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path: root/drivers/irqchip/irq-gic-v3-its.c
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Diffstat (limited to 'drivers/irqchip/irq-gic-v3-its.c')
-rw-r--r--drivers/irqchip/irq-gic-v3-its.c249
1 files changed, 193 insertions, 56 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index c2df341ff6fa..db20e992a40f 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -19,13 +19,16 @@
#include <linux/acpi_iort.h>
#include <linux/bitmap.h>
#include <linux/cpu.h>
+#include <linux/crash_dump.h>
#include <linux/delay.h>
#include <linux/dma-iommu.h>
+#include <linux/efi.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/list.h>
#include <linux/list_sort.h>
#include <linux/log2.h>
+#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/msi.h>
#include <linux/of.h>
@@ -52,6 +55,7 @@
#define ITS_FLAGS_SAVE_SUSPEND_STATE (1ULL << 3)
#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
+#define RDIST_FLAGS_RD_TABLES_PREALLOCATED (1 << 1)
static u32 lpi_id_bits;
@@ -64,7 +68,7 @@ static u32 lpi_id_bits;
#define LPI_PROPBASE_SZ ALIGN(BIT(LPI_NRBITS), SZ_64K)
#define LPI_PENDBASE_SZ ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K)
-#define LPI_PROP_DEFAULT_PRIO 0xa0
+#define LPI_PROP_DEFAULT_PRIO GICD_INT_DEF_PRI
/*
* Collection structure - just an ID, and a redistributor address to
@@ -173,6 +177,7 @@ static DEFINE_RAW_SPINLOCK(vmovp_lock);
static DEFINE_IDA(its_vpeid_ida);
#define gic_data_rdist() (raw_cpu_ptr(gic_rdists->rdist))
+#define gic_data_rdist_cpu(cpu) (per_cpu_ptr(gic_rdists->rdist, cpu))
#define gic_data_rdist_rd_base() (gic_data_rdist()->rd_base)
#define gic_data_rdist_vlpi_base() (gic_data_rdist_rd_base() + SZ_128K)
@@ -1028,7 +1033,7 @@ static inline u32 its_get_event_id(struct irq_data *d)
static void lpi_write_config(struct irq_data *d, u8 clr, u8 set)
{
irq_hw_number_t hwirq;
- struct page *prop_page;
+ void *va;
u8 *cfg;
if (irqd_is_forwarded_to_vcpu(d)) {
@@ -1036,7 +1041,7 @@ static void lpi_write_config(struct irq_data *d, u8 clr, u8 set)
u32 event = its_get_event_id(d);
struct its_vlpi_map *map;
- prop_page = its_dev->event_map.vm->vprop_page;
+ va = page_address(its_dev->event_map.vm->vprop_page);
map = &its_dev->event_map.vlpi_maps[event];
hwirq = map->vintid;
@@ -1044,11 +1049,11 @@ static void lpi_write_config(struct irq_data *d, u8 clr, u8 set)
map->properties &= ~clr;
map->properties |= set | LPI_PROP_GROUP1;
} else {
- prop_page = gic_rdists->prop_page;
+ va = gic_rdists->prop_table_va;
hwirq = d->hwirq;
}
- cfg = page_address(prop_page) + hwirq - 8192;
+ cfg = va + hwirq - 8192;
*cfg &= ~clr;
*cfg |= set | LPI_PROP_GROUP1;
@@ -1597,6 +1602,15 @@ static void its_lpi_free(unsigned long *bitmap, u32 base, u32 nr_ids)
kfree(bitmap);
}
+static void gic_reset_prop_table(void *va)
+{
+ /* Priority 0xa0, Group-1, disabled */
+ memset(va, LPI_PROP_DEFAULT_PRIO | LPI_PROP_GROUP1, LPI_PROPBASE_SZ);
+
+ /* Make sure the GIC will observe the written configuration */
+ gic_flush_dcache_to_poc(va, LPI_PROPBASE_SZ);
+}
+
static struct page *its_allocate_prop_table(gfp_t gfp_flags)
{
struct page *prop_page;
@@ -1605,13 +1619,7 @@ static struct page *its_allocate_prop_table(gfp_t gfp_flags)
if (!prop_page)
return NULL;
- /* Priority 0xa0, Group-1, disabled */
- memset(page_address(prop_page),
- LPI_PROP_DEFAULT_PRIO | LPI_PROP_GROUP1,
- LPI_PROPBASE_SZ);
-
- /* Make sure the GIC will observe the written configuration */
- gic_flush_dcache_to_poc(page_address(prop_page), LPI_PROPBASE_SZ);
+ gic_reset_prop_table(page_address(prop_page));
return prop_page;
}
@@ -1622,20 +1630,74 @@ static void its_free_prop_table(struct page *prop_page)
get_order(LPI_PROPBASE_SZ));
}
-static int __init its_alloc_lpi_tables(void)
+static bool gic_check_reserved_range(phys_addr_t addr, unsigned long size)
{
- phys_addr_t paddr;
+ phys_addr_t start, end, addr_end;
+ u64 i;
- lpi_id_bits = min_t(u32, GICD_TYPER_ID_BITS(gic_rdists->gicd_typer),
- ITS_MAX_LPI_NRBITS);
- gic_rdists->prop_page = its_allocate_prop_table(GFP_NOWAIT);
- if (!gic_rdists->prop_page) {
- pr_err("Failed to allocate PROPBASE\n");
- return -ENOMEM;
+ /*
+ * We don't bother checking for a kdump kernel as by
+ * construction, the LPI tables are out of this kernel's
+ * memory map.
