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* [PATCH v3 0/6] Fixmap support and MM cleanups
@ 2019-02-12 14:00 Anup Patel
  2019-02-12 14:00 ` [PATCH v3 1/6] RISC-V: Move free_initrd_mem() to kernel/setup.c Anup Patel
                   ` (5 more replies)
  0 siblings, 6 replies; 8+ messages in thread
From: Anup Patel @ 2019-02-12 14:00 UTC (permalink / raw)
  To: Palmer Dabbelt, Albert Ou
  Cc: Anup Patel, linux-kernel, Christoph Hellwig, Atish Patra,
	Paul Walmsley, linux-riscv

From: Anup Patel <anup@brainfault.org>

This patchset does:
1. Moves MM related code from kernel/setup.c to mm/init.c
2. Implements compile-time fixed mappings

Using fixed mappings available, we can now get earlyprints
even without SBI calls. For example, we can use kernel
parameter "earlycon=uart8250,mmio,0x10000000" to get early
prints on QEMU virt machine without using SBI calls.

The patchset is tested on QEMU virt machine. It is based on
Linux-5.0-rc6 and can be found at riscv_fixmap_v3 branch of:
https://github.com/avpatel/linux.git.

Changes since v2:
 - Fixed commit description of PATCH6
 - Ensured commit description of all PATCH use upto 72
   characters per line

Changes since v1:
 - Use more characters per line in changelog of PATCH3
 - Removed #ifndef __ASSEMBLY__ from PATCH5
 - Use more characters per line in commets of PATCH5
 - Added PATCH6 to implement keepinitrd kernel parameter

Anup Patel (6):
  RISC-V: Move free_initrd_mem() to kernel/setup.c
  RISC-V: Setup init_mm before parse_early_param()
  RISC-V: Move setup_bootmem() to mm/init.c
  RISC-V: Move setup_vm() to mm/init.c
  RISC-V: Implement compile-time fixed mappings
  RISC-V: Implement keepinitrd kernel parameter

 arch/riscv/Kconfig               |   3 +
 arch/riscv/include/asm/fixmap.h  |  44 +++++++++++
 arch/riscv/include/asm/pgtable.h |   1 +
 arch/riscv/kernel/setup.c        | 114 ++++++----------------------
 arch/riscv/mm/init.c             | 124 ++++++++++++++++++++++++++++++-
 5 files changed, 189 insertions(+), 97 deletions(-)
 create mode 100644 arch/riscv/include/asm/fixmap.h

-- 
2.17.1


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^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v3 1/6] RISC-V: Move free_initrd_mem() to kernel/setup.c
  2019-02-12 14:00 [PATCH v3 0/6] Fixmap support and MM cleanups Anup Patel
@ 2019-02-12 14:00 ` Anup Patel
  2019-02-12 14:00 ` [PATCH v3 2/6] RISC-V: Setup init_mm before parse_early_param() Anup Patel
                   ` (4 subsequent siblings)
  5 siblings, 0 replies; 8+ messages in thread
From: Anup Patel @ 2019-02-12 14:00 UTC (permalink / raw)
  To: Palmer Dabbelt, Albert Ou
  Cc: Anup Patel, linux-kernel, Christoph Hellwig, Atish Patra,
	Paul Walmsley, linux-riscv

We move free_initrd_mem() to kernel/setup.c so that all initrd related
functions are in one place.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 arch/riscv/kernel/setup.c | 4 ++++
 arch/riscv/mm/init.c      | 7 -------
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 77564310235f..36f60b4d2147 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -96,6 +96,10 @@ static void __init setup_initrd(void)
 	initrd_start = 0;
 	initrd_end = 0;
 }
+
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+}
 #endif /* CONFIG_BLK_DEV_INITRD */
 
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 658ebf645f42..504a5e491f5a 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -14,7 +14,6 @@
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/memblock.h>
-#include <linux/initrd.h>
 #include <linux/swap.h>
 #include <linux/sizes.h>
 
@@ -64,9 +63,3 @@ void free_initmem(void)
 {
 	free_initmem_default(0);
 }
-
-#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
-{
-}
-#endif /* CONFIG_BLK_DEV_INITRD */
-- 
2.17.1


