Commit 4fe516d2 authored by Alison Schofield's avatar Alison Schofield Committed by Dave Jiang
Browse files

cxl/acpi: Make the XOR calculations available for testing 



In preparation for adding a test module that can exercise the address
translation functions performed by the CXL Driver, refactor the XOR
implementation like this:

- Extract the core calculation into a standalone helper function,
- Export the new function for use by test module cxl_translate only,
- Enhance the parameter validation since this new function will be
  called from a test module with no guarantee of valid parameters,
- Move the define of struct cxl_cxims_data to cxl.h so the test module
  can build xormaps.

Reviewed-by: default avatarDave Jiang <dave.jiang@intel.com>
Reviewed-by: default avatarJonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: default avatarAlison Schofield <alison.schofield@intel.com>
Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
parent b78b9e7b

drivers/cxl/acpi.c

+30 −11
Original line number Diff line number Diff line
@@ -11,25 +11,36 @@ 
#include "cxlpci.h"

#include "cxl.h"



struct cxl_cxims_data {

	int nr_maps;

	u64 xormaps[] __counted_by(nr_maps);

};



static const guid_t acpi_cxl_qtg_id_guid =

	GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071,

		  0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52);



static u64 cxl_apply_xor_maps(struct cxl_root_decoder *cxlrd, u64 addr)

#define HBIW_TO_NR_MAPS_SIZE (CXL_DECODER_MAX_INTERLEAVE + 1)

static const int hbiw_to_nr_maps[HBIW_TO_NR_MAPS_SIZE] = {

	[1] = 0, [2] = 1, [3] = 0, [4] = 2, [6] = 1, [8] = 3, [12] = 2, [16] = 4

};



static const int valid_hbiw[] = { 1, 2, 3, 4, 6, 8, 12, 16 };



u64 cxl_do_xormap_calc(struct cxl_cxims_data *cximsd, u64 addr, int hbiw)

{

	struct cxl_cxims_data *cximsd = cxlrd->platform_data;

	int hbiw = cxlrd->cxlsd.nr_targets;

	int nr_maps_to_apply = -1;

	u64 val;

	int pos;



	/* No xormaps for host bridge interleave ways of 1 or 3 */

	if (hbiw == 1 || hbiw == 3)

		return addr;

	/*

	 * Strictly validate hbiw since this function is used for testing and

	 * that nullifies any expectation of trusted parameters from the CXL

	 * Region Driver.

	 */

	for (int i = 0; i < ARRAY_SIZE(valid_hbiw); i++) {

		if (valid_hbiw[i] == hbiw) {

			nr_maps_to_apply = hbiw_to_nr_maps[hbiw];

			break;

		}

	}

	if (nr_maps_to_apply == -1 || nr_maps_to_apply > cximsd->nr_maps)

		return ULLONG_MAX;



	/*

	 * In regions using XOR interleave arithmetic the CXL HPA may not
@@ -60,6 +71,14 @@ static u64 cxl_apply_xor_maps(struct cxl_root_decoder *cxlrd, u64 addr) 


	return addr;

}

EXPORT_SYMBOL_FOR_MODULES(cxl_do_xormap_calc, "cxl_translate");



static u64 cxl_apply_xor_maps(struct cxl_root_decoder *cxlrd, u64 addr)

{

	struct cxl_cxims_data *cximsd = cxlrd->platform_data;



	return cxl_do_xormap_calc(cximsd, addr, cxlrd->cxlsd.nr_targets);

}



struct cxl_cxims_context {

	struct device *dev;

drivers/cxl/cxl.h

+13 −0
Original line number Diff line number Diff line
@@ -743,6 +743,19 @@ int cxl_validate_translation_params(u8 eiw, u16 eig, int pos); 
u64 cxl_calculate_hpa_offset(u64 dpa_offset, int pos, u8 eiw, u16 eig);

u64 cxl_calculate_dpa_offset(u64 hpa_offset, u8 eiw, u16 eig);

int cxl_calculate_position(u64 hpa_offset, u8 eiw, u16 eig);

struct cxl_cxims_data {

	int nr_maps;

	u64 xormaps[] __counted_by(nr_maps);

};



#if IS_ENABLED(CONFIG_CXL_ACPI)

u64 cxl_do_xormap_calc(struct cxl_cxims_data *cximsd, u64 addr, int hbiw);

#else

static inline u64 cxl_do_xormap_calc(struct cxl_cxims_data *cximsd, u64 addr, int hbiw)

{

	return ULLONG_MAX;

}

#endif



int cxl_num_decoders_committed(struct cxl_port *port);

bool is_cxl_port(const struct device *dev);