Merge tag 'riscv/for-v5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Paul Walmsley:

 - Hugepage support

 - "Image" header support for RISC-V kernel binaries, compatible with
   the current ARM64 "Image" header

 - Initial page table setup now split into two stages

 - CONFIG_SOC support (starting with SiFive SoCs)

 - Avoid reserving memory between RAM start and the kernel in
   setup_bootmem()

 - Enable high-res timers and dynamic tick in the RV64 defconfig

 - Remove long-deprecated gate area stubs

 - MAINTAINERS updates to switch to the newly-created shared RISC-V git
   tree, and to fix a get_maintainers.pl issue for patches involving
   SiFive E-mail addresses

Also, one integration fix to resolve a build problem introduced during
in the v5.3-rc1 merge window:

 - Fix build break after macro-to-function conversion in
   asm-generic/cacheflush.h

* tag 'riscv/for-v5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: fix build break after macro-to-function conversion in generic cacheflush.h
  RISC-V: Add an Image header that boot loader can parse.
  RISC-V: Setup initial page tables in two stages
  riscv: remove free_initrd_mem
  riscv: ccache: Remove unused variable
  riscv: Introduce huge page support for 32/64bit kernel
  x86, arm64: Move ARCH_WANT_HUGE_PMD_SHARE config in arch/Kconfig
  RISC-V: Fix memory reservation in setup_bootmem()
  riscv: defconfig: enable SOC_SIFIVE
  riscv: select SiFive platform drivers with SOC_SIFIVE
  arch: riscv: add config option for building SiFive's SoC resource
  riscv: Remove gate area stubs
  MAINTAINERS: change the arch/riscv git tree to the new shared tree
  MAINTAINERS: don't automatically patches involving SiFive to the linux-riscv list
  RISC-V: defconfig: Enable NO_HZ_IDLE and HIGH_RES_TIMERS

Documentation/riscv/boot-image-header.txt

+				Boot image header in RISC-V Linux
+			=============================================
+
+Author: Atish Patra <atish.patra@wdc.com>
+Date  : 20 May 2019
+
+This document only describes the boot image header details for RISC-V Linux.
+The complete booting guide will be available at Documentation/riscv/booting.txt.
+
+The following 64-byte header is present in decompressed Linux kernel image.
+
+	u32 code0;		  /* Executable code */
+	u32 code1; 		  /* Executable code */
+	u64 text_offset;	  /* Image load offset, little endian */
+	u64 image_size;		  /* Effective Image size, little endian */
+	u64 flags;		  /* kernel flags, little endian */
+	u32 version;		  /* Version of this header */
+	u32 res1  = 0;		  /* Reserved */
+	u64 res2  = 0;    	  /* Reserved */
+	u64 magic = 0x5643534952; /* Magic number, little endian, "RISCV" */
+	u32 res3;		  /* Reserved for additional RISC-V specific header */
+	u32 res4;		  /* Reserved for PE COFF offset */
+
+This header format is compliant with PE/COFF header and largely inspired from
+ARM64 header. Thus, both ARM64 & RISC-V header can be combined into one common
+header in future.
+
+Notes:
+- This header can also be reused to support EFI stub for RISC-V in future. EFI
+  specification needs PE/COFF image header in the beginning of the kernel image
+  in order to load it as an EFI application. In order to support EFI stub,
+  code0 should be replaced with "MZ" magic string and res5(at offset 0x3c) should
+  point to the rest of the PE/COFF header.
+
+- version field indicate header version number.
+	Bits 0:15  - Minor version
+	Bits 16:31 - Major version
+
+  This preserves compatibility across newer and older version of the header.
+  The current version is defined as 0.1.
+
+- res3 is reserved for offset to any other additional fields. This makes the
+  header extendible in future. One example would be to accommodate ISA
+  extension for RISC-V in future. For current version, it is set to be zero.
+
+- In current header, the flag field has only one field.
+	Bit 0: Kernel endianness. 1 if BE, 0 if LE.
+
+- Image size is mandatory for boot loader to load kernel image. Booting will
+  fail otherwise.

