RISC-V: Add early ioremap support
UEFI uses early IO or memory mappings for runtime services before
normal ioremap() is usable. Add the necessary fixmap bindings and
pmd mappings for generic ioremap support to work.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 2b651f6..b75ebe8 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -403,6 +403,9 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
uintptr_t load_pa = (uintptr_t)(&_start);
uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
+#ifndef __PAGETABLE_PMD_FOLDED
+ pmd_t fix_bmap_spmd, fix_bmap_epmd;
+#endif
va_pa_offset = PAGE_OFFSET - load_pa;
pfn_base = PFN_DOWN(load_pa);
@@ -456,6 +459,36 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL);
dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1));
dtb_early_pa = dtb_pa;
+
+ /*
+ * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
+ * range can not span multiple pmds.
+ */
+ BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
+ != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
+
+#ifndef __PAGETABLE_PMD_FOLDED
+ /*
+ * Early ioremap fixmap is already created as it lies within first 2MB
+ * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
+ * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
+ * the user if not.
+ */
+ fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
+ fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
+ if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
+ WARN_ON(1);
+ pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
+ pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
+ pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
+ fix_to_virt(FIX_BTMAP_BEGIN));
+ pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
+ fix_to_virt(FIX_BTMAP_END));
+
+ pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
+ pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN);
+ }
+#endif
}
static void __init setup_vm_final(void)