| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <cbfs.h> |
| #include <commonlib/helpers.h> |
| #include <console/console.h> |
| #include <cpu/cpu.h> |
| #include <cpu/x86/cr.h> |
| #include <cpu/x86/msr.h> |
| #include <cpu/x86/pae.h> |
| #include <string.h> |
| #include <symbols.h> |
| #include <types.h> |
| |
| #define PDPTE_PRES (1ULL << 0) |
| #define PDPTE_ADDR_MASK (~((1ULL << 12) - 1)) |
| |
| #define PDE_PRES (1ULL << 0) |
| #define PDE_RW (1ULL << 1) |
| #define PDE_US (1ULL << 2) |
| #define PDE_PWT (1ULL << 3) |
| #define PDE_PCD (1ULL << 4) |
| #define PDE_A (1ULL << 5) |
| #define PDE_D (1ULL << 6) // only valid with PS=1 |
| #define PDE_PS (1ULL << 7) |
| #define PDE_G (1ULL << 8) // only valid with PS=1 |
| #define PDE_PAT (1ULL << 12) // only valid with PS=1 |
| #define PDE_XD (1ULL << 63) |
| #define PDE_ADDR_MASK (~((1ULL << 12) - 1)) |
| |
| #define PTE_PRES (1ULL << 0) |
| #define PTE_RW (1ULL << 1) |
| #define PTE_US (1ULL << 2) |
| #define PTE_PWT (1ULL << 3) |
| #define PTE_PCD (1ULL << 4) |
| #define PTE_A (1ULL << 5) |
| #define PTE_D (1ULL << 6) |
| #define PTE_PAT (1ULL << 7) |
| #define PTE_G (1ULL << 8) |
| #define PTE_XD (1ULL << 63) |
| |
| #define PDPTE_IDX_SHIFT 30 |
| #define PDPTE_IDX_MASK 0x3 |
| |
| #define PDE_IDX_SHIFT 21 |
| #define PDE_IDX_MASK 0x1ff |
| |
| #define PTE_IDX_SHIFT 12 |
| #define PTE_IDX_MASK 0x1ff |
| |
| #define OVERLAP(a, b, s, e) ((b) > (s) && (a) < (e)) |
| |
| static const size_t s2MiB = 2 * MiB; |
| static const size_t s4KiB = 4 * KiB; |
| |
| struct pde { |
| uint32_t addr_lo; |
| uint32_t addr_hi; |
| } __packed; |
| struct pg_table { |
| struct pde pd[2048]; |
| struct pde pdp[512]; |
| } __packed; |
| |
| void paging_enable_pae_cr3(uintptr_t cr3) |
| { |
| /* Load the page table address */ |
| write_cr3(cr3); |
| paging_enable_pae(); |
| } |
| |
| void paging_enable_pae(void) |
| { |
| CRx_TYPE cr0; |
| CRx_TYPE cr4; |
| |
| /* Enable PAE */ |
| cr4 = read_cr4(); |
| cr4 |= CR4_PAE; |
| write_cr4(cr4); |
| |
| /* Enable Paging */ |
| cr0 = read_cr0(); |
| cr0 |= CR0_PG; |
| write_cr0(cr0); |
| } |
| |
| void paging_disable_pae(void) |
| { |
| CRx_TYPE cr0; |
| CRx_TYPE cr4; |
| |
| /* Disable Paging */ |
| cr0 = read_cr0(); |
| cr0 &= ~(CRx_TYPE)CR0_PG; |
| write_cr0(cr0); |
| |
| /* Disable PAE */ |
| cr4 = read_cr4(); |
| cr4 &= ~(CRx_TYPE)CR4_PAE; |
| write_cr4(cr4); |
| } |
| |
| /* |
| * Use PAE to map a page and then memset it with the pattern specified. |
| * In order to use PAE pagetables for virtual addressing are set up and reloaded |
| * on a 2MiB boundary. After the function is done, virtual addressing mode is |
| * disabled again. The PAT are set to all cacheable, but MTRRs still apply. |
| * |
| * Requires a scratch memory for pagetables and a virtual address for |
| * non identity mapped memory. |
| * |
| * The scratch memory area containing pagetables must not overlap with the |
| * memory range to be cleared. |
| * The scratch memory area containing pagetables must not overlap with the |
| * virtual address for non identity mapped memory. |
| * |
| * @param vmem_addr Where the virtual non identity mapped page resides, must |
| * be 2 aligned MiB and at least 2 MiB in size. |
| * Content at physical address is preserved. |
| * @param pgtbl Where pagetables reside, must be 4 KiB aligned and 20 KiB in |
| * size. |
| * Must not overlap memory range pointed to by dest. |
| * Must not overlap memory range pointed to by vmem_addr. |
| * Content at physical address isn't preserved. |
| * @param length The length of the memory segment to memset |
| * @param dest Physical memory address to memset |
| * @param pat The pattern to write to the physical memory |
| * @return 0 on success, 1 on error |
| */ |
| int memset_pae(uint64_t dest, unsigned char pat, uint64_t length, void *pgtbl, |
| void *vmem_addr) |
| { |
| struct pg_table *pgtbl_buf = (struct pg_table *)pgtbl; |
| ssize_t offset; |
| |
| printk(BIOS_DEBUG, "%s: Using virtual address %p as scratchpad\n", |
