[IA64] simplified efi memory map parsing

New version leaves the original memory map unmodified.
Also saves any granule trimmings for use by the uncached
memory allocator.

Inspired by Khalid Aziz (various traces of his patch still
remain).  Fixes to uncached_build_memmap() and sn2 testing
by Martin Hicks.
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/efi.c

@@ -239,57 +239,30 @@ is_available_memory (efi_memory_desc_t *md)
 	return 0;
 }
 
-/*
- * Trim descriptor MD so its starts at address START_ADDR.  If the descriptor covers
- * memory that is normally available to the kernel, issue a warning that some memory
- * is being ignored.
- */
-static void
-trim_bottom (efi_memory_desc_t *md, u64 start_addr)
-{
-	u64 num_skipped_pages;
-
-	if (md->phys_addr >= start_addr || !md->num_pages)
-		return;
-
-	num_skipped_pages = (start_addr - md->phys_addr) >> EFI_PAGE_SHIFT;
-	if (num_skipped_pages > md->num_pages)
-		num_skipped_pages = md->num_pages;
+typedef struct kern_memdesc {
+	u64 attribute;
+	u64 start;
+	u64 num_pages;
+} kern_memdesc_t;
 
-	if (is_available_memory(md))
-		printk(KERN_NOTICE "efi.%s: ignoring %luKB of memory at 0x%lx due to granule hole "
-		       "at 0x%lx\n", __FUNCTION__,
-		       (num_skipped_pages << EFI_PAGE_SHIFT) >> 10,
-		       md->phys_addr, start_addr - IA64_GRANULE_SIZE);
-	/*
-	 * NOTE: Don't set md->phys_addr to START_ADDR because that could cause the memory
-	 * descriptor list to become unsorted.  In such a case, md->num_pages will be
-	 * zero, so the Right Thing will happen.
-	 */
-	md->phys_addr += num_skipped_pages << EFI_PAGE_SHIFT;
-	md->num_pages -= num_skipped_pages;
-}
+static kern_memdesc_t *kern_memmap;
 
 static void
-trim_top (efi_memory_desc_t *md, u64 end_addr)
+walk (efi_freemem_callback_t callback, void *arg, u64 attr)
 {
-	u64 num_dropped_pages, md_end_addr;
+	kern_memdesc_t *k;
+	u64 start, end, voff;
 
-	md_end_addr = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
-
-	if (md_end_addr <= end_addr || !md->num_pages)
-		return;
-
-	num_dropped_pages = (md_end_addr - end_addr) >> EFI_PAGE_SHIFT;
-	if (num_dropped_pages > md->num_pages)
-		num_dropped_pages = md->num_pages;
-
-	if (is_available_memory(md))
-		printk(KERN_NOTICE "efi.%s: ignoring %luKB of memory at 0x%lx due to granule hole "
-		       "at 0x%lx\n", __FUNCTION__,
-		       (num_dropped_pages << EFI_PAGE_SHIFT) >> 10,
-		       md->phys_addr, end_addr);
-	md->num_pages -= num_dropped_pages;
+	voff = (attr == EFI_MEMORY_WB) ? PAGE_OFFSET : __IA64_UNCACHED_OFFSET;
+	for (k = kern_memmap; k->start != ~0UL; k++) {
+		if (k->attribute != attr)
+			continue;
+		start = PAGE_ALIGN(k->start);
+		end = (k->start + (k->num_pages << EFI_PAGE_SHIFT)) & PAGE_MASK;
+		if (start < end)
+			if ((*callback)(start + voff, end + voff, arg) < 0)
+				return;
+	}
 }
 