MAINTAINERS

@@ -13720,7 +13720,7 @@ RISC-V ARCHITECTURE
 M:	Palmer Dabbelt <palmer@sifive.com>
 M:	Albert Ou <aou@eecs.berkeley.edu>
 L:	linux-riscv@lists.infradead.org
-T:	git git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux.git
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git
 S:	Supported
 F:	arch/riscv/
 K:	riscv
@@ -14582,7 +14582,7 @@ M:	Paul Walmsley <paul.walmsley@sifive.com>
 L:	linux-riscv@lists.infradead.org
 T:	git git://github.com/sifive/riscv-linux.git
 S:	Supported
-K:	sifive
+K:	[^@]sifive
 N:	sifive
 
 SIFIVE FU540 SYSTEM-ON-CHIP

arch/Kconfig

@@ -569,6 +569,9 @@ config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 config HAVE_ARCH_HUGE_VMAP
 	bool
 
+config ARCH_WANT_HUGE_PMD_SHARE
+	bool
+
 config HAVE_ARCH_SOFT_DIRTY
 	bool
 

arch/arm64/Kconfig

@@ -73,6 +73,7 @@ config ARM64
 	select ARCH_SUPPORTS_NUMA_BALANCING
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
 	select ARCH_WANT_FRAME_POINTERS
+	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARM_AMBA
 	select ARM_ARCH_TIMER
@@ -906,7 +907,6 @@ config SYS_SUPPORTS_HUGETLBFS
 	def_bool y
 
 config ARCH_WANT_HUGE_PMD_SHARE
-	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
 
 config ARCH_HAS_CACHE_LINE_SIZE
 	def_bool y

arch/riscv/Kconfig

@@ -52,6 +52,8 @@ config RISCV
 	select ARCH_HAS_MMIOWB
 	select HAVE_EBPF_JIT if 64BIT
 	select EDAC_SUPPORT
+	select ARCH_HAS_GIGANTIC_PAGE
+	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
 
 config MMU
 	def_bool y
@@ -66,6 +68,12 @@ config PAGE_OFFSET
 	default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
 	default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
 
+config ARCH_WANT_GENERAL_HUGETLB
+	def_bool y
+
+config SYS_SUPPORTS_HUGETLBFS
+	def_bool y
+
 config STACKTRACE_SUPPORT
 	def_bool y
 
@@ -97,6 +105,8 @@ config PGTABLE_LEVELS
 	default 3 if 64BIT
 	default 2
 
+source "arch/riscv/Kconfig.socs"
+
 menu "Platform type"
 
 choice

arch/riscv/Kconfig.socs

+menu "SoC selection"
+
+config SOC_SIFIVE
+       bool "SiFive SoCs"
+       select SERIAL_SIFIVE
+       select SERIAL_SIFIVE_CONSOLE
+       select CLK_SIFIVE
+       select CLK_SIFIVE_FU540_PRCI
+       select SIFIVE_PLIC
+       help
+         This enables support for SiFive SoC platform hardware.
+
+endmenu

arch/riscv/boot/dts/sifive/Makefile

 # SPDX-License-Identifier: GPL-2.0
-dtb-y += hifive-unleashed-a00.dtb
+dtb-$(CONFIG_SOC_SIFIVE) += hifive-unleashed-a00.dtb

arch/riscv/configs/defconfig

 CONFIG_SYSVIPC=y
 CONFIG_POSIX_MQUEUE=y
+CONFIG_NO_HZ_IDLE=y
+CONFIG_HIGH_RES_TIMERS=y
 CONFIG_IKCONFIG=y
 CONFIG_IKCONFIG_PROC=y
 CONFIG_CGROUPS=y
@@ -12,6 +14,7 @@ CONFIG_CHECKPOINT_RESTORE=y
 CONFIG_BLK_DEV_INITRD=y
 CONFIG_EXPERT=y
 CONFIG_BPF_SYSCALL=y
+CONFIG_SOC_SIFIVE=y
 CONFIG_SMP=y
 CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
@@ -49,8 +52,6 @@ CONFIG_SERIAL_8250=y
 CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
 CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
-CONFIG_SERIAL_SIFIVE=y
-CONFIG_SERIAL_SIFIVE_CONSOLE=y
 CONFIG_HVC_RISCV_SBI=y
 # CONFIG_PTP_1588_CLOCK is not set
 CONFIG_DRM=y
@@ -66,9 +67,6 @@ CONFIG_USB_OHCI_HCD_PLATFORM=y
 CONFIG_USB_STORAGE=y
 CONFIG_USB_UAS=y
 CONFIG_VIRTIO_MMIO=y
-CONFIG_CLK_SIFIVE=y
-CONFIG_CLK_SIFIVE_FU540_PRCI=y
-CONFIG_SIFIVE_PLIC=y
 CONFIG_SPI_SIFIVE=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y

arch/riscv/configs/rv32_defconfig

 CONFIG_SYSVIPC=y
 CONFIG_POSIX_MQUEUE=y
+CONFIG_NO_HZ_IDLE=y
+CONFIG_HIGH_RES_TIMERS=y
 CONFIG_IKCONFIG=y
 CONFIG_IKCONFIG_PROC=y
 CONFIG_CGROUPS=y

arch/riscv/include/asm/cacheflush.h

@@ -6,11 +6,66 @@
 #ifndef _ASM_RISCV_CACHEFLUSH_H
 #define _ASM_RISCV_CACHEFLUSH_H
 
