libpayload arm64: Add function to get new range from available memranges

Provide a function to obtain a new memrange with requested properties (type,
size, alignment, max_addr and other restrictions) from the set of available
memranges passed in coreboot table. One user of this function would be getting
memrange for dma, another one would be framebuffer.

BUG=chrome-os-partner:31634
BRANCH=None
TEST=Compiles successfully and boots to kernel prompt

Change-Id: Ic5a63ca2dca6c71f4ca2d77e2e2c8180d32a38e0
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 3cd75756e1405e044c029f2878bfcc9c8c962bdf
Original-Change-Id: I187d73a4d55d3c6f49afbe9852901672d25de8dc
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/222110
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/8794
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 144 insertions, 66 deletions

diff --git a/payloads/libpayload/arch/arm64/mmu.c b/payloads/libpayload/arch/arm64/mmu.c
index 123b9b1576..b69dac26d0 100644
--- a/payloads/libpayload/arch/arm64/mmu.c
+++ b/payloads/libpayload/arch/arm64/mmu.c
@@ -391,8 +391,54 @@ void mmu_enable(void)
 }
 
 /*
- * Func: mmu_is_dma_range_valid
- * Desc: We need to ensure that the dma buffer being allocated doesnt overlap
+ * Func: mmu_add_memrange
+ * Desc: Adds a new memory range
+ */
+static struct mmu_memrange *mmu_add_memrange(struct mmu_ranges *r,
+					     uint64_t base, uint64_t size,
+					     uint64_t type)
+{
+	struct mmu_memrange *curr = NULL;
+	int i = r->used;
+
+	if (i < ARRAY_SIZE(r->entries)) {
+		curr = &r->entries[i];
+		curr->base = base;
+		curr->size = size;
+		curr->type = type;
+
+		r->used = i + 1;
+	}
+
+	return curr;
+}
+
+/* Structure to define properties of new memrange request */
+struct mmu_new_range_prop {
+	/* Type of memrange */
+	uint64_t type;
+	/* Size of the range */
+	uint64_t size;
+	/*
+	 * If any restrictions on the max addr limit(This addr is exclusive for
+	 * the range), else 0
+	 */
+	uint64_t lim_excl;
+	/* If any restrictions on alignment of the range base, else 0 */
+	uint64_t align;
+	/*
+	 * Function to test whether selected range is fine.
+	 * NULL=any range is fine
+	 * Return value 1=valid range, 0=otherwise
+	 */
+	int (*is_valid_range)(uint64_t, uint64_t);
+	/* From what type of source range should this range be extracted */
+	uint64_t src_type;
+};
+
+/*
+ * Func: mmu_is_range_free
+ * Desc: We need to ensure that the new range being allocated doesnt overlap
  * with any used memory range. Basically:
  * 1. Memory ranges used by the payload (usedmem_ranges)
  * 2. Any area that falls below _end symbol in linker script (Kernel needs to be
@@ -404,22 +450,23 @@ void mmu_enable(void)
  * proper. If there is any memory used above the _end symbol, then it should be
  * marked as used memory in usedmem_ranges during the presysinfo_scan.
  */
-static int mmu_is_dma_range_valid(uint64_t dma_base,
-				  uint64_t dma_end)
+static int mmu_is_range_free(uint64_t r_base,
+			     uint64_t r_end)
 {
 	uint64_t payload_end = (uint64_t)&_end;
-	uint64_t i = 0;
+	uint64_t i;
 	struct mmu_memrange *r = &usedmem_ranges.entries[0];
 
-	if ((dma_base <= payload_end) || (dma_end <= payload_end))
+	/* Allocate memranges only above payload */
+	if ((r_base <= payload_end) || (r_end <= payload_end))
 		return 0;
 
-	for (; i < usedmem_ranges.used; i++) {
+	for (i = 0; i < usedmem_ranges.used; i++) {
 		uint64_t start = r[i].base;
 		uint64_t end = start + r[i].size;
 
-		if (((dma_base >= start) && (dma_base <= end)) ||
-		    ((dma_end >= start) && (dma_end <= end)))
+		if (((r_base >= start) && (r_base <= end)) ||
+		    ((r_end >= start) && (r_end <= end)))
 			return 0;
 	}
 