 /*
@@ -299,148 +272,19 @@ trim_top (efi_memory_desc_t *md, u64 end_addr)
 void
 efi_memmap_walk (efi_freemem_callback_t callback, void *arg)
 {
-	int prev_valid = 0;
-	struct range {
-		u64 start;
-		u64 end;
-	} prev, curr;
-	void *efi_map_start, *efi_map_end, *p, *q;
-	efi_memory_desc_t *md, *check_md;
-	u64 efi_desc_size, start, end, granule_addr, last_granule_addr, first_non_wb_addr = 0;
-	unsigned long total_mem = 0;
-
-	efi_map_start = __va(ia64_boot_param->efi_memmap);
-	efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
-	efi_desc_size = ia64_boot_param->efi_memdesc_size;
-
-	for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
-		md = p;
-
-		/* skip over non-WB memory descriptors; that's all we're interested in... */
-		if (!(md->attribute & EFI_MEMORY_WB))
-			continue;
-
-		/*
-		 * granule_addr is the base of md's first granule.
-		 * [granule_addr - first_non_wb_addr) is guaranteed to
-		 * be contiguous WB memory.
-		 */
-		granule_addr = GRANULEROUNDDOWN(md->phys_addr);
-		first_non_wb_addr = max(first_non_wb_addr, granule_addr);
-
-		if (first_non_wb_addr < md->phys_addr) {
-			trim_bottom(md, granule_addr + IA64_GRANULE_SIZE);
-			granule_addr = GRANULEROUNDDOWN(md->phys_addr);
-			first_non_wb_addr = max(first_non_wb_addr, granule_addr);
-		}
-
-		for (q = p; q < efi_map_end; q += efi_desc_size) {
-			check_md = q;
-
-			if ((check_md->attribute & EFI_MEMORY_WB) &&
-			    (check_md->phys_addr == first_non_wb_addr))
-				first_non_wb_addr += check_md->num_pages << EFI_PAGE_SHIFT;
-			else
-				break;		/* non-WB or hole */
-		}
-
-		last_granule_addr = GRANULEROUNDDOWN(first_non_wb_addr);
-		if (last_granule_addr < md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT))
-			trim_top(md, last_granule_addr);
-
-		if (is_available_memory(md)) {
-			if (md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) >= max_addr) {
-				if (md->phys_addr >= max_addr)
-					continue;
-				md->num_pages = (max_addr - md->phys_addr) >> EFI_PAGE_SHIFT;
-				first_non_wb_addr = max_addr;
-			}
-
-			if (total_mem >= mem_limit)
-				continue;
-
-			if (total_mem + (md->num_pages << EFI_PAGE_SHIFT) > mem_limit) {
-				unsigned long limit_addr = md->phys_addr;
-
-				limit_addr += mem_limit - total_mem;
-				limit_addr = GRANULEROUNDDOWN(limit_addr);
-
-				if (md->phys_addr > limit_addr)
-					continue;
-
-				md->num_pages = (limit_addr - md->phys_addr) >>
-				                EFI_PAGE_SHIFT;
-				first_non_wb_addr = max_addr = md->phys_addr +
-				              (md->num_pages << EFI_PAGE_SHIFT);
-			}
-			total_mem += (md->num_pages << EFI_PAGE_SHIFT);
-
-			if (md->num_pages == 0)
-				continue;
-
-			curr.start = PAGE_OFFSET + md->phys_addr;
-			curr.end   = curr.start + (md->num_pages << EFI_PAGE_SHIFT);
-
-			if (!prev_valid) {
-				prev = curr;
-				prev_valid = 1;
-			} else {
-				if (curr.start < prev.start)
-					printk(KERN_ERR "Oops: EFI memory table not ordered!\n");
-
-				if (prev.end == curr.start) {
-					/* merge two consecutive memory ranges */
-					prev.end = curr.end;
-				} else {
-					start = PAGE_ALIGN(prev.start);
-					end = prev.end & PAGE_MASK;
-					if ((end > start) && (*callback)(start, end, arg) < 0)
-						return;
-					prev = curr;
-				}
-			}
-		}
-	}
-	if (prev_valid) {
-		start = PAGE_ALIGN(prev.start);
-		end = prev.end & PAGE_MASK;
-		if (end > start)
-			(*callback)(start, end, arg);
-	}
+	walk(callback, arg, EFI_MEMORY_WB);
 }
 
