soc/intel/cannonlake: Refactor memory layout calculation

This patch split entire memory layout calculation into
two parts. 1. Generic memory layout 2. SoC specific
reserve memory layout.

usable memory start = TOLUD - Generic memory size -
                   - soc specific reserve memory size.

Change-Id: I56e253504a331c0663efb2b90eaa0567613aa508
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/21984
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 119 insertions, 48 deletions

diff --git a/src/soc/intel/cannonlake/memmap.c b/src/soc/intel/cannonlake/memmap.c
index 0259cda7d6..e5117ad81d 100644
--- a/src/soc/intel/cannonlake/memmap.c
+++ b/src/soc/intel/cannonlake/memmap.c
@@ -104,6 +104,115 @@ static bool is_ptt_enable(void)
 	return false;
 }
 
+/* Calculate PTT size */
+static size_t get_ptt_size(void)
+{
+	/* Allocate 4KB for PTT if enabled */
+	return is_ptt_enable() ? 4*KiB : 0;
+}
+
+/* Calculate ME Stolen size */
+static size_t get_imr_size(void)
+{
+	size_t imr_size;
+
+	/* ME stolen memory */
+	imr_size = MCHBAR32(IMRLIMIT) - MCHBAR32(IMRBASE);
+
+	return imr_size;
+}
+
+/* Calculate PRMRR size based on user input PRMRR size and alignment */
+static size_t get_prmrr_size(uintptr_t dram_base,
+		const struct soc_intel_cannonlake_config *config)
+{
+	uintptr_t prmrr_base = dram_base;
+	size_t prmrr_size;
+
+	prmrr_size = config->PrmrrSize;
+
+	/* Allocate PRMRR memory for C6DRAM */
+	if (!prmrr_size) {
+		if (config->enable_c6dram)
+			prmrr_size = 1*MiB;
+		else
+			return 0;
+	}
+
+	/*
+	 * PRMRR Sizes that are > 1MB and < 32MB are
+	 * not supported and will fail out.
+	 */
+	if ((prmrr_size > 1*MiB) && (prmrr_size < 32*MiB))
+		die("PRMRR Sizes that are > 1MB and < 32MB are not"
+				"supported!\n");
+
+	prmrr_base -= prmrr_size;
+	if (prmrr_size >= 32*MiB)
+		prmrr_base = ALIGN_DOWN(prmrr_base, 128*MiB);
+	else
+		prmrr_base = ALIGN_DOWN(prmrr_base, 16*MiB);
+	/* PRMRR Area Size */
+	prmrr_size = dram_base - prmrr_base;
+
+	return prmrr_size;
+}
+
+/* Calculate Intel Traditional Memory size based on GSM, DSM, TSEG and DPR. */
+static size_t calculate_traditional_mem_size(uintptr_t dram_base,
+		const struct device *dev)
+{
+	uintptr_t traditional_mem_base = dram_base;
+	size_t traditional_mem_size;
+
+	if (dev->enabled) {
+		/* Read BDSM from Host Bridge */
+		traditional_mem_base -= sa_get_dsm_size();
+
+		/* Read BGSM from Host Bridge */
+		traditional_mem_base -= sa_get_gsm_size();
+	}
+	/* Get TSEG size */
+	traditional_mem_base -= sa_get_tseg_size();
+
+	/* Get DPR size */
+	if (IS_ENABLED(CONFIG_SA_ENABLE_DPR))
+		traditional_mem_base -= sa_get_dpr_size();
+
+	/* Traditional Area Size */
+	traditional_mem_size = dram_base - traditional_mem_base;
+
+	return traditional_mem_size;
+}
+
+/*
+ * Calculate Intel Reserved Memory size based on
+ * PRMRR size, Me stolen memory and PTT selection.
+ */
+static size_t calculate_reserved_mem_size(uintptr_t dram_base,
+		const struct device *dev)
+{
+	uintptr_t reserve_mem_base = dram_base;
+	size_t reserve_mem_size;
+	const struct soc_intel_cannonlake_config *config;
+
+	config = dev->chip_info;
+
+	/* Get PRMRR size */
+	reserve_mem_base -= get_prmrr_size(reserve_mem_base, config);
+
+	/* Get Tracehub size */
+	reserve_mem_base -= get_imr_size();
+
+	/* Get PTT size */
+	reserve_mem_base -= get_ptt_size();
+
+	/* Traditional Area Size */
+	reserve_mem_size = dram_base - reserve_mem_base;
+
+	return reserve_mem_size;
+}
+
 /*
  * Host Memory Map:
  *
@@ -136,64 +245,25 @@ static bool is_ptt_enable(void)
  * the base registers from each other to determine sizes of the regions. In
  * other words, the memory map is in a fixed order no matter what.
  */
-static uintptr_t calculate_dram_base(void)
+static uintptr_t calculate_dram_base(size_t *reserved_mem_size)
 {
-	const struct soc_intel_cannonlake_config *config;
-	const struct device *dev;
 	uintptr_t dram_base;
-	uintptr_t prmrr_base;
-	size_t prmrr_size;
-	size_t imr_size;
+	const struct device *dev;
 
