arch/powerpc/sysdev/xics/icp-native.c - kernel/bruno - Git at Google

 /*
  * Copyright 2011 IBM Corporation.
  *
  *  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/types.h>
 #include <linux/kernel.h>
 #include <linux/irq.h>
 #include <linux/smp.h>
 #include <linux/interrupt.h>
 #include <linux/init.h>
 #include <linux/cpu.h>
 #include <linux/of.h>
 #include <linux/spinlock.h>
 #include <linux/module.h>

 #include <asm/prom.h>
 #include <asm/io.h>
 #include <asm/smp.h>
 #include <asm/irq.h>
 #include <asm/errno.h>
 #include <asm/xics.h>
 #include <asm/kvm_ppc.h>
 #include <asm/dbell.h>

 struct icp_ipl {
 	union {
 		u32 word;
 		u8 bytes[4];
 	} xirr_poll;
 	union {
 		u32 word;
 		u8 bytes[4];
 	} xirr;
 	u32 dummy;
 	union {
 		u32 word;
 		u8 bytes[4];
 	} qirr;
 	u32 link_a;
 	u32 link_b;
 	u32 link_c;
 };

 static struct icp_ipl __iomem *icp_native_regs[NR_CPUS];

 static inline unsigned int icp_native_get_xirr(void)
 {
 	int cpu = smp_processor_id();
 	unsigned int xirr;

 	/* Handled an interrupt latched by KVM */
 	xirr = kvmppc_get_xics_latch();
 	if (xirr)
 		return xirr;

 	return in_be32(&icp_native_regs[cpu]->xirr.word);
 }

 static inline void icp_native_set_xirr(unsigned int value)
 {
 	int cpu = smp_processor_id();

 	out_be32(&icp_native_regs[cpu]->xirr.word, value);
 }

 static inline void icp_native_set_cppr(u8 value)
 {
 	int cpu = smp_processor_id();

 	out_8(&icp_native_regs[cpu]->xirr.bytes[0], value);
 }

 static inline void icp_native_set_qirr(int n_cpu, u8 value)
 {
 	out_8(&icp_native_regs[n_cpu]->qirr.bytes[0], value);
 }

 static void icp_native_set_cpu_priority(unsigned char cppr)
 {
 	xics_set_base_cppr(cppr);
 	icp_native_set_cppr(cppr);
 	iosync();
 }

 void icp_native_eoi(struct irq_data *d)
 {
 	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);

 	iosync();
 	icp_native_set_xirr((xics_pop_cppr() << 24) | hw_irq);
 }

 static void icp_native_teardown_cpu(void)
 {
 	int cpu = smp_processor_id();

 	/* Clear any pending IPI */
 	icp_native_set_qirr(cpu, 0xff);
 }

 static void icp_native_flush_ipi(void)
 {
 	/* We take the ipi irq but and never return so we
 	 * need to EOI the IPI, but want to leave our priority 0
 	 *
 	 * should we check all the other interrupts too?
 	 * should we be flagging idle loop instead?
 	 * or creating some task to be scheduled?
 	 */

 	icp_native_set_xirr((0x00 << 24) | XICS_IPI);
 }

 static unsigned int icp_native_get_irq(void)
 {
 	unsigned int xirr = icp_native_get_xirr();
 	unsigned int vec = xirr & 0x00ffffff;
 	unsigned int irq;

 	if (vec == XICS_IRQ_SPURIOUS)
 		return NO_IRQ;

 	irq = irq_find_mapping(xics_host, vec);
 	if (likely(irq != NO_IRQ)) {
 		xics_push_cppr(vec);
 		return irq;
 	}

 	/* We don't have a linux mapping, so have rtas mask it. */
 	xics_mask_unknown_vec(vec);

 	/* We might learn about it later, so EOI it */
 	icp_native_set_xirr(xirr);

 	return NO_IRQ;
 }

 #ifdef CONFIG_SMP

 static void icp_native_cause_ipi(int cpu, unsigned long data)
 {
 	kvmppc_set_host_ipi(cpu, 1);
 #ifdef CONFIG_PPC_DOORBELL
 	if (cpu_has_feature(CPU_FTR_DBELL)) {
 		if (cpumask_test_cpu(cpu, cpu_sibling_mask(get_cpu()))) {
 			doorbell_cause_ipi(cpu, data);
 			put_cpu();
 			return;
 		}
 		put_cpu();
 	}
 #endif
 	icp_native_set_qirr(cpu, IPI_PRIORITY);
 }

