On Mon, Mar 02, 2020 at 10:47:27AM +0000, Will Deacon wrote:
[+Anshuman and Catalin]
On Mon, Mar 02, 2020 at 01:58:26PM +0530, Naresh Kamboju wrote:
Linux-Next 20200302 arm64 build failed due to below errors, Suspecting patch causing this build break.
87d900aef3e2 arm/arm64: add support for folded p4d page tables
Error log,
arch/arm64/mm/mmu.c: In function 'unmap_hotplug_pud_range': include/linux/compiler.h:284:1: error: incompatible type for argument 1 of 'p4d_page_paddr' ({ \ ^ arch/arm64/include/asm/memory.h:270:45: note: in definition of macro '__phys_to_virt' #define __phys_to_virt(x) ((unsigned long)((x) - physvirt_offset)) ^ arch/arm64/include/asm/pgtable.h:629:42: note: in expansion of macro '__va' #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr)))) ^~~~ include/linux/compiler.h:293:22: note: in expansion of macro '__READ_ONCE' #define READ_ONCE(x) __READ_ONCE(x, 1) ^~~~~~~~~~~ arch/arm64/include/asm/pgtable.h:628:52: note: in expansion of macro 'READ_ONCE' #define pud_offset_phys(dir, addr) (p4d_page_paddr(READ_ONCE(*(dir)))
- pud_index(addr) * sizeof(pud_t)) ^~~~~~~~~
arch/arm64/include/asm/pgtable.h:629:47: note: in expansion of macro 'pud_offset_phys' #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr)))) ^~~~~~~~~~~~~~~ arch/arm64/mm/mmu.c:827:10: note: in expansion of macro 'pud_offset' pudp = pud_offset(pgdp, addr); ^~~~~~~~~~
Looks like we need an implementation of unmap_hotplug_p4d_range() to walk the dummy p4d level. Unfortunately, we don't have the folded p4d patches in the arm64 tree so we'll either need a common branch or the hotplug patches will need to be dropped for the moment.
unmap_hotplug_p4d_range() is easy :)
From c7a5d08ff51ca2057b6b0289c4423bdfd7643518 Mon Sep 17 00:00:00 2001
From: Mike Rapoport rppt@linux.ibm.com Date: Mon, 2 Mar 2020 15:53:17 +0200 Subject: [PATCH] arm64/mm: implement unmap_hotplug_p4d_range
Signed-off-by: Mike Rapoport rppt@linux.ibm.com --- arch/arm64/mm/mmu.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 05ec8e5f1436..c76b11577558 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -840,6 +840,24 @@ static void unmap_hotplug_pud_range(pgd_t *pgdp, unsigned long addr, } while (addr = next, addr < end); }
+static void unmap_hotplug_p4d_range(pgd_t *pgd, unsigned long addr, + unsigned long end, bool free_mapped) +{ + unsigned long next; + pgd_t *p4dp, p4d; + + do { + next = p4d_addr_end(addr, end); + p4dp = p4d_offset(pgd, addr); + p4d = READ_ONCE(*p4dp); + if (p4d_none(p4d)) + continue; + + WARN_ON(!p4d_present(p4d)); + unmap_hotplug_pud_range(p4dp, addr, next, free_mapped); + } while (addr = next, addr < end); +} + static void unmap_hotplug_range(unsigned long addr, unsigned long end, bool free_mapped) { @@ -854,7 +872,7 @@ static void unmap_hotplug_range(unsigned long addr, unsigned long end, continue;
WARN_ON(!pgd_present(pgd)); - unmap_hotplug_pud_range(pgdp, addr, next, free_mapped); + unmap_hotplug_p4d_range(pgdp, addr, next, free_mapped); } while (addr = next, addr < end); }