[Skiboot] [PATCH Skiboot v1.2 3/3] Advertise the self-save and self-restore attributes in the device tree

[Vasant Hegde]

On 10/10/19 5:40 PM, Pratik Rajesh Sampat wrote:
> Support for self save and self restore interface is advertised in the
> device tree, along with the list of SPRs it supports for each.
> 
> The Special Purpose Register identification is encoded in a 2048 bitmask
> structure, where each bit signifies the identification key of that SPR
> which is consistent with that of the Linux kernel for that register.\

I assume this feature needs supported HCODE level. How do you determine whether 
HCODE supports
new feature or not?

-Vasant

> 
> Signed-off-by: Pratik Rajesh Sampat <psampat at linux.ibm.com>
> ---
>   hw/slw.c          | 72 +++++++++++++++++++++++++++++++++++++++++++++++
>   include/skiboot.h |  1 +
>   2 files changed, 73 insertions(+)
> 
> diff --git a/hw/slw.c b/hw/slw.c
> index b79aaab3..d9c2d091 100644
> --- a/hw/slw.c
> +++ b/hw/slw.c
> @@ -22,6 +22,7 @@
>   #include <opal-api.h>
>   #include <nvram.h>
>   #include <sbe-p8.h>
> +#include <bitmap.h>
> 
>   #include <p9_stop_api.H>
>   #include <p8_pore_table_gen_api.H>
> @@ -753,6 +754,70 @@ static void slw_late_init_p9(struct proc_chip *chip)
>   	}
>   }
> 
> +/* Add device tree properties to determine self-save | restore */
> +void add_cpu_self_save_properties(struct dt_node *power_mgt)
> +{
> +	int i;
> +	struct dt_node *self_restore, *self_save;
> +	bitmap_t *self_restore_map, *self_save_map;
> +	/* 32 times 64 bits needed to store a 2048 bits bitmask*/
> +	const int bits_nr = 32;
> +
> +	const uint64_t self_restore_regs[] = {
> +		0x130, // HSPRG0
> +		0x13E, // LPCR
> +		0x151, // HMEER
> +		0x3F0, // HID0
> +		0x3F1, // HID1
> +		0x3F4, // HID4
> +		0x3F6, // HID5
> +		0x7D0, // MSR
> +		0x357 // PSCCR
> +	};
> +
> +	const uint64_t self_save_regs[] = {
> +		0x130, // HSPRG0
> +		0x13E, // LPCR
> +		0x151, // HMEER
> +		0x7D0, // MSR
> +		0x357 // PSCCR
> +	};
> +	const int self_save_regs_nr	=	ARRAY_SIZE(self_save_regs);
> +	const int self_restore_regs_nr	=	ARRAY_SIZE(self_restore_regs);
> +
> +	self_save_map = zalloc(BITMAP_BYTES(0x800));
> +	self_restore_map = zalloc(BITMAP_BYTES(0x800));
> +
> +	for (i = 0; i < self_save_regs_nr; i++)
> +		bitmap_set_bit(*self_save_map, self_save_regs[i]);
> +
> +	for (i = 0; i < self_restore_regs_nr; i++)
> +		bitmap_set_bit(*self_restore_map, self_restore_regs[i]);
> +
> +	self_restore = dt_new(power_mgt, "self-restore");
> +	if (!self_restore) {
> +		prerror("OCC: Failed to create self restore node");
> +		return;
> +	}
> +	dt_add_property_cells(self_restore, "active", 0x1);
> +
> +	dt_add_property(self_restore, "sprn-bitmask", *self_restore_map,
> +			bits_nr * sizeof(uint64_t));
> +
> +	self_save = dt_new(power_mgt, "self-save");
> +	if (!self_save) {
> +		prerror("OCC: Failed to create self save node");
> +		return;
> +	}
> +	if (proc_gen == proc_gen_p9) {
> +		dt_add_property_cells(self_save, "active", 0x1);
> +
> +		dt_add_property(self_save, "sprn-bitmask", *self_save_map,
> +				bits_nr * sizeof(uint64_t));
> +	} else
> +		dt_add_property_cells(self_save, "active", 0x0);
> +}
> +
>   /* Add device tree properties to describe idle states */
>   void add_cpu_idle_state_properties(void)
>   {
> @@ -1543,6 +1608,7 @@ opal_call(OPAL_SLW_SELF_SAVE_REG, opal_slw_self_save_reg, 2);
>   void slw_init(void)
>   {
>   	struct proc_chip *chip;
> +	struct dt_node *power_mgt;
> 
>   	if (proc_chip_quirks & QUIRK_MAMBO_CALLOUTS) {
>   		wakeup_engine_state = WAKEUP_ENGINE_NOT_PRESENT;
> @@ -1568,4 +1634,10 @@ void slw_init(void)
>   		}
>   	}
>   	add_cpu_idle_state_properties();
> +	power_mgt = dt_find_by_path(dt_root, "/ibm,opal/power-mgt");
> +	if (!power_mgt) {
> +		prerror("OCC: dt node /ibm,opal/power-mgt not found\n");
> +		return;
> +	}
> +	add_cpu_self_save_properties(power_mgt);
>   }
> diff --git a/include/skiboot.h b/include/skiboot.h
> index 1aa8bf7c..e8f0f755 100644
> --- a/include/skiboot.h
> +++ b/include/skiboot.h
> @@ -202,6 +202,7 @@ extern void early_uart_init(void);
>   extern void homer_init(void);
>   extern void slw_init(void);
>   extern void add_cpu_idle_state_properties(void);
> +extern void add_cpu_self_save_properties(struct dt_node *power_mgt);
>   extern void lpc_rtc_init(void);
> 
>   /* flash support */
>