 /*
  * Called when an interrupt is received on an off-line CPU to
  * clear the interrupt, so that the CPU can go back to nap mode.
  */
 void icp_native_flush_interrupt(void)
 {
 	unsigned int xirr = icp_native_get_xirr();
 	unsigned int vec = xirr & 0x00ffffff;

 	if (vec == XICS_IRQ_SPURIOUS)
 		return;
 	if (vec == XICS_IPI) {
 		/* Clear pending IPI */
 		int cpu = smp_processor_id();
 		kvmppc_set_host_ipi(cpu, 0);
 		icp_native_set_qirr(cpu, 0xff);
 	} else {
 		pr_err("XICS: hw interrupt 0x%x to offline cpu, disabling\n",
 		       vec);
 		xics_mask_unknown_vec(vec);
 	}
 	/* EOI the interrupt */
 	icp_native_set_xirr(xirr);
 }

 void xics_wake_cpu(int cpu)
 {
 	icp_native_set_qirr(cpu, IPI_PRIORITY);
 }
 EXPORT_SYMBOL_GPL(xics_wake_cpu);

 static irqreturn_t icp_native_ipi_action(int irq, void *dev_id)
 {
 	int cpu = smp_processor_id();

 	kvmppc_set_host_ipi(cpu, 0);
 	icp_native_set_qirr(cpu, 0xff);

 	return smp_ipi_demux();
 }

 #endif /* CONFIG_SMP */

 static int __init icp_native_map_one_cpu(int hw_id, unsigned long addr,
 					 unsigned long size)
 {
 	char *rname;
 	int i, cpu = -1;

 	/* This may look gross but it's good enough for now, we don't quite
 	 * have a hard -> linux processor id matching.
 	 */
 	for_each_possible_cpu(i) {
 		if (!cpu_present(i))
 			continue;
 		if (hw_id == get_hard_smp_processor_id(i)) {
 			cpu = i;
 			break;
 		}
 	}

 	/* Fail, skip that CPU. Don't print, it's normal, some XICS come up
 	 * with way more entries in there than you have CPUs
 	 */
 	if (cpu == -1)
 		return 0;

 	rname = kasprintf(GFP_KERNEL, "CPU %d [0x%x] Interrupt Presentation",
 			  cpu, hw_id);

 	if (!request_mem_region(addr, size, rname)) {
 		pr_warning("icp_native: Could not reserve ICP MMIO"
 			   " for CPU %d, interrupt server #0x%x\n",
 			   cpu, hw_id);
 		return -EBUSY;
 	}

 	icp_native_regs[cpu] = ioremap(addr, size);
 	kvmppc_set_xics_phys(cpu, addr);
 	if (!icp_native_regs[cpu]) {
 		pr_warning("icp_native: Failed ioremap for CPU %d, "
 			   "interrupt server #0x%x, addr %#lx\n",
 			   cpu, hw_id, addr);
 		release_mem_region(addr, size);
 		return -ENOMEM;
 	}
 	return 0;
 }

 static int __init icp_native_init_one_node(struct device_node *np,
 					   unsigned int *indx)
 {
 	unsigned int ilen;
 	const __be32 *ireg;
 	int i;
 	int reg_tuple_size;
 	int num_servers = 0;

 	/* This code does the theorically broken assumption that the interrupt
 	 * server numbers are the same as the hard CPU numbers.
 	 * This happens to be the case so far but we are playing with fire...
 	 * should be fixed one of these days. -BenH.
 	 */
 	ireg = of_get_property(np, "ibm,interrupt-server-ranges", &ilen);