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^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v3 2/6] RISC-V: Setup init_mm before parse_early_param()
  2019-02-12 14:00 [PATCH v3 0/6] Fixmap support and MM cleanups Anup Patel
  2019-02-12 14:00 ` [PATCH v3 1/6] RISC-V: Move free_initrd_mem() to kernel/setup.c Anup Patel
@ 2019-02-12 14:00 ` Anup Patel
  2019-02-12 14:00 ` [PATCH v3 3/6] RISC-V: Move setup_bootmem() to mm/init.c Anup Patel
                   ` (3 subsequent siblings)
  5 siblings, 0 replies; 8+ messages in thread
From: Anup Patel @ 2019-02-12 14:00 UTC (permalink / raw)
  To: Palmer Dabbelt, Albert Ou
  Cc: Anup Patel, linux-kernel, Christoph Hellwig, Atish Patra,
	Paul Walmsley, linux-riscv

We should setup init_mm before doing parse_early_param() in setup_arch()
to be consistent with setup_arch() of other architectures such as x86,
ARM, and ARM64.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 arch/riscv/kernel/setup.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 36f60b4d2147..9e6395b7d409 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -208,15 +208,15 @@ static void __init setup_bootmem(void)
 
 void __init setup_arch(char **cmdline_p)
 {
-	*cmdline_p = boot_command_line;
-
-	parse_early_param();
-
 	init_mm.start_code = (unsigned long) _stext;
 	init_mm.end_code   = (unsigned long) _etext;
 	init_mm.end_data   = (unsigned long) _edata;
 	init_mm.brk        = (unsigned long) _end;
 
+	*cmdline_p = boot_command_line;
+
+	parse_early_param();
+
 	setup_bootmem();
 	paging_init();
 	unflatten_device_tree();
@@ -235,4 +235,3 @@ void __init setup_arch(char **cmdline_p)
 
 	riscv_fill_hwcap();
 }
-
-- 
2.17.1


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^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v3 3/6] RISC-V: Move setup_bootmem() to mm/init.c
  2019-02-12 14:00 [PATCH v3 0/6] Fixmap support and MM cleanups Anup Patel
  2019-02-12 14:00 ` [PATCH v3 1/6] RISC-V: Move free_initrd_mem() to kernel/setup.c Anup Patel
  2019-02-12 14:00 ` [PATCH v3 2/6] RISC-V: Setup init_mm before parse_early_param() Anup Patel
@ 2019-02-12 14:00 ` Anup Patel
  2019-02-12 14:00 ` [PATCH v3 4/6] RISC-V: Move setup_vm() " Anup Patel
                   ` (2 subsequent siblings)
  5 siblings, 0 replies; 8+ messages in thread
From: Anup Patel @ 2019-02-12 14:00 UTC (permalink / raw)
  To: Palmer Dabbelt, Albert Ou
  Cc: Anup Patel, linux-kernel, Christoph Hellwig, Atish Patra,
	Paul Walmsley, linux-riscv

The setup_bootmem() mainly populates memblocks and does early memory
reservations. The right location for this function is mm/init.c.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 arch/riscv/include/asm/pgtable.h |  1 +
 arch/riscv/kernel/setup.c        | 48 ++++----------------------------
 arch/riscv/mm/init.c             | 40 ++++++++++++++++++++++++++
 3 files changed, 46 insertions(+), 43 deletions(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 16301966d65b..35893810cba3 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -404,6 +404,7 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
 #define kern_addr_valid(addr)   (1) /* FIXME */
 #endif
 
+extern void setup_bootmem(void);
 extern void paging_init(void);
 
 static inline void pgtable_cache_init(void)
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 9e6395b7d409..ab29a66a17fc 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -163,49 +163,6 @@ void __init parse_dtb(unsigned int hartid, void *dtb)
 #endif
 }
 
-static void __init setup_bootmem(void)
-{
-	struct memblock_region *reg;
-	phys_addr_t mem_size = 0;
-
-	/* 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);
-		}
-	}
-	BUG_ON(mem_size == 0);
-
-	set_max_mapnr(PFN_DOWN(mem_size));
-	max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
-
-#ifdef CONFIG_BLK_DEV_INITRD
-	setup_initrd();
-#endif /* CONFIG_BLK_DEV_INITRD */
-
-	early_init_fdt_reserve_self();
-	early_init_fdt_scan_reserved_mem();
-	memblock_allow_resize();
-	memblock_dump_all();
-
-	for_each_memblock(memory, reg) {
-		unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
-		unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
-
-		memblock_set_node(PFN_PHYS(start_pfn),
-		                  PFN_PHYS(end_pfn - start_pfn),
-		                  &memblock.memory, 0);
-	}
-}
-
 void __init setup_arch(char **cmdline_p)
 {
 	init_mm.start_code = (unsigned long) _stext;
@@ -218,6 +175,11 @@ void __init setup_arch(char **cmdline_p)
 	parse_early_param();
 
 	setup_bootmem();
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	setup_initrd();
+#endif /* CONFIG_BLK_DEV_INITRD */
+
 	paging_init();
 	unflatten_device_tree();
 
