Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - mm switching fix where the kernel pgd ends up in the user TTBR0 after
   returning from an EFI run-time services call

 - fix __GFP_ZERO handling for atomic pool and CMA DMA allocations (the
   generic code does get the gfp flags, so it's left with the arch code
   to memzero accordingly)

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Honor __GFP_ZERO in dma allocations
  arm64: efi: don't restore TTBR0 if active_mm points at init_mm

3 files changed, 19 insertions, 5 deletions

diff --git a/arch/arm64/include/asm/proc-fns.h b/arch/arm64/include/asm/proc-fns.h
index 9a8fd84f8fb2..941c375616e2 100644
--- a/arch/arm64/include/asm/proc-fns.h
+++ b/arch/arm64/include/asm/proc-fns.h
@@ -39,7 +39,11 @@ extern u64 cpu_do_resume(phys_addr_t ptr, u64 idmap_ttbr);
 
 #include <asm/memory.h>
 
-#define cpu_switch_mm(pgd,mm) cpu_do_switch_mm(virt_to_phys(pgd),mm)
+#define cpu_switch_mm(pgd,mm)                           \
+do {                                                    \
+        BUG_ON(pgd == swapper_pg_dir);                  \
+        cpu_do_switch_mm(virt_to_phys(pgd),mm);         \
+} while (0)
 
 #define cpu_get_pgd()                                   \
 ({                                                      \
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index 2b8d70164428..ab21e0d58278 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -337,7 +337,11 @@ core_initcall(arm64_dmi_init);
 
 static void efi_set_pgd(struct mm_struct *mm)
 {
-        cpu_switch_mm(mm->pgd, mm);
+        if (mm == &init_mm)
+                cpu_set_reserved_ttbr0();
+        else
+                cpu_switch_mm(mm->pgd, mm);
+
         flush_tlb_all();
         if (icache_is_aivivt())
                 __flush_icache_all();
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 58e0c2bdde04..ef7d112f5ce0 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -51,7 +51,7 @@ static int __init early_coherent_pool(char *p)
 }
 early_param("coherent_pool", early_coherent_pool);
 
-static void *__alloc_from_pool(size_t size, struct page **ret_page)
+static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
 {
         unsigned long val;
         void *ptr = NULL;
@@ -67,6 +67,8 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page)
 
                 *ret_page = phys_to_page(phys);
                 ptr = (void *)val;
+                if (flags & __GFP_ZERO)
+                        memset(ptr, 0, size);
         }
 
         return ptr;
@@ -101,6 +103,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size,
                 flags |= GFP_DMA;
         if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_WAIT)) {
                 struct page *page;
+                void *addr;
 
                 size = PAGE_ALIGN(size);
                 page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
@@ -109,7 +112,10 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size,
                         return NULL;
 
                 *dma_handle = phys_to_dma(dev, page_to_phys(page));
-                return page_address(page);
+                addr = page_address(page);
+                if (flags & __GFP_ZERO)
+                        memset(addr, 0, size);
+                return addr;
         } else {
                 return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
         }
@@ -146,7 +152,7 @@ static void *__dma_alloc(struct device *dev, size_t size,
 
         if (!coherent && !(flags & __GFP_WAIT)) {
                 struct page *page = NULL;
-                void *addr = __alloc_from_pool(size, &page);
+                void *addr = __alloc_from_pool(size, &page, flags);
 
                 if (addr)
                         *dma_handle = phys_to_dma(dev, page_to_phys(page));