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authorZhichang Yuan <yuanzhichang@hisilicon.com>2018-03-15 02:15:50 +0800
committerBjorn Helgaas <bhelgaas@google.com>2018-03-21 17:18:34 -0500
commit031e3601869c815582ca1d49d1ff73de58e446b0 (patch)
tree8e621f8247f2b3ba11bbb14623e3338f5260d6aa /lib
parent7928b2cbe55b2a410a0f5c1f154610059c57b1b2 (diff)
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lib: Add generic PIO mapping method
41f8bba7f555 ("of/pci: Add pci_register_io_range() and pci_pio_to_address()") added support for PCI I/O space mapped into CPU physical memory space. With that support, the I/O ranges configured for PCI/PCIe hosts on some architectures can be mapped to logical PIO and converted easily between CPU address and the corresponding logical PIO. Based on this, PCI I/O port space can be accessed via in/out accessors that use memory read/write. But on some platforms, there are bus hosts that access I/O port space with host-local I/O port addresses rather than memory addresses. Add a more generic I/O mapping method to support those devices. With this patch, both the CPU addresses and the host-local port can be mapped into the logical PIO space with different logical/fake PIOs. After this, all the I/O accesses to either PCI MMIO devices or host-local I/O peripherals can be unified into the existing I/O accessors defined in asm-generic/io.h and be redirected to the right device-specific hooks based on the input logical PIO. Tested-by: dann frazier <dann.frazier@canonical.com> Signed-off-by: Zhichang Yuan <yuanzhichang@hisilicon.com> Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com> Signed-off-by: John Garry <john.garry@huawei.com> [bhelgaas: remove -EFAULT return from logic_pio_register_range() per https://lkml.kernel.org/r/20180403143909.GA21171@ulmo, fix NULL pointer checking per https://lkml.kernel.org/r/20180403211505.GA29612@embeddedor.com] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig16
-rw-r--r--lib/Makefile2
-rw-r--r--lib/logic_pio.c280
3 files changed, 298 insertions, 0 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index e96089499371..5fe577673b98 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -55,6 +55,22 @@ config ARCH_USE_CMPXCHG_LOCKREF
config ARCH_HAS_FAST_MULTIPLIER
bool
+config INDIRECT_PIO
+ bool "Access I/O in non-MMIO mode"
+ depends on ARM64
+ help
+ On some platforms where no separate I/O space exists, there are I/O
+ hosts which can not be accessed in MMIO mode. Using the logical PIO
+ mechanism, the host-local I/O resource can be mapped into system
+ logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the
+ system can access the I/O devices with the mapped-logic PIO through
+ I/O accessors.
+
+ This way has relatively little I/O performance cost. Please make
+ sure your devices really need this configure item enabled.
+
+ When in doubt, say N.
+
config CRC_CCITT
tristate "CRC-CCITT functions"
help
diff --git a/lib/Makefile b/lib/Makefile
index a90d4fcd748f..4a9eacda3c8b 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -81,6 +81,8 @@ obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o
obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o
obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
+obj-y += logic_pio.o
+
obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
obj-$(CONFIG_BTREE) += btree.o
diff --git a/lib/logic_pio.c b/lib/logic_pio.c
new file mode 100644
index 000000000000..feea48fd1a0d
--- /dev/null
+++ b/lib/logic_pio.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017 HiSilicon Limited, All Rights Reserved.
+ * Author: Gabriele Paoloni <gabriele.paoloni@huawei.com>
+ * Author: Zhichang Yuan <yuanzhichang@hisilicon.com>
+ */
+
+#define pr_fmt(fmt) "LOGIC PIO: " fmt
+
+#include <linux/of.h>
+#include <linux/io.h>
+#include <linux/logic_pio.h>
+#include <linux/mm.h>
+#include <linux/rculist.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+/* The unique hardware address list */
+static LIST_HEAD(io_range_list);
+static DEFINE_MUTEX(io_range_mutex);
+
+/* Consider a kernel general helper for this */
+#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
+
+/**
+ * logic_pio_register_range - register logical PIO range for a host
+ * @new_range: pointer to the IO range to be registered.
+ *
+ * Returns 0 on success, the error code in case of failure.
+ *
+ * Register a new IO range node in the IO range list.
