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authorPalmer Dabbelt <palmer@sifive.com>2019-03-04 11:41:36 -0800
committerPalmer Dabbelt <palmer@sifive.com>2019-03-04 11:47:04 -0800
commit13fd5de06514458eb320188b7a815d65696efd99 (patch)
treefaa6d1ce1c20eb3b909ccecf481b865869463083 /arch/riscv
parentarch: riscv: fix logic error in parse_dtb (diff)
parentRISC-V: Free-up initrd in free_initrd_mem() (diff)
downloadlinux-dev-13fd5de06514458eb320188b7a815d65696efd99.tar.xz
linux-dev-13fd5de06514458eb320188b7a815d65696efd99.zip
RISC-V: Fixmap support and MM cleanups
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, we get earlyprints even without SBI calls. For example, we can now 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. Palmer: It looks like some of the code movement here conflicted with the patches to move hartid handling around. As far as I can tell the only changed code was in smp_setup_processor_id(), and I've kept the one in smp.c.
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/Kconfig3
-rw-r--r--arch/riscv/include/asm/fixmap.h44
-rw-r--r--arch/riscv/include/asm/pgtable.h1
-rw-r--r--arch/riscv/kernel/setup.c130
-rw-r--r--arch/riscv/kernel/smp.c2
-rw-r--r--arch/riscv/mm/init.c156
6 files changed, 208 insertions, 128 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index b60f4e3e36f4..ceed055179c8 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/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index a8179a8c1491..1141364d990e 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 12a16df4d422..ecb654f6a79e 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -23,7 +23,6 @@
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/sched.h>
-#include <linux/initrd.h>
#include <linux/console.h>
#include <linux/screen_info.h>
#include <linux/of_fdt.h>
@@ -61,83 +60,6 @@ EXPORT_SYMBOL(empty_zero_page);
atomic_t hart_lottery;
unsigned long boot_cpu_hartid;
-#ifdef CONFIG_BLK_DEV_INITRD
-static void __init setup_initrd(void)
-{
- unsigned long size;
-
- if (initrd_start >= initrd_end) {
- pr_info("initrd not found or empty");
- goto disable;
- }
- if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
- pr_err("initrd extends beyond end of memory");
- goto disable;
- }
-
- size = initrd_end - initrd_start;
- memblock_reserve(__pa(initrd_start), size);
- initrd_below_start_ok = 1;
-
- pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
- (void *)(initrd_start), size);
- return;
-disable:
- pr_cont(" - disabling initrd\n");
- initrd_start = 0;
- initrd_end = 0;
-}
-#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)))
@@ -150,60 +72,17 @@ 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)
{
- *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();
@@ -222,4 +101,3 @@ void __init setup_arch(char **cmdline_p)
riscv_fill_hwcap();
}
-
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index ca99f0fb49b1..0c41d07ec281 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -42,7 +42,7 @@ unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
void __init smp_setup_processor_id(void)
{
- cpuid_to_hartid_map(0) = boot_cpu_hartid;
+ cpuid_to_hartid_map(0) = boot_cpu_hartid;
}
/* A collection of single bit ipi messages. */
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 658ebf645f42..b379a75ac6a6 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -17,7 +17,9 @@
#include <linux/initrd.h>
#include <linux/swap.h>
#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>
@@ -66,7 +68,159 @@ void free_initmem(void)
}
#ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
+static void __init setup_initrd(void)
{
+ unsigned long size;
+
+ if (initrd_start >= initrd_end) {
+ pr_info("initrd not found or empty");
+ goto disable;
+ }
+ if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
+ pr_err("initrd extends beyond end of memory");
+ goto disable;
+ }
+
+ size = initrd_end - initrd_start;
+ memblock_reserve(__pa(initrd_start), size);
+ initrd_below_start_ok = 1;
+
+ pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
+ (void *)(initrd_start), size);
+ return;
+disable:
+ pr_cont(" - disabling initrd\n");
+ 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;
+
+ /* 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);
+ }
+}
+
+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);
+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;
+ 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);
+
+ 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
+}