@@ -427,76 +474,58 @@ static int mmu_is_dma_range_valid(uint64_t dma_base,
 }
 
 /*
- * Func: mmu_add_memrange
- * Desc: Adds a new memory range
- */
-static struct mmu_memrange* mmu_add_memrange(struct mmu_ranges *r,
-						uint64_t base, uint64_t size,
-						uint64_t type)
-{
-	struct mmu_memrange *curr = NULL;
-	int i = r->used;
-
-	if (i < ARRAY_SIZE(r->entries)) {
-		curr = &r->entries[i];
-		curr->base = base;
-		curr->size = size;
-		curr->type = type;
-
-		r->used = i + 1;
-	}
-
-	return curr;
-}
-
-/*
- * Func: mmu_add_dma_range
- * Desc: Add a memrange for dma operations. This is special because we want to
- * initialize this memory as non-cacheable. We have a constraint that the DMA
- * buffer should be below 4GiB(32-bit only). So, we lookup a TYPE_NORMAL_MEM
- * from the lowest available addresses and align it to page size i.e. 64KiB.
+ * Func: mmu_get_new_range
+ * Desc: Add a requested new memrange. We take as input set of all memranges and
+ * a structure to define the new memrange properties i.e. its type, size,
+ * max_addr it can grow upto, alignment restrictions, source type to take range
+ * from and finally a function pointer to check if the chosen range is valid.
  */
-static struct mmu_memrange* mmu_add_dma_range(struct mmu_ranges *mmu_ranges)
+static struct mmu_memrange *mmu_get_new_range(struct mmu_ranges *mmu_ranges,
+					      struct mmu_new_range_prop *new)
 {
 	int i = 0;
 	struct mmu_memrange *r = &mmu_ranges->entries[0];
 
+	if (new->size == 0) {
+		printf("MMU Error: Invalid range size\n");
+		return NULL;
+	}
+
 	for (; i < mmu_ranges->used; i++) {
 
-		if ((r[i].type != TYPE_NORMAL_MEM) ||
-		    (r[i].size < DMA_DEFAULT_SIZE) ||
-		    (r[i].base >= MIN_64_BIT_ADDR))
+		if ((r[i].type != new->src_type) ||
+		    (r[i].size < new->size) ||
+		    (new->lim_excl && (r[i].base >= new->lim_excl)))
 			continue;
 
 		uint64_t base_addr;
 		uint64_t range_end_addr = r[i].base + r[i].size;
-		uint64_t size;
 		uint64_t end_addr = range_end_addr;
 
-		/* Make sure we choose only 32-bit address range for DMA */
-		if (end_addr > MIN_64_BIT_ADDR)
-			end_addr = MIN_64_BIT_ADDR;
+		/* Make sure we do not go above max if it is non-zero */
+		if (new->lim_excl && (end_addr >= new->lim_excl))
+			end_addr = new->lim_excl;
 
-		/*
-		 * We need to ensure that we do not step over payload regions or
-		 * the coreboot_table
-		 */
 		while (1) {
 			/*
-			 * If end_addr is aligned to GRANULE_SIZE,
-			 * then base_addr will be too.
-			 * (DMA_DEFAULT_SIZE is multiple of GRANULE_SIZE)
+			 * In case of alignment requirement,
+			 * if end_addr is aligned, then base_addr will be too.
 			 */
-			assert((DMA_DEFAULT_SIZE % GRANULE_SIZE) == 0);
-			end_addr = ALIGN_DOWN(end_addr, GRANULE_SIZE);
+			if (new->align)
+				end_addr = ALIGN_DOWN(end_addr, new->align);
 
-			base_addr = end_addr - DMA_DEFAULT_SIZE;
-			size = end_addr - base_addr;
+			base_addr = end_addr - new->size;
 
 			if (base_addr < r[i].base)
 				break;
 
