diff options
Diffstat (limited to 'arch/powerpc/sysdev/xics/icp-hv.c')
| -rw-r--r-- | arch/powerpc/sysdev/xics/icp-hv.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/xics/icp-hv.c b/arch/powerpc/sysdev/xics/icp-hv.c new file mode 100644 index 00000000000..9518d367a64 --- /dev/null +++ b/arch/powerpc/sysdev/xics/icp-hv.c @@ -0,0 +1,164 @@ +/* + * 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 <asm/smp.h> +#include <asm/irq.h> +#include <asm/errno.h> +#include <asm/xics.h> +#include <asm/io.h> +#include <asm/hvcall.h> + +static inline unsigned int icp_hv_get_xirr(unsigned char cppr) +{ + unsigned long retbuf[PLPAR_HCALL_BUFSIZE]; + long rc; + + rc = plpar_hcall(H_XIRR, retbuf, cppr); + if (rc != H_SUCCESS) + panic(" bad return code xirr - rc = %lx\n", rc); + return (unsigned int)retbuf[0]; +} + +static inline void icp_hv_set_xirr(unsigned int value) +{ + long rc = plpar_hcall_norets(H_EOI, value); + if (rc != H_SUCCESS) + panic("bad return code EOI - rc = %ld, value=%x\n", rc, value); +} + +static inline void icp_hv_set_cppr(u8 value) +{ + long rc = plpar_hcall_norets(H_CPPR, value); + if (rc != H_SUCCESS) + panic("bad return code cppr - rc = %lx\n", rc); +} + +static inline void icp_hv_set_qirr(int n_cpu , u8 value) +{ + long rc = plpar_hcall_norets(H_IPI, get_hard_smp_processor_id(n_cpu), + value); + if (rc != H_SUCCESS) + panic("bad return code qirr - rc = %lx\n", rc); +} + +static void icp_hv_eoi(struct irq_data *d) +{ + unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); + + iosync(); + icp_hv_set_xirr((xics_pop_cppr() << 24) | hw_irq); +} + +static void icp_hv_teardown_cpu(void) +{ + int cpu = smp_processor_id(); + + /* Clear any pending IPI */ + icp_hv_set_qirr(cpu, 0xff); +} + +static void icp_hv_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_hv_set_xirr((0x00 << 24) | XICS_IPI); +} + +static unsigned int icp_hv_get_irq(void) +{ + unsigned int xirr = icp_hv_get_xirr(xics_cppr_top()); + unsigned int vec = xirr & 0x00ffffff; + unsigned int irq; + + if (vec == XICS_IRQ_SPURIOUS) + return NO_IRQ; + + irq = irq_radix_revmap_lookup(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_hv_set_xirr(xirr); + + return NO_IRQ; +} + +static void icp_hv_set_cpu_priority(unsigned char cppr) +{ + xics_set_base_cppr(cppr); + icp_hv_set_cppr(cppr); + iosync(); +} + +#ifdef CONFIG_SMP + +static void icp_hv_cause_ipi(int cpu, unsigned long data) +{ + icp_hv_set_qirr(cpu, IPI_PRIORITY); +} + +static irqreturn_t icp_hv_ipi_action(int irq, void *dev_id) +{ + int cpu = smp_processor_id(); + + icp_hv_set_qirr(cpu, 0xff); + + return smp_ipi_demux(); +} + +#endif /* CONFIG_SMP */ + +static const struct icp_ops icp_hv_ops = { + .get_irq = icp_hv_get_irq, + .eoi = icp_hv_eoi, + .set_priority = icp_hv_set_cpu_priority, + .teardown_cpu = icp_hv_teardown_cpu, + .flush_ipi = icp_hv_flush_ipi, +#ifdef CONFIG_SMP + .ipi_action = icp_hv_ipi_action, + .cause_ipi = icp_hv_cause_ipi, +#endif +}; + +int icp_hv_init(void) +{ + struct device_node *np; + + np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xicp"); + if (!np) + np = of_find_node_by_type(NULL, + "PowerPC-External-Interrupt-Presentation"); + if (!np) + return -ENODEV; + + icp_ops = &icp_hv_ops; + + return 0; +} + |