+ */
+ if (is_kdump_kernel())
+ return true;
+
+ addr_end = addr + size - 1;
+
+ for_each_reserved_mem_region(i, &start, &end) {
+ if (addr >= start && addr_end <= end)
+ return true;
+ }
+
+ /* Not found, not a good sign... */
+ pr_warn("GICv3: Expected reserved range [%pa:%pa], not found\n",
+ &addr, &addr_end);
+ add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);
+ return false;
+}
+
+static int gic_reserve_range(phys_addr_t addr, unsigned long size)
+{
+ if (efi_enabled(EFI_CONFIG_TABLES))
+ return efi_mem_reserve_persistent(addr, size);
+
+ return 0;
+}
+
+static int __init its_setup_lpi_prop_table(void)
+{
+ if (gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED) {
+ u64 val;
+
+ val = gicr_read_propbaser(gic_data_rdist_rd_base() + GICR_PROPBASER);
+ lpi_id_bits = (val & GICR_PROPBASER_IDBITS_MASK) + 1;
+
+ gic_rdists->prop_table_pa = val & GENMASK_ULL(51, 12);
+ gic_rdists->prop_table_va = memremap(gic_rdists->prop_table_pa,
+ LPI_PROPBASE_SZ,
+ MEMREMAP_WB);
+ gic_reset_prop_table(gic_rdists->prop_table_va);
+ } else {
+ struct page *page;
+
+ lpi_id_bits = min_t(u32,
+ GICD_TYPER_ID_BITS(gic_rdists->gicd_typer),
+ ITS_MAX_LPI_NRBITS);
+ page = its_allocate_prop_table(GFP_NOWAIT);
+ if (!page) {
+ pr_err("Failed to allocate PROPBASE\n");
+ return -ENOMEM;
+ }
+
+ gic_rdists->prop_table_pa = page_to_phys(page);
+ gic_rdists->prop_table_va = page_address(page);
+ WARN_ON(gic_reserve_range(gic_rdists->prop_table_pa,
+ LPI_PROPBASE_SZ));
}
- paddr = page_to_phys(gic_rdists->prop_page);
- pr_info("GIC: using LPI property table @%pa\n", &paddr);
+ pr_info("GICv3: using LPI property table @%pa\n",
+ &gic_rdists->prop_table_pa);
return its_lpi_init(lpi_id_bits);
}
@@ -1924,12 +1986,9 @@ static int its_alloc_collections(struct its_node *its)
static struct page *its_allocate_pending_table(gfp_t gfp_flags)
{
struct page *pend_page;
- /*
- * The pending pages have to be at least 64kB aligned,
- * hence the 'max(LPI_PENDBASE_SZ, SZ_64K)' below.
- */
+
pend_page = alloc_pages(gfp_flags | __GFP_ZERO,
- get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K)));
+ get_order(LPI_PENDBASE_SZ));
if (!pend_page)
return NULL;
@@ -1941,36 +2000,103 @@ static struct page *its_allocate_pending_table(gfp_t gfp_flags)
static void its_free_pending_table(struct page *pt)
{
- free_pages((unsigned long)page_address(pt),
- get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K)));
+ free_pages((unsigned long)page_address(pt), get_order(LPI_PENDBASE_SZ));
+}
+
+/*
+ * Booting with kdump and LPIs enabled is generally fine. Any other
+ * case is wrong in the absence of firmware/EFI support.
+ */
+static bool enabled_lpis_allowed(void)
+{
+ phys_addr_t addr;
+ u64 val;
+
+ /* Check whether the property table is in a reserved region */
+ val = gicr_read_propbaser(gic_data_rdist_rd_base() + GICR_PROPBASER);
+ addr = val & GENMASK_ULL(51, 12);
+
+ return gic_check_reserved_range(addr, LPI_PROPBASE_SZ);
+}
+
+static int __init allocate_lpi_tables(void)
+{
+ u64 val;
+ int err, cpu;
+
+ /*
+ * If LPIs are enabled while we run this from the boot CPU,
+ * flag the RD tables as pre-allocated if the stars do align.
+ */
+ val = readl_relaxed(gic_data_rdist_rd_base() + GICR_CTLR);
+ if ((val & GICR_CTLR_ENABLE_LPIS) && enabled_lpis_allowed()) {
+ gic_rdists->flags |= (RDIST_FLAGS_RD_TABLES_PREALLOCATED |
+ RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING);
+ pr_info("GICv3: Using preallocated redistributor tables\n");
+ }
+
+ err = its_setup_lpi_prop_table();
+ if (err)
+ return err;
+
+ /*
+ * We allocate all the pending tables anyway, as we may have a
+ * mix of RDs that have had LPIs enabled, and some that
+ * don't. We'll free the unused ones as each CPU comes online.
