MFC r286667 & r286723

Better support memory mapped console devices, such as VGA and EFI
frame buffers and memory mapped UARTs.

PR:		191564, 194952, 202276

2 files changed, 109 insertions, 41 deletions

diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 3244be6..ab543fe 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -3320,6 +3320,40 @@ init386(first)
 	 */
 	i8254_init();
 
+	finishidentcpu();	/* Final stage of CPU initialization */
+	setidt(IDT_UD, &IDTVEC(ill),  SDT_SYS386TGT, SEL_KPL,
+	    GSEL(GCODE_SEL, SEL_KPL));
+	setidt(IDT_GP, &IDTVEC(prot),  SDT_SYS386TGT, SEL_KPL,
+	    GSEL(GCODE_SEL, SEL_KPL));
+	initializecpu();	/* Initialize CPU registers */
+	initializecpucache();
+
+	/* pointer to selector slot for %fs/%gs */
+	PCPU_SET(fsgs_gdt, &gdt[GUFS_SEL].sd);
+
+	dblfault_tss.tss_esp = dblfault_tss.tss_esp0 = dblfault_tss.tss_esp1 =
+	    dblfault_tss.tss_esp2 = (int)&dblfault_stack[sizeof(dblfault_stack)];
+	dblfault_tss.tss_ss = dblfault_tss.tss_ss0 = dblfault_tss.tss_ss1 =
+	    dblfault_tss.tss_ss2 = GSEL(GDATA_SEL, SEL_KPL);
+#if defined(PAE) || defined(PAE_TABLES)
+	dblfault_tss.tss_cr3 = (int)IdlePDPT;
+#else
+	dblfault_tss.tss_cr3 = (int)IdlePTD;
+#endif
+	dblfault_tss.tss_eip = (int)dblfault_handler;
+	dblfault_tss.tss_eflags = PSL_KERNEL;
+	dblfault_tss.tss_ds = dblfault_tss.tss_es =
+	    dblfault_tss.tss_gs = GSEL(GDATA_SEL, SEL_KPL);
+	dblfault_tss.tss_fs = GSEL(GPRIV_SEL, SEL_KPL);
+	dblfault_tss.tss_cs = GSEL(GCODE_SEL, SEL_KPL);
+	dblfault_tss.tss_ldt = GSEL(GLDT_SEL, SEL_KPL);
+
+	vm86_initialize();
+	getmemsize(first);
+	init_param2(physmem);
+
+	/* now running on new page tables, configured,and u/iom is accessible */
+
 	/*
 	 * Initialize the console before we print anything out.
 	 */
@@ -3361,40 +3395,6 @@ init386(first)
 		kdb_enter(KDB_WHY_BOOTFLAGS, "Boot flags requested debugger");
 #endif
 
-	finishidentcpu();	/* Final stage of CPU initialization */
-	setidt(IDT_UD, &IDTVEC(ill),  SDT_SYS386TGT, SEL_KPL,
-	    GSEL(GCODE_SEL, SEL_KPL));
-	setidt(IDT_GP, &IDTVEC(prot),  SDT_SYS386TGT, SEL_KPL,
-	    GSEL(GCODE_SEL, SEL_KPL));
-	initializecpu();	/* Initialize CPU registers */
-	initializecpucache();
-
-	/* pointer to selector slot for %fs/%gs */
-	PCPU_SET(fsgs_gdt, &gdt[GUFS_SEL].sd);
-
-	dblfault_tss.tss_esp = dblfault_tss.tss_esp0 = dblfault_tss.tss_esp1 =
-	    dblfault_tss.tss_esp2 = (int)&dblfault_stack[sizeof(dblfault_stack)];
-	dblfault_tss.tss_ss = dblfault_tss.tss_ss0 = dblfault_tss.tss_ss1 =
-	    dblfault_tss.tss_ss2 = GSEL(GDATA_SEL, SEL_KPL);
-#if defined(PAE) || defined(PAE_TABLES)
-	dblfault_tss.tss_cr3 = (int)IdlePDPT;
-#else
-	dblfault_tss.tss_cr3 = (int)IdlePTD;
-#endif
-	dblfault_tss.tss_eip = (int)dblfault_handler;
-	dblfault_tss.tss_eflags = PSL_KERNEL;
-	dblfault_tss.tss_ds = dblfault_tss.tss_es =
-	    dblfault_tss.tss_gs = GSEL(GDATA_SEL, SEL_KPL);
-	dblfault_tss.tss_fs = GSEL(GPRIV_SEL, SEL_KPL);
-	dblfault_tss.tss_cs = GSEL(GCODE_SEL, SEL_KPL);
-	dblfault_tss.tss_ldt = GSEL(GLDT_SEL, SEL_KPL);
-
-	vm86_initialize();
-	getmemsize(first);
-	init_param2(physmem);
-
-	/* now running on new page tables, configured,and u/iom is accessible */
-
 	msgbufinit(msgbufp, msgbufsize);
 #ifdef DEV_NPX
 	npxinit(true);
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c
index 4e09a90..540eb65 100644
--- a/sys/i386/i386/pmap.c
+++ b/sys/i386/i386/pmap.c
@@ -232,6 +232,18 @@ SYSCTL_INT(_vm_pmap, OID_AUTO, pg_ps_enabled, CTLFLAG_RDTUN, &pg_ps_enabled, 0,
 #define	PAT_INDEX_SIZE	8
 static int pat_index[PAT_INDEX_SIZE];	/* cache mode to PAT index conversion */
 
