Subject: linux-next: manual merge of the arm64 tree with the mm tree

From: Stephen Rothwell <[email-masked]>
Date: Thu, 24 Oct 2024 10:37:09 +1100

Hi all,

Today's linux-next merge of the arm64 tree got a conflict in:

  arch/arm64/mm/pageattr.c

between commit:

  040ee4186d6c ("arch: introduce set_direct_map_valid_noflush()")

from the mm-unstable branch of the mm tree and commit:

  42be24a4178f ("arm64: Enable memory encrypt for Realms")

from the arm64 tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc arch/arm64/mm/pageattr.c
index 01225900293a,6ae6ae806454..000000000000
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@@ -192,16 -202,86 +202,96 @@@ int set_direct_map_default_noflush(stru
  				   PAGE_SIZE, change_page_range, &data);
  }
  
 +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
 +{
 +	unsigned long addr = (unsigned long)page_address(page);
 +
 +	if (!can_set_direct_map())
 +		return 0;
 +
 +	return set_memory_valid(addr, nr, valid);
 +}
 +
+ static int __set_memory_enc_dec(unsigned long addr,
+ 				int numpages,
+ 				bool encrypt)
+ {
+ 	unsigned long set_prot = 0, clear_prot = 0;
+ 	phys_addr_t start, end;
+ 	int ret;
+ 
+ 	if (!is_realm_world())
+ 		return 0;
+ 
+ 	if (!__is_lm_address(addr))
+ 		return -EINVAL;
+ 
+ 	start = __virt_to_phys(addr);
+ 	end = start + numpages * PAGE_SIZE;
+ 
+ 	if (encrypt)
+ 		clear_prot = PROT_NS_SHARED;
+ 	else
+ 		set_prot = PROT_NS_SHARED;
+ 
+ 	/*
+ 	 * Break the mapping before we make any changes to avoid stale TLB
+ 	 * entries or Synchronous External Aborts caused by RIPAS_EMPTY
+ 	 */
+ 	ret = __change_memory_common(addr, PAGE_SIZE * numpages,
+ 				     __pgprot(set_prot),
+ 				     __pgprot(clear_prot | PTE_VALID));
+ 
+ 	if (ret)
+ 		return ret;
+ 
+ 	if (encrypt)
+ 		ret = rsi_set_memory_range_protected(start, end);
+ 	else
+ 		ret = rsi_set_memory_range_shared(start, end);
+ 
+ 	if (ret)
+ 		return ret;
+ 
+ 	return __change_memory_common(addr, PAGE_SIZE * numpages,
+ 				      __pgprot(PTE_VALID),
+ 				      __pgprot(0));
+ }
+ 
+ static int realm_set_memory_encrypted(unsigned long addr, int numpages)
+ {
+ 	int ret = __set_memory_enc_dec(addr, numpages, true);
+ 
+ 	/*
+ 	 * If the request to change state fails, then the only sensible cause
+ 	 * of action for the caller is to leak the memory
+ 	 */
+ 	WARN(ret, "Failed to encrypt memory, %d pages will be leaked",
+ 	     numpages);
+ 
+ 	return ret;
+ }
+ 
+ static int realm_set_memory_decrypted(unsigned long addr, int numpages)
+ {
+ 	int ret = __set_memory_enc_dec(addr, numpages, false);
+ 
+ 	WARN(ret, "Failed to decrypt memory, %d pages will be leaked",
+ 	     numpages);
+ 
+ 	return ret;
+ }
+ 
+ static const struct arm64_mem_crypt_ops realm_crypt_ops = {
+ 	.encrypt = realm_set_memory_encrypted,
+ 	.decrypt = realm_set_memory_decrypted,
+ };
+ 
+ int realm_register_memory_enc_ops(void)
+ {
+ 	return arm64_mem_crypt_ops_register(&realm_crypt_ops);
+ }
+ 
  #ifdef CONFIG_DEBUG_PAGEALLOC
  void __kernel_map_pages(struct page *page, int numpages, int enable)
  {