From 24891abdb2843c61ba8496ddb8935d894692f135 Mon Sep 17 00:00:00 2001 From: Mitchell Horne Date: Mon, 6 Apr 2020 22:48:43 +0000 Subject: [PATCH] RISC-V: copy the DTB to early KVA The location of the device-tree blob is passed to the kernel by the previous booting stage (i.e. BBL or OpenSBI). Currently, we leave it untouched and mark the 1MB of memory holding it as unavailable. Instead, do what is done by other fake_preload_metadata() routines and copy to the DTB to KVA space. This is more in line with what loader(8) will provide us in the future, and it allows us to reclaim the hole in physical memory. Reviewed by: markj, kp (earlier version) Differential Revision: https://reviews.freebsd.org/D24152 --- sys/riscv/include/machdep.h | 1 - sys/riscv/include/metadata.h | 35 +++++++++++++++++++++++++ sys/riscv/include/vmparam.h | 2 ++ sys/riscv/riscv/genassym.c | 3 ++- sys/riscv/riscv/locore.S | 3 +-- sys/riscv/riscv/machdep.c | 50 +++++++++++++++++++++--------------- sys/riscv/riscv/pmap.c | 10 ++++++++ 7 files changed, 80 insertions(+), 24 deletions(-) create mode 100644 sys/riscv/include/metadata.h diff --git a/sys/riscv/include/machdep.h b/sys/riscv/include/machdep.h index 1cd34c22d64..ccfa22db312 100644 --- a/sys/riscv/include/machdep.h +++ b/sys/riscv/include/machdep.h @@ -42,7 +42,6 @@ struct riscv_bootparams { vm_offset_t kern_phys; /* Kernel base (physical) addr */ vm_offset_t kern_stack; vm_offset_t dtbp_virt; /* Device tree blob virtual addr */ - vm_offset_t dtbp_phys; /* Device tree blob physical addr */ }; extern vm_paddr_t physmap[]; diff --git a/sys/riscv/include/metadata.h b/sys/riscv/include/metadata.h new file mode 100644 index 00000000000..2d9d8242163 --- /dev/null +++ b/sys/riscv/include/metadata.h @@ -0,0 +1,35 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2020 Mitchell Horne + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#ifndef _MACHINE_METADATA_H_ +#define _MACHINE_METADATA_H_ + +#define MODINFOMD_DTBP 0x1001 + +#endif /* !_MACHINE_METADATA_H_ */ diff --git a/sys/riscv/include/vmparam.h b/sys/riscv/include/vmparam.h index 1ed90e4a15e..8c8a871a0ed 100644 --- a/sys/riscv/include/vmparam.h +++ b/sys/riscv/include/vmparam.h @@ -192,6 +192,8 @@ #define KERNENTRY (0) +#define VM_EARLY_DTB_ADDRESS (VM_MAX_KERNEL_ADDRESS - (2 * L2_SIZE)) + /* * How many physical pages per kmem arena virtual page. */ diff --git a/sys/riscv/riscv/genassym.c b/sys/riscv/riscv/genassym.c index d164ef8d326..fa5ca242102 100644 --- a/sys/riscv/riscv/genassym.c +++ b/sys/riscv/riscv/genassym.c @@ -56,10 +56,12 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include ASSYM(KERNBASE, KERNBASE); ASSYM(VM_MAXUSER_ADDRESS, VM_MAXUSER_ADDRESS); ASSYM(VM_MAX_KERNEL_ADDRESS, VM_MAX_KERNEL_ADDRESS); +ASSYM(VM_EARLY_DTB_ADDRESS, VM_EARLY_DTB_ADDRESS); ASSYM(TDF_ASTPENDING, TDF_ASTPENDING); ASSYM(TDF_NEEDRESCHED, TDF_NEEDRESCHED); @@ -104,4 +106,3 @@ ASSYM(RISCV_BOOTPARAMS_KERN_PHYS, offsetof(struct riscv_bootparams, kern_phys)); ASSYM(RISCV_BOOTPARAMS_KERN_STACK, offsetof(struct riscv_bootparams, kern_stack)); ASSYM(RISCV_BOOTPARAMS_DTBP_VIRT, offsetof(struct riscv_bootparams, dtbp_virt)); -ASSYM(RISCV_BOOTPARAMS_DTBP_PHYS, offsetof(struct riscv_bootparams, dtbp_phys)); diff --git a/sys/riscv/riscv/locore.S b/sys/riscv/riscv/locore.S index a794851bcb6..0f4a84260c4 100644 --- a/sys/riscv/riscv/locore.S +++ b/sys/riscv/riscv/locore.S @@ -217,9 +217,8 @@ va: la t0, initstack sd t0, RISCV_BOOTPARAMS_KERN_STACK(sp) - li t0, (VM_MAX_KERNEL_ADDRESS - 2 * L2_SIZE) + li t0, (VM_EARLY_DTB_ADDRESS) sd t0, RISCV_BOOTPARAMS_DTBP_VIRT(sp) - sd a1, RISCV_BOOTPARAMS_DTBP_PHYS(sp) mv a0, sp call _C_LABEL(initriscv) /* Off we go */ diff --git a/sys/riscv/riscv/machdep.c b/sys/riscv/riscv/machdep.c index 8dc05a70e28..872d6406077 100644 --- a/sys/riscv/riscv/machdep.c +++ b/sys/riscv/riscv/machdep.c @@ -81,6 +81,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include #include @@ -93,6 +94,7 @@ __FBSDID("$FreeBSD$"); #endif #ifdef FDT +#include #include #include #endif @@ -741,11 +743,19 @@ add_physmap_entry(uint64_t base, uint64_t length, vm_paddr_t *physmap, #ifdef FDT static void -try_load_dtb(caddr_t kmdp, vm_offset_t dtbp) +try_load_dtb(caddr_t kmdp) { + vm_offset_t dtbp; + + dtbp = MD_FETCH(kmdp, MODINFOMD_DTBP, vm_offset_t); #if defined(FDT_DTB_STATIC) - dtbp = (vm_offset_t)&fdt_static_dtb; + /* + * In case the device tree blob was not retrieved (from metadata) try + * to use the statically embedded one. + */ + if (dtbp == (vm_offset_t)NULL) + dtbp = (vm_offset_t)&fdt_static_dtb; #endif if (dtbp == (vm_offset_t)NULL) { @@ -777,13 +787,14 @@ cache_setup(void) * RISCVTODO: This needs to be done via loader (when it's available). */ vm_offset_t -fake_preload_metadata(struct riscv_bootparams *rvbp __unused) +fake_preload_metadata(struct riscv_bootparams *rvbp) { static uint32_t fake_preload[35]; #ifdef DDB vm_offset_t zstart = 0, zend = 0; #endif vm_offset_t lastaddr; + size_t dtb_size; int i; i = 0; @@ -824,10 +835,23 @@ fake_preload_metadata(struct riscv_bootparams *rvbp __unused) #endif #endif lastaddr = (vm_offset_t)&end; + + /* Copy the DTB to KVA space. */ + lastaddr = roundup(lastaddr, sizeof(int)); + fake_preload[i++] = MODINFO_METADATA | MODINFOMD_DTBP; + fake_preload[i++] = sizeof(vm_offset_t); + *(vm_offset_t *)&fake_preload[i] = (vm_offset_t)lastaddr; + i += sizeof(vm_offset_t) / sizeof(uint32_t); + dtb_size = fdt_totalsize(rvbp->dtbp_virt); + memmove((void *)lastaddr, (const void *)rvbp->dtbp_virt, dtb_size); + lastaddr = roundup(lastaddr + dtb_size, sizeof(int)); + fake_preload[i++] = 0; fake_preload[i] = 0; preload_metadata = (void *)fake_preload; + KASSERT(i < nitems(fake_preload), ("Too many fake_preload items")); + return (lastaddr); } @@ -836,8 +860,6 @@ initriscv(struct riscv_bootparams *rvbp) { struct mem_region mem_regions[FDT_MEM_REGIONS]; struct pcpu *pcpup; - vm_offset_t rstart, rend; - vm_offset_t s, e; int mem_regions_sz; vm_offset_t lastaddr; vm_size_t kernlen; @@ -873,7 +895,7 @@ initriscv(struct riscv_bootparams *rvbp) kern_envp = NULL; #ifdef FDT - try_load_dtb(kmdp, rvbp->dtbp_virt); + try_load_dtb(kmdp); #endif /* Load the physical memory ranges */ @@ -884,21 +906,9 @@ initriscv(struct riscv_bootparams *rvbp) if (fdt_get_mem_regions(mem_regions, &mem_regions_sz, NULL) != 0) panic("Cannot get physical memory regions"); - s = rvbp->dtbp_phys; - e = s + DTB_SIZE_MAX; - for (i = 0; i < mem_regions_sz; i++) { - rstart = mem_regions[i].mr_start; - rend = (mem_regions[i].mr_start + mem_regions[i].mr_size); - - if ((rstart < s) && (rend > e)) { - /* Exclude DTB region. */ - add_physmap_entry(rstart, (s - rstart), physmap, &physmap_idx); - add_physmap_entry(e, (rend - e), physmap, &physmap_idx); - } else { - add_physmap_entry(mem_regions[i].mr_start, - mem_regions[i].mr_size, physmap, &physmap_idx); - } + add_physmap_entry(mem_regions[i].mr_start, + mem_regions[i].mr_size, physmap, &physmap_idx); } #endif diff --git a/sys/riscv/riscv/pmap.c b/sys/riscv/riscv/pmap.c index 86b10cc9c03..9a8a83906a2 100644 --- a/sys/riscv/riscv/pmap.c +++ b/sys/riscv/riscv/pmap.c @@ -558,6 +558,7 @@ pmap_bootstrap(vm_offset_t l1pt, vm_paddr_t kernstart, vm_size_t kernlen) vm_offset_t freemempos; vm_offset_t dpcpu, msgbufpv; vm_paddr_t end, max_pa, min_pa, pa, start; + pt_entry_t *l2p; int i; printf("pmap_bootstrap %lx %lx %lx\n", l1pt, kernstart, kernlen); @@ -610,6 +611,15 @@ pmap_bootstrap(vm_offset_t l1pt, vm_paddr_t kernstart, vm_size_t kernlen) freemempos = pmap_bootstrap_l3(l1pt, VM_MAX_KERNEL_ADDRESS - L2_SIZE, freemempos); + /* + * Invalidate the mapping we created for the DTB. At this point a copy + * has been created, and we no longer need it. We want to avoid the + * possibility of an aliased mapping in the future. + */ + l2p = pmap_l2(kernel_pmap, VM_EARLY_DTB_ADDRESS); + KASSERT((pmap_load(l2p) & PTE_V) != 0, ("dtpb not mapped")); + pmap_clear(l2p); + sfence_vma(); #define alloc_pages(var, np) \