cregit-Linux how code gets into the kernel

Release 4.14 arch/powerpc/sysdev/xics/icp-native.c

/*
 * 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); }

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Benjamin Herrenschmidt47100.00%2100.00%
Total47100.00%2100.00%


static inline void icp_native_set_xirr(unsigned int value) { int cpu = smp_processor_id(); out_be32(&icp_native_regs[cpu]->xirr.word, value); }

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Benjamin Herrenschmidt32100.00%1100.00%
Total32100.00%1100.00%


static inline void icp_native_set_cppr(u8 value) { int cpu = smp_processor_id(); out_8(&icp_native_regs[cpu]->xirr.bytes[0], value); }

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Benjamin Herrenschmidt34100.00%1100.00%
Total34100.00%1100.00%


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

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Benjamin Herrenschmidt31100.00%1100.00%
Total31100.00%1100.00%


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

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Benjamin Herrenschmidt23100.00%1100.00%
Total23100.00%1100.00%


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); }

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Benjamin Herrenschmidt3797.37%150.00%
Grant C. Likely12.63%150.00%
Total38100.00%2100.00%


static void icp_native_teardown_cpu(void) { int cpu = smp_processor_id(); /* Clear any pending IPI */ icp_native_set_qirr(cpu, 0xff); }

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Benjamin Herrenschmidt22100.00%1100.00%
Total22100.00%1100.00%


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); }

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Benjamin Herrenschmidt20100.00%1100.00%
Total20100.00%1100.00%


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 0; irq = irq_find_mapping(xics_host, vec); if (likely(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 0; }

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PersonTokensPropCommitsCommitProp
Benjamin Herrenschmidt7596.15%133.33%
Michael Ellerman22.56%133.33%
Grant C. Likely11.28%133.33%
Total78100.00%3100.00%

#ifdef CONFIG_SMP
static void icp_native_cause_ipi(int cpu) { kvmppc_set_host_ipi(cpu, 1); icp_native_set_qirr(cpu, IPI_PRIORITY); }

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Benjamin Herrenschmidt2086.96%266.67%
Milton D. Miller II313.04%133.33%
Total23100.00%3100.00%

#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
void icp_native_cause_ipi_rm(int cpu) { /* * Currently not used to send IPIs to another CPU * on the same core. Only caller is KVM real mode. * Need the physical address of the XICS to be * previously saved in kvm_hstate in the paca. */ void __iomem *xics_phys; /* * Just like the cause_ipi functions, it is required to * include a full barrier before causing the IPI. */ xics_phys = paca[cpu].kvm_hstate.xics_phys; mb(); __raw_rm_writeb(IPI_PRIORITY, xics_phys + XICS_MFRR); }

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PersonTokensPropCommitsCommitProp
Suresh E. Warrier2873.68%150.00%
Benjamin Herrenschmidt1026.32%150.00%
Total38100.00%2100.00%

#endif /* * 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); }

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Paul Mackerras79100.00%1100.00%
Total79100.00%1100.00%


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

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Paul Mackerras15100.00%1100.00%
Total15100.00%1100.00%

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(); }

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Benjamin Herrenschmidt3594.59%266.67%
Milton D. Miller II25.41%133.33%
Total37100.00%3100.00%

#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; }

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Benjamin Herrenschmidt16295.86%150.00%
Paul Mackerras74.14%150.00%
Total169100.00%2100.00%


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; }

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PersonTokensPropCommitsCommitProp
Benjamin Herrenschmidt28198.25%133.33%
Joe Perches41.40%133.33%
Anton Blanchard10.35%133.33%
Total286100.00%3100.00%

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; }

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PersonTokensPropCommitsCommitProp
Benjamin Herrenschmidt9598.96%150.00%
Arnaud Lacombe11.04%150.00%
Total96100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Benjamin Herrenschmidt109286.80%321.43%
Paul Mackerras1138.98%214.29%
Suresh E. Warrier332.62%17.14%
Milton D. Miller II70.56%17.14%
Joe Perches40.32%17.14%
Michael Neuling30.24%17.14%
Grant C. Likely20.16%214.29%
Michael Ellerman20.16%17.14%
Arnaud Lacombe10.08%17.14%
Anton Blanchard10.08%17.14%
Total1258100.00%14100.00%
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