 /*
- * Walk the EFI memory map to pull out leftover pages in the lower
- * memory regions which do not end up in the regular memory map and
- * stick them into the uncached allocator
- *
- * The regular walk function is significantly more complex than the
- * uncached walk which means it really doesn't make sense to try and
- * marge the two.
+ * Walks the EFI memory map and calls CALLBACK once for each EFI memory descriptor that
+ * has memory that is available for uncached allocator.
  */
-void __init
-efi_memmap_walk_uc (efi_freemem_callback_t callback)
+void
+efi_memmap_walk_uc (efi_freemem_callback_t callback, void *arg)
 {
-	void *efi_map_start, *efi_map_end, *p;
-	efi_memory_desc_t *md;
-	u64 efi_desc_size, start, end;
-
-	efi_map_start = __va(ia64_boot_param->efi_memmap);
-	efi_map_end = efi_map_start + ia64_boot_param->efi_memmap_size;
-	efi_desc_size = ia64_boot_param->efi_memdesc_size;
-
-	for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
-		md = p;
-		if (md->attribute == EFI_MEMORY_UC) {
-			start = PAGE_ALIGN(md->phys_addr);
-			end = PAGE_ALIGN((md->phys_addr+(md->num_pages << EFI_PAGE_SHIFT)) & PAGE_MASK);
-			if ((*callback)(start, end, NULL) < 0)
-				return;
-		}
-	}
+	walk(callback, arg, EFI_MEMORY_UC);
 }
 