+ */
+ for_each_possible_cpu(cpu) {
+ struct page *pend_page;
+
+ pend_page = its_allocate_pending_table(GFP_NOWAIT);
+ if (!pend_page) {
+ pr_err("Failed to allocate PENDBASE for CPU%d\n", cpu);
+ return -ENOMEM;
+ }
+
+ gic_data_rdist_cpu(cpu)->pend_page = pend_page;
+ }
+
+ return 0;
}
static void its_cpu_init_lpis(void)
{
void __iomem *rbase = gic_data_rdist_rd_base();
struct page *pend_page;
+ phys_addr_t paddr;
u64 val, tmp;
- /* If we didn't allocate the pending table yet, do it now */
- pend_page = gic_data_rdist()->pend_page;
- if (!pend_page) {
- phys_addr_t paddr;
+ if (gic_data_rdist()->lpi_enabled)
+ return;
- pend_page = its_allocate_pending_table(GFP_NOWAIT);
- if (!pend_page) {
- pr_err("Failed to allocate PENDBASE for CPU%d\n",
- smp_processor_id());
- return;
- }
+ val = readl_relaxed(rbase + GICR_CTLR);
+ if ((gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED) &&
+ (val & GICR_CTLR_ENABLE_LPIS)) {
+ /*
+ * Check that we get the same property table on all
+ * RDs. If we don't, this is hopeless.
+ */
+ paddr = gicr_read_propbaser(rbase + GICR_PROPBASER);
+ paddr &= GENMASK_ULL(51, 12);
+ if (WARN_ON(gic_rdists->prop_table_pa != paddr))
+ add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);
+
+ paddr = gicr_read_pendbaser(rbase + GICR_PENDBASER);
+ paddr &= GENMASK_ULL(51, 16);
- paddr = page_to_phys(pend_page);
- pr_info("CPU%d: using LPI pending table @%pa\n",
- smp_processor_id(), &paddr);
- gic_data_rdist()->pend_page = pend_page;
+ WARN_ON(!gic_check_reserved_range(paddr, LPI_PENDBASE_SZ));
+ its_free_pending_table(gic_data_rdist()->pend_page);
+ gic_data_rdist()->pend_page = NULL;
+
+ goto out;
}
+ pend_page = gic_data_rdist()->pend_page;
+ paddr = page_to_phys(pend_page);
+ WARN_ON(gic_reserve_range(paddr, LPI_PENDBASE_SZ));
+
/* set PROPBASE */
- val = (page_to_phys(gic_rdists->prop_page) |
+ val = (gic_rdists->prop_table_pa |
GICR_PROPBASER_InnerShareable |
GICR_PROPBASER_RaWaWb |
((LPI_NRBITS - 1) & GICR_PROPBASER_IDBITS_MASK));
@@ -2020,6 +2146,12 @@ static void its_cpu_init_lpis(void)
/* Make sure the GIC has seen the above */
dsb(sy);
+out:
+ gic_data_rdist()->lpi_enabled = true;
+ pr_info("GICv3: CPU%d: using %s LPI pending table @%pa\n",
+ smp_processor_id(),
+ gic_data_rdist()->pend_page ? "allocated" : "reserved",
+ &paddr);
}
static void its_cpu_init_collection(struct its_node *its)
@@ -3498,16 +3630,6 @@ static int redist_disable_lpis(void)
u64 timeout = USEC_PER_SEC;
u64 val;
- /*
- * If coming via a CPU hotplug event, we don't need to disable
- * LPIs before trying to re-enable them. They are already
- * configured and all is well in the world. Detect this case
- * by checking the allocation of the pending table for the
- * current CPU.
- */
- if (gic_data_rdist()->pend_page)
- return 0;
-
if (!gic_rdists_supports_plpis()) {
pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
return -ENXIO;
@@ -3517,7 +3639,21 @@ static int redist_disable_lpis(void)
if (!(val & GICR_CTLR_ENABLE_LPIS))
return 0;
- pr_warn("CPU%d: Booted with LPIs enabled, memory probably corrupted\n",
+ /*
+ * If coming via a CPU hotplug event, we don't need to disable
+ * LPIs before trying to re-enable them. They are already
+ * configured and all is well in the world.
+ *
+ * If running with preallocated tables, there is nothing to do.
+ */
+ if (gic_data_rdist()->lpi_enabled ||
+ (gic_rdists->flags & RDIST_FLAGS_RD_TABLES_PREALLOCATED))
+ return 0;
+
+ /*
+ * From that point on, we only try to do some damage control.
+ */
+ pr_warn("GICv3: CPU%d: Booted with LPIs enabled, memory probably corrupted\n",
smp_processor_id());
add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);
@@ -3773,7 +3909,8 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
}
gic_rdists = rdists;
- err = its_alloc_lpi_tables();
+
+ err = allocate_lpi_tables();
if (err)
return err;