-#include <asm-generic/cacheflush.h>
+#include <linux/mm.h>
 
-#undef flush_icache_range
-#undef flush_icache_user_range
-#undef flush_dcache_page
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
+
+/*
+ * The cache doesn't need to be flushed when TLB entries change when
+ * the cache is mapped to physical memory, not virtual memory
+ */
+static inline void flush_cache_all(void)
+{
+}
+
+static inline void flush_cache_mm(struct mm_struct *mm)
+{
+}
+
+static inline void flush_cache_dup_mm(struct mm_struct *mm)
+{
+}
+
+static inline void flush_cache_range(struct vm_area_struct *vma,
+				     unsigned long start,
+				     unsigned long end)
+{
+}
+
+static inline void flush_cache_page(struct vm_area_struct *vma,
+				    unsigned long vmaddr,
+				    unsigned long pfn)
+{
+}
+
+static inline void flush_dcache_mmap_lock(struct address_space *mapping)
+{
+}
+
+static inline void flush_dcache_mmap_unlock(struct address_space *mapping)
+{
+}
+
+static inline void flush_icache_page(struct vm_area_struct *vma,
+				     struct page *page)
+{
+}
+
+static inline void flush_cache_vmap(unsigned long start, unsigned long end)
+{
+}
+
+static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
+{
+}
+
+#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
+	do { \
+		memcpy(dst, src, len); \
+		flush_icache_user_range(vma, page, vaddr, len); \
+	} while (0)
+#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
+	memcpy(dst, src, len)
 
 static inline void local_flush_icache_all(void)
 {

arch/riscv/include/asm/fixmap.h

@@ -21,6 +21,11 @@
  */
 enum fixed_addresses {
 	FIX_HOLE,
+#define FIX_FDT_SIZE	SZ_1M
+	FIX_FDT_END,
+	FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,
+	FIX_PTE,
+	FIX_PMD,
 	FIX_EARLYCON_MEM_BASE,
 	__end_of_fixed_addresses
 };

arch/riscv/include/asm/hugetlb.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_RISCV_HUGETLB_H
+#define _ASM_RISCV_HUGETLB_H
+
+#include <asm-generic/hugetlb.h>
+#include <asm/page.h>
+
+static inline int is_hugepage_only_range(struct mm_struct *mm,
+					 unsigned long addr,
+					 unsigned long len) {
+	return 0;
+}
+
+static inline void arch_clear_hugepage_flags(struct page *page)
+{
+}
+
+#endif /* _ASM_RISCV_HUGETLB_H */

arch/riscv/include/asm/image.h

+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_IMAGE_H
+#define __ASM_IMAGE_H
+
+#define RISCV_IMAGE_MAGIC	"RISCV"
+
+#define RISCV_IMAGE_FLAG_BE_SHIFT	0
+#define RISCV_IMAGE_FLAG_BE_MASK	0x1
+
+#define RISCV_IMAGE_FLAG_LE		0
+#define RISCV_IMAGE_FLAG_BE		1
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#error conversion of header fields to LE not yet implemented
+#else
+#define __HEAD_FLAG_BE		RISCV_IMAGE_FLAG_LE
+#endif
+
+#define __HEAD_FLAG(field)	(__HEAD_FLAG_##field << \
+				RISCV_IMAGE_FLAG_##field##_SHIFT)
+
+#define __HEAD_FLAGS		(__HEAD_FLAG(BE))
+
+#define RISCV_HEADER_VERSION_MAJOR 0
+#define RISCV_HEADER_VERSION_MINOR 1
+
+#define RISCV_HEADER_VERSION (RISCV_HEADER_VERSION_MAJOR << 16 | \
+			      RISCV_HEADER_VERSION_MINOR)
+
+#ifndef __ASSEMBLY__
+/**
+ * struct riscv_image_header - riscv kernel image header
+ * @code0:		Executable code
+ * @code1:		Executable code
+ * @text_offset:	Image load offset (little endian)
+ * @image_size:		Effective Image size (little endian)
+ * @flags:		kernel flags (little endian)
+ * @version:		version
+ * @res1:		reserved
+ * @res2:		reserved
+ * @magic:		Magic number
+ * @res3:		reserved (will be used for additional RISC-V specific
+ *			header)
+ * @res4:		reserved (will be used for PE COFF offset)
+ *
+ * The intention is for this header format to be shared between multiple
+ * architectures to avoid a proliferation of image header formats.
+ */
+
+struct riscv_image_header {
+	u32 code0;
+	u32 code1;
+	u64 text_offset;
+	u64 image_size;
+	u64 flags;
+	u32 version;
+	u32 res1;
+	u64 res2;
+	u64 magic;
+	u32 res3;
+	u32 res4;
+};
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_IMAGE_H */

arch/riscv/include/asm/page.h

@@ -16,6 +16,16 @@
 #define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
 #define PAGE_MASK	(~(PAGE_SIZE - 1))
 