-
 /*
  * Look for the PAL_CODE region reported by EFI and maps it using an
  * ITR to enable safe PAL calls in virtual mode.  See IA-64 Processor
@@ -862,3 +706,220 @@ efi_uart_console_only(void)
 	printk(KERN_ERR "Malformed %s value\n", name);
 	return 0;
 }
+
+#define efi_md_size(md)	(md->num_pages << EFI_PAGE_SHIFT)
+
+static inline u64
+kmd_end(kern_memdesc_t *kmd)
+{
+	return (kmd->start + (kmd->num_pages << EFI_PAGE_SHIFT));
+}
+
+static inline u64
+efi_md_end(efi_memory_desc_t *md)
+{
+	return (md->phys_addr + efi_md_size(md));
+}
+
+static inline int
+efi_wb(efi_memory_desc_t *md)
+{
+	return (md->attribute & EFI_MEMORY_WB);
+}
+
+static inline int
+efi_uc(efi_memory_desc_t *md)
+{
+	return (md->attribute & EFI_MEMORY_UC);
+}
+
+/*
+ * Look for the first granule aligned memory descriptor memory
+ * that is big enough to hold EFI memory map. Make sure this
+ * descriptor is atleast granule sized so it does not get trimmed
+ */
+struct kern_memdesc *
+find_memmap_space (void)
+{
+	u64	contig_low=0, contig_high=0;
+	u64	as = 0, ae;
+	void *efi_map_start, *efi_map_end, *p, *q;
+	efi_memory_desc_t *md, *pmd = NULL, *check_md;
+	u64	space_needed, efi_desc_size;
+	unsigned long total_mem = 0;
+
+	efi_map_start = __va(ia64_boot_param->efi_memmap);
+	efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
+	efi_desc_size = ia64_boot_param->efi_memdesc_size;
+
+	/*
+	 * Worst case: we need 3 kernel descriptors for each efi descriptor
+	 * (if every entry has a WB part in the middle, and UC head and tail),
+	 * plus one for the end marker.
+	 */
+	space_needed = sizeof(kern_memdesc_t) *
+		(3 * (ia64_boot_param->efi_memmap_size/efi_desc_size) + 1);
+
+	for (p = efi_map_start; p < efi_map_end; pmd = md, p += efi_desc_size) {
+		md = p;
+		if (!efi_wb(md)) {
+			continue;
+		}
+		if (pmd == NULL || !efi_wb(pmd) || efi_md_end(pmd) != md->phys_addr) {
+			contig_low = GRANULEROUNDUP(md->phys_addr);
+			contig_high = efi_md_end(md);
+			for (q = p + efi_desc_size; q < efi_map_end; q += efi_desc_size) {
+				check_md = q;
+				if (!efi_wb(check_md))
+					break;
+				if (contig_high != check_md->phys_addr)
+					break;
+				contig_high = efi_md_end(check_md);
+			}
+			contig_high = GRANULEROUNDDOWN(contig_high);
+		}
+		if (!is_available_memory(md) || md->type == EFI_LOADER_DATA)
+			continue;
+
+		/* Round ends inward to granule boundaries */
+		as = max(contig_low, md->phys_addr);
+		ae = min(contig_high, efi_md_end(md));
+
+		/* keep within max_addr= command line arg */
+		ae = min(ae, max_addr);
+		if (ae <= as)
+			continue;
+
+		/* avoid going over mem= command line arg */
+		if (total_mem + (ae - as) > mem_limit)
+			ae -= total_mem + (ae - as) - mem_limit;
+
+		if (ae <= as)
+			continue;
+
+		if (ae - as > space_needed)
+			break;
+	}
+	if (p >= efi_map_end)
+		panic("Can't allocate space for kernel memory descriptors");
+
+	return __va(as);
+}
+
+/*
+ * Walk the EFI memory map and gather all memory available for kernel
+ * to use.  We can allocate partial granules only if the unavailable
+ * parts exist, and are WB.
+ */
+void
+efi_memmap_init(unsigned long *s, unsigned long *e)
+{
+	struct kern_memdesc *k, *prev = 0;
+	u64	contig_low=0, contig_high=0;
+	u64	as, ae, lim;
+	void *efi_map_start, *efi_map_end, *p, *q;
+	efi_memory_desc_t *md, *pmd = NULL, *check_md;
+	u64	efi_desc_size;
+	unsigned long total_mem = 0;
+
+	k = kern_memmap = find_memmap_space();
+
+	efi_map_start = __va(ia64_boot_param->efi_memmap);
+	efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
+	efi_desc_size = ia64_boot_param->efi_memdesc_size;
+
+	for (p = efi_map_start; p < efi_map_end; pmd = md, p += efi_desc_size) {
+		md = p;
+		if (!efi_wb(md)) {
+			if (efi_uc(md) && (md->type == EFI_CONVENTIONAL_MEMORY ||
+				    	   md->type == EFI_BOOT_SERVICES_DATA)) {
+				k->attribute = EFI_MEMORY_UC;
+				k->start = md->phys_addr;
+				k->num_pages = md->num_pages;
+				k++;
+			}
+			continue;
+		}
+		if (pmd == NULL || !efi_wb(pmd) || efi_md_end(pmd) != md->phys_addr) {
+			contig_low = GRANULEROUNDUP(md->phys_addr);
+			contig_high = efi_md_end(md);
+			for (q = p + efi_desc_size; q < efi_map_end; q += efi_desc_size) {
+				check_md = q;
+				if (!efi_wb(check_md))
+					break;
+				if (contig_high != check_md->phys_addr)
+					break;
+				contig_high = efi_md_end(check_md);
+			}
+			contig_high = GRANULEROUNDDOWN(contig_high);
+		}
+		if (!is_available_memory(md))
+			continue;
+
+		/*
+		 * Round ends inward to granule boundaries
+		 * Give trimmings to uncached allocator
+		 */
+		if (md->phys_addr < contig_low) {
+			lim = min(efi_md_end(md), contig_low);
+			if (efi_uc(md)) {
+				if (k > kern_memmap && (k-1)->attribute == EFI_MEMORY_UC &&
+				    kmd_end(k-1) == md->phys_addr) {
+					(k-1)->num_pages += (lim - md->phys_addr) >> EFI_PAGE_SHIFT;
+				} else {
+					k->attribute = EFI_MEMORY_UC;
+					k->start = md->phys_addr;
+					k->num_pages = (lim - md->phys_addr) >> EFI_PAGE_SHIFT;
+					k++;
+				}
+			}
+			as = contig_low;
+		} else
+			as = md->phys_addr;
+
+		if (efi_md_end(md) > contig_high) {
+			lim = max(md->phys_addr, contig_high);
+			if (efi_uc(md)) {
+				if (lim == md->phys_addr && k > kern_memmap &&
+				    (k-1)->attribute == EFI_MEMORY_UC &&
+				    kmd_end(k-1) == md->phys_addr) {
+					(k-1)->num_pages += md->num_pages;
+				} else {
+					k->attribute = EFI_MEMORY_UC;
+					k->start = lim;
+					k->num_pages = (efi_md_end(md) - lim) >> EFI_PAGE_SHIFT;
+					k++;
+				}
+			}
+			ae = contig_high;
+		} else
+			ae = efi_md_end(md);
+
+		/* keep within max_addr= command line arg */
+		ae = min(ae, max_addr);
+		if (ae <= as)
+			continue;
+
+		/* avoid going over mem= command line arg */
+		if (total_mem + (ae - as) > mem_limit)
+			ae -= total_mem + (ae - as) - mem_limit;
+
+		if (ae <= as)
+			continue;
+		if (prev && kmd_end(prev) == md->phys_addr) {
+			prev->num_pages += (ae - as) >> EFI_PAGE_SHIFT;
+			total_mem += ae - as;
+			continue;
+		}
+		k->attribute = EFI_MEMORY_WB;
+		k->start = as;
+		k->num_pages = (ae - as) >> EFI_PAGE_SHIFT;
+		total_mem += ae - as;
+		prev = k++;
+	}
+	k->start = ~0L; /* end-marker */
+
+	/* reserve the memory we are using for kern_memmap */
+	*s = (u64)kern_memmap;
+	*e = (u64)++k;
+}

