_INPUT == m_ptr->DIO_REQUEST) {
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for (i=0; i < m_ptr->DIO_VEC_SIZE; i++)
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pvw_pairs[i].value = inw(pvw_pairs[i].port);
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} else {
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for (i=0; i < m_ptr->DIO_VEC_SIZE; i++)
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outw(pvw_pairs[i].port, pvw_pairs[i].value);
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}
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break;
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case DIO_LONG: /* fall through: long values */
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default: /* only DIO_LONG can arrive here, see above switch */
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pvl_pairs = (pvl_pair_t *) vdevio_pv_buf;
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if (DIO_INPUT == m_ptr->DIO_REQUEST) {
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for (i=0; i < m_ptr->DIO_VEC_SIZE; i++)
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pvl_pairs[i].value = inl(pvl_pairs[i].port);
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} else {
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for (i=0; i < m_ptr->DIO_VEC_SIZE; i++)
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outl(pvb_pairs[i].port, pvl_pairs[i].value);
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}
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}
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unlock();
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/* Almost done, copy back results for input requests. */
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if (DIO_INPUT == m_ptr->REQUEST)
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phys_copy(kernel_phys, caller_phys, (phys_bytes) bytes);
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return(OK);
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}
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