+#ifdef CONFIG_64BIT
+#define HUGE_MAX_HSTATE		2
+#else
+#define HUGE_MAX_HSTATE		1
+#endif
+#define HPAGE_SHIFT		PMD_SHIFT
+#define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
+#define HPAGE_MASK              (~(HPAGE_SIZE - 1))
+#define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
+
 /*
  * PAGE_OFFSET -- the first address of the first page of memory.
  * When not using MMU this corresponds to the first free page in
@@ -115,8 +125,4 @@ extern unsigned long min_low_pfn;
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
-/* vDSO support */
-/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
-#define __HAVE_ARCH_GATE_AREA
-
 #endif /* _ASM_RISCV_PAGE_H */

arch/riscv/include/asm/pgtable-64.h

@@ -70,6 +70,11 @@ static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot)
 	return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
 }
 
+static inline unsigned long _pmd_pfn(pmd_t pmd)
+{
+	return pmd_val(pmd) >> _PAGE_PFN_SHIFT;
+}
+
 #define pmd_ERROR(e) \
 	pr_err("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
 

arch/riscv/include/asm/pgtable.h

@@ -59,6 +59,8 @@
 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
 
+#define PAGE_TABLE		__pgprot(_PAGE_TABLE)
+
 extern pgd_t swapper_pg_dir[];
 
 /* MAP_PRIVATE permissions: xwr (copy-on-write) */
@@ -113,12 +115,16 @@ static inline void pmd_clear(pmd_t *pmdp)
 	set_pmd(pmdp, __pmd(0));
 }
 
-
 static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
 {
 	return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
 }
 
+static inline unsigned long _pgd_pfn(pgd_t pgd)
+{
+	return pgd_val(pgd) >> _PAGE_PFN_SHIFT;
+}
+
 #define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 
 /* Locate an entry in the page global directory */
@@ -250,6 +256,11 @@ static inline pte_t pte_mkspecial(pte_t pte)
 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
 }
 
+static inline pte_t pte_mkhuge(pte_t pte)
+{
+	return pte;
+}
+
 /* Modify page protection bits */
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
@@ -396,6 +407,7 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
 #define kern_addr_valid(addr)   (1) /* FIXME */
 #endif
 
+extern void *dtb_early_va;
 extern void setup_bootmem(void);
 extern void paging_init(void);
 
@@ -409,7 +421,7 @@ static inline void pgtable_cache_init(void)
 #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
 
 /*
- * Task size is 0x40000000000 for RV64 or 0xb800000 for RV32.
+ * Task size is 0x4000000000 for RV64 or 0xb800000 for RV32.
  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
  */
 #ifdef CONFIG_64BIT

arch/riscv/kernel/head.S

@@ -11,9 +11,41 @@
 #include <asm/thread_info.h>
 #include <asm/page.h>
 #include <asm/csr.h>
+#include <asm/image.h>
 
 __INIT
 ENTRY(_start)
+	/*
+	 * Image header expected by Linux boot-loaders. The image header data
+	 * structure is described in asm/image.h.
+	 * Do not modify it without modifying the structure and all bootloaders
+	 * that expects this header format!!
+	 */
+	/* jump to start kernel */
+	j _start_kernel
+	/* reserved */
+	.word 0
+	.balign 8
+#if __riscv_xlen == 64
+	/* Image load offset(2MB) from start of RAM */
+	.dword 0x200000
+#else
+	/* Image load offset(4MB) from start of RAM */
+	.dword 0x400000
+#endif
+	/* Effective size of kernel image */
+	.dword _end - _start
+	.dword __HEAD_FLAGS
+	.word RISCV_HEADER_VERSION
+	.word 0
+	.dword 0
+	.asciz RISCV_IMAGE_MAGIC
+	.word 0
+	.balign 4
+	.word 0
+
+.global _start_kernel
+_start_kernel:
 	/* Mask all interrupts */
 	csrw CSR_SIE, zero
 	csrw CSR_SIP, zero
@@ -55,7 +87,9 @@ clear_bss_done:
 
 	/* Initialize page tables and relocate to virtual addresses */
 	la sp, init_thread_union + THREAD_SIZE
+	mv a0, s1
 	call setup_vm
+	la a0, early_pg_dir
 	call relocate
 
 	/* Restore C environment */
@@ -64,25 +98,23 @@ clear_bss_done:
 	la sp, init_thread_union + THREAD_SIZE
 