 	/* Do that ever happen ? we'll know soon enough... but even good'old
 	 * f80 does have that property ..
 	 */
 	WARN_ON((ireg == NULL) || (ilen != 2*sizeof(u32)));

 	if (ireg) {
 		*indx = of_read_number(ireg, 1);
 		if (ilen >= 2*sizeof(u32))
 			num_servers = of_read_number(ireg + 1, 1);
 	}

 	ireg = of_get_property(np, "reg", &ilen);
 	if (!ireg) {
 		pr_err("icp_native: Can't find interrupt reg property");
 		return -1;
 	}

 	reg_tuple_size = (of_n_addr_cells(np) + of_n_size_cells(np)) * 4;
 	if (((ilen % reg_tuple_size) != 0)
 	    || (num_servers && (num_servers != (ilen / reg_tuple_size)))) {
 		pr_err("icp_native: ICP reg len (%d) != num servers (%d)",
 		       ilen / reg_tuple_size, num_servers);
 		return -1;
 	}

 	for (i = 0; i < (ilen / reg_tuple_size); i++) {
 		struct resource r;
 		int err;

 		err = of_address_to_resource(np, i, &r);
 		if (err) {
 			pr_err("icp_native: Could not translate ICP MMIO"
 			       " for interrupt server 0x%x (%d)\n", *indx, err);
 			return -1;
 		}

 		if (icp_native_map_one_cpu(*indx, r.start, resource_size(&r)))
 			return -1;

 		(*indx)++;
 	}
 	return 0;
 }

 static const struct icp_ops icp_native_ops = {
 	.get_irq	= icp_native_get_irq,
 	.eoi		= icp_native_eoi,
 	.set_priority	= icp_native_set_cpu_priority,
 	.teardown_cpu	= icp_native_teardown_cpu,
 	.flush_ipi	= icp_native_flush_ipi,
 #ifdef CONFIG_SMP
 	.ipi_action	= icp_native_ipi_action,
 	.cause_ipi	= icp_native_cause_ipi,
 #endif
 };

 int __init icp_native_init(void)
 {
 	struct device_node *np;
 	u32 indx = 0;
 	int found = 0;

 	for_each_compatible_node(np, NULL, "ibm,ppc-xicp")
 		if (icp_native_init_one_node(np, &indx) == 0)
 			found = 1;
 	if (!found) {
 		for_each_node_by_type(np,
 			"PowerPC-External-Interrupt-Presentation") {
 				if (icp_native_init_one_node(np, &indx) == 0)
 					found = 1;
 		}
 	}

 	if (found == 0)
 		return -ENODEV;

 	icp_ops = &icp_native_ops;

 	return 0;
 }
	/*
	* Copyright 2011 IBM Corporation.
	*
	* 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/types.h>
	#include <linux/kernel.h>
	#include <linux/irq.h>
	#include <linux/smp.h>
	#include <linux/interrupt.h>
	#include <linux/init.h>
	#include <linux/cpu.h>
	#include <linux/of.h>
	#include <linux/spinlock.h>
	#include <linux/module.h>

	#include <asm/prom.h>
	#include <asm/io.h>
	#include <asm/smp.h>
	#include <asm/irq.h>
	#include <asm/errno.h>
	#include <asm/xics.h>
	#include <asm/kvm_ppc.h>
	#include <asm/dbell.h>

	struct icp_ipl {
	union {
	u32 word;
	u8 bytes[4];
	} xirr_poll;
	union {
	u32 word;
	u8 bytes[4];
	} xirr;
	u32 dummy;
	union {
	u32 word;
	u8 bytes[4];
	} qirr;
	u32 link_a;
	u32 link_b;
	u32 link_c;
	};

	static struct icp_ipl __iomem *icp_native_regs[NR_CPUS];

	static inline unsigned int icp_native_get_xirr(void)
	{
	int cpu = smp_processor_id();
	unsigned int xirr;

