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[util] Remove enum_bitfields

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The enum_bitfields system never worked quite right, and always had edge cases where name
resolution for the SFINAE would fail. Move everything over to use util::bitset, which can
be constexpr and boils down to inline integer bitops in release mode.

Improved util::bitset itself, moving the array-backed base implementation into a new
util::sized_bitset, and making the single-inttype backed implementation the base case.
Also added a distinction between | or |= (which work with real bit values) and + or +=
(which work with bit indexes).
This commit is contained in:
Justin C. Miller
2024-02-25 23:40:14 -08:00
parent f7ea46e49e
commit 9f54927a82
36 changed files with 352 additions and 622 deletions
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29
src/kernel/gdt.cpp
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@@ -22,6 +22,9 @@ static constexpr uint8_t tss_index = 6; // Note that this takes TWO GDT en
static util::no_construct<GDT> __g_bsp_gdt_storage;
GDT &g_bsp_gdt = __g_bsp_gdt_storage.value;
static constexpr util::bitset8 ring3 = util::bitset8::of( GDT::type::ring1, GDT::type::ring2 );
static constexpr util::bitset8 rw = util::bitset8::of( GDT::type::read_write );
static constexpr util::bitset8 rwx = util::bitset8::of( GDT::type::read_write, GDT::type::execute );
GDT::GDT(TSS *tss) :
m_tss(tss)
@@ -32,13 +35,13 @@ GDT::GDT(TSS *tss) :
m_ptr.base = &m_entries[0];
// Kernel CS/SS - always 64bit
set(kern_cs_index, 0, 0xfffff, true, type::read_write | type::execute);
set(kern_ss_index, 0, 0xfffff, true, type::read_write);
set(kern_cs_index, 0, 0xfffff, true, rwx);
set(kern_ss_index, 0, 0xfffff, true, rw);
// User CS32/SS/CS64 - layout expected by SYSRET
set(user_cs32_index, 0, 0xfffff, false, type::ring3 | type::read_write | type::execute);
set(user_ss_index, 0, 0xfffff, true, type::ring3 | type::read_write);
set(user_cs64_index, 0, 0xfffff, true, type::ring3 | type::read_write | type::execute);
set(user_cs32_index, 0, 0xfffff, false, ring3 | rwx);
set(user_ss_index, 0, 0xfffff, true, ring3 | rw);
set(user_cs64_index, 0, 0xfffff, true, ring3 | rwx);
set_tss(tss);
}
@@ -61,7 +64,7 @@ GDT::install() const
}
void
GDT::set(uint8_t i, uint32_t base, uint64_t limit, bool is64, type t)
GDT::set(uint8_t i, uint32_t base, uint64_t limit, bool is64, util::bitset8 t)
{
m_entries[i].limit_low = limit & 0xffff;
m_entries[i].size = (limit >> 16) & 0xf;
@@ -71,7 +74,9 @@ GDT::set(uint8_t i, uint32_t base, uint64_t limit, bool is64, type t)
m_entries[i].base_mid = (base >> 16) & 0xff;
m_entries[i].base_high = (base >> 24) & 0xff;
m_entries[i].type = t | type::system | type::present;
static constexpr util::bitset8 sp = util::bitset8::of( type::system, type::present );
m_entries[i].type = t;
m_entries[i].type |= sp;
}
struct tss_descriptor
@@ -79,7 +84,7 @@ struct tss_descriptor
uint16_t limit_low;
uint16_t base_00;
uint8_t base_16;
GDT::type type;
util::bitset8 type;
uint8_t size;
uint8_t base_24;
uint32_t base_32;
@@ -102,11 +107,9 @@ GDT::set_tss(TSS *tss)
tssd.base_32 = (base >> 32) & 0xffffffff;
tssd.reserved = 0;
tssd.type =
type::accessed |
type::execute |
type::ring3 |
type::present;
static constexpr util::bitset8 tss_mark =
util::bitset8::of(type::accessed, type::execute, type::present);
tssd.type = ring3 | tss_mark;
memcpy(&m_entries[tss_index], &tssd, sizeof(tss_descriptor));
}