 	dev = dev_find_slot(0, PCI_DEVFN(SA_DEV_SLOT_IGD, 0));
 	if (!dev)
-		die("ERROR - device not found!");
+		die("ERROR - IGD device not found!");
 
 	/* Read TOLUD from Host Bridge offset */
 	dram_base = sa_get_tolud_base();
 
-	if (dev->enabled) {
-		/* Read BDSM from Host Bridge */
-		dram_base -= sa_get_dsm_size();
-
-		/* Read BGSM from Host Bridge */
-		dram_base -= sa_get_gsm_size();
-	}
-	/* Get TSEG size */
-	dram_base -= sa_get_tseg_size();
-
-	/* Get DPR size */
-	if (IS_ENABLED(CONFIG_SA_ENABLE_DPR))
-		dram_base -= sa_get_dpr_size();
-
-	config = dev->chip_info;
-	prmrr_size = config->PrmrrSize;
+	/* Get Intel Traditional Memory Range Size */
+	dram_base -= calculate_traditional_mem_size(dram_base, dev);
 
-	if (prmrr_size > 0) {
-		/*
-		 * PRMRR Sizes that are > 1MB and < 32MB are
-		 * not supported and will fail out.
-		 */
-		if ((prmrr_size > 1*MiB) && (prmrr_size < 32*MiB))
-			die("PRMRR Sizes that are > 1MB and < 32MB are not"
-					"supported!\n");
-
-		prmrr_base = dram_base - prmrr_size;
-		if (prmrr_size >= 32*MiB)
-			prmrr_base = ALIGN_DOWN(prmrr_base, 128*MiB);
-		dram_base = prmrr_base;
-	} else if (config->enable_c6dram && prmrr_size == 0) {
-		/* Allocate PRMRR memory for C6DRAM */
-		dram_base -= 1*MiB;
-	}
-
-	/* ME stolen memory */
-	imr_size = MCHBAR32(IMRLIMIT) - MCHBAR32(IMRBASE);
-	if (imr_size > 0)
-		dram_base -= imr_size;
+	/* Get Intel Reserved Memory Range Size */
+	*reserved_mem_size = calculate_reserved_mem_size(dram_base, dev);
 
-	if (is_ptt_enable())
-		dram_base -= 4*KiB; /* Allocate 4KB for PTT if enable */
+	dram_base -= *reserved_mem_size;
 
 	return dram_base;
 }
@@ -201,8 +271,9 @@ static uintptr_t calculate_dram_base(void)
 void cbmem_top_init(void)
 {
 	uintptr_t top;
+	size_t chipset_mem_size;
 
-	top = calculate_dram_base();
+	top = calculate_dram_base(&chipset_mem_size);
 
 	write32(top_of_ram_register(), top);
 }