 	/* Start the kernel */
-	mv a0, s1
 	call parse_dtb
 	tail start_kernel
 
 relocate:
 	/* Relocate return address */
 	li a1, PAGE_OFFSET
-	la a0, _start
-	sub a1, a1, a0
+	la a2, _start
+	sub a1, a1, a2
 	add ra, ra, a1
 
 	/* Point stvec to virtual address of intruction after satp write */
-	la a0, 1f
-	add a0, a0, a1
-	csrw CSR_STVEC, a0
+	la a2, 1f
+	add a2, a2, a1
+	csrw CSR_STVEC, a2
 
 	/* Compute satp for kernel page tables, but don't load it yet */
-	la a2, swapper_pg_dir
-	srl a2, a2, PAGE_SHIFT
+	srl a2, a0, PAGE_SHIFT
 	li a1, SATP_MODE
 	or a2, a2, a1
 
@@ -148,6 +180,7 @@ relocate:
 	fence
 
 	/* Enable virtual memory and relocate to virtual address */
+	la a0, swapper_pg_dir
 	call relocate
 
 	tail smp_callin

arch/riscv/kernel/setup.c

@@ -39,11 +39,9 @@ struct screen_info screen_info = {
 atomic_t hart_lottery;
 unsigned long boot_cpu_hartid;
 
-void __init parse_dtb(phys_addr_t dtb_phys)
+void __init parse_dtb(void)
 {
-	void *dtb = __va(dtb_phys);
-
-	if (early_init_dt_scan(dtb))
+	if (early_init_dt_scan(dtb_early_va))
 		return;
 
 	pr_err("No DTB passed to the kernel\n");

arch/riscv/kernel/vdso.c

@@ -92,22 +92,3 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 		return "[vdso]";
 	return NULL;
 }
-
-/*
- * Function stubs to prevent linker errors when AT_SYSINFO_EHDR is defined
- */
-
-int in_gate_area_no_mm(unsigned long addr)
-{
-	return 0;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
-	return 0;
-}
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-	return NULL;
-}

arch/riscv/mm/Makefile

@@ -12,3 +12,5 @@ obj-y += ioremap.o
 obj-y += cacheflush.o
 obj-y += context.o
 obj-y += sifive_l2_cache.o
+
+obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o

arch/riscv/mm/hugetlbpage.c

+// SPDX-License-Identifier: GPL-2.0
+#include <linux/hugetlb.h>
+#include <linux/err.h>
+
+int pud_huge(pud_t pud)
+{
+	return pud_present(pud) &&
+		(pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+}
+
+int pmd_huge(pmd_t pmd)
+{
+	return pmd_present(pmd) &&
+		(pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+}
+
+static __init int setup_hugepagesz(char *opt)
+{
+	unsigned long ps = memparse(opt, &opt);
+
+	if (ps == HPAGE_SIZE) {
+		hugetlb_add_hstate(HPAGE_SHIFT - PAGE_SHIFT);
+	} else if (IS_ENABLED(CONFIG_64BIT) && ps == PUD_SIZE) {
+		hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+	} else {
+		hugetlb_bad_size();
+		pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
+		return 0;
+	}
+
+	return 1;
+}
+__setup("hugepagesz=", setup_hugepagesz);
+
+#ifdef CONFIG_CONTIG_ALLOC
+static __init int gigantic_pages_init(void)
+{
+	/* With CONTIG_ALLOC, we can allocate gigantic pages at runtime */
+	if (IS_ENABLED(CONFIG_64BIT) && !size_to_hstate(1UL << PUD_SHIFT))
+		hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+	return 0;
+}
+arch_initcall(gigantic_pages_init);
+#endif

arch/riscv/mm/init.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
  */
 
 #include <linux/init.h>
@@ -21,6 +22,8 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
 							__page_aligned_bss;
 EXPORT_SYMBOL(empty_zero_page);
 
+extern char _start[];
+
 static void __init zone_sizes_init(void)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
@@ -39,13 +42,6 @@ void setup_zero_page(void)
 	memset((void *)empty_zero_page, 0, PAGE_SIZE);
 }
 
-void __init paging_init(void)
-{
-	setup_zero_page();
-	local_flush_tlb_all();
-	zone_sizes_init();
-}
-
 void __init mem_init(void)
 {
 #ifdef CONFIG_FLATMEM
@@ -84,29 +80,20 @@ static void __init setup_initrd(void)
 	initrd_start = 0;
 	initrd_end = 0;
 }
-
-void __init free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
 #endif /* CONFIG_BLK_DEV_INITRD */
 
 void __init setup_bootmem(void)
 {
 	struct memblock_region *reg;
 	phys_addr_t mem_size = 0;
+	phys_addr_t vmlinux_end = __pa(&_end);
+	phys_addr_t vmlinux_start = __pa(&_start);
 
