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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-12 09:34:19 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-12 09:34:19 +0400
commit66a173b926891023e34e78cb32f4681d19777e01 (patch)
treee6018f50fbceea7c07e6e27368ee817f9adb34f2 /arch/powerpc/platforms/powernv/opal-xscom.c
parent11db81a59d0b2e563e30512cd76f23d0db384780 (diff)
parent0c4888ef1d8a8b82c29075ce7e257ff795af15c7 (diff)
downloadlinux-66a173b926891023e34e78cb32f4681d19777e01.tar.xz
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc updates from Benjamin Herrenschmidt: "The bulk of this is LE updates. One should now be able to build an LE kernel and even run some things in it. I'm still sitting on a handful of patches to enable the new ABI that I *might* still send this merge window around, but due to the incertainty (they are pretty fresh) I want to keep them separate. Other notable changes are some infrastructure bits to better handle PCI pass-through under KVM, some bits and pieces added to the new PowerNV platform support such as access to the CPU SCOM bus via sysfs, and support for EEH error handling on PHB3 (Power8 PCIe). We also grew arch_get_random_long() for both pseries and powernv when running on P7+ and P8, exploiting the HW rng. And finally various embedded updates from freescale" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (154 commits) powerpc: Fix fatal SLB miss when restoring PPR powerpc/powernv: Reserve the correct PE number powerpc/powernv: Add PE to its own PELTV powerpc/powernv: Add support for indirect XSCOM via debugfs powerpc/scom: Improve debugfs interface powerpc/scom: Enable 64-bit addresses powerpc/boot: Properly handle the base "of" boot wrapper powerpc/bpf: Support MOD operation powerpc/bpf: Fix DIVWU instruction opcode of: Move definition of of_find_next_cache_node into common code. powerpc: Remove big endianness assumption in of_find_next_cache_node powerpc/tm: Remove interrupt disable in __switch_to() powerpc: word-at-a-time optimization for 64-bit Little Endian powerpc/bpf: BPF JIT compiler for 64-bit Little Endian powerpc: Only save/restore SDR1 if in hypervisor mode powerpc/pmu: Fix ADB_PMU_LED_IDE dependencies powerpc/nvram: Fix endian issue when using the partition length powerpc/nvram: Fix endian issue when reading the NVRAM size powerpc/nvram: Scan partitions only once powerpc/mpc512x: remove unnecessary #if ...
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-xscom.c')
-rw-r--r--arch/powerpc/platforms/powernv/opal-xscom.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-xscom.c b/arch/powerpc/platforms/powernv/opal-xscom.c
new file mode 100644
index 000000000000..4d99a8fd55ac
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-xscom.c
@@ -0,0 +1,128 @@
+/*
+ * PowerNV LPC bus handling.
+ *
+ * Copyright 2013 IBM Corp.
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/bug.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+#include <asm/opal.h>
+#include <asm/scom.h>
+
+/*
+ * We could probably fit that inside the scom_map_t
+ * which is a void* after all but it's really too ugly
+ * so let's kmalloc it for now
+ */
+struct opal_scom_map {
+ uint32_t chip;
+ uint64_t addr;
+};
+
+static scom_map_t opal_scom_map(struct device_node *dev, u64 reg, u64 count)
+{
+ struct opal_scom_map *m;
+ const __be32 *gcid;
+
+ if (!of_get_property(dev, "scom-controller", NULL)) {
+ pr_err("%s: device %s is not a SCOM controller\n",
+ __func__, dev->full_name);
+ return SCOM_MAP_INVALID;
+ }
+ gcid = of_get_property(dev, "ibm,chip-id", NULL);
+ if (!gcid) {
+ pr_err("%s: device %s has no ibm,chip-id\n",
+ __func__, dev->full_name);
+ return SCOM_MAP_INVALID;
+ }
+ m = kmalloc(sizeof(struct opal_scom_map), GFP_KERNEL);
+ if (!m)
+ return NULL;
+ m->chip = be32_to_cpup(gcid);
+ m->addr = reg;
+
+ return (scom_map_t)m;
+}
+
+static void opal_scom_unmap(scom_map_t map)
+{
+ kfree(map);
+}
+
+static int opal_xscom_err_xlate(int64_t rc)
+{
+ switch(rc) {
+ case 0:
+ return 0;
+ /* Add more translations if necessary */
+ default:
+ return -EIO;
+ }
+}
+
+static u64 opal_scom_unmangle(u64 reg)
+{
+ /*
+ * XSCOM indirect addresses have the top bit set. Additionally
+ * the reset of the top 3 nibbles is always 0.
+ *
+ * Because the debugfs interface uses signed offsets and shifts
+ * the address left by 3, we basically cannot use the top 4 bits
+ * of the 64-bit address, and thus cannot use the indirect bit.
+ *
+ * To deal with that, we support the indirect bit being in bit
+ * 4 (IBM notation) instead of bit 0 in this API, we do the
+ * conversion here. To leave room for further xscom address
+ * expansion, we only clear out the top byte
+ *
+ */
+ if (reg & (1ull << 59))
+ reg = (reg & ~(0xffull << 56)) | (1ull << 63);
+ return reg;
+}
+
+static int opal_scom_read(scom_map_t map, u64 reg, u64 *value)
+{
+ struct opal_scom_map *m = map;
+ int64_t rc;
+
+ reg = opal_scom_unmangle(reg);
+ rc = opal_xscom_read(m->chip, m->addr + reg, (uint64_t *)__pa(value));
+ return opal_xscom_err_xlate(rc);
+}
+
+static int opal_scom_write(scom_map_t map, u64 reg, u64 value)
+{
+ struct opal_scom_map *m = map;
+ int64_t rc;
+
+ reg = opal_scom_unmangle(reg);
+ rc = opal_xscom_write(m->chip, m->addr + reg, value);
+ return opal_xscom_err_xlate(rc);
+}
+
+static const struct scom_controller opal_scom_controller = {
+ .map = opal_scom_map,
+ .unmap = opal_scom_unmap,
+ .read = opal_scom_read,
+ .write = opal_scom_write
+};
+
+static int opal_xscom_init(void)
+{
+ if (firmware_has_feature(FW_FEATURE_OPALv3))
+ scom_init(&opal_scom_controller);
+ return 0;
+}
+arch_initcall(opal_xscom_init);