On Fri, May 06, 2022 at 09:55:49PM +0100, Nikos Nikoleris wrote:
> For systems with ACPI support, we can discover timers through the ACPI
> GTDT table. This change implements the code to discover timers through
> the GTDT and adds ACPI support in timer_save_state. This change
> retains the default behavior; we check if a valid DT is provided, if
> not, we try to discover timers using ACPI.
>
> Signed-off-by: Nikos Nikoleris <nikos.nikoleris@xxxxxxx>
> ---
> arm/Makefile.common | 1 +
> lib/arm/asm/timer.h | 2 ++
> lib/acpi.h | 18 +++++++++++
> lib/arm/setup.c | 39 ------------------------
> lib/arm/timer.c | 73 +++++++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 94 insertions(+), 39 deletions(-)
> create mode 100644 lib/arm/timer.c
>
> diff --git a/arm/Makefile.common b/arm/Makefile.common
> index 8e9b3bb..5be42c0 100644
> --- a/arm/Makefile.common
> +++ b/arm/Makefile.common
> @@ -53,6 +53,7 @@ cflatobjs += lib/arm/psci.o
> cflatobjs += lib/arm/smp.o
> cflatobjs += lib/arm/delay.o
> cflatobjs += lib/arm/gic.o lib/arm/gic-v2.o lib/arm/gic-v3.o
> +cflatobjs += lib/arm/timer.o
>
> OBJDIRS += lib/arm
>
> diff --git a/lib/arm/asm/timer.h b/lib/arm/asm/timer.h
> index f75cc67..aaf839f 100644
> --- a/lib/arm/asm/timer.h
> +++ b/lib/arm/asm/timer.h
> @@ -27,5 +27,7 @@ extern struct timer_state __timer_state;
> #define TIMER_PTIMER_IRQ (__timer_state.ptimer.irq)
> #define TIMER_VTIMER_IRQ (__timer_state.vtimer.irq)
>
> +void timer_save_state(void);
> +
> #endif /* !__ASSEMBLY__ */
> #endif /* _ASMARM_TIMER_H_ */
> diff --git a/lib/acpi.h b/lib/acpi.h
> index 5213299..297ad87 100644
> --- a/lib/acpi.h
> +++ b/lib/acpi.h
> @@ -17,6 +17,7 @@
> #define FACP_SIGNATURE ACPI_SIGNATURE('F','A','C','P')
> #define FACS_SIGNATURE ACPI_SIGNATURE('F','A','C','S')
> #define SPCR_SIGNATURE ACPI_SIGNATURE('S','P','C','R')
> +#define GTDT_SIGNATURE ACPI_SIGNATURE('G','T','D','T')
>
>
> #define ACPI_SIGNATURE_8BYTE(c1, c2, c3, c4, c5, c6, c7, c8) \
> @@ -172,6 +173,23 @@ struct spcr_descriptor {
> u32 reserved2;
> } __attribute__ ((packed));
>
> +struct acpi_table_gtdt {
> + ACPI_TABLE_HEADER_DEF /* ACPI common table header */
> + u64 counter_block_addresss;
> + u32 reserved;
> + u32 secure_el1_interrupt;
> + u32 secure_el1_flags;
> + u32 non_secure_el1_interrupt;
> + u32 non_secure_el1_flags;
> + u32 virtual_timer_interrupt;
> + u32 virtual_timer_flags;
> + u32 non_secure_el2_interrupt;
> + u32 non_secure_el2_flags;
> + u64 counter_read_block_address;
> + u32 platform_timer_count;
> + u32 platform_timer_offset;
> +} __attribute__ ((packed));
> +
> void set_efi_rsdp(struct rsdp_descriptor *rsdp);
> void* find_acpi_table_addr(u32 sig);
>
> diff --git a/lib/arm/setup.c b/lib/arm/setup.c
> index bcdf0d7..1572c64 100644
> --- a/lib/arm/setup.c
> +++ b/lib/arm/setup.c
> @@ -35,8 +35,6 @@
>
> extern unsigned long etext;
>
> -struct timer_state __timer_state;
> -
> char *initrd;
> u32 initrd_size;
>
> @@ -199,43 +197,6 @@ static void mem_init(phys_addr_t freemem_start)
> page_alloc_ops_enable();
> }
>
> -static void timer_save_state(void)
> -{
> - const struct fdt_property *prop;
> - const void *fdt = dt_fdt();
> - int node, len;
> - u32 *data;
> -
> - node = fdt_node_offset_by_compatible(fdt, -1, "arm,armv8-timer");
> - assert(node >= 0 || node == -FDT_ERR_NOTFOUND);
> -
> - if (node == -FDT_ERR_NOTFOUND) {
> - __timer_state.ptimer.irq = -1;
> - __timer_state.vtimer.irq = -1;
