New subject: Change in coreboot[master]: lib: Rewrite qemu-armv7 ramdetect

1 Jul 2019

Patrick Rudolph has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/33934
Change subject: lib: Rewrite qemu-armv7 ramdetect
......................................................................
lib: Rewrite qemu-armv7 ramdetect
* Move armv7 RAM dection to a common place
* Enable it for all emulated platforms
* Use 32bit probe values and restore memory even on failure
* Use the new logic on the following boards:
** qemu-armv7
** qemu-riscv
Tested on qemu-system-riscv:
Fixes kernel panic due to wrong memory limits reported.
Change-Id: I37386c6a95bfc3b7b25aeae32c6e14cff9913513
Signed-off-by: Patrick Rudolph patrick.rudolph@9elements.com
---
A src/include/ramdetect.h
M src/lib/Makefile.inc
A src/lib/ramdetect.c
M src/mainboard/emulation/qemu-armv7/Kconfig
M src/mainboard/emulation/qemu-armv7/cbmem.c
M src/mainboard/emulation/qemu-armv7/mainboard.c
M src/mainboard/emulation/qemu-riscv/mainboard.c
M src/soc/ucb/riscv/cbmem.c
8 files changed, 115 insertions(+), 58 deletions(-)
git pull ssh://review.coreboot.org:29418/coreboot refs/changes/34/33934/1