+ */
+int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
+{
+ struct logic_pio_hwaddr *range;
+ resource_size_t start;
+ resource_size_t end;
+ resource_size_t mmio_sz = 0;
+ resource_size_t iio_sz = MMIO_UPPER_LIMIT;
+ int ret = 0;
+
+ if (!new_range || !new_range->fwnode || !new_range->size)
+ return -EINVAL;
+
+ start = new_range->hw_start;
+ end = new_range->hw_start + new_range->size;
+
+ mutex_lock(&io_range_mutex);
+ list_for_each_entry_rcu(range, &io_range_list, list) {
+ if (range->fwnode == new_range->fwnode) {
+ /* range already there */
+ goto end_register;
+ }
+ if (range->flags == LOGIC_PIO_CPU_MMIO &&
+ new_range->flags == LOGIC_PIO_CPU_MMIO) {
+ /* for MMIO ranges we need to check for overlap */
+ if (start >= range->hw_start + range->size ||
+ end < range->hw_start) {
+ mmio_sz += range->size;
+ } else {
+ ret = -EFAULT;
+ goto end_register;
+ }
+ } else if (range->flags == LOGIC_PIO_INDIRECT &&
+ new_range->flags == LOGIC_PIO_INDIRECT) {
+ iio_sz += range->size;
+ }
+ }
+
+ /* range not registered yet, check for available space */
+ if (new_range->flags == LOGIC_PIO_CPU_MMIO) {
+ if (mmio_sz + new_range->size - 1 > MMIO_UPPER_LIMIT) {
+ /* if it's too big check if 64K space can be reserved */
+ if (mmio_sz + SZ_64K - 1 > MMIO_UPPER_LIMIT) {
+ ret = -E2BIG;
+ goto end_register;
+ }
+ new_range->size = SZ_64K;
+ pr_warn("Requested IO range too big, new size set to 64K\n");
+ }
+ new_range->io_start = mmio_sz;
+ } else if (new_range->flags == LOGIC_PIO_INDIRECT) {
+ if (iio_sz + new_range->size - 1 > IO_SPACE_LIMIT) {
+ ret = -E2BIG;
+ goto end_register;
+ }
+ new_range->io_start = iio_sz;
+ } else {
+ /* invalid flag */
+ ret = -EINVAL;
+ goto end_register;
+ }
+
+ list_add_tail_rcu(&new_range->list, &io_range_list);
+
+end_register:
+ mutex_unlock(&io_range_mutex);
+ return ret;
+}
+
+/**
+ * find_io_range_by_fwnode - find logical PIO range for given FW node
+ * @fwnode: FW node handle associated with logical PIO range
+ *
+ * Returns pointer to node on success, NULL otherwise.
+ *
+ * Traverse the io_range_list to find the registered node for @fwnode.
+ */
+struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode)
+{
+ struct logic_pio_hwaddr *range;
+
+ list_for_each_entry_rcu(range, &io_range_list, list) {
+ if (range->fwnode == fwnode)
+ return range;
+ }
+ return NULL;
+}
+
+/* Return a registered range given an input PIO token */
+static struct logic_pio_hwaddr *find_io_range(unsigned long pio)
+{
+ struct logic_pio_hwaddr *range;
+
+ list_for_each_entry_rcu(range, &io_range_list, list) {
+ if (in_range(pio, range->io_start, range->size))
+ return range;
+ }
+ pr_err("PIO entry token %lx invalid\n", pio);
+ return NULL;
+}
+
+/**
+ * logic_pio_to_hwaddr - translate logical PIO to HW address
+ * @pio: logical PIO value
+ *
+ * Returns HW address if valid, ~0 otherwise.
+ *
+ * Translate the input logical PIO to the corresponding hardware address.
+ * The input PIO should be unique in the whole logical PIO space.