 	/* Find the memory region containing the kernel */
 	for_each_memblock(memory, reg) {
-		phys_addr_t vmlinux_end = __pa(_end);
 		phys_addr_t end = reg->base + reg->size;
 
 		if (reg->base <= vmlinux_end && vmlinux_end <= end) {
-			/*
-			 * Reserve from the start of the region to the end of
-			 * the kernel
-			 */
-			memblock_reserve(reg->base, vmlinux_end - reg->base);
 			mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
 
 			/*
@@ -120,6 +107,9 @@ void __init setup_bootmem(void)
 	}
 	BUG_ON(mem_size == 0);
 
+	/* Reserve from the start of the kernel to the end of the kernel */
+	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
+
 	set_max_mapnr(PFN_DOWN(mem_size));
 	max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
 
@@ -147,17 +137,15 @@ EXPORT_SYMBOL(va_pa_offset);
 unsigned long pfn_base;
 EXPORT_SYMBOL(pfn_base);
 
+void *dtb_early_va;
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
-pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
+pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
+pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
+static bool mmu_enabled;
 
-#ifndef __PAGETABLE_PMD_FOLDED
-#define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
-pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
-pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
-pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
-#endif
+#define MAX_EARLY_MAPPING_SIZE	SZ_128M
 
-pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
+pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 
 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
 {
@@ -176,6 +164,156 @@ void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
 	}
 }
 
+static pte_t *__init get_pte_virt(phys_addr_t pa)
+{
+	if (mmu_enabled) {
+		clear_fixmap(FIX_PTE);
+		return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
+	} else {
+		return (pte_t *)((uintptr_t)pa);
+	}
+}
+
+static phys_addr_t __init alloc_pte(uintptr_t va)
+{
+	/*
+	 * We only create PMD or PGD early mappings so we
+	 * should never reach here with MMU disabled.
+	 */
+	BUG_ON(!mmu_enabled);
+
+	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+}
+
+static void __init create_pte_mapping(pte_t *ptep,
+				      uintptr_t va, phys_addr_t pa,
+				      phys_addr_t sz, pgprot_t prot)
+{
+	uintptr_t pte_index = pte_index(va);
+
+	BUG_ON(sz != PAGE_SIZE);
+
+	if (pte_none(ptep[pte_index]))
+		ptep[pte_index] = pfn_pte(PFN_DOWN(pa), prot);
+}
+
+#ifndef __PAGETABLE_PMD_FOLDED
+
+pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
+pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
+
+#if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
+#define NUM_EARLY_PMDS		1UL
+#else
+#define NUM_EARLY_PMDS		(1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
+#endif
+pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
+
+static pmd_t *__init get_pmd_virt(phys_addr_t pa)
+{
+	if (mmu_enabled) {
+		clear_fixmap(FIX_PMD);
+		return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
+	} else {
+		return (pmd_t *)((uintptr_t)pa);
+	}
+}
+
+static phys_addr_t __init alloc_pmd(uintptr_t va)
+{
+	uintptr_t pmd_num;
+
+	if (mmu_enabled)
+		return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+
+	pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
+	BUG_ON(pmd_num >= NUM_EARLY_PMDS);
+	return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
+}
+
+static void __init create_pmd_mapping(pmd_t *pmdp,
+				      uintptr_t va, phys_addr_t pa,
+				      phys_addr_t sz, pgprot_t prot)
+{
+	pte_t *ptep;
+	phys_addr_t pte_phys;
+	uintptr_t pmd_index = pmd_index(va);
+
+	if (sz == PMD_SIZE) {
+		if (pmd_none(pmdp[pmd_index]))
+			pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pa), prot);
+		return;
+	}
+
+	if (pmd_none(pmdp[pmd_index])) {
+		pte_phys = alloc_pte(va);
+		pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
+		ptep = get_pte_virt(pte_phys);
+		memset(ptep, 0, PAGE_SIZE);
+	} else {
+		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_index]));
+		ptep = get_pte_virt(pte_phys);
+	}
+
+	create_pte_mapping(ptep, va, pa, sz, prot);
+}
+
+#define pgd_next_t		pmd_t
+#define alloc_pgd_next(__va)	alloc_pmd(__va)
+#define get_pgd_next_virt(__pa)	get_pmd_virt(__pa)
+#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
+	create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
+#define PTE_PARENT_SIZE		PMD_SIZE
+#define fixmap_pgd_next		fixmap_pmd
+#else
+#define pgd_next_t		pte_t
+#define alloc_pgd_next(__va)	alloc_pte(__va)
+#define get_pgd_next_virt(__pa)	get_pte_virt(__pa)
+#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
+	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
+#define PTE_PARENT_SIZE		PGDIR_SIZE
+#define fixmap_pgd_next		fixmap_pte
+#endif
+
+static void __init create_pgd_mapping(pgd_t *pgdp,
+				      uintptr_t va, phys_addr_t pa,
+				      phys_addr_t sz, pgprot_t prot)
+{
+	pgd_next_t *nextp;
+	phys_addr_t next_phys;
+	uintptr_t pgd_index = pgd_index(va);
+
+	if (sz == PGDIR_SIZE) {
+		if (pgd_val(pgdp[pgd_index]) == 0)
+			pgdp[pgd_index] = pfn_pgd(PFN_DOWN(pa), prot);
+		return;
+	}
+
+	if (pgd_val(pgdp[pgd_index]) == 0) {
+		next_phys = alloc_pgd_next(va);
+		pgdp[pgd_index] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
+		nextp = get_pgd_next_virt(next_phys);
+		memset(nextp, 0, PAGE_SIZE);
+	} else {
+		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_index]));
+		nextp = get_pgd_next_virt(next_phys);
+	}
+
+	create_pgd_next_mapping(nextp, va, pa, sz, prot);
+}
+
+static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
+{
+	uintptr_t map_size = PAGE_SIZE;
+
+	/* Upgrade to PMD/PGDIR mappings whenever possible */
+	if (!(base & (PTE_PARENT_SIZE - 1)) &&
+	    !(size & (PTE_PARENT_SIZE - 1)))
+		map_size = PTE_PARENT_SIZE;
+
+	return map_size;
+}
+
 /*
  * setup_vm() is called from head.S with MMU-off.
  *
@@ -195,55 +333,115 @@ void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
 	"not use absolute addressing."
 #endif
 
