From: Palmer Dabbelt <palmer@sifive.com>
Date: Mon, 4 Mar 2019 19:41:36 +0000 (-0800)
Subject: RISC-V: Fixmap support and MM cleanups
X-Git-Tag: v5.1-rc1~129^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=13fd5de06514458eb320188b7a815d65696efd99;p=thirdparty%2Fkernel%2Flinux.git

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.
---

13fd5de06514458eb320188b7a815d65696efd99
diff --cc arch/riscv/kernel/setup.c
index 12a16df4d422f,cffe0b3caba42..ecb654f6a79ef
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@@ -61,86 -60,18 +60,9 @@@ 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
 -unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
 -	[0 ... NR_CPUS-1] = INVALID_HARTID
 -};
--
- asmlinkage void __init setup_vm(void)
 -void __init smp_setup_processor_id(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
 -	cpuid_to_hartid_map(0) = boot_cpu_hartid;
--}
--
  void __init parse_dtb(unsigned int hartid, void *dtb)
  {
 -	if (!early_init_dt_scan(__va(dtb)))
 +	if (early_init_dt_scan(__va(dtb)))
  		return;
  
  	pr_err("No DTB passed to the kernel\n");
diff --cc arch/riscv/kernel/smp.c
index ca99f0fb49b16,246635eac7bb5..0c41d07ec281e
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@@ -36,15 -36,6 +36,15 @@@ enum ipi_message_type 
  	IPI_MAX
  };
  
 +unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
 +	[0 ... NR_CPUS-1] = INVALID_HARTID
 +};
 +
 +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.  */
  static struct {
  	unsigned long stats[IPI_MAX] ____cacheline_aligned;