mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 04:18:39 +08:00
c86fa3470c
Confidential Computing environments such as pKVM and Arm's CCA distinguish between shared (i.e. emulated) and private (i.e. assigned) MMIO regions. Introduce a hook into our implementation of ioremap_prot() so that MMIO regions can be shared if necessary. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Steven Price <steven.price@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240830130150.8568-6-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
59 lines
1.2 KiB
C
59 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/io.h>
|
|
|
|
static ioremap_prot_hook_t ioremap_prot_hook;
|
|
|
|
int arm64_ioremap_prot_hook_register(ioremap_prot_hook_t hook)
|
|
{
|
|
if (WARN_ON(ioremap_prot_hook))
|
|
return -EBUSY;
|
|
|
|
ioremap_prot_hook = hook;
|
|
return 0;
|
|
}
|
|
|
|
void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
|
|
unsigned long prot)
|
|
{
|
|
unsigned long last_addr = phys_addr + size - 1;
|
|
pgprot_t pgprot = __pgprot(prot);
|
|
|
|
/* Don't allow outside PHYS_MASK */
|
|
if (last_addr & ~PHYS_MASK)
|
|
return NULL;
|
|
|
|
/* Don't allow RAM to be mapped. */
|
|
if (WARN_ON(pfn_is_map_memory(__phys_to_pfn(phys_addr))))
|
|
return NULL;
|
|
|
|
/*
|
|
* If a hook is registered (e.g. for confidential computing
|
|
* purposes), call that now and barf if it fails.
|
|
*/
|
|
if (unlikely(ioremap_prot_hook) &&
|
|
WARN_ON(ioremap_prot_hook(phys_addr, size, &pgprot))) {
|
|
return NULL;
|
|
}
|
|
|
|
return generic_ioremap_prot(phys_addr, size, pgprot);
|
|
}
|
|
EXPORT_SYMBOL(ioremap_prot);
|
|
|
|
/*
|
|
* Must be called after early_fixmap_init
|
|
*/
|
|
void __init early_ioremap_init(void)
|
|
{
|
|
early_ioremap_setup();
|
|
}
|
|
|
|
bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
|
|
unsigned long flags)
|
|
{
|
|
unsigned long pfn = PHYS_PFN(offset);
|
|
|
|
return pfn_is_map_memory(pfn);
|
|
}
|