cpu/x86/pae/pgtbl.c: remove dead paging_identity_map_addr()

This function had roughly the same use (except PAT) as part of
memset_pae(), however the latter is able to make use of PAE and map
physical memory located above 4 GB. Remove paging_identity_map_addr()
to avoid semi-duplicated code.

The function has been unused since CB:26745.

Change-Id: I7a4ebd84a6f5d222c3b2c6c6e3d26d6464cf01b8
Signed-off-by: Krystian Hebel <krystian.hebel@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82248
Reviewed-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 0 insertions, 179 deletions

diff --git a/src/cpu/x86/pae/pgtbl.c b/src/cpu/x86/pae/pgtbl.c
index 2bcb67c980c3..e1803aa40ea4 100644
--- a/src/cpu/x86/pae/pgtbl.c
+++ b/src/cpu/x86/pae/pgtbl.c
@@ -277,177 +277,3 @@ int paging_enable_for_car(const char *pdpt_name, const char *pt_name)
 
 	return 0;
 }
-
-static void *get_pdpt_addr(void)
-{
-	if (preram_symbols_available())
-		return _pdpt;
-	return (void *)(uintptr_t)read_cr3();
-}
-
-static uint64_t pde_pat_flags(int pat)
-{
-	switch (pat) {
-	case PAT_UC:
-		return 0 | PDE_PCD | PDE_PWT;
-	case PAT_WC:
-		return 0 | 0 | PDE_PWT;
-	case PAT_WT:
-		return PDE_PAT | PDE_PCD | PDE_PWT;
-	case PAT_WP:
-		return PDE_PAT | 0 | PDE_PWT;
-	case PAT_WB:
-		return 0 | 0 | 0;
-	case PAT_UC_MINUS:
-		return 0 | PDE_PCD | 0;
-	default:
-		printk(BIOS_ERR, "PDE PAT defaulting to WB: %x\n", pat);
-		return pde_pat_flags(PAT_WB);
-	}
-}
-
-static uint64_t pde_page_flags(int pat)
-{
-	uint64_t flags = PDE_PS | PDE_PRES | PDE_RW | PDE_A | PDE_D;
-
-	return flags | pde_pat_flags(pat);
-}
-
-static uint64_t pte_pat_flags(int pat)
-{
-	switch (pat) {
-	case PAT_UC:
-		return 0 | PTE_PCD | PTE_PWT;
-	case PAT_WC:
-		return 0 | 0 | PTE_PWT;
-	case PAT_WT:
-		return PTE_PAT | PTE_PCD | PTE_PWT;
-	case PAT_WP:
-		return PTE_PAT | 0 | PTE_PWT;
-	case PAT_WB:
-		return 0 | 0 | 0;
-	case PAT_UC_MINUS:
-		return 0 | PTE_PCD | 0;
-	default:
-		printk(BIOS_ERR, "PTE PAT defaulting to WB: %x\n", pat);
-		return pte_pat_flags(PAT_WB);
-	}
-}
-
-static uint64_t pte_page_flags(int pat)
-{
-	uint64_t flags = PTE_PRES | PTE_RW | PTE_A | PTE_D;
-	return flags | pte_pat_flags(pat);
-}
-
-/* Identity map an address. This function does not handle splitting or adding
- * new pages to the page tables. It's assumed all the page tables are already
- * seeded with the correct amount and topology. */
-static int identity_map_one_page(uintptr_t base, size_t size, int pat,
-				int commit)
-{
-	uint64_t (*pdpt)[4];
-	uint64_t pdpte;
-	uint64_t (*pd)[512];
-	uint64_t pde;
-
-	pdpt = get_pdpt_addr();
-
-	pdpte = (*pdpt)[(base >> PDPTE_IDX_SHIFT) & PDPTE_IDX_MASK];
-
-	/* No page table page allocation. */
-	if (!(pdpte & PDPTE_PRES))