diff --git a/src/include/ramdetect.h b/src/include/ramdetect.h
new file mode 100644
index 0000000..b63cdf1
--- /dev/null
+++ b/src/include/ramdetect.h
@@ -0,0 +1,22 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * Probe an area if it's read/writable.
+ * Primary use case is the detection of DRAM amount on emulators.
+ *
+ * @param dram_start Physical address of DRAM start
+ * @param probe_size Maximum size in MiB to probe for
+ * @return The detected DRAM size in MiB
+ */
+size_t probe_ramsize(const uintptr_t dram_start, const size_t probe_size);
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index 16d5c64..a006182 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -67,6 +67,7 @@
 verstage-$(CONFIG_GENERIC_UDELAY) += timer.c
 verstage-$(CONFIG_GENERIC_GPIO_LIB) += gpio.c
+romstage-$(CONFIG_VENDOR_EMULATION) += ramdetect.c
 romstage-y += prog_loaders.c
 romstage-y += prog_ops.c
 romstage-y += memchr.c
@@ -109,6 +110,7 @@
romstage-$(CONFIG_GENERIC_UDELAY) += timer.c
+ramstage-$(CONFIG_VENDOR_EMULATION) += ramdetect.c
 ramstage-y += prog_loaders.c
 ramstage-y += prog_ops.c
 ramstage-y += hardwaremain.c
@@ -159,6 +161,7 @@
 ramstage-y += imd_cbmem.c
 ramstage-y += imd.c
+postcar-$(CONFIG_VENDOR_EMULATION) += ramdetect.c
 postcar-y += cbmem_common.c
 postcar-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c
 postcar-y += imd_cbmem.c
diff --git a/src/lib/ramdetect.c b/src/lib/ramdetect.c
new file mode 100644
index 0000000..1cdb378
--- /dev/null
+++ b/src/lib/ramdetect.c
@@ -0,0 +1,77 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <stddef.h>
+#include <symbols.h>
+#include <device/mmio.h>
+#include <ramdetect.h>
+#include <console/console.h>
+
+#define PATTERN1 0x55aa55aa
+#define PATTERN2 0x12345678
+
+#define OVERLAP(a, b, s, e) ((b) > (a) && (a) < (e))
+
+static int probe_mb(const uintptr_t dram_start, const uintptr_t mib)
+{
+	uintptr_t addr = dram_start + (mib * MiB) - sizeof(uint32_t);
+	void *ptr = (void *) addr;
+	int ret = 0;
+
+	/* Don't accidentally clobering oneself. */
+	if (OVERLAP(addr, addr + sizeof(uint32_t), (uintptr_t)_program, (uintptr_t) _eprogram))
+		return 1;
+
+	uint32_t old = read32(ptr);
+
+	write32(ptr, PATTERN1);
+	if (read32(ptr) != PATTERN1)
+		goto out;
+	write32(ptr, PATTERN2);
+	if (read32(ptr) != PATTERN2)
+		goto out;
+	ret = 1;
+out:
+	write32(ptr, old);
+	return ret;
+}
+
+/* Probe an area if it's read/writable. */
+size_t probe_ramsize(const uintptr_t dram_start, const size_t probe_size)
+{
+	int i;
+	int msb = 1;
+	size_t discovered = 0;
+
+	static size_t saved_result;
+	if (saved_result)
+		return saved_result;
+
+	/* Find the MSB + 1. */
+	size_t tmp = probe_size;
+	while (tmp >>= 1)
+		msb++;
+
+	/* Limit search to accessible address space */
+	if (msb > (sizeof(size_t) * 8 - 20))
+		msb = sizeof(size_t) * 8 - 20;
+
+	/* Compact binary search.  */
+	for (i = msb; i >= 0; i--)
+		if (probe_mb(dram_start, (discovered | (1 << i))))
+			discovered |= (1 << i);
+
+	saved_result = discovered;
+	printk(BIOS_DEBUG, "RAMDETECT: Found %zu MiB RAM\n", discovered);
+	return discovered;
+}
diff --git a/src/mainboard/emulation/qemu-armv7/Kconfig b/src/mainboard/emulation/qemu-armv7/Kconfig
index 0bb5f3a..75cede9 100644
--- a/src/mainboard/emulation/qemu-armv7/Kconfig
+++ b/src/mainboard/emulation/qemu-armv7/Kconfig
@@ -52,4 +52,8 @@
    string
    default "ARM Ltd."
+config DRAM_SIZE_MB
+	int
+	default 1024
+
 endif #  BOARD_EMULATION_QEMU_ARMV7
diff --git a/src/mainboard/emulation/qemu-armv7/cbmem.c b/src/mainboard/emulation/qemu-armv7/cbmem.c
index 927bd42..09ba289 100644
--- a/src/mainboard/emulation/qemu-armv7/cbmem.c
+++ b/src/mainboard/emulation/qemu-armv7/cbmem.c
@@ -11,55 +11,10 @@
  * GNU General Public License for more details.
  */
-#include <stddef.h>
 #include <cbmem.h>
-#include <symbols.h>
-#include <device/mmio.h>
-#include "mainboard.h"
-
-#define PATTERN1 0x55
-#define PATTERN2 0xaa
-
-/* Returns 1 if mebibyte mb is present and 0 otherwise.  */
-static int probe_mb(int mb)
-{
-	char *ptr = (char *) 0x60000000 + (mb << 20) + 0xfffff;
-	char old;
-	if (ptr < (char *) &_eprogram) {
-		/* Don't probe below _end to avoid accidentally clobering
-		   oneself.  */
-		return 1;
-	}
-
-	old = read8(ptr);
-	write8(ptr, PATTERN1);
-	if (read8(ptr) != PATTERN1)
-		return 0;
-	write8(ptr, PATTERN2);
-	if (read8(ptr) != PATTERN2)
-		return 0;
-	write8(ptr, old);
-	return 1;
-}
-
-int probe_ramsize(void)
-{
-	int i;
-	int discovered = 0;
-	static int saved_result;
-	if (saved_result)
-		return saved_result;
-	/* Compact binary search.  */
-	/* 1 GiB is the largest supported RAM by this machine.  */
-	for (i = 9; i >= 0; i--)
-		if (probe_mb(discovered | (1 << i)))
-			discovered |= (1 << i);
-	discovered++;
-	saved_result = discovered;
-	return discovered;
-}
+#include <ramdetect.h>
void *cbmem_top(void)
 {
-	return _dram + (probe_ramsize() << 20);
+	return _dram + (probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB) << 20);
 }
diff --git a/src/mainboard/emulation/qemu-armv7/mainboard.c b/src/mainboard/emulation/qemu-armv7/mainboard.c
index cc14dd8..c04645d 100644
--- a/src/mainboard/emulation/qemu-armv7/mainboard.c
+++ b/src/mainboard/emulation/qemu-armv7/mainboard.c
@@ -57,7 +57,7 @@
    	halt();
    }
-	discovered = probe_ramsize();
+	discovered = probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB);
    printk(BIOS_DEBUG, "%d MiB of RAM discovered\n", discovered);
    ram_resource(dev, 0, 0x60000000 >> 10, discovered << 10);
    cbmem_recovery(0);
diff --git a/src/mainboard/emulation/qemu-riscv/mainboard.c b/src/mainboard/emulation/qemu-riscv/mainboard.c
index 4b428aa..66ba56ed 100644
--- a/src/mainboard/emulation/qemu-riscv/mainboard.c
+++ b/src/mainboard/emulation/qemu-riscv/mainboard.c
@@ -17,6 +17,7 @@
 #include <device/device.h>
 #include <cbmem.h>
 #include <symbols.h>
+#include <ramdetect.h>
static void mainboard_enable(struct device *dev)
 {
@@ -25,7 +26,8 @@
    	die("No dev0; die\n");
    }
-	ram_resource(dev, 0, (uintptr_t)_dram / KiB, CONFIG_DRAM_SIZE_MB * KiB);
+	ram_resource(dev, 0, (uintptr_t)_dram / KiB,
+		     probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB) << 10);
    cbmem_recovery(0);
 }
diff --git a/src/soc/ucb/riscv/cbmem.c b/src/soc/ucb/riscv/cbmem.c
index 2ee400a..1a1d86b 100644
--- a/src/soc/ucb/riscv/cbmem.c
+++ b/src/soc/ucb/riscv/cbmem.c
@@ -12,16 +12,10 @@
  */
#include <cbmem.h>
+#include <symbols.h>
+#include <ramdetect.h>
void *cbmem_top(void)
 {
-	uintptr_t base;
-	size_t size;
-
-	/* Use dummy values until we can query the memory size again */
-	//query_mem(configstring(), &base, &size);
-	base = 0x80000000;
-	size = 128 * MiB;
-
-	return (void *)(base + size);
+	return _dram + (probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB) << 20);
 }
-- 
To view, visit https://review.coreboot.org/c/coreboot/+/33934
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Gerrit-Project: coreboot
Gerrit-Branch: master
Gerrit-Change-Id: I37386c6a95bfc3b7b25aeae32c6e14cff9913513
Gerrit-Change-Number: 33934
Gerrit-PatchSet: 1
Gerrit-Owner: Patrick Rudolph patrick.rudolph@9elements.com
Gerrit-MessageType: newchange



    

Change in ...coreboot[master]: lib: Rewrite qemu-armv7 ramdetect