	/* Handled an interrupt latched by KVM */
	xirr = kvmppc_get_xics_latch();
	if (xirr)
	return xirr;

	return in_be32(&icp_native_regs[cpu]->xirr.word);
	}

	static inline void icp_native_set_xirr(unsigned int value)
	{
	int cpu = smp_processor_id();

	out_be32(&icp_native_regs[cpu]->xirr.word, value);
	}

	static inline void icp_native_set_cppr(u8 value)
	{
	int cpu = smp_processor_id();

	out_8(&icp_native_regs[cpu]->xirr.bytes[0], value);
	}

	static inline void icp_native_set_qirr(int n_cpu, u8 value)
	{
	out_8(&icp_native_regs[n_cpu]->qirr.bytes[0], value);
	}

	static void icp_native_set_cpu_priority(unsigned char cppr)
	{
	xics_set_base_cppr(cppr);
	icp_native_set_cppr(cppr);
	iosync();
	}

	void icp_native_eoi(struct irq_data *d)
	{
	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);

	iosync();
	icp_native_set_xirr((xics_pop_cppr() << 24) \| hw_irq);
	}

	static void icp_native_teardown_cpu(void)
	{
	int cpu = smp_processor_id();

	/* Clear any pending IPI */
	icp_native_set_qirr(cpu, 0xff);
	}

	static void icp_native_flush_ipi(void)
	{
	/* We take the ipi irq but and never return so we
	* need to EOI the IPI, but want to leave our priority 0
	*
	* should we check all the other interrupts too?
	* should we be flagging idle loop instead?
	* or creating some task to be scheduled?
	*/

	icp_native_set_xirr((0x00 << 24) \| XICS_IPI);
	}

	static unsigned int icp_native_get_irq(void)
	{
	unsigned int xirr = icp_native_get_xirr();
	unsigned int vec = xirr & 0x00ffffff;
	unsigned int irq;

	if (vec == XICS_IRQ_SPURIOUS)
	return NO_IRQ;

	irq = irq_find_mapping(xics_host, vec);
	if (likely(irq != NO_IRQ)) {
	xics_push_cppr(vec);
	return irq;
	}

	/* We don't have a linux mapping, so have rtas mask it. */
	xics_mask_unknown_vec(vec);

	/* We might learn about it later, so EOI it */
	icp_native_set_xirr(xirr);

	return NO_IRQ;
	}

	#ifdef CONFIG_SMP

	static void icp_native_cause_ipi(int cpu, unsigned long data)
	{
	kvmppc_set_host_ipi(cpu, 1);
	#ifdef CONFIG_PPC_DOORBELL
	if (cpu_has_feature(CPU_FTR_DBELL)) {
	if (cpumask_test_cpu(cpu, cpu_sibling_mask(get_cpu()))) {
	doorbell_cause_ipi(cpu, data);
	put_cpu();
	return;
	}
	put_cpu();
	}
	#endif
	icp_native_set_qirr(cpu, IPI_PRIORITY);
	}

	/*
	* Called when an interrupt is received on an off-line CPU to
	* clear the interrupt, so that the CPU can go back to nap mode.
	*/
	void icp_native_flush_interrupt(void)
	{
	unsigned int xirr = icp_native_get_xirr();
	unsigned int vec = xirr & 0x00ffffff;

	if (vec == XICS_IRQ_SPURIOUS)
	return;
	if (vec == XICS_IPI) {
	/* Clear pending IPI */
	int cpu = smp_processor_id();
	kvmppc_set_host_ipi(cpu, 0);
	icp_native_set_qirr(cpu, 0xff);
	} else {
	pr_err("XICS: hw interrupt 0x%x to offline cpu, disabling\n",
	vec);
	xics_mask_unknown_vec(vec);
	}
	/* EOI the interrupt */
	icp_native_set_xirr(xirr);
	}

	void xics_wake_cpu(int cpu)
	{
	icp_native_set_qirr(cpu, IPI_PRIORITY);
	}
	EXPORT_SYMBOL_GPL(xics_wake_cpu);

	static irqreturn_t icp_native_ipi_action(int irq, void *dev_id)
	{
	int cpu = smp_processor_id();

	kvmppc_set_host_ipi(cpu, 0);
	icp_native_set_qirr(cpu, 0xff);

	return smp_ipi_demux();
	}

	#endif /* CONFIG_SMP */

	static int __init icp_native_map_one_cpu(int hw_id, unsigned long addr,
	unsigned long size)
	{
	char *rname;
	int i, cpu = -1;

	/* This may look gross but it's good enough for now, we don't quite
	* have a hard -> linux processor id matching.
	*/
	for_each_possible_cpu(i) {
	if (!cpu_present(i))
	continue;
	if (hw_id == get_hard_smp_processor_id(i)) {
	cpu = i;
	break;
	}
	}