+/*
+ * pmap_mapdev support pre initialization (i.e. console)
+ */
+#define	PMAP_PREINIT_MAPPING_COUNT	8
+static struct pmap_preinit_mapping {
+	vm_paddr_t	pa;
+	vm_offset_t	va;
+	vm_size_t	sz;
+	int		mode;
+} pmap_preinit_mapping[PMAP_PREINIT_MAPPING_COUNT];
+static int pmap_initialized;
+
 static struct rwlock_padalign pvh_global_lock;
 
 /*
@@ -731,6 +743,7 @@ pmap_ptelist_init(vm_offset_t *head, void *base, int npages)
 void
 pmap_init(void)
 {
+	struct pmap_preinit_mapping *ppim;
 	vm_page_t mpte;
 	vm_size_t s;
 	int i, pv_npg;
@@ -814,6 +827,17 @@ pmap_init(void)
 	    UMA_ZONE_VM | UMA_ZONE_NOFREE);
 	uma_zone_set_allocf(pdptzone, pmap_pdpt_allocf);
 #endif
+
+	pmap_initialized = 1;
+	if (!bootverbose)
+		return;
+	for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) {
+		ppim = pmap_preinit_mapping + i;
+		if (ppim->va == 0)
+			continue;
+		printf("PPIM %u: PA=%#jx, VA=%#x, size=%#x, mode=%#x\n", i,
+		    (uintmax_t)ppim->pa, ppim->va, ppim->sz, ppim->mode);
+	}
 }
 
 
@@ -5162,8 +5186,10 @@ pmap_pde_attr(pd_entry_t *pde, int cache_bits)
 void *
 pmap_mapdev_attr(vm_paddr_t pa, vm_size_t size, int mode)
 {
+	struct pmap_preinit_mapping *ppim;
 	vm_offset_t va, offset;
 	vm_size_t tmpsize;
+	int i;
 
 	offset = pa & PAGE_MASK;
 	size = round_page(offset + size);
@@ -5171,11 +5197,36 @@ pmap_mapdev_attr(vm_paddr_t pa, vm_size_t size, int mode)
 
 	if (pa < KERNLOAD && pa + size <= KERNLOAD)
 		va = KERNBASE + pa;
-	else
+	else if (!pmap_initialized) {
+		va = 0;
+		for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) {
+			ppim = pmap_preinit_mapping + i;
+			if (ppim->va == 0) {
+				ppim->pa = pa;
+				ppim->sz = size;
+				ppim->mode = mode;
+				ppim->va = virtual_avail;
+				virtual_avail += size;
+				va = ppim->va;
+				break;
+			}
+		}
+		if (va == 0)
+			panic("%s: too many preinit mappings", __func__);
+	} else {
+		/*
+		 * If we have a preinit mapping, re-use it.
+		 */
+		for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) {
+			ppim = pmap_preinit_mapping + i;
+			if (ppim->pa == pa && ppim->sz == size &&
+			    ppim->mode == mode)
+				return ((void *)(ppim->va + offset));
+		}
 		va = kva_alloc(size);
-	if (!va)
-		panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
-
+		if (va == 0)
+			panic("%s: Couldn't allocate KVA", __func__);
+	}
 	for (tmpsize = 0; tmpsize < size; tmpsize += PAGE_SIZE)
 		pmap_kenter_attr(va + tmpsize, pa + tmpsize, mode);
 	pmap_invalidate_range(kernel_pmap, va, va + tmpsize);
@@ -5200,14 +5251,31 @@ pmap_mapbios(vm_paddr_t pa, vm_size_t size)
 void
 pmap_unmapdev(vm_offset_t va, vm_size_t size)
 {
-	vm_offset_t base, offset;
+	struct pmap_preinit_mapping *ppim;
+	vm_offset_t offset;
+	int i;
 
 	if (va >= KERNBASE && va + size <= KERNBASE + KERNLOAD)
 		return;
-	base = trunc_page(va);
 	offset = va & PAGE_MASK;
 	size = round_page(offset + size);
-	kva_free(base, size);
+	va = trunc_page(va);
+	for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) {
+		ppim = pmap_preinit_mapping + i;
+		if (ppim->va == va && ppim->sz == size) {
+			if (pmap_initialized)
+				return;
+			ppim->pa = 0;
+			ppim->va = 0;
+			ppim->sz = 0;
+			ppim->mode = 0;
+			if (va + size == virtual_avail)
+				virtual_avail = va;
+			return;
+		}
+	}
+	if (pmap_initialized)
+		kva_free(va, size);
 }
 
 /*