> - return;
> - }
> -
> - /*
> - * From Linux devicetree timer binding documentation
> - *
> - * interrupts <type irq flags>:
> - * secure timer irq
> - * non-secure timer irq (ptimer)
> - * virtual timer irq (vtimer)
> - * hypervisor timer irq
> - */
> - prop = fdt_get_property(fdt, node, "interrupts", &len);
> - assert(prop && len == (4 * 3 * sizeof(u32)));
> -
> - data = (u32 *)prop->data;
> - assert(fdt32_to_cpu(data[3]) == 1 /* PPI */);
> - __timer_state.ptimer.irq = fdt32_to_cpu(data[4]);
> - __timer_state.ptimer.irq_flags = fdt32_to_cpu(data[5]);
> - assert(fdt32_to_cpu(data[6]) == 1 /* PPI */);
> - __timer_state.vtimer.irq = fdt32_to_cpu(data[7]);
> - __timer_state.vtimer.irq_flags = fdt32_to_cpu(data[8]);
> -}
> -
> void setup(const void *fdt, phys_addr_t freemem_start)
> {
> void *freemem;
> diff --git a/lib/arm/timer.c b/lib/arm/timer.c
> new file mode 100644
> index 0000000..eceabdf
> --- /dev/null
> +++ b/lib/arm/timer.c
> @@ -0,0 +1,73 @@
> +/*
> + * Initialize timers.
> + *
> + * Copyright (C) 2022, Arm Ltd., Nikos Nikoleris <nikos.nikoleris@xxxxxxx>
> + * Copyright (C) 2014, Red Hat Inc, Andrew Jones <drjones@xxxxxxxxxx>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.
> + */
> +#include <libcflat.h>
> +#include <asm/timer.h>
nit: I usually prefer an order like this for #includes
#include <lib-include1, usually libcflat.h>
#include <lib-include2>
...
#include <sublib-include1, libfdt/* and linux/*>
#include <sublib-include2>
...
#include <asm-include1>
#include <asm-include2>
> +
> +#include <acpi.h>
> +#include <devicetree.h>
> +#include <libfdt/libfdt.h>
> +
> +struct timer_state __timer_state;
> +
> +static void timer_save_state_fdt(void)
> +{
> + const struct fdt_property *prop;
> + const void *fdt = dt_fdt();
> + int node, len;
> + u32 *data;
> +
> + node = fdt_node_offset_by_compatible(fdt, -1, "arm,armv8-timer");
> + assert(node >= 0 || node == -FDT_ERR_NOTFOUND);
> +
> + if (node == -FDT_ERR_NOTFOUND) {
> + __timer_state.ptimer.irq = -1;
> + __timer_state.vtimer.irq = -1;
> + return;
> + }
> +
> + /*
> + * From Linux devicetree timer binding documentation
> + *
> + * interrupts <type irq flags>:
> + * secure timer irq
> + * non-secure timer irq (ptimer)
> + * virtual timer irq (vtimer)
> + * hypervisor timer irq
> + */
> + prop = fdt_get_property(fdt, node, "interrupts", &len);
> + assert(prop && len == (4 * 3 * sizeof(u32)));
> +
> + data = (u32 *)prop->data;
> + assert(fdt32_to_cpu(data[3]) == 1 /* PPI */);
> + __timer_state.ptimer.irq = fdt32_to_cpu(data[4]);
> + __timer_state.ptimer.irq_flags = fdt32_to_cpu(data[5]);
> + assert(fdt32_to_cpu(data[6]) == 1 /* PPI */);
> + __timer_state.vtimer.irq = fdt32_to_cpu(data[7]);
> + __timer_state.vtimer.irq_flags = fdt32_to_cpu(data[8]);
> +}
> +
> +static void timer_save_state_acpi(void)
> +{
> + struct acpi_table_gtdt *gtdt = find_acpi_table_addr(GTDT_SIGNATURE);
> +
> + assert_msg(gtdt, "Unable to find ACPI GTDT");
> + __timer_state.ptimer.irq = gtdt->non_secure_el1_interrupt;
> + __timer_state.ptimer.irq_flags = gtdt->non_secure_el1_flags;
> +
> + __timer_state.vtimer.irq = gtdt->virtual_timer_interrupt;
> + __timer_state.vtimer.irq_flags = gtdt->virtual_timer_flags;
> +}
> +
> +void timer_save_state(void)
> +{
> + if (dt_available())
> + timer_save_state_fdt();
> + else
> + timer_save_state_acpi();
> +}
> --
> 2.25.1
>
Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
Thanks,
drew