-asmlinkage void __init setup_vm(void)
+asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 {
-	extern char _start;
-	uintptr_t i;
-	uintptr_t pa = (uintptr_t) &_start;
-	pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
+	uintptr_t va, end_va;
+	uintptr_t load_pa = (uintptr_t)(&_start);
+	uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
+	uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
 
-	va_pa_offset = PAGE_OFFSET - pa;
-	pfn_base = PFN_DOWN(pa);
+	va_pa_offset = PAGE_OFFSET - load_pa;
+	pfn_base = PFN_DOWN(load_pa);
+
+	/*
+	 * Enforce boot alignment requirements of RV32 and
+	 * RV64 by only allowing PMD or PGD mappings.
+	 */
+	BUG_ON(map_size == PAGE_SIZE);
 
 	/* Sanity check alignment and size */
 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
-	BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
+	BUG_ON((load_pa % map_size) != 0);
+	BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
+
+	/* Setup early PGD for fixmap */
+	create_pgd_mapping(early_pg_dir, FIXADDR_START,
+			   (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
 
 #ifndef __PAGETABLE_PMD_FOLDED
-	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
-		pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
-			__pgprot(_PAGE_TABLE));
-	trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
+	/* Setup fixmap PMD */
+	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
+			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
+	/* Setup trampoline PGD and PMD */
+	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
+			   (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
+	create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
+			   load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
+#else
+	/* Setup trampoline PGD */
+	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
+			   load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
+#endif
 
-	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
-		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
+	/*
+	 * Setup early PGD covering entire kernel which will allows
+	 * us to reach paging_init(). We map all memory banks later
+	 * in setup_vm_final() below.
+	 */
+	end_va = PAGE_OFFSET + load_sz;
+	for (va = PAGE_OFFSET; va < end_va; va += map_size)
+		create_pgd_mapping(early_pg_dir, va,
+				   load_pa + (va - PAGE_OFFSET),
+				   map_size, PAGE_KERNEL_EXEC);
+
+	/* Create fixed mapping for early FDT parsing */
+	end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
+	for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
+		create_pte_mapping(fixmap_pte, va,
+				   dtb_pa + (va - __fix_to_virt(FIX_FDT)),
+				   PAGE_SIZE, PAGE_KERNEL);
+
+	/* Save pointer to DTB for early FDT parsing */
+	dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
+}
 
-		swapper_pg_dir[o] =
-			pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
-				__pgprot(_PAGE_TABLE));
-	}
-	for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
-		swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
-
-	swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
-		pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd),
-				__pgprot(_PAGE_TABLE));
-	fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] =
-		pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte),
-				__pgprot(_PAGE_TABLE));
-#else
-	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
-		pfn_pgd(PFN_DOWN(pa), prot);
+static void __init setup_vm_final(void)
+{
+	uintptr_t va, map_size;
+	phys_addr_t pa, start, end;
+	struct memblock_region *reg;
 
