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refactor(mm): rework how map_kernel is defined

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Loïc Grégoire
2026-04-18 20:56:52 -04:00
parent c48ae7fc1e
commit 1d747029c4
1 changed files with 75 additions and 80 deletions
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src/mm/init.zig
+75 -80
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@@ -4,101 +4,96 @@ const mm = r.mm;
const mi = mm.private; const mi = mm.private;
const config = @import("config"); const config = @import("config");
const is_um = @hasDecl(config, "CONFIG_ARCH_UM"); extern var text_start_addr: u8;
extern var text_end_addr: u8;
extern var rodata_start_addr: u8;
extern var rodata_end_addr: u8;
extern var data_start_addr: u8;
extern var data_end_addr: u8;
pub const map_kernel = if (!is_um) fn map_kernel(boot_info: *pl.BootInfo) void {
struct { const kaddr = boot_info.kernel_address;
extern var text_start_addr: u8;
extern var text_end_addr: u8;
extern var rodata_start_addr: u8;
extern var rodata_end_addr: u8;
extern var data_start_addr: u8;
extern var data_end_addr: u8;
pub fn call(boot_info: *pl.BootInfo) void {
const kaddr = boot_info.kernel_address;
const text_start = @intFromPtr(&text_start_addr); const text_start = @intFromPtr(&text_start_addr);
const text_end = @intFromPtr(&text_end_addr); const text_end = @intFromPtr(&text_end_addr);
const rodata_start = @intFromPtr(&rodata_start_addr); const rodata_start = @intFromPtr(&rodata_start_addr);
const rodata_end = @intFromPtr(&rodata_end_addr); const rodata_end = @intFromPtr(&rodata_end_addr);
const data_start = @intFromPtr(&data_start_addr); const data_start = @intFromPtr(&data_start_addr);
const data_end = @intFromPtr(&data_end_addr); const data_end = @intFromPtr(&data_end_addr);
const text_size = text_end - text_start; const text_size = text_end - text_start;
const rodata_size = rodata_end - rodata_start; const rodata_size = rodata_end - rodata_start;
const data_size = data_end - data_start; const data_size = data_end - data_start;
const start_phys = kaddr.physical_base; const start_phys = kaddr.physical_base;
const start_virt = kaddr.virtual_base; const start_virt = kaddr.virtual_base;
const until_size = text_start - start_virt; const until_size = text_start - start_virt;
mi.kernel_pmap.map_contiguous_range(start_virt, start_phys, until_size, .{
.read = true,
.write = true,
.global = true,
});
mi.kernel_pmap.map_contiguous_range(text_start, kaddr.physical_base + (text_start - kaddr.virtual_base), text_size, .{ mi.kernel_pmap.map_contiguous_range(start_virt, start_phys, until_size, .{
.read = true, .read = true,
.execute = true, .write = true,
.global = true, .global = true,
}); });
mi.kernel_pmap.map_contiguous_range(rodata_start, kaddr.physical_base + (rodata_start - kaddr.virtual_base), rodata_size, .{ mi.kernel_pmap.map_contiguous_range(text_start, kaddr.physical_base + (text_start - kaddr.virtual_base), text_size, .{
.read = true, .read = true,
.global = true, .execute = true,
}); .global = true,
});
mi.kernel_pmap.map_contiguous_range(data_start, kaddr.physical_base + (data_start - kaddr.virtual_base), data_size, .{ mi.kernel_pmap.map_contiguous_range(rodata_start, kaddr.physical_base + (rodata_start - kaddr.virtual_base), rodata_size, .{
.read = true, .read = true,
.write = true, .global = true,
.global = true, });
});
mi.kernel_pmap.map_contiguous_range(mm.p2v(0), 0, mi.impl.hhdm_minimum_max_address, .{ mi.kernel_pmap.map_contiguous_range(data_start, kaddr.physical_base + (data_start - kaddr.virtual_base), data_size, .{
.read = true, .read = true,
.write = true, .write = true,
.global = true, .global = true,
}); });
// Now go through every usable entry and map to the HHDM every part that isnt covered by [0, hhdm_minimum_max_address). mi.kernel_pmap.map_contiguous_range(mm.p2v(0), 0, mi.impl.hhdm_minimum_max_address, .{
// We can't blindly map until the maximum usable physical address because on some CPUs this might cause MCEs. .read = true,
// See https://github.com/torvalds/linux/commit/66520ebc2df3fe52eb4792f8101fac573b766baf .write = true,
for (0..boot_info.memory_map.entry_count) |i| { .global = true,
const entry = boot_info.memory_map.entries[i]; });
if ((entry.type != .Free and entry.type != .LoaderReclaimable) or entry.size < mm.page_size) { // Now go through every usable entry and map to the HHDM every part that isnt covered by [0, hhdm_minimum_max_address).
continue; // We can't blindly map until the maximum usable physical address because on some CPUs this might cause MCEs.
} // See https://github.com/torvalds/linux/commit/66520ebc2df3fe52eb4792f8101fac573b766baf
for (0..boot_info.memory_map.entry_count) |i| {
const entry = boot_info.memory_map.entries[i];
if (entry.base + entry.size <= mi.impl.hhdm_minimum_max_address) { if ((entry.type != .Free and entry.type != .LoaderReclaimable) or entry.size < mm.page_size) {
continue; continue;
}
var entry_start = entry.base;
var entry_size = entry.size;
if (entry.base < mi.impl.hhdm_minimum_max_address) {
const adjust = mi.impl.hhdm_minimum_max_address - entry.base;
entry_start += adjust;
entry_size -= adjust;
}
mi.kernel_pmap.map_contiguous_range(mm.p2v(entry_start), entry_start, entry_size, .{
.read = true,
.write = true,
.global = true,
});
}
} }
}.call
else if (entry.base + entry.size <= mi.impl.hhdm_minimum_max_address) {
struct { continue;
pub fn call(_: *pl.BootInfo) void {} }
}.call;
var entry_start = entry.base;
var entry_size = entry.size;
if (entry.base < mi.impl.hhdm_minimum_max_address) {
const adjust = mi.impl.hhdm_minimum_max_address - entry.base;
entry_start += adjust;
entry_size -= adjust;
}
mi.kernel_pmap.map_contiguous_range(mm.p2v(entry_start), entry_start, entry_size, .{
.read = true,
.write = true,
.global = true,
});
}
}
pub fn init(boot_info: *pl.BootInfo) linksection(r.init) void { pub fn init(boot_info: *pl.BootInfo) linksection(r.init) void {
mi.phys.init(boot_info); mi.phys.init(boot_info);
map_kernel(boot_info); if (!@hasDecl(config, "CONFIG_ARCH_UM")) {
map_kernel(boot_info);
}
mi.kernel_pmap.activate(); mi.kernel_pmap.activate();
mi.phys.init_pfndb(); mi.phys.init_pfndb();
mi.zone.early_init(); mi.zone.early_init();