| __func__, vmem_addr); |
| printk(BIOS_DEBUG, "%s: Using address %p for page tables\n", |
| __func__, pgtbl_buf); |
| |
| /* Cover some basic error conditions */ |
| if (!IS_ALIGNED((uintptr_t)pgtbl_buf, s4KiB) || |
| !IS_ALIGNED((uintptr_t)vmem_addr, s2MiB)) { |
| printk(BIOS_ERR, "%s: Invalid alignment\n", __func__); |
| return 1; |
| } |
| const uintptr_t pgtbl_s = (uintptr_t)pgtbl_buf; |
| const uintptr_t pgtbl_e = pgtbl_s + sizeof(struct pg_table); |
| |
| if (OVERLAP(dest, dest + length, pgtbl_s, pgtbl_e)) { |
| printk(BIOS_ERR, "%s: destination overlaps page tables\n", |
| __func__); |
| return 1; |
| } |
| |
| if (OVERLAP((uintptr_t)vmem_addr, (uintptr_t)vmem_addr + s2MiB, |
| pgtbl_s, pgtbl_e)) { |
| printk(BIOS_ERR, "%s: vmem address overlaps page tables\n", |
| __func__); |
| return 1; |
| } |
| |
| paging_disable_pae(); |
| |
| struct pde *pd = pgtbl_buf->pd, *pdp = pgtbl_buf->pdp; |
| /* Point the page directory pointers at the page directories. */ |
| memset(pgtbl_buf->pdp, 0, sizeof(pgtbl_buf->pdp)); |
| |
| pdp[0].addr_lo = ((uintptr_t)&pd[512*0]) | PDPTE_PRES; |
| pdp[1].addr_lo = ((uintptr_t)&pd[512*1]) | PDPTE_PRES; |
| pdp[2].addr_lo = ((uintptr_t)&pd[512*2]) | PDPTE_PRES; |
| pdp[3].addr_lo = ((uintptr_t)&pd[512*3]) | PDPTE_PRES; |
| |
| offset = dest - ALIGN_DOWN(dest, s2MiB); |
| dest = ALIGN_DOWN(dest, s2MiB); |
| |
| /* Identity map the whole 32-bit address space */ |
| for (size_t i = 0; i < 2048; i++) { |
| pd[i].addr_lo = (i << PDE_IDX_SHIFT) | PDE_PS | PDE_PRES | PDE_RW; |
| pd[i].addr_hi = 0; |
| } |
| |
| /* Get pointer to PD that's not identity mapped */ |
| pd = &pgtbl_buf->pd[((uintptr_t)vmem_addr) >> PDE_IDX_SHIFT]; |
| |
| paging_enable_pae_cr3((uintptr_t)pdp); |
| |
| do { |
| const size_t len = MIN(length, s2MiB - offset); |
| |
| /* |
| * Map a page using PAE at virtual address vmem_addr. |
| * dest is already 2 MiB aligned. |
| */ |
| pd->addr_lo = dest | PDE_PS | PDE_PRES | PDE_RW; |
| pd->addr_hi = dest >> 32; |
| |
| /* Update page tables */ |
| asm volatile ("invlpg (%0)" :: "b"(vmem_addr) : "memory"); |
| |
| printk(BIOS_SPEW, "%s: Clearing %llx[%lx] - %zx\n", __func__, |
| dest + offset, (uintptr_t)vmem_addr + offset, len); |
| |
| memset(vmem_addr + offset, pat, len); |
| |
| dest += s2MiB; |
| length -= len; |
| offset = 0; |
| } while (length > 0); |
| |
| paging_disable_pae(); |
| |
| return 0; |
| } |
| |
| void paging_set_nxe(int enable) |
| { |
| msr_t msr = rdmsr(IA32_EFER); |
| |
| if (enable) |
| msr.lo |= EFER_NXE; |
| else |
| msr.lo &= ~EFER_NXE; |
| |
| wrmsr(IA32_EFER, msr); |
| } |
| |
| void paging_set_pat(uint64_t pat) |
| { |
| msr_t msr; |
| msr.lo = pat; |
| msr.hi = pat >> 32; |
| wrmsr(IA32_PAT, msr); |
| } |
| |
| /* PAT encoding used in util/x86/x86_page_tables.go. It matches the linux |
| * kernel settings: |
| * PTE encoding: |
| * PAT |
| * |PCD |
| * ||PWT PAT |
| * ||| slot |
| * 000 0 WB : _PAGE_CACHE_MODE_WB |
| * 001 1 WC : _PAGE_CACHE_MODE_WC |
| * 010 2 UC-: _PAGE_CACHE_MODE_UC_MINUS |
| * 011 3 UC : _PAGE_CACHE_MODE_UC |
| * 100 4 WB : Reserved |
| * 101 5 WP : _PAGE_CACHE_MODE_WP |
| * 110 6 UC-: Reserved |
| * 111 7 WT : _PAGE_CACHE_MODE_WT |
| */ |
| void paging_set_default_pat(void) |
| { |
| uint64_t pat = PAT_ENCODE(WB, 0) | PAT_ENCODE(WC, 1) | |
| PAT_ENCODE(UC_MINUS, 2) | PAT_ENCODE(UC, 3) | |
| PAT_ENCODE(WB, 4) | PAT_ENCODE(WP, 5) | |
| PAT_ENCODE(UC_MINUS, 6) | PAT_ENCODE(WT, 7); |
| paging_set_pat(pat); |
| } |
| |
| int paging_enable_for_car(const char *pdpt_name, const char *pt_name) |
| { |
| if (!preram_symbols_available()) |
| return -1; |
| |
| if (!cbfs_load(pdpt_name, _pdpt, REGION_SIZE(pdpt))) { |
| printk(BIOS_ERR, "Couldn't load pdpt\n"); |
| return -1; |
| } |
| |
| if (!cbfs_load(pt_name, _pagetables, REGION_SIZE(pagetables))) { |
| printk(BIOS_ERR, "Couldn't load page tables\n"); |
| return -1; |
| } |
| |
| paging_enable_pae_cr3((uintptr_t)_pdpt); |
| |
| return 0; |
| } |