/*
* Map a set of physical memory pages into the kernel virtual address space.
* Return a pointer to where it is mapped.
*
* This uses a pre-established static mapping if one exists for the requested
* range, otherwise it allocates kva space and maps the physical pages into it.
*
* This routine is intended to be used for mapping device memory, NOT real
* memory; the mapping type is inherently VM_MEMATTR_DEVICE in
* pmap_kenter_device().
*/
void *
pmap_mapdev(vm_offset_t pa, vm_size_t size)
{
vm_offset_t va, offset;
void * rva;
/* First look in the static mapping table. */
if ((rva = arm_devmap_ptov(pa, size)) != NULL)
return (rva);
offset = pa & PAGE_MASK;
pa = trunc_page(pa);
size = round_page(size + offset);
#ifdef __aarch64__
if (early_boot) {
akva_devmap_vaddr = trunc_page(akva_devmap_vaddr - size);
va = akva_devmap_vaddr;
KASSERT(va >= VM_MAX_KERNEL_ADDRESS - L2_SIZE,
("Too many early devmap mappings"));
} else
#endif
va = kva_alloc(size);
if (!va)
panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
pmap_kenter_device(va, size, pa);
return ((void *)(va + offset));
}
/*
* This code which manipulates the watchdog hardware is here to implement
* cpu_reset() because the watchdog is the only way for software to reset the
* chip. Why here and not in imx_wdog.c? Because there's no requirement that
* the watchdog driver be compiled in, but it's nice to be able to reboot even
* if it's not.
*/
void
imx_wdog_cpu_reset(vm_offset_t wdcr_physaddr)
{
volatile uint16_t * pcr;
/*
* The deceptively simple write of WDOG_CR_WDE enables the watchdog,
* sets the timeout to its minimum value (half a second), and also
* clears the SRS bit which results in the SFTW (software-requested
* reset) bit being set in the watchdog status register after the reset.
* This is how software can distinguish a reset from a wdog timeout.
*/
if ((pcr = arm_devmap_ptov(wdcr_physaddr, sizeof(*pcr))) == NULL) {
printf("cpu_reset() can't find its control register... locking up now.");
} else {
*pcr = WDOG_CR_WDE;
}
for (;;)
continue;
}