	/* Fail, skip that CPU. Don't print, it's normal, some XICS come up
	* with way more entries in there than you have CPUs
	*/
	if (cpu == -1)
	return 0;

	rname = kasprintf(GFP_KERNEL, "CPU %d [0x%x] Interrupt Presentation",
	cpu, hw_id);

	if (!request_mem_region(addr, size, rname)) {
	pr_warning("icp_native: Could not reserve ICP MMIO"
	" for CPU %d, interrupt server #0x%x\n",
	cpu, hw_id);
	return -EBUSY;
	}

	icp_native_regs[cpu] = ioremap(addr, size);
	kvmppc_set_xics_phys(cpu, addr);
	if (!icp_native_regs[cpu]) {
	pr_warning("icp_native: Failed ioremap for CPU %d, "
	"interrupt server #0x%x, addr %#lx\n",
	cpu, hw_id, addr);
	release_mem_region(addr, size);
	return -ENOMEM;
	}
	return 0;
	}

	static int __init icp_native_init_one_node(struct device_node *np,
	unsigned int *indx)
	{
	unsigned int ilen;
	const __be32 *ireg;
	int i;
	int reg_tuple_size;
	int num_servers = 0;

	/* This code does the theorically broken assumption that the interrupt
	* server numbers are the same as the hard CPU numbers.
	* This happens to be the case so far but we are playing with fire...
	* should be fixed one of these days. -BenH.
	*/
	ireg = of_get_property(np, "ibm,interrupt-server-ranges", &ilen);

	/* Do that ever happen ? we'll know soon enough... but even good'old
	* f80 does have that property ..
	*/
	WARN_ON((ireg == NULL) \|\| (ilen != 2*sizeof(u32)));

	if (ireg) {
	*indx = of_read_number(ireg, 1);
	if (ilen >= 2*sizeof(u32))
	num_servers = of_read_number(ireg + 1, 1);
	}

	ireg = of_get_property(np, "reg", &ilen);
	if (!ireg) {
	pr_err("icp_native: Can't find interrupt reg property");
	return -1;
	}

	reg_tuple_size = (of_n_addr_cells(np) + of_n_size_cells(np)) * 4;
	if (((ilen % reg_tuple_size) != 0)
	\|\| (num_servers && (num_servers != (ilen / reg_tuple_size)))) {
	pr_err("icp_native: ICP reg len (%d) != num servers (%d)",
	ilen / reg_tuple_size, num_servers);
	return -1;
	}

	for (i = 0; i < (ilen / reg_tuple_size); i++) {
	struct resource r;
	int err;

	err = of_address_to_resource(np, i, &r);
	if (err) {
	pr_err("icp_native: Could not translate ICP MMIO"
	" for interrupt server 0x%x (%d)\n", *indx, err);
	return -1;
	}

	if (icp_native_map_one_cpu(*indx, r.start, resource_size(&r)))
	return -1;

	(*indx)++;
	}
	return 0;
	}

	static const struct icp_ops icp_native_ops = {
	.get_irq = icp_native_get_irq,
	.eoi = icp_native_eoi,
	.set_priority = icp_native_set_cpu_priority,
	.teardown_cpu = icp_native_teardown_cpu,
	.flush_ipi = icp_native_flush_ipi,
	#ifdef CONFIG_SMP
	.ipi_action = icp_native_ipi_action,
	.cause_ipi = icp_native_cause_ipi,
	#endif
	};

	int __init icp_native_init(void)
	{
	struct device_node *np;
	u32 indx = 0;
	int found = 0;

	for_each_compatible_node(np, NULL, "ibm,ppc-xicp")
	if (icp_native_init_one_node(np, &indx) == 0)
	found = 1;
	if (!found) {
	for_each_node_by_type(np,
	"PowerPC-External-Interrupt-Presentation") {
	if (icp_native_init_one_node(np, &indx) == 0)
	found = 1;
	}
	}

	if (found == 0)
	return -ENODEV;

	icp_ops = &icp_native_ops;

	return 0;
	}