-			if (mmu_is_dma_range_valid(base_addr, end_addr))
+			/*
+			 * If the selected range is not used and valid for the
+			 * user, move ahead with it
+			 */
+			if (mmu_is_range_free(base_addr, end_addr) &&
+			    ((new->is_valid_range == NULL) ||
+			     new->is_valid_range(base_addr, end_addr)))
 				break;
 
 			/* Drop to the next address. */
@@ -506,11 +535,6 @@ static struct mmu_memrange* mmu_add_dma_range(struct mmu_ranges *mmu_ranges)
 		if (base_addr < r[i].base)
 			continue;
 
-		if (r[i].size == size) {
-			r[i].type = TYPE_DMA_MEM;
-			return &r[i];
-		}
-
 		if (end_addr != range_end_addr) {
 			/* Add a new memrange since we split up one
 			 * range crossing the 4GiB boundary or doing an
@@ -519,13 +543,19 @@ static struct mmu_memrange* mmu_add_dma_range(struct mmu_ranges *mmu_ranges)
 			r[i].size -= (range_end_addr - end_addr);
 			if (mmu_add_memrange(mmu_ranges, end_addr,
 					     range_end_addr - end_addr,
-					     TYPE_NORMAL_MEM) == NULL)
+					     r[i].type) == NULL)
 				mmu_error();
 		}
 
-		r[i].size -= size;
+		if (r[i].size == new->size) {
+			r[i].type = new->type;
+			return &r[i];
+		}
 
-		r = mmu_add_memrange(mmu_ranges, base_addr, size, TYPE_DMA_MEM);
+		r[i].size -= new->size;
+
+		r = mmu_add_memrange(mmu_ranges, base_addr, new->size,
+				     new->type);
 
 		if (r == NULL)
 			mmu_error();
@@ -534,11 +564,59 @@ static struct mmu_memrange* mmu_add_dma_range(struct mmu_ranges *mmu_ranges)
 	}
 
 	/* Should never reach here if everything went fine */
-	printf("ARM64 ERROR: No DMA region allocated\n");
+	printf("ARM64 ERROR: No region allocated\n");
 	return NULL;
 }
 
 /*
+ * Func: mmu_alloc_range
+ * Desc: Call get_new_range to get a new memrange which is unused and mark it as
+ * used to avoid same range being allocated for different purposes.
+ */
+static struct mmu_memrange *mmu_alloc_range(struct mmu_ranges *mmu_ranges,
+					    struct mmu_new_range_prop *p)
+{
+	struct mmu_memrange *r = mmu_get_new_range(mmu_ranges, p);
+
+	if (r == NULL)
+		return NULL;
+
+	/*
+	 * Mark this memrange as used memory. Important since function
+	 * can be called multiple times and we do not want to reuse some
+	 * range already allocated.
+	 */
+	if (mmu_add_memrange(&usedmem_ranges, r->base, r->size, r->type)
+	    == NULL)
+		mmu_error();
+
+	return r;
+}
+
+/*
+ * Func: mmu_add_dma_range
+ * Desc: Add a memrange for dma operations. This is special because we want to
+ * initialize this memory as non-cacheable. We have a constraint that the DMA
+ * buffer should be below 4GiB(32-bit only). So, we lookup a TYPE_NORMAL_MEM
+ * from the lowest available addresses and align it to page size i.e. 64KiB.
+ */
+static struct mmu_memrange *mmu_add_dma_range(struct mmu_ranges *mmu_ranges)
+{
+	struct mmu_new_range_prop prop;
+
+	prop.type = TYPE_DMA_MEM;
+	/* DMA_DEFAULT_SIZE is multiple of GRANULE_SIZE */
+	assert((DMA_DEFAULT_SIZE % GRANULE_SIZE) == 0);
+	prop.size = DMA_DEFAULT_SIZE;
+	prop.lim_excl = MIN_64_BIT_ADDR;
+	prop.align = GRANULE_SIZE;
+	prop.is_valid_range = NULL;
+	prop.src_type = TYPE_NORMAL_MEM;
+
+	return mmu_alloc_range(mmu_ranges, &prop);
+}
+
+/*
  * Func: mmu_extract_ranges
  * Desc: Assumption is that coreboot tables have memranges in sorted
  * order. So, if there is an opportunity to combine ranges, we do that as