-	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
-		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
+	/* Set mmu_enabled flag */
+	mmu_enabled = true;
 
-		swapper_pg_dir[o] =
-			pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
+	/* Setup swapper PGD for fixmap */
+	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
+			   __pa(fixmap_pgd_next),
+			   PGDIR_SIZE, PAGE_TABLE);
+
+	/* Map all memory banks */
+	for_each_memblock(memory, reg) {
+		start = reg->base;
+		end = start + reg->size;
+
+		if (start >= end)
+			break;
+		if (memblock_is_nomap(reg))
+			continue;
+		if (start <= __pa(PAGE_OFFSET) &&
+		    __pa(PAGE_OFFSET) < end)
+			start = __pa(PAGE_OFFSET);
+
+		map_size = best_map_size(start, end - start);
+		for (pa = start; pa < end; pa += map_size) {
+			va = (uintptr_t)__va(pa);
+			create_pgd_mapping(swapper_pg_dir, va, pa,
+					   map_size, PAGE_KERNEL_EXEC);
+		}
 	}
 
-	swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
-		pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte),
-				__pgprot(_PAGE_TABLE));
-#endif
+	/* Clear fixmap PTE and PMD mappings */
+	clear_fixmap(FIX_PTE);
+	clear_fixmap(FIX_PMD);
+
+	/* Move to swapper page table */
+	csr_write(sptbr, PFN_DOWN(__pa(swapper_pg_dir)) | SATP_MODE);
+	local_flush_tlb_all();
+}
+
+void __init paging_init(void)
+{
+	setup_vm_final();
+	setup_zero_page();
+	zone_sizes_init();
 }

arch/riscv/mm/sifive_l2_cache.c

@@ -109,13 +109,14 @@ EXPORT_SYMBOL_GPL(unregister_sifive_l2_error_notifier);
 
 static irqreturn_t l2_int_handler(int irq, void *device)
 {
-	unsigned int regval, add_h, add_l;
+	unsigned int add_h, add_l;
 
 	if (irq == g_irq[DIR_CORR]) {
 		add_h = readl(l2_base + SIFIVE_L2_DIRECCFIX_HIGH);
 		add_l = readl(l2_base + SIFIVE_L2_DIRECCFIX_LOW);
 		pr_err("L2CACHE: DirError @ 0x%08X.%08X\n", add_h, add_l);
-		regval = readl(l2_base + SIFIVE_L2_DIRECCFIX_COUNT);
+		/* Reading this register clears the DirError interrupt sig */
+		readl(l2_base + SIFIVE_L2_DIRECCFIX_COUNT);
 		atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_CE,
 					   "DirECCFix");
 	}
@@ -123,7 +124,8 @@ static irqreturn_t l2_int_handler(int irq, void *device)
 		add_h = readl(l2_base + SIFIVE_L2_DATECCFIX_HIGH);
 		add_l = readl(l2_base + SIFIVE_L2_DATECCFIX_LOW);
 		pr_err("L2CACHE: DataError @ 0x%08X.%08X\n", add_h, add_l);
-		regval = readl(l2_base + SIFIVE_L2_DATECCFIX_COUNT);
+		/* Reading this register clears the DataError interrupt sig */
+		readl(l2_base + SIFIVE_L2_DATECCFIX_COUNT);
 		atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_CE,
 					   "DatECCFix");
 	}
@@ -131,7 +133,8 @@ static irqreturn_t l2_int_handler(int irq, void *device)
 		add_h = readl(l2_base + SIFIVE_L2_DATECCFAIL_HIGH);
 		add_l = readl(l2_base + SIFIVE_L2_DATECCFAIL_LOW);
 		pr_err("L2CACHE: DataFail @ 0x%08X.%08X\n", add_h, add_l);
-		regval = readl(l2_base + SIFIVE_L2_DATECCFAIL_COUNT);
+		/* Reading this register clears the DataFail interrupt sig */
+		readl(l2_base + SIFIVE_L2_DATECCFAIL_COUNT);
 		atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_UE,
 					   "DatECCFail");
 	}

arch/x86/Kconfig

@@ -94,6 +94,7 @@ config X86
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
 	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
+	select ARCH_WANT_HUGE_PMD_SHARE
 	select ARCH_WANTS_THP_SWAP		if X86_64
 	select BUILDTIME_EXTABLE_SORT
 	select CLKEVT_I8253
@@ -307,9 +308,6 @@ config ARCH_HIBERNATION_POSSIBLE
 config ARCH_SUSPEND_POSSIBLE
 	def_bool y
 
-config ARCH_WANT_HUGE_PMD_SHARE
-	def_bool y
-
 config ARCH_WANT_GENERAL_HUGETLB
 	def_bool y