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 504a5e491f5a..a57dba8ac9e7 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -16,6 +16,7 @@
 #include <linux/memblock.h>
 #include <linux/swap.h>
 #include <linux/sizes.h>
+#include <linux/of_fdt.h>
 
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
@@ -63,3 +64,42 @@ void free_initmem(void)
 {
 	free_initmem_default(0);
 }
+
+void __init setup_bootmem(void)
+{
+	struct memblock_region *reg;
+	phys_addr_t mem_size = 0;
+
+	/* 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);
+		}
+	}
+	BUG_ON(mem_size == 0);
+
+	set_max_mapnr(PFN_DOWN(mem_size));
+	max_low_pfn = memblock_end_of_DRAM();
+
+	early_init_fdt_reserve_self();
+	early_init_fdt_scan_reserved_mem();
+	memblock_allow_resize();
+	memblock_dump_all();
+
+	for_each_memblock(memory, reg) {
+		unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
+		unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
+
+		memblock_set_node(PFN_PHYS(start_pfn),
+				  PFN_PHYS(end_pfn - start_pfn),
+				  &memblock.memory, 0);
+	}
+}
-- 
2.17.1


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^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v3 4/6] RISC-V: Move setup_vm() to mm/init.c
  2019-02-12 14:00 [PATCH v3 0/6] Fixmap support and MM cleanups Anup Patel
                   ` (2 preceding siblings ...)
  2019-02-12 14:00 ` [PATCH v3 3/6] RISC-V: Move setup_bootmem() to mm/init.c Anup Patel
@ 2019-02-12 14:00 ` " Anup Patel
  2019-02-12 14:00 ` [PATCH v3 5/6] RISC-V: Implement compile-time fixed mappings Anup Patel
  2019-02-12 14:01 ` [PATCH v3 6/6] RISC-V: Implement keepinitrd kernel parameter Anup Patel
  5 siblings, 0 replies; 8+ messages in thread
From: Anup Patel @ 2019-02-12 14:00 UTC (permalink / raw)
  To: Palmer Dabbelt, Albert Ou
  Cc: Anup Patel, linux-kernel, Christoph Hellwig, Atish Patra,
	Paul Walmsley, linux-riscv

The setup_vm() is responsible for setting up initial page table hence
should be placed in mm/init.c.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 arch/riscv/kernel/setup.c | 49 ---------------------------------------
 arch/riscv/mm/init.c      | 49 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 49 deletions(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index ab29a66a17fc..9cd583b6d1cd 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -102,55 +102,6 @@ void free_initrd_mem(unsigned long start, unsigned long end)
 }
 #endif /* CONFIG_BLK_DEV_INITRD */
 
-pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
-pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
-
-#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);
-#endif
-
-asmlinkage void __init setup_vm(void)
-{
-	extern char _start;
-	uintptr_t i;
-	uintptr_t pa = (uintptr_t) &_start;
-	pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
-
-	va_pa_offset = PAGE_OFFSET - pa;
-	pfn_base = PFN_DOWN(pa);
-
-	/* Sanity check alignment and size */
-	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
-	BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
-
-#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);
-
-	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
-		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
-		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);
-#else
-	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
-		pfn_pgd(PFN_DOWN(pa), prot);
-
-	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
-		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
-		swapper_pg_dir[o] =
-			pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
-	}
-#endif
-}
-
 void __init parse_dtb(unsigned int hartid, void *dtb)
 {
 	if (!early_init_dt_scan(__va(dtb)))
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index a57dba8ac9e7..7ed6ae90cf6b 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -103,3 +103,52 @@ void __init setup_bootmem(void)
 				  &memblock.memory, 0);
 	}
 }
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
+pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
+
+#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);
+#endif
+
+asmlinkage void __init setup_vm(void)
+{
+	extern char _start;
+	uintptr_t i;
+	uintptr_t pa = (uintptr_t) &_start;
+	pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
+
+	va_pa_offset = PAGE_OFFSET - pa;
+	pfn_base = PFN_DOWN(pa);
+
+	/* Sanity check alignment and size */
+	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
+	BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
+
+#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);
+
+	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
+		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
+		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);
+#else
+	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
+		pfn_pgd(PFN_DOWN(pa), prot);
+
+	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
+		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
+		swapper_pg_dir[o] =
+			pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
+	}
+#endif
+}
-- 
2.17.1


