diff options
Diffstat (limited to 'c/src/lib/libbsp/m68k/gen68360/startup/alloc360.c')
-rw-r--r-- | c/src/lib/libbsp/m68k/gen68360/startup/alloc360.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/gen68360/startup/alloc360.c b/c/src/lib/libbsp/m68k/gen68360/startup/alloc360.c new file mode 100644 index 0000000000..99bfb3352e --- /dev/null +++ b/c/src/lib/libbsp/m68k/gen68360/startup/alloc360.c @@ -0,0 +1,96 @@ +/* + * MC68360 buffer descriptor allocation routines + * + * W. Eric Norum + * Saskatchewan Accelerator Laboratory + * University of Saskatchewan + * Saskatoon, Saskatchewan, CANADA + * eric@skatter.usask.ca + * + * $Id$ + */ + +#include <rtems.h> +#include <bsp.h> +#include <m68360.h> +#include <rtems/error.h> + +/* + * Allocation order: + * - Dual-Port RAM section 1 + * - Dual-Port RAM section 3 + * - Dual-Port RAM section 0 + * - Dual-Port RAM section 2 + */ +static struct { + char *base; + unsigned int size; + unsigned int used; +} bdregions[] = { + { (char *)&m360.dpram1[0], sizeof m360.dpram1, 0 }, + { (char *)&m360.dpram3[0], sizeof m360.dpram3, 0 }, + { (char *)&m360.dpram0[0], sizeof m360.dpram0, 0 }, + { (char *)&m360.dpram2[0], sizeof m360.dpram2, 0 }, +}; + +/* + * Send a command to the CPM RISC processer + */ +void * +M360AllocateBufferDescriptors (int count) +{ + unsigned int i; + ISR_Level level; + void *bdp = NULL; + unsigned int want = count * sizeof(m360BufferDescriptor_t); + + /* + * Running with interrupts disabled is usually considered bad + * form, but this routine is probably being run as part of an + * initialization sequence so the effect shouldn't be too severe. + */ + _ISR_Disable (level); + for (i = 0 ; i < sizeof(bdregions) / sizeof(bdregions[0]) ; i++) { + /* + * Verify that the region exists. + * This test is necessary since some chips have + * less dual-port RAM. + */ + if (bdregions[i].used == 0) { + volatile unsigned char *cp = bdregions[i].base; + *cp = 0xAA; + if (*cp != 0xAA) { + bdregions[i].used = bdregions[i].size; + continue; + } + *cp = 0x55; + if (*cp != 0x55) { + bdregions[i].used = bdregions[i].size; + continue; + } + *cp = 0x0; + } + if (bdregions[i].size - bdregions[i].used >= want) { + bdp = bdregions[i].base + bdregions[i].used; + bdregions[i].used += want; + break; + } + } + _ISR_Enable (level); + if (bdp == NULL) + rtems_panic ("Can't allocate %d buffer descriptor(s).\n", count); + return bdp; +} + +void * +M360AllocateRiscTimers (int count) +{ + /* + * Convert the count to the number of buffer descriptors + * of equal or larger size. This ensures that all buffer + * descriptors are allocated with appropriate alignment. + */ + return M360AllocateBufferDescriptors (((count * 4) + + sizeof(m360BufferDescriptor_t) - 1) / + sizeof(m360BufferDescriptor_t)); +} |