+ */
+resource_size_t logic_pio_to_hwaddr(unsigned long pio)
+{
+ struct logic_pio_hwaddr *range;
+
+ range = find_io_range(pio);
+ if (range)
+ return range->hw_start + pio - range->io_start;
+
+ return (resource_size_t)~0;
+}
+
+/**
+ * logic_pio_trans_hwaddr - translate HW address to logical PIO
+ * @fwnode: FW node reference for the host
+ * @addr: Host-relative HW address
+ * @size: size to translate
+ *
+ * Returns Logical PIO value if successful, ~0UL otherwise
+ */
+unsigned long logic_pio_trans_hwaddr(struct fwnode_handle *fwnode,
+ resource_size_t addr, resource_size_t size)
+{
+ struct logic_pio_hwaddr *range;
+
+ range = find_io_range_by_fwnode(fwnode);
+ if (!range || range->flags == LOGIC_PIO_CPU_MMIO) {
+ pr_err("IO range not found or invalid\n");
+ return ~0UL;
+ }
+ if (range->size < size) {
+ pr_err("resource size %pa cannot fit in IO range size %pa\n",
+ &size, &range->size);
+ return ~0UL;
+ }
+ return addr - range->hw_start + range->io_start;
+}
+
+unsigned long logic_pio_trans_cpuaddr(resource_size_t addr)
+{
+ struct logic_pio_hwaddr *range;
+
+ list_for_each_entry_rcu(range, &io_range_list, list) {
+ if (range->flags != LOGIC_PIO_CPU_MMIO)
+ continue;
+ if (in_range(addr, range->hw_start, range->size))
+ return addr - range->hw_start + range->io_start;
+ }
+ pr_err("addr %llx not registered in io_range_list\n",
+ (unsigned long long) addr);
+ return ~0UL;
+}
+
+#if defined(CONFIG_INDIRECT_PIO) && defined(PCI_IOBASE)
+#define BUILD_LOGIC_IO(bw, type) \
+type logic_in##bw(unsigned long addr) \
+{ \
+ type ret = (type)~0; \
+ \
+ if (addr < MMIO_UPPER_LIMIT) { \
+ ret = read##bw(PCI_IOBASE + addr); \
+ } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
+ struct logic_pio_hwaddr *entry = find_io_range(addr); \
+ \
+ if (entry && entry->ops) \
+ ret = entry->ops->in(entry->hostdata, \
+ addr, sizeof(type)); \
+ else \
+ WARN_ON_ONCE(1); \
+ } \
+ return ret; \
+} \
+ \
+void logic_out##bw(type value, unsigned long addr) \
+{ \
+ if (addr < MMIO_UPPER_LIMIT) { \
+ write##bw(value, PCI_IOBASE + addr); \
+ } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
+ struct logic_pio_hwaddr *entry = find_io_range(addr); \
+ \
+ if (entry && entry->ops) \
+ entry->ops->out(entry->hostdata, \
+ addr, value, sizeof(type)); \
+ else \
+ WARN_ON_ONCE(1); \
+ } \
+} \
+ \
+void logic_ins##bw(unsigned long addr, void *buffer, \
+ unsigned int count) \
+{ \
+ if (addr < MMIO_UPPER_LIMIT) { \
+ reads##bw(PCI_IOBASE + addr, buffer, count); \
+ } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
+ struct logic_pio_hwaddr *entry = find_io_range(addr); \
+ \
+ if (entry && entry->ops) \
+ entry->ops->ins(entry->hostdata, \
+ addr, buffer, sizeof(type), count); \
+ else \
+ WARN_ON_ONCE(1); \
+ } \
+ \
+} \
+ \
+void logic_outs##bw(unsigned long addr, const void *buffer, \
+ unsigned int count) \
+{ \
+ if (addr < MMIO_UPPER_LIMIT) { \
+ writes##bw(PCI_IOBASE + addr, buffer, count); \
+ } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \
+ struct logic_pio_hwaddr *entry = find_io_range(addr); \
+ \
+ if (entry && entry->ops) \
+ entry->ops->outs(entry->hostdata, \
+ addr, buffer, sizeof(type), count); \
+ else \
+ WARN_ON_ONCE(1); \
+ } \
+}
+
+BUILD_LOGIC_IO(b, u8)
+EXPORT_SYMBOL(logic_inb);
+EXPORT_SYMBOL(logic_insb);
+EXPORT_SYMBOL(logic_outb);
+EXPORT_SYMBOL(logic_outsb);
+
+BUILD_LOGIC_IO(w, u16)
+EXPORT_SYMBOL(logic_inw);
+EXPORT_SYMBOL(logic_insw);
+EXPORT_SYMBOL(logic_outw);
+EXPORT_SYMBOL(logic_outsw);
+
+BUILD_LOGIC_IO(l, u32)
+EXPORT_SYMBOL(logic_inl);
+EXPORT_SYMBOL(logic_insl);
+EXPORT_SYMBOL(logic_outl);
+EXPORT_SYMBOL(logic_outsl);
+
+#endif /* CONFIG_INDIRECT_PIO && PCI_IOBASE */