arch/ia64/kernel/setup.c

@@ -211,6 +211,9 @@ reserve_memory (void)
 	}
 #endif
 
+	efi_memmap_init(&rsvd_region[n].start, &rsvd_region[n].end);
+	n++;
+
 	/* end of memory marker */
 	rsvd_region[n].start = ~0UL;
 	rsvd_region[n].end   = ~0UL;

arch/ia64/kernel/uncached.c

@@ -205,23 +205,18 @@ EXPORT_SYMBOL(uncached_free_page);
 static int __init
 uncached_build_memmap(unsigned long start, unsigned long end, void *arg)
 {
-	long length;
-	unsigned long vstart, vend;
+	long length = end - start;
 	int node;
 
-	length = end - start;
-	vstart = start + __IA64_UNCACHED_OFFSET;
-	vend = end + __IA64_UNCACHED_OFFSET;
-
 	dprintk(KERN_ERR "uncached_build_memmap(%lx %lx)\n", start, end);
 
-	memset((char *)vstart, 0, length);
+	memset((char *)start, 0, length);
 
-	node = paddr_to_nid(start);
+	node = paddr_to_nid(start - __IA64_UNCACHED_OFFSET);
 
-	for (; vstart < vend ; vstart += PAGE_SIZE) {
-		dprintk(KERN_INFO "sticking %lx into the pool!\n", vstart);
-		gen_pool_free(uncached_pool[node], vstart, PAGE_SIZE);
+	for (; start < end ; start += PAGE_SIZE) {
+		dprintk(KERN_INFO "sticking %lx into the pool!\n", start);
+		gen_pool_free(uncached_pool[node], start, PAGE_SIZE);
 	}
 
 	return 0;

include/asm-ia64/meminit.h

@@ -16,10 +16,11 @@
  * 	- initrd (optional)
  * 	- command line string
  * 	- kernel code & data
+ * 	- Kernel memory map built from EFI memory map
  *
  * More could be added if necessary
  */
-#define IA64_MAX_RSVD_REGIONS 5
+#define IA64_MAX_RSVD_REGIONS 6
 
 struct rsvd_region {
 	unsigned long start;	/* virtual address of beginning of element */
@@ -33,6 +34,7 @@ extern void find_memory (void);
 extern void reserve_memory (void);
 extern void find_initrd (void);
 extern int filter_rsvd_memory (unsigned long start, unsigned long end, void *arg);
+extern void efi_memmap_init(unsigned long *, unsigned long *);
 
 /*
  * For rounding an address to the next IA64_GRANULE_SIZE or order