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^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v3 5/6] RISC-V: Implement compile-time fixed mappings
  2019-02-12 14:00 [PATCH v3 0/6] Fixmap support and MM cleanups Anup Patel
                   ` (3 preceding siblings ...)
  2019-02-12 14:00 ` [PATCH v3 4/6] RISC-V: Move setup_vm() " Anup Patel
@ 2019-02-12 14:00 ` Anup Patel
  2019-02-12 14:01 ` [PATCH v3 6/6] RISC-V: Implement keepinitrd kernel parameter Anup Patel
  5 siblings, 0 replies; 8+ messages in thread
From: Anup Patel @ 2019-02-12 14:00 UTC (permalink / raw)
  To: Palmer Dabbelt, Albert Ou
  Cc: Anup Patel, linux-kernel, Christoph Hellwig, Atish Patra,
	Paul Walmsley, linux-riscv

This patch implements compile-time virtual to physical mappings. These
compile-time fixed mappings can be used by earlycon, ACPI, and early
ioremap for creating fixed mappings when FIX_EARLYCON_MEM=y.

To start with, we have enabled compile-time fixed mappings for earlycon.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 arch/riscv/Kconfig              |  3 +++
 arch/riscv/include/asm/fixmap.h | 44 +++++++++++++++++++++++++++++++++
 arch/riscv/mm/init.c            | 34 +++++++++++++++++++++++++
 3 files changed, 81 insertions(+)
 create mode 100644 arch/riscv/include/asm/fixmap.h

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 515fc3cc9687..3cfd10d35a28 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -89,6 +89,9 @@ config GENERIC_CSUM
 config GENERIC_HWEIGHT
 	def_bool y
 
+config FIX_EARLYCON_MEM
+	def_bool y
+
 config PGTABLE_LEVELS
 	int
 	default 3 if 64BIT
diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h
new file mode 100644
index 000000000000..57afe604b495
--- /dev/null
+++ b/arch/riscv/include/asm/fixmap.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ */
+
+#ifndef _ASM_RISCV_FIXMAP_H
+#define _ASM_RISCV_FIXMAP_H
+
+#include <linux/kernel.h>
+#include <linux/sizes.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+/*
+ * Here we define all the compile-time 'special' virtual addresses.
+ * The point is to have a constant address at compile time, but to
+ * set the physical address only in the boot process.
+ *
+ * These 'compile-time allocated' memory buffers are page-sized. Use
+ * set_fixmap(idx,phys) to associate physical memory with fixmap indices.
+ */
+enum fixed_addresses {
+	FIX_HOLE,
+	FIX_EARLYCON_MEM_BASE,
+	__end_of_fixed_addresses
+};
+
+#define FIXADDR_SIZE		(__end_of_fixed_addresses * PAGE_SIZE)
+#define FIXADDR_TOP		(PAGE_OFFSET)
+#define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)
+
+#define FIXMAP_PAGE_IO		PAGE_KERNEL
+
+#define __early_set_fixmap	__set_fixmap
+
+#define __late_set_fixmap	__set_fixmap
+#define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
+
+extern void __set_fixmap(enum fixed_addresses idx,
+			 phys_addr_t phys, pgprot_t prot);
+
+#include <asm-generic/fixmap.h>
+
+#endif /* _ASM_RISCV_FIXMAP_H */
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 7ed6ae90cf6b..efcbdb9b3da3 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -18,6 +18,7 @@
 #include <linux/sizes.h>
 #include <linux/of_fdt.h>
 
+#include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
 #include <asm/pgtable.h>
@@ -111,8 +112,28 @@ pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 #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
 
+pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
+
+void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
+{
+	unsigned long addr = __fix_to_virt(idx);
+	pte_t *ptep;
+
+	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
+
+	ptep = &fixmap_pte[pte_index(addr)];
+
+	if (pgprot_val(prot)) {
+		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
+	} else {
+		pte_clear(&init_mm, addr, ptep);
+		local_flush_tlb_page(addr);
+	}
+}
+
 asmlinkage void __init setup_vm(void)
 {
 	extern char _start;
@@ -135,20 +156,33 @@ asmlinkage void __init setup_vm(void)
 
 	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
+
 		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);
 
 	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
+
 		swapper_pg_dir[o] =
 			pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
 	}
+
+	swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
+		pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte),
+				__pgprot(_PAGE_TABLE));
 #endif
 }
-- 
2.17.1


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^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v3 6/6] RISC-V: Implement keepinitrd kernel parameter
  2019-02-12 14:00 [PATCH v3 0/6] Fixmap support and MM cleanups Anup Patel
                   ` (4 preceding siblings ...)
  2019-02-12 14:00 ` [PATCH v3 5/6] RISC-V: Implement compile-time fixed mappings Anup Patel
@ 2019-02-12 14:01 ` Anup Patel
  2019-02-12 14:07   ` Andreas Schwab
  5 siblings, 1 reply; 8+ messages in thread
From: Anup Patel @ 2019-02-12 14:01 UTC (permalink / raw)
  To: Palmer Dabbelt, Albert Ou
  Cc: Anup Patel, linux-kernel, Christoph Hellwig, Atish Patra,
	Paul Walmsley, linux-riscv

This patch implements keepinitrd kernel parameter. By default,
keepinitrd=0 so initrd memory will be freed by default freed but
users can pass "keepinitrd=1" to keep the initrd memory.

The keepinitrd kernel parameter is already implemented by unicore32,
arm, and arm64 architectures and it is documented at:
Documentation/admin-guide/kernel-parameters.txt

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 arch/riscv/kernel/setup.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 9cd583b6d1cd..46e547dd8245 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -97,8 +97,20 @@ static void __init setup_initrd(void)
 	initrd_end = 0;
 }
 
-void free_initrd_mem(unsigned long start, unsigned long end)
+static int keep_initrd __initdata;
+
+static int __init keepinitrd_setup(char *__unused)
+{
+	keep_initrd = 1;
+	return 1;
+}
+
+__setup("keepinitrd", keepinitrd_setup);
+
+void __init free_initrd_mem(unsigned long start, unsigned long end)
 {
+	if (!keep_initrd)
+		memblock_free(__pa(start), end - start);
 }
 #endif /* CONFIG_BLK_DEV_INITRD */
 
-- 
2.17.1


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^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v3 6/6] RISC-V: Implement keepinitrd kernel parameter
  2019-02-12 14:01 ` [PATCH v3 6/6] RISC-V: Implement keepinitrd kernel parameter Anup Patel
@ 2019-02-12 14:07   ` Andreas Schwab
  0 siblings, 0 replies; 8+ messages in thread
From: Andreas Schwab @ 2019-02-12 14:07 UTC (permalink / raw)
  To: Anup Patel
  Cc: Albert Ou, Palmer Dabbelt, linux-kernel, Christoph Hellwig,
	Atish Patra, Paul Walmsley, linux-riscv

On Feb 12 2019, Anup Patel <Anup.Patel@wdc.com> wrote:

> This patch implements keepinitrd kernel parameter. By default,
> keepinitrd=0 so initrd memory will be freed by default freed but

-freed

Andreas.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

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^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, back to index

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-02-12 14:00 [PATCH v3 0/6] Fixmap support and MM cleanups Anup Patel
2019-02-12 14:00 ` [PATCH v3 1/6] RISC-V: Move free_initrd_mem() to kernel/setup.c Anup Patel
2019-02-12 14:00 ` [PATCH v3 2/6] RISC-V: Setup init_mm before parse_early_param() Anup Patel
2019-02-12 14:00 ` [PATCH v3 3/6] RISC-V: Move setup_bootmem() to mm/init.c Anup Patel
2019-02-12 14:00 ` [PATCH v3 4/6] RISC-V: Move setup_vm() " Anup Patel
2019-02-12 14:00 ` [PATCH v3 5/6] RISC-V: Implement compile-time fixed mappings Anup Patel
2019-02-12 14:01 ` [PATCH v3 6/6] RISC-V: Implement keepinitrd kernel parameter Anup Patel
2019-02-12 14:07   ` Andreas Schwab

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