-		return -1;
-
-	pd = (void *)(uintptr_t)(pdpte & PDPTE_ADDR_MASK);
-
-	/* Map in a 2MiB page. */
-	if (size == s2MiB) {
-		if (!commit)
-			return 0;
-		pde = base;
-		pde |= pde_page_flags(pat);
-		(*pd)[(base >> PDE_IDX_SHIFT) & PDE_IDX_MASK] = pde;
-		return 0;
-	}
-
-	if (size == s4KiB) {
-		uint64_t (*pt)[512];
-		uint64_t pte;
-
-		pde = (*pd)[(base >> PDE_IDX_SHIFT) & PDE_IDX_MASK];
-
-		/* No page table page allocation. */
-		if (!(pde & PDE_PRES)) {
-			printk(BIOS_ERR, "Cannot allocate page table for pde %p\n",
-				(void *)base);
-			return -1;
-		}
-
-		/* No splitting pages */
-		if (pde & PDE_PS) {
-			printk(BIOS_ERR, "Cannot split pde %p\n", (void *)base);
-			return -1;
-		}
-
-		if (!commit)
-			return 0;
-
-		pt = (void *)(uintptr_t)(pde & PDE_ADDR_MASK);
-		pte = base;
-		pte |= pte_page_flags(pat);
-		(*pt)[(base >> PTE_IDX_SHIFT) & PTE_IDX_MASK] = pte;
-
-		return 0;
-	}
-
-	return -1;
-}
-
-static int _paging_identity_map_addr(uintptr_t base, size_t size, int pat,
-					int commit)
-{
-	while (size != 0) {
-		size_t map_size;
-
-		map_size = IS_ALIGNED(base, s2MiB) ? s2MiB : s4KiB;
-		map_size = MIN(size, map_size);
-
-		if (identity_map_one_page(base, map_size, pat, commit) < 0)
-			return -1;
-
-		base += map_size;
-		size -= map_size;
-	}
-
-	return 0;
-}
-
-static int paging_is_enabled(void)
-{
-	return !!(read_cr0() & CR0_PG);
-}
-
-int paging_identity_map_addr(uintptr_t base, size_t size, int pat)
-{
-	if (!paging_is_enabled()) {
-		printk(BIOS_ERR, "Paging is not enabled.\n");
-		return -1;
-	}
-
-	if (!IS_ALIGNED(base, s2MiB) && !IS_ALIGNED(base, s4KiB)) {
-		printk(BIOS_ERR, "base %p is not aligned.\n", (void *)base);
-		return -1;
-	}
-
-	if (!IS_ALIGNED(size, s2MiB) && !IS_ALIGNED(size, s4KiB)) {
-		printk(BIOS_ERR, "size %zx is not aligned.\n", size);
-		return -1;
-	}
-
-	/* First try without committing. If success commit. */
-	if (_paging_identity_map_addr(base, size, pat, 0))
-		return -1;
-
-	return _paging_identity_map_addr(base, size, pat, 1);
-}
diff --git a/src/include/cpu/x86/pae.h b/src/include/cpu/x86/pae.h
index 3accd9e66712..d1cf7347c26f 100644
--- a/src/include/cpu/x86/pae.h
+++ b/src/include/cpu/x86/pae.h
@@ -35,11 +35,6 @@ void paging_set_default_pat(void);
  * failure. */
 int paging_enable_for_car(const char *pdpt_name, const char *pt_name);
 
-/* Identity map the region indicated by 'base' and 'size'. Both 'base' and
- * 'size' need to be 4KiB or 2 MiB aligned. 'pat' should be one of the
- * PAT defines above. 0 is returned on success, < 0 on failure. */
-int paging_identity_map_addr(uintptr_t base, size_t size, int pat);
-
 /* To be used with memset_pae */
 #define MEMSET_PAE_VMEM_ALIGN (2 * MiB)
 #define MEMSET_PAE_VMEM_SIZE (2 * MiB)